CHAPTER 1

INTRODUCTION

Servomotors are kind of rotary actuators that can have a precise control of velocity,

acceleration and angular position. It comprises of a suitable motor and a sensor who both

coupled to sense the position feedback. In most of the cases sophisticated controller is

also used which is a dedicated module specifically designed for servo motors.

Servomotors term is mostly used for a motor dedicated for usage in closed loop system as

they don’t fall in specific class of motors. Servomotors applications include

process/industrial control, robots, CNC etc.

Servomotors are a close loop servomechanism which utilizes position feedback to control

the motion and final position. It has an input of analogue or a digital signal according to

which the commanding output is given to motor shaft.

A type of Encoder is paired with the motor which give speed and position feedback.

Position is measured in the simplest case. Measured position of the external input is

compared to the controller, and output to the command position. If the position of the

output is different from the required, error signal is produced inducing motor to rotate in

either direction, which is required for appropriate positioning of the output shaft. The

error signal approaches to zero as the position approach to required and motor finally

stops [1].

The simplest of the servomotors use only position sensing through bang-bang control and

potentiometer of their motor; the motor rotation is always at full speed or stopped.

Servomotors of such type are are the basis of cheap and simple servos used in radio-

controlled models.

Servomotors of sophisticated kind measure both the speed and the position of the output

shaft. Not only this they can also control the motor speed, instead of always being at full

speed. Both of these improvements, usually along with a PID controlalgorithm, bring the

servomotor to its commanded position precisely and more quickly, with less overshooting

[1].

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1.1 STEPPER MOTORS VS SERVOMOTORS

Stepper continuously consumes power to reach the commanded position and then to hold

that position. Whereas, a servomotor consumes power for reaching the commanded

position but after it they rests.

Servomotors are regarded as high performance substitute of stepper motor. The stepper

motor has built-in output steps, which makes it intrinsic ability to control position.

Therefore, they are often used as an open-loop control without having a feedback

encoder, because the drive signals given to it defines the number of steps for movement

to rotate, but this requires the stepper motor on power up to make the controller ‘know’

the position. Hence, the stepper motor will be activated by the controller, on first power

up, the end limit switch is activated. When the inkjet printer is switch on, it can be

observed that the controller will move ink jet carrier to extreme left and right for

establishing the end positions. Now in case of servomotor, it will immediately turn to the

angle instructed by the controller, irrespective of the initial position at power up.

Performance of stepper motor is limited due absence of feedback feature, which make it

to only drive the load which is well within its capacity, otherwise under load missed steps

may generate positioning errors which may lead to system restart or recalibration [2].

The controller and encoder makes servomotor costly, but it is compensated by the all of

power, accuracy and speed) in relation to the capacity of the basic motor. Servomotors

have the advantage in larger systems, where a powerful motor shares an increasing

proportion cost of the system.

In recent years, increasing popularity has been observed in used of closed loop stepper

motors. They are similar to servomotor but have a difference in achieving the smooth

motion through software control. Magnetic encoders as the feedback device have been

employed by the top 3 manufactures of the closed loop system due to resistance to

vibration and low cost. The closed loop stepper motor has the cost to performance ratio

benefit. Also PID controller is not needed to be tune on a closed loop stepper system

which saves time [1].

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Laser cutting machines can be offered in two ranges, the high-performance range using

servomotors and low-priced range using stepper motors, along with many other

applications.

1.2 ENCODERS

Encoders were made along with the first servomotors. During World War II, intensive

work was done on these systems in development of anti-aircraft artillery and radar.

Resistive potentiometers are used as position encoder in simple servomotors. They have a

close competition with stepper motors and are mostly used at the cheapest and simplest

level. During potentiometer track they have electrical noise and wear. Although the speed

signal can be generated by electrically differentiating the position signal, PID controllers

are a more precise encoder which utilizes the same speed signal [3].

Rotary encoders, either incremental or absolute are used in current servomotors. At

power on, absolute encoder can determine their position but these are expensive and

complicated. However incremental encoders are cheap, work at faster speeds and simple

in use. Stepped motors which is an incremental system, mostly combine simple zero

sensor with their inherent ability of measuring rotation intervals to set position at start-up.

In some cases a motor with a separate and external linear encoder is used instead of

servomotors. Though these linear encoder systems with the addition of motors avoid

erroneousness in the drive train between linear carriage and motor [3], their design is

complicated as they are not a factory-made compact system.

1.3 MOTORS

Permanent magnet DC motors with brushes are the simplest to be used as they are simple

and cheap. Servomotors used in small industry are typically electronically commutated

motors without brushes. AC induction motors are used in large industrial servomotors,

often allowing control of their speed with the help of variable frequency drives. Brushless

AC motors having permanent magnetic field are used as a compact package for ultimate

performance and large versions having DC motors [1].

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Standard industrial component is a drive module for servomotors. These modules are

designed on the basis of three-phase MOSFET H Bridge. Their input is pulse count

(rotation distance) and single direction. They may also have over torque, over

temperature and stall detection features. As the Overall System dynamics and gear head

ratio depends on the application, which makes the encoder type are mostly implemented

as part of the main controller.

1.4 DC MOTOR AND IT’STYPES

Motor is a device which converts electrical energy into mechanical energy. Motor can be

divided into two categories:

1. Alternating current (AC) motor

2. Direct current (DC) motor

In a simple DC motor torque for rotation is produce by the interaction between the

electricity and magnetic field. Permanent magnet DC motor is better than AC motor

because it provide better control on speed with high torque and is used widely in industry

[5].

DC motors can be used with portable sources like batteries and solar cells which makes

them more usable and provide cost effective solution because AC power supply is not

available everywhere. DC motor shows response at both current and voltage. Current in

the armature winding gives the torque while the voltage shows the speed of the motor [4].

The load and current has a proportional relation if the load is increased the drawing

current from supply will increase to maintain the speed constant and if supply does not

provide the enough current the speed will reduce. In other words applied voltage effect

speed and torque is controlled by current. If the chopping circuit is used the results drawn

from DC motor become more effective [3]. In lifting and transportation we mostly use

low power DC motors as low power AC motors torque capability is not as good.

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DC motor are used in the application where torque cannot be compromised like electric

cars, railway engines, car windows, robotic applications, elevators, complex industrial

mixing process and wide variety of small appliances. There are several types of DC

motor but most common are brushless DC motor, servo motor, stepper motor, and

brushed DC motor [2]. DC motors have three winding techniques such as series DC

motor, shunt DC motor and compound DC motor.

Fig 1.1 Parts DC motor

1.4.1 Brushless Dc Motor

It is a DC current synchronous electric motor with electronic communication system.

This motor does not have brushes or commentator like mechanical parts. There is a linear

relationship between current to torque and voltage to rpm. In this type there is no

permanent magnet on stator while motor have a rotating permanent magnet [3].

Controller converts the DC current given to motor into AC current. Such kind of design is

useful in removing difficulties like transferring power to rotor. It advantages include little

maintenance, long life and high efficiency while more complicated controller and high

capital cost are its disadvantages. AC motor and brushless motor are very similar to each

other and both required an external communication for generating torque.

These are fuehrer divided into two subtype motors,

1. Reluctance motor

2. Stepper motor

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Reluctance motors are kind of motors which do not have a permanent magnet and its pole

are pulled for alignment by moving stator drive [4].Whereas stepper motors are normally

run by controllers and have many poles on stator. They are used mostly in highly precise

CNC machines.

1.4.2. Brushed Dc Motor

These types of DC motors have a permanent magnet and its rotor has an electrical magnet

that moves and generates torque in proportion to applied DC power. Lorentz force

principle is used in this motor, the principle says that a current carrying conductor placed

in a magnetic field environment then it experiences a torque or force. It advantages

include low initial cost, simple speed control technique and high reliability.

Disadvantages include high maintenance cost of small life time. The replacement and

cleaning of commentator, brushes and springs are included in its maintenance [6].

Brushed DC motor use three type of wound techniques which are given below:

1.4.3. Shunt Wound

In this type of motor shunt filed coils are in parallel with armature [5]. So the current is

moving independently in armature and field coils as shown in figure 1.2. Such motors are

where high power and excellent speed control is required.

Fig 1.2 Shunt wound DC motor

1.4.4. Series Wound

In this type of motor shunt filed coils are in series with armature which makes current

dependent on one another as shown in figure 1.3. These motor provides high torque [2].

The current increases in the armature and stator as load increases which makes its

application in high loads. But it has a draw-back of not giving excellent speed control.

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Fig 1.3 Series wound DC motor

1.4.5. Compound Wound

It is combination of a series wound and shunt wound motors as shown in Fig 1.4. This

motor provides both high torques as well excellent speed control as compared to series-

wound and shunt wound [5].

Fig 1.4 Compound-wound DC motor

1.4.6 Salient Features Of Brushless Dc Motor

In such a kind of motor the stator is the part of the motor where heat is produced and

removal of heat is quite easier. These kinds of motors are very smart and lighter in the

weight as they have a coil made up of permanent magnets [7]. The most imperative

characteristic of Brushless DC electric motors is that they got a very much smoother

relationship between the current and linear torque. BLDC motors are quite smart and

clean, are quite fast and even they have an edge on other kinds of motors when it comes

to efficiency.

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Fig 1.5 A Schematic view of Brushless DC motor

BLDC motors have quite a different kind of structure as shown in Fig 1.5. In these

motors the stator is moveable while the rotor is stationary. The stationary rotor is made

up of permanent magnet. The moveable stator and stationary rotor results in very low

maintenance requirement and making the BLDC motors to evolve as a very economical.

The most interesting characteristic of the BLDC motors is that these motors do not work

on the DC power as they got windings on its moveable stator and permanent magnets as

rotor and are electronically commutated.

1.5 DC MOTION

Electromagnetism is the responsible for the rotational motion of the motor’s spindle.

When a coil carrying current is allowed in the vicinity of the magnetic field, a torque is

produced [8]. Torque thus produced is directly proportional to the current applied to the

conductor. The generated torque is reason of the rotational motion of the spindle of the

motor. inthe mathematical formula for the calculation of the Magnetic force is as follows.

F=B× L× I

Where;

B= Magnetic field

L = Length

I= current

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Fig 1.6 DC motor

The magnetic force F is perpendicular to both the current (I) and magnetic field intensity

(B). Applying right hand rule the direction of the force acting can be found out as shown

in figure1.7. Forces are thus equal in magnitude but clearly opposite in direction,

therefore, producing a torque [5].

After every half revolution, the current is needed to be reversed for making the produced

torque to be in the same direction. To accomplish this commentator is engaged. Torque is

actually directly proportional to the magnetic field (B) [6].The motor is actually a device

designed to generate the rotational motion resulting from the magnetic field and coil

magnetic interaction.

Fig 1.7 DC motor

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Within the following case the current flows out of the coil and direction of the magnetic

field is north-south, consequently, the resultant force will tend to move the armature to

left. Rotational motion is finally obtained and this continues due a number of poles of a

motor. Applied current is responsible for the torque produced while the speed is

depended upon the voltage supplied [7].

1.6 MOTOR AND ITS CONTROLLING (SPEED CONTROLLERS)

Motors have got a variety of applications, so controlling the speed of motor is of very

much implication. There are a number of different applications where we need high speed

and some where we need lower speeds. Each certain application needs the speed of motor

with certain specific range. Consequently, making speed control of motor a very vital

feature [8]. For example robotics is field where we see immense use of motors but robots

cannot perform the way we want them to, when speed of motors is not controlled in a

very precise and exact way. In CNC machining centre, where error as small as 1mm

cannot be compromised. For such an applications the speed control of motors should be

exact and accurate. Closed loop speed controllers are normally employed for controlling

the speed of motors.

Voltage supplied is responsible for speed of the dc motor. Voltage is decreased, the speed

is reduced and when the voltage is allowed to increase the speed of the motor rises. In

case of the constant voltage supplies or batteries this speed control is achieved by making

use of the speed controllers. The speed controllers function by allowing variable voltage

to the motors and thus controlling their speeds [7]. The speed controllers have very quick

response and they can switch the voltage supply ON-OFF very fast therefore making an

average voltage supplied to motor as mandatory. This process is known to be pulse width

modulation. There are many forms of the speed controllers are available now-a-days and

each having their own pros and cons. Speed controllers used in this project are as follows

a) Pole placement controller.

b) PID controller.

c) Fuzzy logic controllers22

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This is a simple electrical motor which is controlled by servomechanism. The DC motor

controlled with servomechanism called as DC Servo Motor. In other side if the motor is

controlled by AC, so it likely to be called as AC Servo Motor [8].

There are some motors have special type of application. Application is that to rotate

motor for certain angle and not for long continuous period. For the purpose of this

application some special motors are required with special arrangement. Hence, for given

electrical input electrical signal it rotates at certain angle. Because of that there is an

existence of servo motor. Servomotor is a simple DC Motor which is normally controlled

by special angular rotation with the help of servomechanism. It is type of closed loop

control system feedback. In recent time servo system has a wide scope in industries [9]. It

has scope in industrial application. Controlling of Linear motion of remote controlled car

is an example in day to day life. CD or DVD player tray is also a good example of it.

Beside of these applications there are so many applications we could observe in our day

to day life. Servo provides angular precision; it could be control by us. We could rotate it

as much as we want and then put on hold for next signal. This is the reason behind using

servo. This is like a normal electrical motor [9]. When we supply electric power to it, it

starts rotating until the power off. Rotational motion of motor cannot be control except

the speed of rotation and ON/OFF of the power supply.

1.7 SERVO MOTOR

Figure 1.8:- Servo Motor

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We need to understand the servomechanism first in order to have working principle of

Servo Motor.

1.7.1 Servo Mechanism

There are three basic component part of servomechanism system- output sensor,

controlled device, feedback system. The system is an example of automatic close loop

control system. The feedback signal, which is generated by comparing reference input

signal and output signal is used to control the system rather than by applying variable

input signal. The command signal (reference input signal) is applied to the system

compared with output reference signal and third signal. The out reference signal is

produced by output sensor and third signal which further act as input signal of the

controlled device is produced by feedback system [10].Because of logical difference

between reference input signal and output signal, input signal to device stays long. After

getting desired output logical difference get vanishes and hence third signal no longer

remain until the next command signal is applied to system. In presence of disturbances to

maintain output of system at desired value is only the primary task of servomechanism.

