Project Sponsor: EE Department Team Members: Michael Abbott, Neil Burkell

Multidisciplinary Engineering Senior Design

Project 6508 Controls Lab Interface Improvement

Critical Design Review2/24/05

Project Sponsor: EE Department

Team Members: Michael Abbott, Neil Burkell

Team Mentor: Dr. Mathew, Dr. Sahin

Coordinator: Dr. Phillips

Kate Gleason College of EngineeringRochester Institute of Technology

Project Overview

• Current Controls Lab:– Current System used was purchased from Feedback

for use in the Controls Lab which included Analog and Digital Control Boards to be used with a DC Motor.

• System was designed for technicians not students

• The Digital Board is outdated

• Past work from a student Ruben Mathew has shown the digital board does not work

Project Overview• Current Controls Lab:

– Digital control is taught through Simulink from varying sampling time and using different methods for converting continuous to discrete transfer functions

– There are no hardware experiments using digital controllers

• A new Digital Board is needed for the lab

Project Overview

• Needs for the Controls Lab:– Need to use Simulink on Lab PC– Need to use current Feedback 33-100 DC Servo

Motor and Power Supply

• The new digital interface must link Simulink to the existing DC motor

• Exploration into feasible interface concepts was needed (SD I deliverable)

Needs Assessment• System must interface Simulink to the motor

• Capture experimental results accurately

• User friendly for the students

• Change sampling time easily for student learning

• Use existing equipment

• Be expandable for future labs or projects

• Have a finished product by the end of Winter quarter

• Protected from students but also be accessible to be

fixed

Requirements Developed

• The Requirements of the Project are as follows:

–Interface MATLAB/Simulink with the servo DC motor

–Simulink block diagram will control the servo DC motor

–Sampling time easily changeable from 1 ms to 300 ms

–Interface will return real time data and output real time signals

–Interface will have 4 additional digital inputs/outputs, 1 additional analog output, and 7 differential analog inputs

Requirements Developed

• The Requirements of the Project (continued)

– Interface will acquire motor speed and position

data

– Analog inputs: resolution of 16 bits, range of

+10V to -10V.

– Analog outputs: resolution of 16 bits, range of

+10V to -10V.

– Interface will be covered

– Use the existing Feedback Power Supply

Overall System Diagram

Lab PCwith Matlab

and Simulink

System Interface

Feedback33-100

DC Servo Motor

FeedbackPower

Supply

Gnd, +-15V, 5V

Analog to Motor +-8V to PA(+ve,-ve)

Digital from Motor 6 Grey Code + Index for Position

Analog from Motor Tachogenerator +-8V

Communication

PA +ve, PA –ve, Tachogenerator

+-, Grey code Position idicator

Mechanical Unit 33-100

Input Shaft Output Shaft

Tachogenerator

MATLAB Software Layout

Analysis & Synthesis of Design

• Multiple Concepts were developed

1) Using a DSP Development Kit

2) Using a USB Data Acquisition Board

Importing Simulink diagram into NI LabVIEW

3) Data Acquisition PCI Card in Windows

4) Separate PC with I/O Capability controlled by

MATLAB

Analysis & Synthesis of Design

• Concept 1: Using a DSP Development Kit

Simulink DSP Kit Interface Board Motor

• Concept 2: Using a USB DAQ Board

Simulink DAQ Board Interface Board MotorUSB

USB

RS232

• Both concepts found not to be feasible

Analysis & Synthesis of Design• Concept 3: PCI DAQ Card

Simulink PCI DAQ Interface Board Motor

– PCI Card meets all requirements for I/O’s– PCI Card is supported by Simulink and Real Time

Workshop– Runs Inside the Windows Environment– No additional software would need to be purchased– Additional breakout hardware would be necessary– System Interface would not be portable– Measurement Computing PCI Card has best value

Ethernet

RS232

– PCI Card meets all requirements for I/O’s– PCI Card is supported by Simulink, Real Time

Workshop, and xPC Target– Runs external from the Windows Environment– Additional breakout hardware would be necessary– System Interface would be portable– Measurement Computing PCI Card has best value

Analysis & Synthesis of Design• Concept 4: Separate PC with PCI DAQ Controlled by MATLAB

