WELCOMEDate:-

26th May-2012

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SPEED AND POSITION CONTROL USING DC MOTOR

Group-43Group-43

Guide: External Guide:-Mr.Ashok FadnisInternal Guide:-Ms.Manisha Mayavanshi

Prepared by: Alok

Shah

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In Coordination withVEDANT ENTERPRISES

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Research & Consultant Company in Instrumentation

Major Working Fields: Power Electronics & Embedded Systems

Main Products:-

Medical InstrumentsWelding MachinesBagging MachinesBatching MachinesServo SystemsAnalytical Pharmaceutical Equipments

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OBJECTIVE OF THE PROJECT

The main core of this project is to design a control system for DC motor by using Microcontroller.

This control system works on the principle of PID Controller and Pulse Width Modulation which will be able to control the DC motor speed at desired speed regardless the change of load.

This system will be also able to perform operations like start and stop on motor at desired position of load.

SPEED

POSITION

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BLOCK DIAGRAM

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Controller-AVR ATMEGA32

LCD Display Power Supply:

MH Bridge

Forward

S1

S4

S2

S3

ENCODERMOTOR

SIMPLE ARRANGEMENT

SUDE

Control Menu

Open Loop

RPM (Speed)

Position

Direction

PWM

Hi-Lo

Counter

S2,S3

S1,S4

DUTY CYCLE

DIRECTION

KEYPAD

LCD & KEYPAD:Keypad: 4*1, LCD: 16*2LCD to display i/p ,o/p & Appropriate MessagesKeypad to take i/p from User

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KEY NO. OPERATIONB1 Start/StopB2 Increment (Up)B3 Decrement (Down)B4 Esc

MICROCONTROLLER:Software Module of ProjectWe use… AVR ATMEGA32Specially Designed InstructionsPWM Generation ModesNormal ModeCTC ModePhase Correct PWM ModeFast PWM Mode

Programmed for Four Separate Controls (Programming Scenario: PID Algorithm)

TECHNICAL SPECIFICATIONS OFAVR-ATMEGA32

Core Size 8 bit

Speed Up to 8MHz

Program Memory (Flash) 32Kbytes

Voltage Supply 2.7V ~ 5.5V

Oscillator Internal (8MHz)

Operating Temperature -40°C ~ 105°C

Package 40-SOIC

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FLOW CHART: RPM CONTROL

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FLOW CHART: POSITION CONTROL

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FLOW CHART:OPEN LOOP CONTROL

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FLOW CHART:DIRECTION CONTROL

MOTOR DRIVER: Main Switching Module (Made of two Parts)

1) Power Circuit:- Require to generate 24Vdc

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Main Supply

Step-down Transformer

Bridge Rectifier

FilterTo Control

Circuit

Require to generate 5Vdc

Main Supply

Step-down Transformer

Diode Bridge & Filter

Voltage Regulator (LM-7805)

To µC & Optocoupler

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POWER SUPPLY SCHEMATIC

2) Control Circuit:- Require to control the motor..

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Optocoupler-1 (6N137)

Power MOSFET (IRFZ46N)

DPDT Relay (2C/O MCC 24D)

From Microcontroller

To Motor

Optocoupler-2 (6N137)

NPN Transistor (BC547)

Duty Cycle Control

Direction Control

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NC1 NC2 NC3 NC4 OPERATION

1 0 0 1 Motor moves right

0 1 1 0 Motor moves Left

0 0 0 0 Motor free runs

0 1 0 1 Motor breaks

1 0 1 0 Motor breaks

H-BRIDGE CONFIGURATION

Formed usingDPDT Relay

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CONTROL CIRCUITSCHEMATIC DIAGRAM

DC MOTOR:-Permanent Magnate Type Advantages:

Low initial costEasy to Control Speed

Disadvantages:High maintenanceLow torque generation

Speed Control Using PWMPulse Width increases=Speed increasesPulse Width decrease=Speed decreases

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TECHNICAL SPECIFICATIONS OFPMDC MOTOR

Supply Voltage 24Vdc

Power 50W

Current 2A

RPM 3200

Outer Dia. 60mm

Length 100mm

Shaft Dia. 8mm

DIGITAL FEEDBCK MECHANISM:-To form the Close loop for Position ControlWe use… Incremental EncoderOne Rotation=One PulseOne Revolution=512 PulsesGenerate Quadrature Pulses with 90° Shifting

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TECHNICAL SPECIFICATIONS OF ENCODER

Supply Voltage 4.5V ~ 5.5V

PPR 512

Ref. Voltage 2.48V

Output Voltage 4.5V ~ 5.5V

Supply Current 65mA ~ 91mA

Ambient Temperature 24°C

Body Dia. 50mm

Shaft Dia. 6mm

No. of Output 2 (AB)

How µC-Count(Position) is trigger??

FROM TO FROM TO

0,1 1,1 0,1 0,0

1,1 1,0 1,1 1,0

1,0 0,0 1,0 1,1

0,0 0,1 0,0 1,0

Forward=Count Up Reverse=Count Down

H

L

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MECHANICAL SYSTEM

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PROJECT HARDWARE

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POWER SUPPLY SIMULATIONIn

put

230V

AC

Acr

oss

Cap

acito

rO

utpu

t24

VD

C

24

At

50%

Dut

y C

ycle

SIMULATION OF PWM PULSESA

t <

50%

Dut

y C

ycle

At

>50

%D

uty

Cyc

le

Time

0s 2ms 4ms 6ms 8ms 10ms 12ms 14ms 16msV(Q3:c,Q6:c)

-10V

0V

10V

20V

Time

0s 2ms 4ms 6ms 8ms 10ms 12ms 14ms 16msV(Q3:c,Q6:c)

-10V

0V

10V

20V

Time

0s 2ms 4ms 6ms 8ms 10ms 12ms 14ms 16msV(Q3:c,Q6:c)

-10V

0V

10V

20V

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OSCILLOSCOPE OUTPUTA

t <

50%

Du

ty C

ycle

At

>50

%D

uty

Cyc

leA

t 50

%D

uty

Cyc

le

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RESPONSE CURVE: Duty Cycle RPM

RPM

Duty Cycle

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RESPONSE CURVE: SPEED CONTROL

At No Load Condition

At Minor Load Condition

IndustrialRobotics Consumer Miltry

Used in any AUTOMATION APPLICATIONS ....................

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APPLICATIONS

Same circuit can be used for stepper motor control..GSM Module can be used to make the control possible with

mobile messages..This system can be used in industrial controlling drives because of

its improved accuracy and fast dynamic response just by modifying following issues:-

Feedback Measurement (Encoder) Control Algorithm (Microcontroller) Switching Module (Motor Driver Circuit)

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FUTURE EXPANSION

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CONCLUSION

The direction (forward/reverse) of the motor is also controlled.

Control and operation of drive is flexible due to the user friendly menu, keyboard and LCD display.

The speed of the motor is controlled accurately using microcontroller ATmega32 having PID algorithm.

In the condition of the load variation the speed of the motor is maintained constant with the designed algorithm.

Position is controlled accurately using PID algorithm and feedback pulses from the encoder in order to develop a precise system.

THANK YOU

ANY QUESTIONS??

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