1.7.2 Servo Motor Working Principle

Generally a servo motor is DC motor; but in some cases AC also. Some special purpose

component used in motor make DC motor a servo. In servo unit you’ll find

potentiometer, intelligent circuitry, gear arrangement and small DC motor [5]. The

intelligent circuitry used in servo system along with potentiometer could make servo

motor to rotate as we want. The high speed small DC motor generate torque is not

capable to move light weight load. By this gear system which is inside the servo comes

into existence. The gear mechanism allow high input speed and at output get slower

speed; but widely applicable and more practical.

At servo motor shaft’s initial position, knob position of potentiometer is like that no

electrical signal is generated at output of it. And output terminal of potentiometer is

connected to one input terminal of error detector amplifier. At another input terminal of

error detector amplifier electrical signal is given. Error detector amplifier amplifies

difference signal to feed DC motor [6].

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Here difference signal is the difference between two signals one comes from

potentiometer and other one comes from external source. The signal amplified by error

detector amplifier is itself an input power for motor, because of that motor starts rotating

at desired linear ion. With the help of gear arrangement knob, potentiometer is coupled

with shaft of motor. Potentiometer knob rotates with progress of motor shaft [7]. Change

in position of potentiometer knob produce electrical signal at its port, resulting increase in

feedback signal. The electrical signal generated in potentiometer is same as external

electrical signal given to amplifier, when potentiometer knob reaches to desired position.

At this point the difference between both signals is nil, as both the signals are same.

Because of that amplifier is unable produce output signal for motor input. Hence, motor

stops rotating. This is how a simple working principle of servo motor.

1.7.3 Servo Motor Control

For better understanding of servo motor control, let take an example. Let a servomotor

feed with signal to rotate by angle of 45° and after that wait for further instruction. With

the help of gear assembly DC motor shaft is coupled with another output shaft [8]. The

general purpose of gear assembly is to step down high rpm to low rpm motor shaft of

servo system at output.

Figure 1.9:- Gear Assembly for DC Servo Motor

The potentiometer voltage adjusting knob is arranged with output shaft in such manner

that when shaft rotates, knob also rotates. This rotating knob creates a varying electrical

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potential, which is according to principle of potentiometer. The electrical potential i.e.

signal increase with angular movement of knob with shaft from 0° to 45° [9]. Further this

particular electrical potential feed to error detector feedback amplifier along input single

voltage.

Figure 1.10:- Position Cog for Gear of DC Servo Motor

The voltage from potentiometer increases with angle of rotation of shaft i.e. from 0° to

45°. When a shaft is reach to 45°, voltage value at output is equal to given input [6].

Hence, at this point there is no difference between reference input voltage and signal

voltage coming from potentiometer. And output of amplifier becomes zero.

Figure 1.11:- Feedback System for Find the Error

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As in the above figure output voltage signal of amplifier is acting as input signal for DC

motor. So, motor is used to stop rotating after every 45° shaft rotation. At this particular

position the motor is in rest and waiting for next instruction to move in desired linear ion.

The example above helps us to understand servo motor theory and servo motor control

[7]. Though in practical servo motor, we use analog or digital position sensor encoder.

Shaft of servo is connected to potentiometer. Potentiometer connected circuitry inside

servo generally known as position of servo. Error detector amplifier is used to compare

current position and desired position [8]. If some mismatch is observed, then error

detection amplifier provide some error signal by which shaft will rotate to get desired

location. Once shaft get to the location it stops and wait for next instruction.

1.7.4 Continuous Rotation Servo Motor

Continuous rotation Servo Motor is the modified version of servo. It’s a 360° rotation

servo, which developed by changing internal mechanical connection of servo [9]. You

could only control linear ion and speed of respected servo but not the position of it.

1.8 ROTOR & STATOR

Moving part of motor is rotor. Rotor is used to turn the shaft to provide mechanical

power. Rotor is covered with metal conductors for carrying current, which interact with

magnetic field of stator and generate power or force. This power or force make rotor shaft

to turn or move [5]. There are also some exceptions. Some rotor carry magnetic field and

stator hold metal conductors to carry current.

Stationary part of motor called as stator. Usually it covered with windings or it has

permanent magnet. Stator of motor is made up of number of thin metal sheets called

lamination [11]. Lamination is useful for reduction of core losses.

In between the stator and rotor there is a small air gap. Air gap should be as small as

possible. Slightly large gap could affect negatively on performance of electric motor.

1.9 WINDING&COMMUTATOR

Windings are the wire coil wrapped around iron core. Iron core is soft and used to

develop magnetic pole.

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1.9.1 Salient Pole Machine

In this type of machine, below the pole face winding wound on pole produce magnetic

field.

1.9.2 Non Salient Pole Machine

It is also called as distributed pole or round rotor machine. Here the windings are

distributed in pole face slot.

Commentator is mechanism which used to alternate input of certain AC machines and

most of DC machines. It is consisting of the slip-ring segments which are insulated one

from other and from shaft of electric motor. Armature current of Motor is generally

supplied through stationary brushes with contact in revolving commentator, which further

causes reversal of required current. Also it applies power in optimal manner to machine.

Rotor used to rotate from one pole to another pole. Motor may brake to stop, in absence

of current reversal [3]. In last few 10 years due to some improved technology in market

sensor less control, permanent magnet motor fields, electronic controller,

electromechanically commutated motors and induction motor are displayed increasingly

by permanent magnet motors and externally commutated induction.

1.10 MOTOR CONTROL AND MOTOR SUPPLY

DC motor is supplied through the slip ring commentator. There are different types of AC

motors commutation [6]. They are- slip ring commentator or externally commutated type,

variable speed or fixed speed control type, asynchronous or synchronous type. Universal

motors run on both DC and AC.

The Fixed speed controlled AC type motors are generally provided with soft start or

linear online starters [8]. Term electronic commentator is associated with the self

commutated brush less switched reluctance motor and DC motor Applica

1.11 BRUSHED DC MOTOR AND ELECTRICALLY EXITED DC MOTOR

Self commutated type DC motors are run on the DC power supply. Most of DC motors

are of small PM-types [9]. To reverse the current of motor windings they have

brushed internal mechanical commutation in synchronism with the rotation.

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Commutated switch which periodically reverses flow of the current in rotor windings.

Every brushed DC type motor has the AC flowing through rotating windings of it.

Current usually flows through the one or more pairs of the brushes which bear on

commentator; brushes connect external source of the electric power to rotating armature

[10].

Rotating armature is consists of coils (one or more) of wire which wound around

laminated, soft magnetic ferromagnetic core [6]. The Current from brushes, flows

through commentator & winding of armature, makes temporary magnet (an electro-

magnet).

Force between both magnetic fields is tending to the rotate motor shaft. Commentator

switches the power to coils as rotor turns and keeping magnetic poles of rotor from fully

aligning with magnetic poles of stator field, thus rotor will never stops (generally what

compass needle does) or keeps it rotating as long as the power supplied.

So much limitations of classic commentator of DC motor are because of need for the

brushes to press against commentator. Sparks are generally created by brushes making &

breaking the circuits through rotor coils as brushes cross insulating gaps between the

commentator sections. And depending on commentator design include brushes shorting

both together adjacent sections and so coil ends momentarily while the crossing gaps.

Inductance of rotor coils causes voltage across each to increase when circuit is opened.

Because of that there is increasing in sparking of brushes. Sparking limits maximum

speed of machine [7]. As too rapid sparking will over heat and erode or even melt

commentator. Current Continuous is per unit area of brushes, in the combination

with resistivity which further limits output of motor. Making & breaking of the electric

contact is also generates some electrical noise. The sparking used to generate RFI. The

Brushes is eventually worn out and thus require replacement. And commentator is itself

subject to wear and maintenance or replacement.

Commentator assembly on large motor is generally costly element. It is requiring

precision and assembly of so many parts. For small motors, commentator is permanently

integrated in rotor. So that replacing it requires replacing whole rotor [8].

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Shapes of most commentators are cylindrical. Some of them are flat discs which

consisting of the several segments specially least three mounted on insulator.

The Large brushes are wanted for the larger brush area contact to maximize the motor

output. Small brushes are wanted for the low mass to maximize speed at which motor

will run without brushes increasingly bouncing and the sparking. The Stiffer brush

springs make brushes of the given mass of work at the higher speed [9]. At cost of the

greater friction losses & accelerated brush & the commentator wear. So that, design of

DC motor brush entails tradeoff efficiency/wear, speed and between output powers.

Armature circuit is winding where load current is carried in stationary or the rotating part

of the motor or the generator.

Field circuit- It is set of the windings, which usually produces magnetic field. The

electromagnetic induction may take-place in the electric machines.

Commutation- It is a mechanical technique where rectification achieved. It is also

place from which the DC derived, in DC machines.

Figure 1.12:- Armature Design of motor

Brushed DC-motor is generally of five types:

(1) DC shunt-wound

(2) DC series-wound

(3) DC compound

(4) Cumulative compound motor

(5) Differentially compounded motor

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1.12 DC MOTOR WITH PERMANENT MAGNET (PERMANENTMAGNET

DCMOTOR)

PM motors do not have field winding on stator frame. Instead of relying on the PMs to

provide magnetic field which against rotor field interacts for to produce torque. The

Compensating windings which are in series with armature can be used on the large

motors to improve the commutation under a load. Because of this, the field is entirely

fixed. And it can’t adjust for the speed control. Stators or PM Fields is convenient in the

miniature motors to eliminate power consumption of field winding [9]. The Most larger

DC motors are of "dynamo" type, which generally have stator windings. PMs would not

be made to gain high flux.

On the off chance that they dismantled; field windings were more viable to get the

required measure of flux. Then again, expansive PMs are excessive, and hazardous and

hard to amass; this favors twisted fields for huge machines.

To minimize general weight and size, small scale PM motors may utilize high vitality

magnets made with neodymium or other key components; most such are neodymium-

iron-boron amalgam. With their higher flux thickness, electric machines with high-

vitality PMs are in any event focused with all ideally composed independently Fed-

synchronous and instigation electric motors. Smaller than usual motors take after the

structure in the representation, aside from that they have no less than three rotor poles (to

guarantee beginning, paying little respect to rotor position) and their external lodging is a

steel tube that attractively connects the outsides of the bended field-magnet [10].

1.13 THE ELECTRONIC COMMUTATOR MOTOR

A portion of the issues of the brushed DC motors are disposed of in the BLDC outline. In

this particular motor, mechanical "revolving switch or rotating switch" or the

commentator is supplanted by an outside electronic switch synchronized to rotor's

position. The BLDC motors machines are regularly 85–90% proficient or more.

Effectiveness for a BLDC motor of up to 96.5% have been reported, though DC motors

with brush gear are normally 75–80% proficient [10].

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The BLDC Motors’s trademark trapezoidal back-elf waveform is gotten somewhat from

the stator windings being uniformly circulated, and mostly from the position of the rotor's

PMs. Otherwise called electronically commutated DC or back to front DC motors, stator

winding of the trapezoidal BLDC motors is able to be with single stage, two stage or

three stage and utilization Hall impact sensors mounted on windings for the rotor position

of detecting and the lower price closed loop control of electronic commentator [11].

Here, BLDC motor machines are regularly utilized where exact rate control is essential,

as in PC plate drives or in feature tape recorders, the axles inside CD, CD-ROM (and so

forth.) drives, and components inside office items, for example, fans, laser printers and

scanners. They have a few points of interest over routine motors:

• Compared to AC fans utilizing shaded pole motors, they are extremely effective,

running much cooler than the proportionate AC motors. This cool operation prompts

quite enhanced existence of the fan's heading.

• Without a commentator to destroy, life of BLDC motor is able to be altogether more

contrasted with a DC motor utilizing brushes and a commentator. Compensation

additionally has a tendency to bring about a lot of electrical and RF clamor; without the

commentator or the brushes, BLDC motor machine might be utilized as a part of

electrically touchy gadgets like sound hardware or PCs.

• The same Hall impact sensors that give the compensation can likewise give a helpful

tachometer sign to servo controlled (closed loop control) applications. Also, in fans,

tachometer sign can be utilized to infer a "fan OK" motion and also give running rate

criticism.

• The motor can be effectively synchronized to an inner or outer clock, induction exact

speed control.

• BLDC motors have no shot of starting, not at all like brushed motors, improving them

suited to situations with unstable chemicals and powers. Additionally, starting produces

ozone which can aggregate in ineffectively ventilated structures gambling mischief to

inhabitants' wellbeing.

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• BLDC motors are generally utilized as a part of little hardware, for example, PCs and

are by and large utilized as a part of fans to dispose of undesirable warmth.

• They are likewise acoustically calm motor which is leverage if being utilized as a part

of gear. Current BLDC motors go in force from a small amount of a watt to numerous

kilowatts. Bigger BLDC motors up to around 100 kW rating are utilized as a part of

electric vehicles. They likewise discover critical use in elite electric model airplane.

There are no PMs or brushes for SRM, and rotor has not any electric streams. Rather,

torque originates from a slight misalignment of shafts on the rotor with posts on the stator

[12]. The rotor adjusts itself to the attractive field of stator, while stator field and stator

windings are consecutively invigorated to pivot the stator field. The attractive flux made

by the field windings takes after the way of slightest attractive reluctance, importance the

flux will course through shafts of the rotor that are nearest to the invigorated posts of the

stator, along these lines charging those posts of the rotor and making torque. As the rotor

turns, distinctive windings will be stimulated, keeping the rotor turning [8].

SRMs are currently being utilized as a part of some appliances.

Figure 1.13:- Motor Coil Design

Advanced ease all universal motor, from a vacuum more clean. Field windings are dimming

copper-hued, at the back, on both the sides. Rotor's covered center is dim metallic, with dim

spaces for winding the loops [13]. The commentator (incompletely covered up) has ended up dim

from utilization. It is toward the front. The huge chestnut shaped plastic piece in the closer view

underpins the brush guides and brushes (both sides), and the front motor bearing [10].

A commutated electrically energized arrangement or parallel wounded motor is alluded

to as an all inclusive motor in light of the fact that it can be intended to work on both AC

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and DC power [11]. Universal motor can work well on AC in light of the fact that the

present in both the field and the armature loops (and henceforth the resultant attractive

fields) will exchange (reverse extremity) in synchronism, and consequently the

subsequent mechanical power will happen in a consistent heading of pivot.