Simulink Computer Interface Board MotorPCI DAQ

System Diagram

• Both concepts use the Real Time Workshop in MATLAB

System Block Diagram

Real TimeWorkshopSimulink

Generated CCode

Real TimeWorkshop

DC MotorPCI CardGenerated C

Code

xPC Kernel PCI Card

Computer

Real Time Windows Target Toolbox

xPC Target Toolbox

InterfaceBoard

Second Computer

Simulink DC MotorInterfaceBoard

Computer

PCI DAQ Card

– Measurement Computing PCI Card• 16 Analog Inputs• 2 Analog Outputs• 24 Digital Inputs or Outputs

Gantt Chart Followed

Events Week 1 Week 2 Week 3 Week 4 Week 5 Week 6 Week 7 Week 8 Week 9 Week 10 Week 11Receive Software

Receive PartsLearn xPC Target ToolboxLearn RTW Target Toolbox

Interface Hardware and Simulink using xPC and RTW

DebugDesign PCB Interface Board

Impliment Test PlanDemonstration

Documentaion of xPC and RTWOrder Additional Lab Setups

Winter Quarter 05-06

Desired Outcomes

• A complete working digital control system:

– Interfaces with Simulink

– Not dependant upon software versions

– Simple to use

– Can be used in other applications

Desired Outcomes

• Compare the differences between using PCI

DAQ Card and external computer with PCI DAQ

Card

– From transient testing for the Control System Design

Class

– Using a more computationally intensive controller

(Fuzzy Logic Controller) to see where each system

fails

Desired Outcomes

• Document the process for developing digital

controllers to be able to implement them in a

laboratory setting

Key Requirements

1) Show that data can be acquired and output at the minimum sampling time of 0.001 seconds at the maximum range of ±10V

2) Use interface board, Feedback Mechanical Unit 33-100, Feedback power supply, and Simulink Control Algorithm to control the speed of the motor.

3) Use interface board, Feedback Mechanical Unit 33-100, Feedback power supply, and Simulink Control Algorithm to control the position of the motor.

4) Documentation, including a user guide, working Simulink models, and a service manual.

Critical Parameters

1. Acquire 20 V peak to peak, 100 Hz sine wave using digital interface and output. Verify with oscilloscope.

Input Wave

Output Wave

Critical Parameters

2. Velocity control of motor to a reference of 1.5 V (600 RPM) recorded on both an Oscilloscope and by MATLAB

Transient Results include Rise Time, Overshoot, Peak Time

step

yMOS sspt

Critical Parameters

– Use a Simulink Integrator Controller

• Verify: -Tachogenerator voltage 1.5 V ± 5%

Step1s

Integrator

5

Gain

0.5

Constant

AnalogOutput

Analog OutputMeasurement ComputingPCI-DAS1602-16 [auto]

AnalogInput

Analog InputMeasurement ComputingPCI-DAS1602-16 [auto]

Add1Add

10 11 12 13 14 15 16 17 18 19 200

0.5

1

1.5

time [sec]

Tac

hom

eter

Vol

tage

[V

]

Results for Integrator Controller

SIMULATION RESULTTachogenerator

Voltage from Motor

Power Amplifier on Motor

Critical Parameters

– Use a Simulink PI Controller

• Verify: -Tachogenerator voltage 1.5 V ± 5%

-Transient Results within ± 5%

s+6.5

s

T ransfer Fcn

Step 2.5

Gain

0.5

Constant

AnalogOutput


AnalogInput


Add1Add

10 11 12 13 14 15 16 17 18 19 200

0.5

1

1.5

time [sec]

Tac

hom

eter

Vol

tage

[V]

Results for Integrator Controller

SIMULATION RESULT

Tachogeneartor Voltage from

Motor


Critical Parameters

– Use a Simulink One Pole Controller

• Verify: -Tachogenerator Voltage within ± 5% Theoretical Steady State Error

-Transient Results within ± 5%

1

s+5

T ransfer Fcn

Step 20

Gain

0.5

Constant

AnalogOutput


AnalogInput


Add1Add

10 11 12 13 14 15 16 17 18 19 20-0.2

0

0.2

0.4

0.6

0.8

1

1.2Results for One Pole Controller

SIMULATION RESULT

Tachogenerator Voltage Output

from Motor


Critical Parameters

3. Position control of motor output shaft from a initial value of 270 degrees to 90 degrees

–Use a Simulink Feedback Controller

• Verify: -Transient results within ± 5% of analog control

1

Gain

AnalogOutput


AnalogInput

Analog Input1Measurement ComputingPCI-DAS1602-16 [auto]

AnalogInput


Add

0 1 2 3 4 5 6 7 8 9 10-10

-5

0

5

time [sec]