Working at ordinary electrical cable frequencies, all inclusive motors are regularly found

in a range under 1000 watts. All universal motors likewise framed the premise of the

conventional rail line footing motor in electric railroads [12]. In this application, the

utilization of AC to power motor initially intended to run on the DC would prompt

productivity misfortunes because of eddy current warming of their attractive parts,

especially motor field poles pieces which, for the DC, would have utilized strong (un-

covered) iron and they’re presently seldom utilized.

Favorable element of the universal motor machine is which AC supplies might be

utilized on the motors which have a few attributes more normal in DC motors,

particularly high beginning torque and extremely minimized outline if high running

speeds are utilized [13]. The negative angle is the support and short life issues created by

the commentator. Such motors are utilized as a part of gadgets, for example, nourishment

blenders (mixer) and force instruments which are utilized just discontinuously, and

frequently have high beginning torque requests. Different taps on the field coil give

(uncertain) step speed control. Family blenders that promote numerous rates as often as

possible join a field loop with a few taps and a diode that can be embedded in

arrangement with the motor (bringing on motor to run/carry on the half-wave-rectified

AC) [14]. General motors’ additionally loan themselves to electronic velocity control

and, accordingly, are a perfect decision for gadgets like local clothes washers. The motor

can be utilized to disturb the drum (both advances and in converse) by exchanging the

field winding regarding the armature.

While SCIMs can't turn a shaft quicker than permitted by the electrical cable recurrence,

all universal motors can run at much higher rates. This makes them valuable for

apparatuses, for example, blenders, vacuum cleaners, and hair dryers where rapid and

light weight are alluring. They are additionally regularly utilized as a part of convenient

force devices, for example, drills, sanders, round and dance saws, where the motor's

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attributes function admirably [15]. Numerous vacuum cleaner and weed trimmer motors

surpass 10,000 rpm, while numerous comparable smaller than expected processors

surpass 30,000 rpm

1.14 EXTERNALLY COMMUTATED AC MACHINE

The outline of AC motors (induction and synchronous) is improved for operation on

single-stage or poly phase sinusoidal or semi sinusoidal waveform power, for example,

supplied for the fixed-speed application from AC power lattice or for the variable-speed-

application from the VFD controllers [8]. The AC motor generally has two sections: a

stationary stator having winding supplied with AC to deliver a rotating magnetic field,

and a rotor connected to output shaft which is given torque by rotating field.

1.15 THE INDUCTION MOTOR

1.15.1 Wound or Cage Rotor Induction Type Motor

An induction motor machine is an offbeat AC motor machine where force is exchanged

to rotor by the electromagnetic induction, very much like the transformer activity [9]. An

induction motor machine takes after rotating transformer, in light of the fact that the

stator (stationary part) is basically the essential side of the transformer and the rotor

(pivoting/rotating part) is the auxiliary side. Poly phase induction’s motors are broadly

utilized as a part of industry.

The induction motors may be further partitioned into the Squirrel-Cage Induction Motors

and the Wound-Rotor Induction Motors. The SCIMs have overwhelming twisting

comprised of strong bars, as rule aluminum or the copper, which joined by the rings at

closures of the rotor. At the point when one considers just the bars and rings in general,

they are much like a creature's pivoting/rotating activity confines, subsequently the name

[4].

Induced current into winding is giving the rotor attractive magnetic field. The state of the

rotor bars decides the rate torque attributes. At low speeds, the current induced in squirrel

cage is almost at line recurrence frequency and has a tendency to be in the external parts

of the rotor confine. As motor quickens, slip frequency gets to be lower, and more present

is in inside of the winding. By molding the bars to change the resistance of twisting

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divides in inside and external parts of pen, successfully a variable resistance is embedded

in the rotor circuit. On other hand, greater part of such motors has uniform bars [10].

In WRIM, rotor winding is made of numerous turns of protected wire and is associated

with slip rings on motor shaft. An outer resistor or other control gadgets can be associated

in rotor circuit. Resistors permit control of motor speed, albeit huge force is disseminated

in outer resistance [13]. Converter can be nourished from rotor circuit and return slip

frequency control that would some way or another be squandered over into force

framework through the inverter or the separate motor-generator.

A WRIM is basically utilized to begin high inactivity burden or heap that obliges high

beginning torque over full speed extent. By accurately selecting the resistors utilized as

part of optional resistance or slip ring starter, motor machine has capacity produce

greatest torque at generally low supply current from zero pace/speed to full speed. This

kind of motor likewise offers controllable velocity [5].

Motor Speed can be changed on grounds that torque bend of motor machine is viably

adjusted by the measure of resistance associated with the rotor circuit. Expanding the

estimation of resistance will move the velocity of greatest torque down. Resistance

associated with rotor is expanded the past point where most extreme torque happens at

zero speed, torque will be further decreased [6].

At the point when utilized with heap that has a torque bend those increments with pace,

the motor will work at the velocity where the torque grew by motor is equivalent to heap

torque. Decreasing heap will bring about motor to accelerate, and expanding the heap

will bring about motor to ease off until the heap and motor torque are break even with.

Worked in this way, slip losses are disseminated in auxiliary resistors and can be

extremely noteworthy. The pace regulation and net effectiveness is additionally

exceptionally poor [7].

1.15.2 Torque Motor

Torque motor is a particular type of electric motor machine which can work uncertainly

while slowed down that is, with the rotor hindered from turning, without acquiring harm

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[8]. In this method of operation, the motor will apply a consistent torque to the heap

(subsequently the name).

A typical utilization of a torque motor would be supply and take up the reel (small)

motors in tape drive. This application is driven from low voltage; qualities of these

motors permit a moderately steady light pressure to be connected to the tape whether the

capstan is nourishing the tape-past-tape-heads [12]. Which driven from higher voltage,

(thus conveying a higher torque), the torque motors can likewise accomplish quick

forward and rewind operation without obliging any extra mechanics, for example,

apparatuses or grips. In the PC gaming world, torque motors are utilized as a part of

power input guiding wheels.

Another normal application is control of throttle of interior ignition motor in conjunction

with an electronic senator. In this utilization, the motor conflicts with an arrival spring to

move the throttle as per the yield of the representative [13]. The last screens motor speed

by numbering electrical heartbeats from the ignition framework or from an attractive

pickup and, contingent upon the velocity, makes little conformity to the measure of

current connected to the motor. On the off chance that the motor begins to ease off with

respect to the sought speed, the present will be expanded, the motor will grow more

torque, pulling against the arrival spring and opening the throttle. Should the motor run

too quick, the senator will decrease the present being connected to the motor, creating the

arrival spring to draw back and close the throttle.

1.16 SYNCHRONOUS TYPE MOTOR MACHINE

A synchronous type electrical motor is the AC motor recognized by a rotor turning with

loops passing magnets with same rate as AC and the coming about attractive field which

drives it. Another method for saying this is that it has zero sneak by normal working

conditions. Stand out this from an actuation motor, which must slip to deliver torque. One

sort of synchronous motor is similar to an incitement motor aside from the rotor is

energized by DC field [4]. The Slip rings & the brushes are utilized to Linear current to

the rotor. The rotor shafts associate with one another and move at the same speed

henceforth the name synchronous motor. Another sort, for low load torque, has pads

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ground onto an ordinary squirrel-confine rotor to make discrete posts. Yet another, for

example, made by Hammond for its pre-world War II clocks, and in the more seasoned

Hammond organs, he has not any rotor windings and the discrete posts/shaft/pole. It is

not self-beginning. The clock obliges manual beginning by a little handle on the back,

while the more seasoned Hammond organs had an assistant beginning motor associated

by a spring-stacked physically worked switch [3].

At long last, hysteresis synchronous motors commonly are (basically) two-stage motors

with a stage moving capacitor for one stage. They begin like induction motors, yet when

slip rate diminishes adequately, the rotor (a smooth barrel) gets to be incidentally

polarized. Its conveyed posts make it which act like PMSM [9]. Rotor material, similar to

that of a typical nail, will stay polarized; yet can likewise be demagnetized with little

trouble. When running, the rotor shafts stay set up; they don't drift Low-control

synchronous timing motors, (for example, those for customary electric timekeepers) may

have multi-post PM outer glass rotors, and utilization shading curls to give beginning

torque. Telethon clock motors have shaded shafts for beginning torque and two spoke

ring-rotor which performs like discrete two post rotor.

1.17 ELECRIC DOUBLY FED MOTOR

Doubly Fed electric motors generally have two free multiphase winding sets, which

contribute dynamic (i.e., working) energy to the vitality transformation process, with no

less than one of winding sets are electronically controlled for the variable speed

operation. The two free multiphase winding sets (i.e., double armature) are the greatest

gave in a solitary bundle without topology duplication [11]. Doubly sustained electric

motors are machines with a successful steady torque speed go that is twice synchronous

velocity for a given recurrence of excitation. This is double the consistent torque speed

extend as independently Fed-electric machines, which have one and only dynamic

winding set.

A doubly Fed motor takes into consideration a littler electronic converter however the

expense of rotor winding and the slip rings may be balance the sparing in the force

gadgets segments.

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1.18SPECIAL TYPE MAGNETIC MOTOR MACHINE

The Rotary Type

Coreless or Ironless Rotor Motor

Miniature Coreless Motor

The guideline of any of the motors portrayed above obliges that the iron (steel) segments

of the rotor really turn. In the event that the delicate attractive material of the rotor is

made as a barrel, then (with the exception of the impact of hysteresis) torque is applied

just on the windings of the electromagnets. Exploiting this is ironless DC motor, specific

manifestation of a PM DC motor. Optimized for fast increasing speed, these motors have

a rotor that is built with no iron center. The rotor can take the manifestation of a winding-

filled chamber, or a self-supporting structure including just the magnet wire and the

holding material [12]. An attractively delicate stationary chamber inside the rotor gives

an arrival way to the stator attractive flux. A second plan has the rotor winding wicker

bin encompassing the stator magnets. In that plan, the rotor fits inside an attractively

delicate chamber that can serve as the lodging for the motor, and similarly gives an

arrival way to the flux. The rotor can quicken a great deal all the more quickly, frequently

accomplishing a mechanical time steady less than one ms. and this is particularly genuine

if the windings use aluminum instead of the heavier copper. Overheating may be an issue

for coreless DC motor plans. Among these types are the plate rotor types, depicted in

more detail in the following area. Vibrator motors for mobile phones are now and then

little barrel shaped PM field types, yet there are likewise plate formed types which have a

flimsy multi-polar circle field magnet, and a deliberately lopsided formed plastic rotor

structure with two reinforced coreless loops. Metal brushes and a level commentator

switch energy to the rotor loops. Related constrained travel actuators have no center and a

fortified loop put between the shafts of high-flux slight PMs [13]. These are the quick set

out positioners toward inflexible circle ("hard plate") drives. Despite the fact that the

contemporary outline varies significantly from that of amplifiers, it is still freely (and

erroneously) alluded to as a "voice loop" structure, in light of the fact that some prior

inflexible plate of an amplifier.

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1.19 PANACAKE OR AXIAL ROTOR MOTOR

A somewhat uncommon motor plan, the printed armature or hotcake motor has the

windings formed as a circle running between exhibits of high-flux magnets. The magnets

are masterminded around confronting the rotor with speed in the middle of to shape a

pivotal air gap. This outline is ordinarily known as the hotcake motor due to its

amazingly level profile, despite the fact that the innovation has had numerous brand

names since its beginning, for example, Servo Disc [15]. The printed armature (initially

framed on the printed circuit-board) in printed armature type motor machine is produced

using punched copper sheets that are overlaid together utilizing propelled composites to

shape a meager inflexible circle. The brushes run straightforwardly on the armature

surface making the entire outline extremely smaller. An option fabricating technique is to

utilize wound copper wire laid level with a focal ordinary commentator, in a bloom and

petal shape. The windings are normally settled by being impregnated with electrical

epoxy preparing frameworks. These are filled epoxies that have moderate blended

consistency and commonly UL 1446 perceived as a preparing compound protected with

180 °C, Class H rating.

There is no cogging (torque varieties brought on by changing fascination between the

iron and the magnets). Parasitic whirlpool streams can't shape in the rotor as it is

absolutely ironless, albeit iron rotors are overlaid. This can extraordinarily enhance

effectiveness, yet variable-speed controllers must utilize a higher exchanging rate (>40

kHz) or DC in light of the diminished electromagnetic induction. These motors were

initially created to drive the capstan(s) of attractive tape drives in the prospering PC

industry, where negligible time to achieve working rate and insignificant halting

separation were basic. Hotcake motors are still broadly utilized as a part of superior servo

controlled frameworks, mechanical frameworks, modern computerization and restorative

gadgets. Because of the mixture of developments now accessible, the innovation is

utilized as a part of utilizations from high temperature military to minimal effort pump

and essential servos [16].

1.20 SERVO MOTOR

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A servomotor is an motor, frequently sold as a complete module, which is utilized inside

a position-control or velocity control criticism control framework principally control

valves, for example, motor worked control valves [17]. Servomotors are utilized as a part

of uses, for example, machine instruments, pen plotters, and different methodology

frameworks. Motors expected for utilization in a servomechanism must have all around

reported attributes for speed, torque, and force. The rate versus torque bend is truly

critical and is high proportion for a servo motor. Dynamic reaction attributes, for

example, winding inductance and rotor idleness are additionally imperative; these

elements confine the general execution of the servomechanism circle. Huge, intense,

however moderate reacting servo circles may utilize customary AC or DC motors and

drive frameworks with position or velocity input on the motor. As dynamic reaction

prerequisites build, more particular motor outlines, for example, coreless motors are

utilized. Air conditioning motors' unrivaled force densityand speeding up attributes

contrasted with that of DC motors has a tendency to support PM synchronous, BLDC,

instigation, and SRM drive applications.

A servo framework varies with input is constant while the motor is running; a stepper

framework depends on the motor not to "miss ventures" for transient exactness, in spite

of the fact that a stepper framework may incorporate a "home" switch or other component

to give long haul security of control [7]. The length of force is on, a bi-Linearional

counter in the printer's chip stays informed regarding print-head position.

1.21 STEPPER MOTOR.

Stepper motor with the delicate iron rotor, with dynamic windings demonstrated. In "A"

the dynamic windings have a tendency to hold rotor in the position. And in "B" an

alternate arrangement of windings are conveying a current, which creates torque and turn.

Stepper motors are a sort of motor every now and again utilized when exact revolutions

are needed. In a stepper motor an interior rotor containing PMs or an attractively delicate

rotor with notable shafts is controlled by a situated of outside magnets that are exchanged

electronically. A stepper motor might likewise be considered as cross in between the DC

electric motor machine and the turning solenoid [5]. As every curl is stimulated thusly,

the rotor adjusts itself to the attractive field created by the empowered field winding.

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Dissimilar to synchronous motor, stepper motor may not be pivot continuously; rather, it

"steps" begins and after that rapidly stops once more starting with one position then onto

the next as field windings are empowered and de-stimulated in arrangement. Contingent

upon the grouping, the rotor may turn advances or in reverse, and it may alter course,

stop, accelerate or ease off subjectively [3].

Straightforward stepper motor drivers completely stimulate or totally de-invigorate the

field windings, driving the rotor to "gear-tooth" to a predetermined number of positions;

more advanced drivers can relatively control the ability to the field windings, permitting

the rotors to position between the machine gear-piece focuses and subsequently pivot to a

great degree easily. This method of operation is regularly called micro-stepping. PC

controlled stepper motors are a standout amongst the most flexible manifestations of

situating frameworks, especially when some piece of an advanced servo-controlled

framework [12].

Stepper motors can be turned to a particular edge in discrete strides no sweat, and

henceforth stepper motors are utilized for read/compose head situating in PC floppy

diskette drives. They were utilized for the same reason as a part of pre gigabyte period

PC plate drives, where the exactness and velocity they offered was satisfactory for the

right situating of the read/compose leader of a hard circle drive . As drive density

expanded, the accuracy and rate confinements of stepper motors made them out of date

for hard drives the exactness restriction made them unusable, and the speed constraint

made them uncompetitive in this way fresher hard circle drives utilization voice loop

based head actuator frameworks. (The expression "voice loop" in this association is

memorable; it alludes to the structure in a run of the mill (cone sort) amplifier. This

structure was utilized for some time to position the heads. Current drives have a turned

curl mount; the loop swings forward and backward, something like a sharpened steel of a

turning fan. In any case, similar to a voice curl, current actuator loop conduits (the

magnet wire) move opposite to the attractive lines of power [13].

Stepper motors were and still are frequently utilized as a part of PC printers, optical

scanners, and advanced scanners to move the optical filtering component, the print head

carriage (of speck grid and inkjet printers), and the platen or food rollers [14]. In like

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manner, numerous PC plotters (which since the mid 1990s have been supplanted with

vast arrangement inkjet and laser printers) utilized revolving stepper motors for pen and

platen development.

Alleged quartz simple wristwatches contain the littlest typical going motors they have

one curl, draw next to no force, and have a PM rotor [15]. The same sort of motor drives

battery-controlled quartz timekeepers. Some of these watches, for example,

chronographs, contain more than one going motor.

Nearly related in configuration to three-stage: SRMs, stepper-motors and AC

synchronous-motors are named variable hesitance motor type [10]. The Stepper type

motor machines were frequently utilized as a part of PC printers, optical scanners, and PC

numerical control (CNC) machines, for example, switches, plasma cutters and CNC

machines.

1.22 LINEAR MOTOR AND ELECTROMAGNETISM

A Linear motor is an "unrolled" electrical motor machine, so that, as opposed to creating

a torque (pivot), it creates a straight-line drive along its length [11]. Linear motors are

most regularly affectation motors or stepper motors. Straight motors are generally found

in numerous crazy rides where the quick movement of motor-less rail car is controlled by

rail.

The principal reason for the larger part of world's electric motor machine is to the

electromagnetically affect relative development in an air hole between a stator and rotor

to create helpful torque or straight com

A/c Lorentz Force Law

Mechanical Power Output of Motor

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HP

Watts

Watts

For asynchronous or induction motor, relation between motor speed and the air gap

power is,

, where

Rr - rotor resistance

Ir2 – current’s square induced in rotor

And s – slip

1.23 BACK EMF AND EFFCIENCY OF MOTOR

The armature windings of an immediate current motor are traveling through an attractive

field; they have a voltage instigated in them. This voltage has a tendency to restrict the

motor supply voltage as is called "back electromotive power (emf)" [16]. The voltage is

corresponding to the running rate of motor. Back emf of motor, in addition to the voltage

drop over the winding inner resistance and brushes, must equivalent the voltage at the

brushes. This gives the principal component of velocity regulation in a DC motor. In the

event that the mechanical burden builds, the motor eases off; a lower back emf results,

and more present is drawn from the supply. This expanded current gives the extra torque

to adjust new load.

In the AC machines, back emf is here and there valuable to consider a back emf source

inside the machine; this is of specific sympathy toward close speed regulation of

incitement motors on VFDs, for example. Losses motor misfortunes are predominantly

because of resistive misfortunes in windings, center misfortunes and mechanical

misfortunes in course, and flight optimized misfortunes, especially where cooling fans

are available, likewise happen [17].

Misfortunes likewise happen in recompense, mechanical commentators sparkle, and

electronic commentators furthermore disseminate heat.

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,

Where   is energy conversion efficiency

Is electrical input power

and   is mechanical output power:

Where   is input voltage,   is input current,   is output torque, and   is output angular

velocity.

1.24 TORQUE CAPACITY OF MOTOR TYPES

All the electromagnetic motors and that incorporate the types specified here get the

torque from the vector result of the connecting fields. For ascertaining the torque it is

important to know the fields noticeable all around crevice. When these have been built by

scientific analysis utilizing FEA or different apparatuses the torque may be figured as the

indispensable of every last one of vectors of power reproduced by the sweep of every

vector. The present streaming in the windings is delivering the fields and for a motor

utilizing an attractive material the field is not linearly proportional to the current. This

makes the figuring troublesome yet a PC can do the numerous computations required.

The greatest torque for a motor will rely on upon the most extreme current in spite of the

fact that this will ordinarily be .just usable until warm contemplations outweigh

everything else. At the point when ideally composed inside a given center immersion

imperative and for a given dynamic current (i.e., torque current), voltage, post pair

number, excitation recurrence (i.e., synchronous speed), and air-crevice flux thickness, all

classifications of electric motors or generators will display practically the same greatest

nonstop shaft torque (i.e., working torque) inside a given air-hole region with winding

openings and back-iron profundity, which decides the physical size of electromagnetic

center [15].A few applications oblige blasts of torque past the most extreme working

torque, for example, short blasts of torque to quicken an electric vehicle from stop.

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Continuously restricted by attractive center immersion or the safe operating temperature

increase and voltage, limit for torque blasts past the most extreme working torque

contrasts altogether between classes of electric motors or generators.

Limit for blasts of torque ought not to be mistaken for field debilitating ability. Field

debilitating permits an electric machine to work past the planned recurrence of excitation.

Field debilitating is done when the most extreme velocity can't be come to by expanding

the connected voltage [16]. This applies to just motors with current controlled fields and

accordingly can't be accomplished with PM motors.

The electric machines without the transformer circuit’s topology, for example, that of

WRSMs or PMSMs, can't understand blasts of torque higher than the most extreme

planned torque without soaking the attractive center and rendering any increment in

present as pointless [17]. Besides, the PM gathering of PMSMs can be hopelessly

harmed, if blasts of torque surpassing the most extreme working torque rating are

endeavored.

Electric machines with transformer circuit topology, for example, incitement machines,

actuation doubly nourished electric machines, and affectation or synchronous injury rotor

doubly sustained (WRDF) machines, display high blasts of torque in light of the fact that

the elf-affected dynamic current on either side of the transformer restrict one another and

hence contribute nothing to the transformer coupled attractive center flux thickness,

which would somehow prompt center immersion. Electric machines that depend on

affectation or non-concurrent standards impede port of the transformer circuit and

accordingly, the receptive impedance of the transformer circuit gets to be prevailing as

slip expands, which confines the extent of dynamic (i.e., genuine) current. Still, blasts of

torque they’re 2 to 3 times higher than most extreme outline torque are feasible.

The brushless injury rotor synchronous doubly sustained (BWRSDF) machine is the main

electric machine with a genuinely double ported transformer topology circuit (i.e., both

ports autonomously energized with no short-circuited port). The double ported

transformer circuit topology is known not temperamental and obliges a multiphase slip-

ring-brush gathering to engender restricted energy to the rotor winding set [18]. In the

event that an exactness means were accessible to promptly control torque point and slip

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for synchronous operation amid motoring or producing while at the same time giving

brushless energy to the rotor winding set, the dynamic current of the BWRSDF machine

would be autonomous of the responsive impedance of the transformer circuit and blasts

of torque altogether higher than the greatest working torque and a long ways past the

down to earth capacity of whatever other kind of electric machine would be feasible.

Torque blasts more noteworthy than eight times working torque have been ascertained.

From experimental data that is used for System Identification the mathematical model

was obtained. It involves importing the input and output data from the experiment with

respect to time. Trends are omitted from imported data during pre-processing. Pre-

processing develops data quality by omitting unwanted data in the imported data. Pre-

processing has filtering, de-trending, selecting range and removing means etc.

Process administration is a conservative articulation of rising the operation of a system,

the profitability of a plant, and along these lines the nature of stock nowadays, the interest

for right temperature administration and air ventilation administration has vanquished a

few of business areas like technique warmth nutritive business, auto, modern territories or

work environment structures wherever the air is cooled in order to deal with a cushy

surroundings for its tenants. One in every of the principal essential contemplations

concerned in warmth space comprise inside of the sought temperature realization and

utilization change. To fulfill such a test one should advance suitable administration ways.

Inside of the most recent decade broadly examination has been made with significance

temperature administration for different sorts of procedures. Inside of the paper the

creators propose a fluffy PID warm framework for a throwing and in the temperature

administration (roundabout versatile general) of modernity of a latent HVAC framework

is style. Ongoing PID administration for warming plant abuse PIC16F887

microcontroller was composed and upheld as is indicated. The creators propose style

outline for water temperature administration. The study infers every obtaining and

demonstrating methods and administration ways upheld PID controller.

An obligatory interest to actualize the pleasantly determination is that the model securing

that depicts the propelled conduct of the framework. The paper concentrates on the model

recognizable proof and administration of temperature in an extremely testing room

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intended for ventilation. The most motivation to determine an espresso esteem

application is that to be proper for different studies with pertinence administration

courses for temperature administration or to be of enthusiasm for plant style. The

objective of this study is to research and add to a scholastic plant that may be utilized at

entirely unexpected application lab wherever understudies study concerning

microcontrollers, information securing, and framework recognizable proof and especially

framework style. Plant usage will basically be reused by clients who don't appear to be

educated in plant style. The research facility configuration anticipated amid this paper

licenses to run tests though collaborating with its components. Administration outline

leave client to actualize data of the administration designing that in clear means. The

planned application with PIC18F4620 is furthermore useful in prophetic administration

investigation for installed controller. Additionally, lately, the necessities for the standard

of administration style in technique amplified because of the processing power high

caliber.

The paper is sorted out as takes after: the second a piece of the paper shows the cooling

framework style and execution with PIC18F4620. Resulting area manages the data

obtaining and model recognizable proof. Inside of the third piece of the paper an impact

framework style bolstered PID controller was produced. Additionally, some ongoing

trials are performed so concerning occurrence the exhibitions of the implemented

controller. At long last a few conclusions are given.

Extensive sizes of an application are committed to oversee temperature terribly

exceptionally sensible environment relevant to fluctuated needs. In this way on get ideal

execution it would be invaluable to give temperature administration structure then by

giving more secure cooling or the glow with higher exhibitions regarding the vitality

productivity, adaptability & mobility. Broadly examination has been made on warming

administration on account of the prerequisite in brilliant applications. Throughout this

paper the build concentrates on a clear technique which may be material to instructive

application arrange incidentally all entirely unexpected administration vogue

perspectives. Planned plant may well be an espresso worth application with components

snappy access. Plant comprises terribly (exceptionally cooler, resistance, sensor &

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microcontrollers that are epitomized terribly) next to no testing room, as is indicated

inside the Fig.1. Simple temperature sensor LM335 will offer information of the current

condition of degrees at each testing time.

To mitigate execution of anticipated cooling framework it’s a need to expand temperature

with an electrical warmth gadget made-up from nickel. The warmth releases inside the

little range are mounted by restricting the estimation of the current with variable voltage

component for different current. Work of cooler are to lessening air temperature from

room. The microcontroller can send evidence to L298 an H-span, who can charge the DC

engine of the cooler as is depicted in Fig. 2. In order to direct the air temperature to the

predefined point, a controller is needed. It's to be said that the analysis begins from an

immovable temperature inside of the room. The glow resistance is framed by nickel and

transmits a warmth sum inside of the environment. To stay away from an amazing

temperature degree, the present fluctuate of the resistance is banished by a voltage

potentiometer to get a 77§C inside of the arranged testing room. This some piece of the

framework utilized a 220 outside supply. One in every of the dynamic parts of the

framework is that the PC cooler. Misuse the L298 charges, the engine can turn regarding

DC engine speed administration technique. The H Bridge L298 can guarantee the

sustenance for the cooler DC engine. The engine velocity is changed from 950 to 3600

giving a most 44.3 CMF. The LM335 simple gadget could be a useful electrical gadget

for the framework. The gadget works kind -40§C to 100§C and amid this application is

utilized the plastic TO bundles gadget, considering essential temperature. With one

degree exactitude and clear to balance utilizing a ten kOhm resistance it offers the

specific Kelvin) degrees. The K degree are conceived again in Celsius degree, in order to

send the information to the microcontroller The anticipated improvement board used in

this paper named MDB01 (motherboard) made by SMTD (Smart specialized Design) was

uniquely intended for application with low esteem microcontrollers like miniaturized

scale chip 8 bits 16xxx and 18xxx, with forty pins, gang. This board contains which may

extensively reduce power utilization all through operation. The forty megahertz agent

recurrence joined with thirteen information channels for Analog-to-Digital Module,

65536 Bytes of Program Memory and 1024 Bytes for learning EEPROM are various the

choices of 18F4620. The microcontroller uses a seventy five direction set and eighty

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three augmented guideline set empowered. The gadget license expanded USART Serial

Communication and moreover concedes five I/O Timers.