Pos

ition

Vol

tage

s [V

]

Feedback Position Results (Motor Initially at 270 degrees and moved to 90 degrees)

Output Shaft Voltage

Input Shaft Voltage

Input Shaft Voltage from

Motor

Output Shaft Voltage from

Motor

Critical Parameters

4. Documentation:

– Include all Simulink diagrams used in testing

–Step by step user guide on how to setup both xPC and RTW Target toolboxes and systems

–Full system design including part numbers, PCB layout files, and schematics of Feedback system

s+6.5

s

T ransfer Fcn

Step 2.5

Gain

0.5

Constant

AnalogOutput


AnalogInput


Add1Add

PCB LAYOUT

Simulink DiagramTest

Points

PCI Connectors

Motor Connector

Major Design Challenges

• Documentation on Feedback System was lacking

–Traced servo DC motor board and analog board to develop schematics to understand the different signals

–Establishing control of the servo DC motor with results similar to the analog controller

• Preliminary testing using breakout box and wires with sockets verified the correct signals needed

Major Design Challenges

• Understanding and using Real Time Workshop using xPC Target Toolbox and Real Time Windows Target Toolbox

–Read manuals on both toolboxes and performed tutorials

• Noise when reading sensor data from the servo DC motor board

–Traced to Feedback switching power supply

–Noise eliminated when using HP power supply currently in lab

Interface Design

-Interface connections needed

Motor Board

5 Analog Sensors1 Analog Input

6 Digital Outputs

PCI DAQ Card

6 Analog Inputs1 Analog Output6 Digital Inputs

Interface Board

Analysis of Design

• Failure Analysis was done for the system

–Measurement Computing contacted to find absolute max ratings for PCI card

–Maximum input/output voltages of Feedback system investigated

–Motor board and PCI card were determined to be safe from damage

Analysis of Design

• Safety codes were investigated

–OSHA code that applies:Guarding of live parts.

1910.303(g)(2)(i)

Except as required or permitted elsewhere in this subpart, live parts of electric equipment operating at 50 volts or more shall be guarded against accidental contact by approved cabinets or other forms of approved enclosures, or by any of the following means:

–Highest rated voltage on interface board is 30 V

–Design safe for laboratory setting

Final Design

-Interface board is redesigned with the previous connections but with different test point locations and additional pads in case extra circuitry is desired

-Larger holes will be designed into the interface board to be able to put a Plexiglas cover

Final Design-For Control Design Lab Real Time Windows Target Toolbox meets the criteria for all controllers that would be implemented

-For other higher level classes the xPC Target Toolbox should be utilized (Fuzzy Logic, Modern Control, Signal Processing, etc)

Computer ComputerRS-232

PCI CardPCI Card

InterfaceBoard

InterfaceBoard

MotorBoard

MotorBoard

Computer

PCI Card

InterfaceBoard

MotorBoard

Two Computer SolutionOne Computer Solution

Testing Results• Integrator Results

Control Algorithm OS (%) % Error OS Tr (sec) % Error Tr Tp (sec) % Error Tp

Integrator Controller (Analog) 38.10 6.46 0.68 7.94 1.09 4.78

Integrator Controller (RTW) 39.60 2.77 0.65 3.17 1.06 1.89

Integrator Controller (xPC) 39.48 3.07 0.64 1.59 1.06 1.89

Integrator Controller (Simulation) 40.20 1.30 0.66 4.76 1.09 4.59

Integrator Controller (Theoretical) 40.73 --- 0.63 --- 1.04 ---

10 11 12 13 14 15 16 17 18 19 20-1.5

-1

-0.5

0

0.5

1

1.5

2

time [sec]

Tac

hom

eter

Vol

tage

[V

]

Results for Integrator Controller (Results Shifted for Viewing Purposes)

Analog Control Board Result

Simulation Control Result

Digital Control MATLAB Real Time Windows Result

Digital Control MATLAB xPC Target Result

step

yMOS sspt

Testing Results• PI Controller Results

Control Algorithm OS (%) % Error OS Tr (sec) % Error Tr Tp (sec) % Error Tp

PI Controller (Analog) 24.30 3.57 0.27 3.85 0.46 2.68

PI Controller (RTW) 25.80 2.38 0.27 3.85 0.47 3.79

PI Controller (xPC) 25.35 0.60 0.26 0.00 0.46 2.68

PI Controller (Simulation) 25.20 --- 0.26 --- 0.45 ---

10 10.5 11 11.5 12 12.5 13 13.5 14 14.5 15-1.5

-1

-0.5

0

0.5

1

1.5

2

time [sec]