The correspondence to the pc is shaped with a USB link that adjusts the sign to serial

correspondence with an equipment gadget FT232RL, as represented in [3]. This office

offers the probability to discover associations with all popular PC or scratch pad. MDB01

is supplied with L298. Full Bridge is giving the summon activities. its high voltage, high

momentum, twin full scaffold driver intended to simply settle for standard TTL rationale

levels & drive inductive bounty like solenoids, transfers, DC & stepper engines. Two

modify inputs are given to change or cripple gadget severally of data signs. All through

this application its utilized one information single DC-engine. Emitters of lower

transistors of every scaffold are associated on and furthermore the relating outside

terminal is utilized for association of an outer gadget. Extra offer information is given so

as that rationale meets expectations at lower voltage. An easy to understand a piece of the

technique is that the shading fluid gem show S1D15G14 with 98x67 pixels interfaced

with eight bits with 18F4620 that is in a position to show in time period the temperature

degree from the sensors

They grew low esteem application is committed so concerning example entirely

unexpected administration courses for temperature administration subject to cooling

advancement. Inside of the following segment, the eye is focused on continuous

information procurement, trailed by the open circle model distinguishing proof.

The study is committed to the instructional exercise exercises inside of the field of

framework style. The general reason for the technique is to verify a fancied temperature

in an exceptionally shut circle framework security operational common sense and for

comprehension the motion of a cooling framework. The vital data concerning the system

portrayal is given in segment II. The point of this segment is for case the best approach to

secure continuous information from the technique, the model distinguishing proof and

framework courses proper for air temperature administration. The framework is direct,

discrete-time and single information single yield. The flagging considered is that the

obligation cycle of the PWM signal and consequently the yield is envisioned by the air

temperature worth measured from the lumen simple gadget.

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The framework exchange capacities are thought to be capacities in nonstop time area.

Securing segment speaks to a fundamental stride in model distinguishing proof of the

progress of the plant that needs exactness in bringing about data summons to the

framework and exact measure of the yield values. This includes a perfect timing between

the charge activity and yield. Information qualities summon flag and yield supply a

decent hazard to make an elegant or disentangled model for the plant. Correspondence

channels ought to be synchronous and protections ought to activity to the potential outer

unsettling influences. The higher model got the bigger execution administration activity

is performed. On the other hand, the circulation of the temperature relies on upon a lot of

things that impact the kind and consequently the parameters of the model. The

administration activity is given by the obligation cycle estimations of the PWM signal

that are connected to the cooling DC engine. The administration summon from the

microcontroller is given utilizing a Micro bundle application, the code being composed in

C++. In order to get the twelve at the DC engine it’s compulsory to utilize a fitting

recurrence to L298 Bridge. The scaffold was wont to repay the PIC18F4620 yield voltage

that was limited to 5 V, as an aftereffect of the PIC voltage reference is given by the PC

USB port. The L298 Bridge offers the 12 V for augmenting the execution. It's to be said

that the L298 H-Bridge replaces the quality D/A gadget. At the point when setting the DC

engine operation recurrence worth to 2.44 kHz, very surprising obligation cycle qualities

were tried. Inside of the framework ID segment, stage info from two hundredth to

ninetieth obligation.

Keeping in mind the end goal to amass a delegate information set it totally was accepted

that inside of the room a 77§C was settled. At this consistent close temperature worth the

investigations began. 1sty it completely was connected a charge activity to the engine at

the two hundredth of the obligation cycle for four min. amid this time the yield the

LM335 gadget were gathered consistently and spared inside of the EEPROM memory.

This quick memory will record awfully revise the A/D sent qualities. Assortments of tests

in C degrees were recorded amid this time. Stationary administration is settled in

concerning four min; a short time later a fresh out of the box new order is conveyed by

the microcontroller to the L298 Bridge. This powers the engine work a ninetieth

obligation cycle and accordingly the air temperature inside of the testing room

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diminishes. The new temperature qualities were recorded when the last yield given by the

two hundredth obligation cycle charge. It are frequently specified that the ninetieth

obligation cycle summon was connected abuse one second inspecting time. The

EEPROM memories were sent to a PC utilizing a USB correspondence link and each one

yield qualities were spared in an extremely PC record. FT232RL interface serves to

change over the serial transmitter of the 18F4620 into an outsized scale USB interface

who acts kind of a serial conveying.

The recurrence for the DC cooling engine was tried all through the securing stage to line

up the pulse expansiveness sum inside of the season of the analyses. At the point when

testing however the framework lives up to expectations at very surprising PWM

recurrence a 2.44 kilohertz was set up. A few tests were made inside of the testing room

shifted the DC cooling force. The PWM summon was resolved on the CRO as indicated

in Fig.

To recognize the parametrical model of the cooling system the Identification apparatus

bureau from Mat lab was utilized. The cooling strategy are frequently portray as a

relentless system anyway we have the capacity to administration it as a particular time

framework. For a fair portrayal of the strategy we need to make a model of the technique.

The correspondence of the framework with a pc is imperative to exchange the

information from the LM335 gadget to the pc. Misuse the USB link the voltage values

from the gadget were output by the simple to advanced gadget at every second and when

changing to C degree the information were send to the PC. To establish the model of the

plant some important information must be urged to be hang on. An open circle reaction

offers essential data to make a genuine model that may be handled inside of the

Identification device bureau from Mat lab environment. A stage is connected to the

framework and thusly the yield reactions are spared in Mat lab space. The inputs for the

framework are frequently thought about the obligation cycle worth of the PWM and can

be considered in % values. Some very surprising estimations of the stride were connected

to the framework and consequently the reactions are planned inside of the Figs. 4 and

figure No.5.

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From the present reactions the last arrangement of learning was wont to set up the

persistent time demonstrate in Mat lab bundle. Inside of the Identification apparatus

bureau the order and consequently the yield reaction were won't to deliver a model. With

these changed qualities a fresh out of the box new constant temperature administration

has been performed, subject to the point changes.

The following analysis begins with at first temperature of 59§C inside of the testing room

the reference was settled to 43§C. a just took the ribbon off new step worth in point was

situated to 30§C. at the point when the fugacious administration the PID controller

achieves.

Technology of vehicular and indoor comfort of environment is known as HAVC , i.e.,

Heating, Ventilating and Air conditioning. Acceptable quality of air indoor and comfort

of thermal is the goal of HAVC. Its systems' design is mechanical engineering sub

discipline. Thermodynamics, heat transfer and fluid mechanics are its principles. It is

sometimes known as HAVC&R or HVACR with the addition of Refrigeration. Also

sometimes Ventilation is omitted and hence it becomes HACR. In large to medium

industries and offices and in marine environments for example aquarium, skyscrapers etc

in which conditions of healthy buildings are required in respect to humidity and

temperature utilizing outdoors for fresh air, HVAC plays a vital and important role.

Process of replacing are continuously changing air of the space in order to provide high

quality of indoor air that includes the control of temperature, replenishment of oxygen,

moisture removal, odor removal, dust and heat removal along with removal of smoke,

carbon dioxide and airborne bacteria. Excessive moisture and unpleasant smells are

removed by ventilation. Stagnant interior air prevention and circulation of air of interior

building is also done by ventilation.

Both circulation and exchange of air are included in ventilation. For making good air

quality and healthy environment inside the building, ventilation is needed. There are two

types of ventilations to ventilate a building-

1. Mechanical/ forced

2. Natural

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Ventilation, heating and air-conditioning are interrelated. Indoor quality of air and

thermal comfort needs are provided within reasonable maintenance cost, operation and

installation. Ventilation, lessen air infiltration and pressure maintenance are provided by

HVAC. Distribution of room air is the term used for delivery of air and its removal from

the space.

One or more than one HVAC system is used nowadays in modern buildings for

controlling system, installation and design. HVAC system is selected and equipments are

provided in small buildings by estimating the capacity and engineer. Designers of

building service, mechanical engineers or engineers of building service, design are

needed for larger buildings to specific HVAC system. The system is then commissioned

and fabricated by the special mechanical contractor. For all buildings, irrespective of their

sizes building permit and inspection of code-compliance is needed.

The equipments involved in HVAC are sometimes extension of larger DH, district

heating or DC district cooling or combination of both DHC network. In such a case,

metering becomes necessary and mandatory to measure the amount of electrical energy

consumed. On larger networks basing HVAC plays an important role in order to have an

economy that has scale which is impossible for individual buildings and utilization of

source of renewable energy for example solar heat, free cooling provided by potential

cooling in places like lakes and finally enabling storage of thermal seasonal energy

storage.

Discoveries and inventions of various scientists as Nicolay Lvov, Willis Carrier etc is the

basis of the HVAC. Different methods of modernization control of system, higher

efficiency along with industrial revolution plays vital role in invention of HVAC

component.

Generation of heat is the basic purpose of the heaters in a building. Central heating is one

of the ways to do it. Boiler, heat pump or furnace can be used to heat, steam or even to air

in a location that is central as for e.g. in home furnace home or in large room it could be

mechanical room. Convection, radiation and conduction can be used to transfer heat.

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Heaters exist for all kind f fuels i.e. solid, liquid and gaseous fuel. Electricity is another

type of source of heat. For portable and baseboard heaters this principle can be used. For

heat pump systems supplement or back up heat can be used by electrical heaters. In

1950s, heat pump acquires popularity. Heat can be extracted from ground, exhaust or

environmental air for heat pump. Usually in moderate climates heat HVAC pump

systems were used but with advance in technologies, their use is increasing even in low

temperature.

Water/steam Piping is used for heat transmission as steam. Circulator is present in most

of the modern heating system to move hot water boiler. Using radiators heat can be

transferred to surrounding air. To give floor heat radiators may be mounted in floor or it

can also be mounted on wall. Hydroids are the medium of heat transfer through water. An

additional heat exchanger in order to supply washing and bathing hot water.

Heated air is distributed by duct work system and they return through fiber glass or metal

ducts. In many systems, same ducts are used for circulation of cool air through an

evaporator coil.

Combustion by- products and volatile organic compounds might be released as the result

of incomplete combustion that occurs due to the installment of boilers, furnaces and

space heaters as indoor heating tool. Incomplete combustion happens due to insufficient

supply of oxygen. Inputs are the fuel that contains various contaminants and outputs are

different kind of harmful by products. Most dangerous output is carbon monoxide gas

that is odorless and tasteless gas that can cause serious health hazards.

Carbon monoxide can be lethal sing at 1000 ppm concentration if there is no proper

ventilation. Carbon monoxide can reduce the bloods' ability to transport oxygen by

binding with it and forming carboxyl hemoglobin.

1.24.1 CONINUOUS TORQUE DENSITY

Torque density (continuous) of ordinary electric machines is dictated by the measure of

the air-crevice territory and the back-iron profundity, which are controlled by the force

rating of the armature winding set, the rate of the machine, and the achievable air-hole

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flux density before center immersion. Regardless of the high coercively of neodymium or

samarium-cobalt PMs, consistent torque density is practically the same amongst electric

machines with ideally outlined armature winding sets. Ceaseless torque density identifies

with technique for cooling and reasonable time of operation before obliteration by

overheating of windings or PM harm.

1.24.2 NON MAGNETIC MOTOR

An electrostatic motor is in view of the fascination and shock of electric charge.

Generally, electrostatic motors are the double of traditional loop based motors. They

ordinarily oblige a high voltage power supply, albeit little motors utilize lower voltages.

Traditional electric motors rather utilize attractive fascination and aversion, and oblige

high level current at the low level voltage. In year 1750s, first electrostatical motors were

produced by the scientist Benjamin Franklin & Andrew Gordon. Today electrostatic

motor discovers for regular use in small scale electro-mechanical frameworks (MEMS)

where their drive voltages are underneath 100 V, where moving and the charged plates

are far simpler to create than loops and iron centers [5].

Likewise, the sub-atomic apparatus which runs living cells is regularly taking into

account straight and rotational electrostatic motors machine.

Piezoelectric motor is a sort of electric motor based upon the adjustment fit as a fiddle of

piezoelectric material as soon as the electric-field is connected. Piezoelectric motors

make utilization of the opposite piezoelectric impact whereby material produces

ultrasonic vibrations or acoustic with a specific end goal to deliver a Linear or rotational

movement. In one instrument, the lengthening in a solitary plane is utilized to make an

arrangement extends and position holds, like the way a caterpillar moves [3].

An electrically controlled speed apparatus drive framework utilizes electric motor

innovation to move rocket in speed, most frameworks being in light of electrically

driving force to high velocity, with a few frameworks being in view of electrodynamics

ties standards of impetus to the magnetosphere [2].

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CHAPTER 2

LITERATURE SURVEY AND EVALUATION

[Bindu R, et-al 2012]The wide use of the DC Servomotors in several servomechanisms

makes the study of positioning control of DC Servomotors very significant. The transient

response of the motors is of very much importance and this can be even improved by the

use of the PID controllers. Some approximate initial values but workable are obtained by

such designed tuning methods these days, and then to end up with certain specific needs

and requirements these values are optimized. For some chosen system specifications, a

very quick and flexible method for determination of the optimized parameters of PID

controller has been presented within this paper based on genetic algorithm. Quite a

number of specifications are met when simulated, using the proposed method of the

tuning [1].

When the PID tuning was carried out based on the genetic algorithm, the results obtained

were far better than those obtained from the conventional ways of tuning. PID tuning

values that can be obtained by making use of the conventional ways and methods

provides good starting values but these values needed to be improved. Gain of the PID

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controller is fully related to the initial population of the range thus selected. The response

was found to be quite satisfying and was around the required when the well-designed GA

tuned PID controller was put into action. Tuning was observed to be well-versed and

effective when, KI in the range of 0.001 to 0.55, while KP was between 10 to 30 and KD

was within 0.001-0.5. if the initial population is increased, generations required for

converging to some optimum value may be increased but the added advantage will be the

broader range of requirements may be dealt with [2].

[MehmatAkar,et-al 2007 ] DC Servomotors’ Control of speed under study. The angular

velocity was controlled by the 3 separate motion controllers and mathematical model and

relations were formed. A model was simulated in the Matlab under variable working

conditions and adaptive neuro fuzzy interference, proportional-integral and fuzzy

interference system controllers respectively were implemented. Minimum influence on

system stability, quickly settling reference values and no overshoot is expected from

servomotor applications [3].

[Sanjay Sing, et-al 2012] 5Nm variable load was executed in this study to DC

servomotor, which has been used as a model with some reference speed. In case of the

3Nm load, 0.4 seconds overshoot was observed as response of system even when PI

controller was at stabilized position. But the response of the fuzzy and andfis controllers

under the same working conditions was observed to be somewhat different. The settling

time for anfis controller was 0.33 seconds and for fuzzy controllers it was 0.38 seconds.

Anfis controller displayed a very different and better response when load moment was

increased to 5Nm on shaft of the motor of the DC servo motor for variable velocity [4].

For the same very working conditions the current response for all of the 3 controllers was

quite reasonable. Owing to the learning characteristic of error, the anfis controller

displayed even better performance as compared to other two of the controllers under

variable velocity and load. Where, anfis and fuzzy controllers exhibit almost the same

response because of the limit of current. PI controller was put under study for the DC

servomotor and simulations were allowed to run onto it. Simulations provided very

favorable results as the gain of the controller was to be manipulated to obtain error

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responses as low as possible. Approximate zero overshoot and minimal stabilizing time

were the results, which were obtained and are quite a significant step forward to

improved designs [5].

[Ahmed M.A. Haidar 2013]Advanced Electromechanical Engineering has taken a step to

new horizons of engineering with the addition of full auto control of the rotation angle of

DC servo motors. It has been very common now days to control the processing of the DC

servo motor with the help of personal computer. And such controllers are also available

that connect the PC and motor so that they can interact to each other without any external

intervention. PIC microcontrollers were taken into action during the test in this paper

along with Graphical User Interface provided by the Matlab and the angle of rotation of

the DC servo motor was traced. Controllers were tested on real time application basis,

Proteus was the software that was incorporated for the simulation linked with Matlab.

Slider movement was considered to be the input signal to microcontroller for altering the

angle of rotation. Obtained results were quite favourable and the results deduced from the

test was the PIC microcontroller working alone with the GUI in software (Matlab) was

big step forward to the rotational angle control [6].

GUI slider movement change was supposed to be the change in desired position of angle

of rotation, and microcontroller with GUI interaction with Matlab was controlling this

change. Test was carried out to check whether this supposition can really perform the

way it looks to be or not. Depending upon the regulated values, rotations of the servo

motor were controlled by the sliders. PC was not able to send signals enough to produce

the rotations actually desired, as these small signals form PC were responsible for signals

not capable enough from microcontrollers to produce the desired actual rotations. To

fulfill this deficiency, and to improve the accuracy of the real time processing an

amplifier was added. This paper proved to be a milestone, as it exhibited, real time

control of the servo motor angle of rotation may be obtained by interface of two different

software [6].

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[Ali Mohamed Yousef 2012] The designing of the controller for controlling DC servo

motor based on ISMC (Integral Sliding Mode Controller). Integral Sliding Mode

Controller’s design was created its model was put to analysis and evaluated for steady

state performance (zero error). Chattering arising from the discontinuous controllers is

actually the major disadvantage of SMC. Switched gains incorporated ISMCs are the

solution to this disadvantage. ISMC with switched gains was compared with the simple

PID controllers to verify the effectiveness of the supposed arrangement. And the results

depicted that such controllers are quite robust and provides high level of tracking. System

order reduction by one, and fast recovery from the disturbance matched, is ensured by

SM along with other features as discussed above [7].

Different controllers like SMC, PID and ISMC were taken in consideration for the

positioning control of the DC servo motor. SMC and ISMC were used with switched

gains to overcome the chattering problem of them. PID are most suitable in conditions

where there is less disturbance in the system. This kind of comparison was carried out to

find the performance and pros and cons of each of the controllers. In Case of SMC

controllers the settling time is longer and chattering problem is still to be dealt with.

When ISMC is used along with the switched gains the required position is obtained with

very much less settling time along with no steady state error and the chattering was also

vanished.

[G. Sudha, 2012] Fuzzy logic controller in this paper, was compared to the conventional

controllers in terms of time specification performance in positioning of DC motor. Direct

control method in position controlling was implemented to PID controller and fuzzy logic

controllers. Implementation of fuzzy logic PID controllers is actually the main reason of

this text. Positioning of the motor was dispensed to fuzzy logic. Datasheet was used to

obtain the motor parameters for real motor. Simulink Toolbox of Matlab was used to

develop a model for simulation and Fuzzy Control Toolbox was used to develop fuzzy

control to provide suitable response times while keeping in view the constraints of the

kind of motor we chose.Mamdani Minimum Inference engine was the one chosen for our

test. The response times obtained were quite appropriate [8].

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Fuzzy based PID designed has a much faster response than that of traditional ones. Fuzzy

logic PID is much better designed when it comes to the peak value and

settling time of the conventional method. It’s evident that improved results are obtained

with the help of fuzzy PID controllers. Fuzzy PID control was implemented in this paper

for controlling the positioning of the DC motor.

[S. S. Patil, et-al] High-speed permanent magnet DC (PMDC) motor speed control

system implementation based on integrated fuzzy logic controller (IFLC) is the main

objective of this paper. Integrated fuzzy logic controller (IFLC) is intended to enhance

the performance of the other conventional controllers. Tests have been conducted with no

load and load conditions respectively for various input testing commands like triangle,

square and ramp etc. when the experimental setup was created and results were obtained,

it revealed that performance of IFLC is many folds better under the conditions as

mentioned above and this is quite evident in the graphical representation of results [9].

After careful observations, the conclusion was reached that IFL as well as FL exhibited

even better performance than conventional PID controllers for nonlinear inputs such as

square and step. On contrary ot it IFL and PID have succeeded in showing better

responses than that of FLC for linear inputs (triangular and sine). The difference

described above would be quite clear if the ramp input is observed as its raising part is

linear in nature and trailing portion is nonlinear. PID controllers displayed above average

response for the linear portion but not impressive response for the nonlinear portion.

While IFL showed outstanding response for the both of the cases.

[PhongsakPhakamach, 2009] The position control system of DC motor using the Fuzzy

Logic Sliding mode Model Following Control id discussed in this paper. This kind of

approach makes use of the variable structure system and integrator. For the eradication of

the steady state error due to ramp or step changes the integral control is presented here.

This also assists in control precision improvement. On the other hand the disturbances

and parameter variations are controlled by the fuzzy control logic [10]. This technique

was incorporated for position control of the DC servomotors. FLSMFC incorporated

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systems showed reduced sensitivity to parameter variations and disturbances, along with

the up told advantages the chattering is also eliminated.

A different but quite inspiring configuration of the FLSMFC has been introduced in this

paper for position controlling of the dc motor servo drive. It has been noted that the

FLSMFC approach makes it possible that tracking performance may be improved to

about 85% and 75% as when compared to the IVSMFC and MIVSC approaches,

respectively. On expense of wide plant parameter variations and external load

disturbances accurate position tracking may be achieved as demonstrated by experimental

outcomes. This approach is fairly robust so it is quite suitable for electrical machine

control system. For this reason it is expected that this FLSMFC approach can be applied

to some very high performance application like industrial scale motors and machine tools

[Mrs. A. A. Thorat, 2013] A perception of fuzzy logic controller to reach some specific

speed control of DC motor has been presented in this paper. Fuzzy logic is very

interesting logic where numerical variables are just replaced by the linguistics. This

linguistic variable used in fuzzy logic controllers is based on some control rules known as

fuzzy rules. Any of the speed profile may be selected by incorporating fuzzy packages

provided by the Personal computers (PCs). Fuzzy controller that has been proposed has

performance better than simple fuzzy controller. The whole process is based onto to

major fragments, software development and the other one is hardware implementation.

When we see into the hardware portion, H-bridge DC Motor driver is to be designed and

evolved. H-bridge DC Motor thus designed, may be used as a liaison between DC motor

and fuzzy controller based on microprocessor technology. Two type of convertors will

be used to provide actual speed signal from rotary tachometer, there convertors include

an analogue to digital converter (ADC) and a frequency to voltage convertor (FVC) and

these are to be used input for fuzzy controller. The other fragment was the software

evolvement. Varying pulse width for DC motor application a digital fuzzy logic speed

controller may be developed. This paper in short represents that fuzzy logic controller can

be evolved for DC motors [11].

DC motors are widely used these days in a number of applications now-a-days .Varying

in size and shape they are found in robotic mechanisms, rolling mills, home electrical

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appliances and many other applications found in our daily life. These types of

applications require some kind of speed controllers which may assist DC motors in jobs

like those as described above. For this reason DC motor speed controller system based on

fuzzy logic using microcontrollers was designed. The systems such designed is real time

closed loop control system, capable of retaining the required speed even when the load

changes. Matlab was the software used for carrying out the comprehensive analysis of

DC motor drive system making use of the fuzzy logic controller. Speed becomes constant

at 0.6sec for the open loop system, and can be verified from the speed wave form. On the

other hand, for the fuzzy PI the constant speed is obtained at 0.1 sec and smooth control

over speed is obtained without any oscillations and even the overshoot is small.

A high level programming language used for programming of the microcontroller called

Mikro C was used to create the fuzzy logic control algorithm. The problems arising in the

C-structured programming may be overcome if the embedded C language has been used

for programming the microcontrollers. Compilation will be done in the memory system

and the fuzzy logic algorithm will be done in it. For driving the DC driver a valid PWM

signal will be generated by fuzzy controller. Real time processing and debugging will be

enabled when PIC microcontroller will be acting between DC speed drive and DC motor

[11].

[Makiko Kobayashi, et-al, 2006] presenting the Thick-film (90 m) piezoelectric ceramic

increased temperature ultrasonic transducers (HTUTs) have been well placed and

deposited on the metallic compounds through the sol-gel spray method. Normally the gel

is made up of the fine powders of the bismuth titan ate speeded in the lead–zircon ate–

titan ate combination and the solution. It has been recorded that the films possessing the

required thickness are gotten following the multilayer coating technique. Normally the

Piezoelectricity is obtained through the corona discharge poling technique. It is evident

that the center frequencies within the ultrasonic network produced through the HTUTs

are approximately 10 MHz and in relation to the network -to-noise ratio (SNR) is greater

than the 30 dB in the pulse-echo mode at the 500 C. basic merit of the modern HTUTs

shows that they are usable in the temperature greater than 500 C, they are also very rare

and lastly they can be combined together on the flat and the curved surfaces. They at the

same time does not require ultrasonic coolant, they can at the same time be handled at

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every reduced and moderate megahertz frequency value range with adequate frequency

bandwidth, and the last merit is that they posses adequate piezoelectric strength and the

SNR. Main role of the HTUTs to actually regulate the polymer injection molding method

in the real-time at the present mold insert of the machine is illustration. Normally the

polymer behavior within the mold cavity was regulated through the differentHTUTs

sensor inserts a joined in the mold inserts at various locations. The Mold inserts are

majorly applied by the injection molders, in the particular, for the multi-cavity molding

processes. The Utilization Of the sensor inserts in the mold insert enhances us to account

for the monitor Of the injection process through the molds of different sizes. Normally

the materialUsed was the injection grade polycarbonate and the molded Section with

rectangular shape. The Flow front from the arrival and the median flow front velocity of

the polymer within the mold cavity wasobtained through the amplitude variation of the

echo reflectedfrom the below of the HTUT sensor placement. At the same time the echo

wasapplied to realize the time of the gap opening of the present mold. Normally the

amplitude and the phase changes of the echoes generating within the molded part was

applied to realize the part ejection andto basically monitor the filling extreme completion

of the present mold cavity through the polymer. It was recorded that the amplitude of the

present echoes was very sensitive to the section attached from the mold to enhance the

incomplete part with fillingrate of a specified percentage to be realized. Normally the

formation of the solid is regulated just to check the molded part was done through

measuring the ultrasonicvelocity and the attenuation in the molded section through the

use of differentechoes generating in the part. It was recorded that the variation of the

ultrasonicvelocity and the attenuation were showing the material characteristics of the

part, like the elastic constants, the viscosity and the density, on the solid formation [19].

[HuailinShu ,et-al,2007] Presets the characteristic of the temperature control injection

molding machine by use of PIDNN. In this paper simulation results are showing the

results for three stage injection molding machine. That is give the point that PIS neural

network is giving the best response time and setting point for the three stage injection

molding machine . PIDNN have three hidden layers P-neutrons, I – neurons and D –

neurons .PIDNN is using for dynamic multilayer network [28].

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[Tao liu, et-al, 2009] presenting the practical barrel-temperature regulator of the

injection molding, the study aspect suggests two identification technique and the united

regulator scheme for multipurpose temperature regulation design. Relating to the unity

step action relating to the full heating action in the temperature-regulation system, an

identification technique is generated to gain an integrating type for the heating-up

regulation design. Through application of relay technique around the set-point

temperature, different identification technique is suggested to bet the type of stable and

the integrating model for regulation system design to reject the load interference during

the system operation. Enhancing identification the robustness, the de-noising plans are to

be presented for the practical uses with the dimensions noise. Actually to enhance

Simplicity for the suggested action, a combined regulator scheme depending on the

internal-model-regulator structure is then suggested for the heating-up and the steady

actions against the load interference. The suggested Analytical regulator-design

techniques and the tuning structures for the rules are relating designed for the quantitative

regulation of the present heating-up action and the load-interference action for the

operation. Normally the current literature and the practical use for the injection molding

are done to illustrate the effectiveness and the advantage of the suggested identification

technique and regulatory scheme. In the temperature-control design a method of

identification relying on the step response has been chosen for obtaining the model of

heating-up, together with another identification method that is based on a relay test which

is done around the set-point temperature and also given forgetting the model that is of

stable or even integrating type for rejection of load-disturbance.all the identification

methods can bring about good robustness towards noise that is measurable. based on the

IMC structure, a united control scheme has been proposed for both the heating-up and the

load-disturbance rejection in stable state because this is capable of lack of overheating in

the heating-up process. the formulas of Analytical controller-design and the

quantitativetuning guidelines have been provided for the employment of the required

heating-up response together with the load-disturbance response plus robust tuning

constraints so as to accommodate some uncertainties processes. In its application to the

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control of the barrel-temperature, an injection-molding machine has demonstrated very

well the proposed identification methods and control scheme effectiveness [4].

[SeyedKamaleddinMousaviMashhadi, et-al, 2013] Presents the fuzzy logic controller

to temperature of injection molding machine .Firstly, time delay is introducing for the

temperature control system. System is design as a linear fuzzy controller for control the

temperature of injection molding machine .A system of time delay is used for

temperature control. The controller and decision maker are design using fuzzy logic [29].

2.1 Issue: Error find in injection molding machine

[Chris m. seaman, et-al, 1994] presenting a wide knowledge that the PID regulator has

been very successful in the past and also widely accepted for the control of the industrial

systems where performance criterion is one of the objective function. Therefore, the task

is whether the same success can be achieved in PID controller for more than one

objective function, while preserving its operator use simplicity. Therefore here we

explore multi-objective optimization use so as to extend PID controllers to applications

requiring multiple objectives optimization. The implementation of An algorithm that runs

in real-time and provides immediate feedback to a process operator of the immediate

point of operation. Its application was to the tuning of a PID controller phase of an

injection molding process. Through an injection molding machine the algorithm was

implemented and allowed via on line to tune the controller. The presentation and

comparison ofSimulation and experimental results is below:

Therefore, this algorithm was then applied to the tuning of a PID controller hence

meeting two objective criteria for the injection molding plastication phase.

Therefore the multi-objective optimization algorithm was applied in tuning a PID

controller for a process empirical model. Here, the process was run for one cycle

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and the Data collected during this cycle was applied by the algorithm to find a

Pareto optimal operating point with reliance to two objective functions here.

Here therefore When a Pareto optimal operating point was obtained, in deciding if

this operating point is desirable the operator was used. So as to determine if other

points should be examined. Finally, a curve that is tradeoff between the two

objectives while also corresponding gains being controlled was realized. In the

repetition of this process and the algorithm allowed in tuning on line the PID

controller.

Therefore, In general this was the expectation from the algorithm. Many

improvement avenues can be explored although the largest area relates to

choosing the step size of the parameter whenever generating the gradient ideas

and conducting the line search experiments.

Here therefore, the algorithm depends on the decision makers “feel” for the

process. The estimation of The gradient is by fitting a linear model to the

experimental data so that The accuracy to this estimate is a function of noise in

the signal measurement together with the dominance of “second-order

geographical features” of the explored response surface. todetermine an index of

the “confidence” that the algorithm and experimenter have in the mode an F ratio

test is used. Also, in conducting the line search, movement of the operating point

from the region holding the gradient maintains. The use of “Zero hypothesis

testing” in continually updating the current gradients viability. Here also, a very

simple and a conservative line search was employed. Incorporate measures of the

second-order effects in increasing the efficiency of this search using the available

information [5].

2.2 Issue: Processing time of injection molding machine

[Makiko Kobayashi, et-al, 2006] presenting the Thick-film (90 m) piezoelectric ceramic

increased temperature ultrasonic transducers (HTUTs) have been well placed and

deposited on the metallic compounds through the sol-gel spray method. Normally the gel

is made up of the fine powders of the bismuth titan ate speeded in the lead–zircon ate–

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titan ate combination and the solution. It has been recorded that the films possessing the

required thickness are gotten following the multilayer coating technique. Normally the

Piezoelectricity is obtained through the corona discharge poling technique. It is evident

that the center frequencies within the ultrasonic network produced through the HTUTs

are approximately 10 MHz and in relation to the network -to-noise ratio (SNR) is greater

than the 30 dB in the pulse-echo mode at the 500 C. basic merit of the modern HTUTs

shows that they are usable in the temperature greater than 500 C, they are also very rare

and lastly they can be combined together on the flat and the curved surfaces. They at the

same time does not require ultrasonic coolant, they can at the same time be handled at

every reduced and moderate megahertz frequency value range with adequate frequency

bandwidth, and the last merit is that they posses adequate piezoelectric strength and the

SNR. Main role of the HTUTs to actually regulate the polymer injection molding method

in the real-time at the present mold insert of the machine is illustration. Normally the

polymer behavior within the mold cavity was regulated through the differentHTUTs

sensor inserts a joined in the mold inserts at various locations. The Mold inserts are

majorly applied by the injection molders, in the particular, for the multi-cavity molding

processes. The Utilization Of the sensor inserts in the mold insert enhances us to account

for the monitor Of the injection process through the molds of different sizes. Normally

the materialUsed was the injection grade polycarbonate and the molded Section with

rectangular shape. The Flow front from the arrival and the median flow front velocity of

the polymer within the mold cavity wasobtained through the amplitude variation of the

echo reflectedfrom the below of the HTUT sensor placement. At the same time the echo

wasapplied to realize the time of the gap opening of the present mold. Normally the

amplitude and the phase changes of the echoes generating within the molded part was

applied to realize the part ejection andto basically monitor the filling extreme completion

of the present mold cavity through the polymer. It was recorded that the amplitude of the

present echoes was very sensitive to the section attached from the mold to enhance the

incomplete part with fillingrate of a specified percentage to be realized. Normally the

formation of the solid is regulated just to check the molded part was done through

measuring the ultrasonicvelocity and the attenuation in the molded section through the

use of differentechoes generating in the part. It was recorded that the variation of the

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ultrasonicvelocity and the attenuation were showing the material characteristics of the

part, like the elastic constants, the viscosity and the density, on the solid formation [19].

[Thomas C Chen,1999] presentingcomputing and the system design of recent custom

designed control systems usually allows for the possibility of the application of modern

control theory towards the injection molding machines in achieving new standards of

performance without employing expensive or even special purpose equipments.

Therefore The new control lines from the Van Dorn Damage Corporation applies digital

filters use, the state transition logic, also the high order temperature state control in

controlling more accurately the molding machine processes in use. Here The use of

digital filters plus the state transition logic lowers the controller response time period

hence improving the cycle-to-cycle repeatability it also forecasts the future positions of

the molding machine clamp in the application of clamp braking process. Here also The

temperature state control system applies the real h e mathematical modeling of the barrel

together with tracking of estimated thermal disturbances to better control the temperature

of the barrel. Also these techniques are used in a variety of injection molding machine

models and sizes and can be performed in a way making the programming and operation

of the machines not difficult as compared to traditional methods application.

In applying the modern control theory together with the software engineering techniques

on the custom hardware and the platforms for the control of machines used in injection

molding, some considerable advances in the machine performance can occur. The

enhancements of this performance may result in plastic products of higher quality also

quicker and then safer machine molding operation. These methods that are described in

this paper indicate only the start of the modern control theory capabilities. In involving

the knowledge of the process that is controlled into the control system being made, better

control is possible here then. whilemore is learned about the process of injection molding,

within the control system, this information may be included [6].

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[B Ribeiro, 1999] presenting the Neural networks technology and it is used in this

system in a way that the first step for fault detection in the injection molding process. The

next step is for implement the system for automatic tuning of machine setups.

There are two main merits (i) high process consistency and (ii) cost effective due to

reduction in production costs are useful to achieve the goal of proposed work [15].

[Dr. Shereen F. Abd. Alkarim, 2007]In the following paper the application and

designing of the controller based upon the fuzzly logic for DC servo motor will be

studied. The main objective of this paper is to enhance the capabilities of the simple

controller by incorporating the fuzzy rules, using a fuzzy logic controller with load

changes of motor. The conclusion of the simulations made it clear the fuzzy logic

controller was more effectively controlling the position of the DC servomotor as

compared to the old conventional controller available in the market [12].

The study of the fuzzy based controller for the DC servomotor was carried out. Its

outcome was compared to that of the controllers available normally in the market.

Simulations were run and the compared to the performance of the conventional ones and

the results indicated that fuzzy logic controllers proved to provide superior performance

as compared to the ones they have been compared with.

[SulochanaWadhwani, 20013 ] The primary goal of this paper was to analyze and study

the use of the two evolutionary computation techniques for optimized tuning of PID

controller parameters and compute their advantages over the other techniques. These

techniques include Swarm Optimization (PSO) &Genetic Algorithm (GA). Both of these

methodologies were implemented for developing a position controller of a DC

servomotor on third order plant model. The results of Ziegler Nichols method were

compared with those obtained from the GA and PSO techniques. It clearly showed that

these techniques produced results which were a hand more useful than those for

traditionally tuned PID controllers [13].

Evolutionary computation techniques were applied to PID controllers being tuned to

control the positioning control of the DC Servomotors. Zeigler-Nichols’s tuning method

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for achieving minimum rise Time was completed outperformed by the GA tuned PID

controllers and PSO tuned PID controllers. The same was observed for overshoot and

steady state (zero error). Moreover it was observed that PSO based PID controllers were

even more accurate and their performance was ab it better than the GA tuned PID

controllers. PSO based PID controllers proved to be more advantageous than GA tuned

PID controllers in the prevailing conditions when the test was carried out.

[M. Gunalan, 2014 ]The DC servomotors are used worldwide in automated industry.

Surface mount technology placement machines were based upon the effectiveness

provided by the DC servomotors. This machine can place the different components on the

PCBs (Printed Circuit Boards) in a very fast manner. The DC servomotors and controllers

for it, have increasingly been becomes one of the most favorite area of the researchers

around the world. No doubt PID controllers have proved to be a helping hand when

dealing with DC servomotors but the main problem which arises is that there is no such

efficient and effective method is available for tuning them to perform the task assigned to

them with precision. The main stress of this paper would be on generating an Met

heuristic Algorithm, more specifically Weight Particle Swarm Optimization (iw-PSO)

algorithm which may enhance the performance of it PID tuning to many folds as

compared to that obtained from the conventional controllers. The results which were

received were well, and iw-PSO-PID performed good along with it the overshoot was

really reduced. The quicker response and controlling of convergence was also an added

advantage.

The main reason of this paper was to discuss and observe the response of the controllers

designed for the servomotors. The iw-PSO-PID,, c-PID and conventional controllers

were put under observation and their comparative results were pondered upon. Iw-PSO-

PID performed in a better way as compared with the c-PID [14].

[A. HarshaVardhan, 2013]This paper actually demonstrates about controlling the

position of DC motor via fuzzy PID controller to end up on the required point. The most

commonly used controller is PID controller; such controllers are easily available in

market. The master advantage of using he PID controller is it’s easier to tune and quite

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robust which makes it possible to be used in the industrial setup where harsh

environments exists. Ziegler-Nicholas (ZN) methodology has been adapted in this paper

for controlling the position of the DC motor using PID controllers. Fuzzy logic

controllers are helpful when PID controllers find the system model not to be exact. Fuzzy

logic is somewhat very interesting kind of logic in which numerical variables are just

eliminated and are replaced by the linguistic variables. Many of the researchers

worldwide are working and taking keen interest in the field of intelligent control systems.

Such system got quite much resemblance with artificial intelligence, so for designing and

creating such system many of the concepts should be derived from there. Simulations

were allowed to run for results of PID controllers and implementation of fuzzy PID

controllers [15].

Fuzzy PID controller and PID controllers were compared in this paper for controlling the

position of DC motors. Results of simulations were gathered using Matlab and

performance of the fizzy PID controllers were compared with Ziegler-Nicholas tuned

PID controllers. These controllers track the changes in the position of the DC motor. The

open loop Z-N tuning rules were exercised for developing the PID controller set point.

Relay feedback test was used to obtain closed loop parameters of Z-N tuning rules. Fizzy

controller (fuzzy PID controller) was used trace the change in position of DC motor and

the software used for this purpose was Simulink/Matlab. It’s quite evident form the

simulation results that stability of time domain performance was enhanced through the

fuzzy PID control methodology.

[Rahul Malhotra, et-al, 2010]Many of the techniques of the artificial intelligence were

used to extract the mathematical model of DC motor speed controlling. Evaluation of

optimum speed of motor is quite difficult due to nonlinear and multivariable nature of the

relation. Overshoot problem is in conventional PI controller is its major drawback. This

problem may be overcome by indulging the methods and concepts of artificial

intelligence. In this paper the fuzzy logic controlled model was created and was

optimized by incorporating genetic algorithm.For the controlling the speed of the servo

motor the digital processor for signal TMS320LF2407A having steady state feedback,

transient time and performance curve IAE and ITEA for the above mentioned controllers

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have been examined. From the results obtained conclude that FLC-GA hybridsation has

more effectiveness and efficiency as compare to conventional PI model and FLC for

controlling the speed of motor it is due the fact that fuzzy logic-GA built in approach has

minimum transient and overshoot and parameters are steady in that case [16].

Now armature controlled DC motor study which is a process control. Using fuzzy based

MCU and electronic signal processor the speed of the DC motor control and embedded

speed control techniques are discussed. Mathematical model is designed first and

conventional PI controller is executed in it. It is observed that PI controller gives high

overshoot and settling time. So the use of artificial intelligence techniques has been

proposed and implemented in the controller design. After this fuzzy logic control is

implemented, and using genetic algorithm its step response is optimized. The results

shows the fuzzy logic control using genetic algorithm has given better response and

optimization than conventional PI controller [16].

[Shayma’s A. Mahdi, 2014]Servo motors have found their application in various

commercial and industrial electronics devices. They have a good speed control feature;

however their maintenance cost is more than induction motor. The paper discuss genetic

algorithm for non-linear electromechanical actuator for determining the best factors of

the PID controller for improving system transient response. Peak time, rise time, settling

time and overshot response are the design parameters which were optimized. Simulation

is performed and results shows that genetic algorithm is flexible and fast tuning technique

in obtaining the optimal PID controller design for wide range of outputs in achieving

satisfactory and stable system performance. It is observed that applying Genetic

Algorithm in PID controller, while maintaining rise time, delay time and peak nearly

constant, enhances transient response and reduces average percent overshoot by 80% as

compared to conventional methods like optimum fuzzy supervisory PID. It also helps in

improving settling time. The use of genetic algorithm in PID controller gives better

results as compared to conventional methods [17].

Conventional techniques give good starting values of the PID tuning.Tuning of the

designed PID controller with the help of genetic algorithm shows the actual response

satisfactory with the required value. The gain of PID controller depends upon the initial

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population selected range. The required output can be broadened by increasing initial

population range but time taken for convergence to optimal position by simulator

increases as number of generations for convergence increases.

CHAPTER 3

PROBLEM STATEMENT

When the PID tuning was carried out based on the genetic algorithm, the results obtained

were far better than those obtained from the conventional ways of tuning. PID tuning

values that can be obtained by making use of the conventional ways and methods

provides good starting values but these values needed to be improved. Gain of the PID

controller is fully related to the initial population of the range thus selected. The response

was found to be quite satisfying and was around the required when the well-designed GA

tuned PID controller was put into action. Tuning was observed to be well-versed and

effective when, KI in the range of 0.001 to 0.55, while KP was between 10 to 30 and KD

was within 0.001-0.5 .If the initial population is increased, generations required for

converging to some optimum value may be increased but the added advantage will be the

broader range of requirements may be dealt with.

Mathematical relationship between the input voltage and angular position the shaft of the

DC motor may be derived using the laws of physics. DC Servo motor in case of point of

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Figure 3.1:- Schematic Diagram of A DC Servo Motor

Figure 3.2:- Block Diagram Representation of A Dc Servo Motor

control system can be assumed to be SISO plant .Thus all the complications and

impediment which have anything to do with multi-input system are just eradicated. Field

coils in DC servo motors are exactly parallel with the armature. Armature current and

field coil current are not dependent on each other.

Ea ( s)=Ra I a (s )+La s I a (s )+Eb ( s)

T m (s )=K t I a (s )

Eb ( s)=Kb sθ ( s )

T m (s )=(J m s2+Dm s)θ ( s )

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For implementation of DC Servomotor the following parameters are considered [3]

Ra=2.45 ohm, La=0.035 H, Kb=1.2 volt/ (rad/sec), J=0.022Kg-m2/rad, B=0.5*10-3 N-m/

(rad/sec).

3.1 ACQUIRED ALGORITHM

The primary goal of the Genetic algorithm (GA) is to find the most suitable and

optimized solution of the problem. The genetic algorithm as in is based upon an

assortment of solutions possible for the presented problem. And As this term Genetic is

taken from biological sciences, another term is taken from its reference and its

“population”. The assortment of the other alternative possible solutions to the chosen

problem is known to be “population”. Any on solution of this assortment, or individual of

population is called chromosome [1]. And the individual singular character in this

chromosome is called genes. To reach more precise possible solution than the one

obtained earlier, a new iteration is to be carried out and the evolution of the new

generation in each of the next iteration of GA takes place. Fraction of the individuals

present in the population which are to be substituted in one generation to the next and so

on is known to be generation gap. Upon this basis, the GA approach has been further

classified into two categories.

Conventional GA

Steady State Algorithm GA

In case of the conventional GA, the generation gap is equal to 1 while when we deal with

other category the generation gap is less than 1.A number of steps is involved in the

generation of a new population. First of all, each individual of the populations is needed

to be evaluated according to a user defined fitness fraction, which is exactly opposite to

the error function. Extremely fit individuals of them are selected out of the population for

reproduction case. Individuals thus selected formulate a pair known as parents. Operation

for reproduction is mutation and crossover. Discussing of the crossover first, some

fragments of two of the parents are just united to produce two new individuals which are

called offspring. Chromosomes are provided a mechanism through this way, for

combining and matching their respective desirable attributes in creating offspring.

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Crossover is executed according to a crossover probability Pc, which is applicable on

each and every pair of parents. Mutation is responsible for creation of new features as

required into the following population. Random changes are produced in the offspring

with a specific factor, called mutation probability (Pm). The entire solution space can be

searched by the crossover operation, which is the main operation for looking for into the

solution space. But it’s not sure that the whole of the solution space may be reachable by

a finite population size. The search space may be refined by launching new genes into the

populations. As we move on with crossover and mutation but there still increases a risk

that optimum solution may get lost, as there no assurance that these operators will

conserve the best available string. A mechanism is used to turndown this problem. Best

possible individual present in a population is preserved into the next new population, is

used to turndown this problem. For enhancing the search process neighbours of good

solution are also involved. The advantage of this thing will result in finer tuning and even

fast and quicker convergence can achieved. In short, immense improvements in the

quality of the solution could be achieved by incorporating the up told scheme. In case of

the Genetic algorithm, the initial generation to start with can be chosen randomly or user

can define it. When the reproduction is complete and new generation will evolve, the

older ones would be replaced by this new generation. This process will keep on going

until it meets the halt criterion.

3.2 GA TUNED BY PID

The main objective of genetic algorithm is to find out the optimal values of PID

controller to optimize the system transient response. For this purpose genetic algorithm

considers the objective function maximization .The objective function delivers a means

for calculating the performance of the PID controller according to the determined gain

parameters, which allows any expert to design the optimized PID controller. Genes are

the gain parameters of the controller KP, KI, and KDwhen they are applied to the PID

controller. Every chromosome is composed of all the needed genes to complete the trial

solution. Fitness of each chromosome is determined using error principle, which then

decides the selection of chromosome for succeeding generation .GA used actual closed

loops and targeted poles for the optimization process. Closed loop poles are obtained in

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every generation. With the help closed loop poles tuning algorithm determine the best

parameters for PID controller. The population size of 20 is use in this work and process is

terminated after 100 generations. Single point cross over method is used in the algorithm.

From average of the good solution we have determine the surrounding of the good

chromosomes. For every generation, fitness function is used for the population

evaluation. Fitness function can be taken as the inverse of error function. Error is

evaluated by comparison of actual and required location of closed loop pole.

It can be written as

ETs =error in settling time

ETD=error in peak time,

Eon and Eof = errors in the location of real poles.

In this, variables α, β γ, δ and λ represents the weight age factors.

Adjustment of these variables, in PID controller parameters can give us the required

value of closed loop response. After evaluating fitness, the fittest of the solutions are

selected which undergo the crossover process for getting offspring? Modification of any

random value can be done to get mutation. This induces a minor change in solution.

Using these imitation methods, for reproduction, the entire population is replaced by the

offspring, best solution and good solution neighbors. Keep on continue the process of

calculation, reproduction, for a number of generations until better solution is obtained.

The summary is as follows, Begin the population; while preset termination condition not

fulfilled;

Determine all these solutions with help of fitness function. It can be the inverse of

error function.

Highly fit solutions should be selected.

Combine them as parents and execute crossover operation to produce offspring.

Execute mutation by marginally changing some arbitrary solution.

Produce some solutions in the surroundings of good solutions by taking their

average.

Save best solution.

Replace all population with offspring, best solution and good solution neighbors.

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Figure 3.3:-Step Response of DC servo motor for the Uncompensated System and

Compensated System Using GA

The Figure 3.3 shows the step response of DC servo motor for the uncompensated system

and the compensated system, from figure the 1% overshoot, 0.25 sec. peak time and

0.336 sec settling time achieved.

The system is more stable by reducing the value of maximum overshoot and settling time

The system is fast stable when it achieved the steady state condition in minimum time

with minimum error.

The results obtain from PID Controller using Genetic Algorithm improved by using fuzzy

logic controller by reducing the settling time and overshoot.

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CHAPTER 4

PROPOSED METHODOLOGY

4.1 FUZZY LOGIC

Fuzzy logic is a kind of many-valued logic in which we deal with approximate values,

rather than exact and fixed reasoning. In binary logic we only deal with two value true

and false but in fuzzy logic we have a truth value which have a range between 0 and 1.

Fuzzy logic comes into usage where the truth value may vary between completely true

and completely false, that is to handle the partial truth. When linguistic variables come

into use, this range introduced by Lotfi A. Zadeh in 1965 as fuzzy set theory. Fuzzy logic

has many applications like in control theory and artificial intelligence. Since 1920 fuzzy

logic has been studied as infinite valued logic notably by Lukasiewics and Tarski.

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Figure 4.1:-Fuzzy Logic

Advanced the idea of fuzzy logic in 1960. He was working on problem related to natural

language understanding in computers. Natural language like many other life activities

cannot be translated into 0 and 1 easily. (It is debatable that we can describe everything in

terms of binary values but still in practice for computer to understand something between

two values we need to much data to be given which results in extensive computing.)In

fuzzy logic we deal with 0 and 1 as the extreme cases and also have number of in

between values as well. For example for the result comparison of between two things

“big” and “small” but 0.47 of smallness. Fuzzy logic working is like our brain. We

cumulate data and form various partial truths which we combine further into higher truths

which give certain results, when more refined, causes same kind of procedure is used in

artificial computer neural network and other sophisticated systems. It can be said that

fuzzy logic is actual way of reasoning working and Boolean or binary logic is its special

case.

4.2 RULES OF FUZZY LOGIC

Fuzzy logic rules are design according to given table number 1. In the design rules 7 are

inputs e rules condition and for de 7 rules condition are available by name of NU, NM,

NS, Z, PS, PM, PU .the range is decide according to figure 4.2 .Fuzzy logic is using for

improve the performance of the required response from the actual response. By

implement fuzzy logic rule we have been achieved the required response near about to

actual response.

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Figure 4.2:- Fuzzy Rule File for First Input (e)

According to Figure 4.2 first input e is a range of -1 to 1. It is showing the limit of first

input in fuzzy rule file. According to figure 4.3 second input de is a range of -1 to 1 & it

showing the limit of second input in fuzzy rule file

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Figure 4.3: - Fuzzy Rule File for Second Input (de)

Fuzzy logic rules give the better actual response with comparison of required response

for the DC motor. According the previous design the actual response was not touching to

required response graph. We have change some rules of proposed fuzzy logic rules file

according to table number 1.The proposed design are giving the result which is touching

the required response graph. According to design fuzzy logic rules file we have

conditions for NU, NM, NS, Z, PS, PM, PU. These are the conditions for the output.

The value of NU, NM, NS, Z, PS, PM, PU are given according to Table 4.1

1 NU [-1.3 -1 -0.64]

2 NM [-1 -0.7 -0.34]

3 NS [-0.64 -0.36 0]

4 Z [-0.34 0 0.3]

5 PS [0 0.36 0.64]

6 PM [0.36 0.7 1]

7 PU [0.64 1 1.3]

Table 4.1:- The Value of NU, NM, NS, Z, PS, PM, PU

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Figure 4.4:- Output Fuzzy Logic Rules Waveform

The figure 4.4 shows output rules in fuzzy rules file. The range is from -1 to 1 .The value

of output is selected according to value of inputs. The output rule file has 7 values from

NU, NM, NS, Z, PS, PM, PU. For Example the output is selected NU when the both

inputs e and de is NU

NU NM NS Z PS PM PU

NU NU NU NU NM NM NS Z

NM NU NU NM NM NS Z PS

NS NU NM NM NS Z PS PS

Z NM NS NS Z PS PS PM

PS NS NS Z PS PS PM PU

PM NS Z PS PM PM PU PU

PU Z PS PM PM PU PU PU

Table 4.2:- Fuzzy Logic Rule File

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Table 4.3 is showing the values of input and output. There are two inputs and one output.

Table is showing the input and output values for the design machine.

Input e Input DE Control

0 0 0.00667

0.183 0.227 0.18

0.349 0.227 0.331

0.477 0.827 0.725

-0.734 0.827 0.0591

-0.734 -0.645 -0.884

Table 4.3:- Values of Input and Output

4.3 SURFACE VIEW: The figure 4.5, 4.6, 4.7 and 4.8 shows the surface view of fuzzy

logic rules

Figure 4.5:- Surface View in Three Dimensions(X, Y,Z)

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Figure 4.6:-Surface View in Two Dimensions (X, Y)

Figure 4.7:-Surface View in Two Dimensions (X, Z)

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Figure 4.8:-Surface View in Two Dimensions (Y, Z)

4.4 SIMULATION MODE:

Figure 4.9:- Design Model of Proposed Design

Figure 4.9 is showing the proposed model for DC motor based design. In this we use

fuzzy logic two times. One time for the actual response with compensation and Second

time without compensation for the required response. For design the Gain of 1/100 we

take the gain model from the simulink model. Give the values according to the table

number 4.3.

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The value of input step in design model is starting from 0 to 20 and step size 1.

The value of derivative constant KD is 0.18 and the value of proportional constant KP is

100

Gain Sample time

1/100 -1

Table 4.4:- Gain and Sample Time For 1/100 Gain Block

As the table number 4.4, we will also design the gain block for the 0.18. For design the

0.18 gain box we will give the value of 0.18 and sample time is -1. The saturation point is

defined by the upper limit and lower limit. Upper limit is 1 and lower limit is -1 and the

sample is -1. Forgive the constant of 100 we use a gain box in which we give the value of

100 with sample of -1.

Figure 4.10:- Block Diagram for DC Servo Motor

For design the block of 1

La. s+Ra take a block of gain the values of numerator

coefficient is 1, Denominator coefficient [La Ra], absolute tolerance auto. For design the

gain Kt take the sample rate -1. Next block is for 1

J . s+B take a block of gain the values

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of numerator coefficient is 1, Denominator coefficient [J B] ,absolute tolerance auto .

For design the gain Kb sample time is -1.

CHAPTER 5

SIMULATION RESULTS

Figure 5.1 & Figure 5.2 showing the step response for the DC servo motor without

Compensation .The graph is starting form 0 to 2 .In this range it is showing the linear

form .The peak value is 2 , maximum % overshoot is 0 and settling time is near 0.06 sec

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Figure 5.1 and 5.2 :- The Step Response For The DC Servo Motor Without

Compensation

Figure 5.3 & Figure 5.4 showing the step response for the DC servo motor with

Compensation .The graph is starting form 0 to 2 .In this range it is showing the linear

form .The peak value is 2.0215 , maximum % overshoot is 2.15, peak time is .04 sec and

settling time is near 0.05 sec

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Figure 5.3 and 5.4:- The Step Response For The DC Servo Motor With

Compensation

Figure 5.5 and 5.6 is showing the comparison of The Step Response For The DC Servo

Motor Without Compensation , with compensation and step response According the

graph it is showing that our requinred response is touching to actual response that means

it is better then the PID controller .

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Fig 5.5 and 5.6:- Comparison of The Step Response for The DC Servo Motor

Without Compensation , With Compensation and Step Response

CHAPTER 6

CONCLUSION & FUTURE SCOPE

The DC Servo Motors has top position in various servomechanisms. It is important to

study DC Servo motor along with its position control study. The simulation results shows

Fuzzy logic satisfied with wide range of requirement with compared to the tuning

method. Instead of PID controller (GA based) the block Fuzzy logic is used.GA based

PID controller has slower steady state response along less undershoot / overshoot during

transition phase as compare to Fuzzy PID controller. Fuzzy logic is using for improve the

performance of the required response from the actual response. By implement fuzzy logic

rule we have been achieved the required response near about to actual response. Fuzzy

logic is improving the results of actual response to required response .In the previous

work required response is not touching the graph of actual response.

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The step response for the DC servo motor with Compensation ,the graph is starting form

0 to 2 .In this range it is showing the linear form .The peak value is 2.0215 , maximum %

overshoot is 2.15 and settling time is near 0.05 sec

The step response for the DC servo motor without Compensation,the graph is starting

form 0 to 2 .In this range it is showing the linear form .The peak value is 2 , maximum %

overshoot is 0 and settling time is near 0.06 sec

So the ouput step response of DC servo motor using Fuzzy logic touch the step response

of input in minimum time with minimum error.so we improve the performnace by

incresing speed,reducing error and minimize the settling time of DC servo motor.

In the future we can improve the performance of dc servomotor by reducing the

Maximum Overshoot & Settling time. As we get from the graph the output is touching to

the step response but it is touching just only one time. It may be contact at the step

response graph. So in future by apply neural network or other technique we can improve

the performance of DC Servomotor.

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