Tac

hom

eter

Vol

tage

[V

]

Results for PI Controller (Results Shifted for Viewing Purposes)





step

yMOS sspt

Testing Results

• One Pole Controller Results

Control Algorithm OS (%) % Error OS Tr (sec) % Error Tr

One Pole Controller (Analog) 27.03 8.68 0.35 4.48One Pole Controller (RTW) 28.01 5.37 0.35 4.48One Pole Controller (xPC) 28.10 5.07 0.35 4.48One Pole Controller (Simulation) 27.03 8.68 0.35 4.48One Pole Controller (Theoretical) 29.60 --- 0.34 ---

Tp (sec) % Error Tp Vss (V) % Error Vss

One Pole Controller (Analog) 0.55 5.83 1.2150 3.61One Pole Controller (RTW) 0.54 4.85 1.2186 3.92One Pole Controller (xPC) 0.54 4.85 1.2158 3.68One Pole Controller (Simulation) 0.54 4.85 1.1728 0.01One Pole Controller (Theoretical) 0.52 --- 1.1727 ---

10 11 12 13 14 15 16 17 18 19 20-1.5

-1

-0.5

0

0.5

1

1.5

Time [sec]

Tac

hom

eter

Vol

tage

[V

]

Results for One Pole Controller (Results Shifted for Viewing Purposes)





step

yMOS sspt

Testing Results

• Two Pole, One Zero Controller Results

Sampling Time [sec] 0.0250 0.0375 0.0500 0.1000 0.2000

Simulation OS [%] 15.000 19.900 24.600 39.800 --

Single Computer [% Error] 3.000 2.010 2.439 3.015

Two Computer [%Error] 0.667 1.508 1.626 3.769

Simulation Tr [sec] 0.429 0.430 0.413 0.410 --


Two Computer [% Error] 3.263 1.163 0.606 7.317

Simulation Tp [sec] 0.600 0.610 0.625 0.650 --


Two Computer [% Error] 0.000 0.000 0.000 0.000

0 2 4 6 8 10 12 14 16 18 20-0.2

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

Time [s]

Tac

hoge

nera

tor

Vol

tage

[V

]

RTW Target Step Response for Different Sampling Times with ZOH Equivalent Discrete Controller

0.0375 Sampling Time

0 2 4 6 8 10 12 14 16 18 20-3

-2

-1

0

1

2

3

4

Time [s]

Tac

hoge

nera

tor

Vol

tage

[V

]

RTW Target Step Response for Different Sampling Times with ZOH Equivalent Discrete Controller

0.2 Sampling Time

Testing Results

• Position Control Results

0 1 2 3 4 5 6 7 8 9 10-10

-5

0

5

time [sec]

Pos

ition

Vol

tage

s [V

]

Feedback Position Results (Motor Initially at 270 degrees and moved to 90 degrees)

Output Shaft Voltage

Input Shaft Voltage

0 1 2 3 4 5 6 7 8 9 10-10

-5

0

5Analog Board Feedback Position Results (Motor Initially at 270 degrees and moved to 90 degrees)

time [sec]

Pos

ition

Vol

tage

s [V

] Output Shaft Voltage

Input Shaft Voltage

Output Shaft

Input Shaft

Testing Results• Power Supply Noise Results

10 11 12 13 14 15 16 17 18 19 20-0.2

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

time [sec]

Ta

cho

me

ter

Vo

ltag

e [V

]

Plot of Tachometer Voltage vs. Time for Different Power Supplies (Shifted for Viewing Purposes)

HP E3631A Power Supply

Feedback 01-100 Power Supply

Testing Results• Fuzzy PI Controller Implementation

Performance Comparison

Sampling Frequency

Single Computer Experiment: Processor

Percentage

Two Computer Experiment: Task Execution Time

1 kHz 4% 49 μs

2 kHz 7% 50 μs

4 kHz 14% 53 μs

8 kHz 29%--Stopped Running 51 μs

10 kHzStopped Running

Immediately54 μs

Conclusions

-Both designs successful

-Both can be used in Current Control Systems Design Lab

-Two Computer Setup can be used in multiple applications

Computer ComputerRS-232

PCI CardPCI Card

InterfaceBoard

InterfaceBoard

MotorBoard

MotorBoard

Computer

PCI Card

InterfaceBoard

MotorBoard

Two Computer SolutionOne Computer Solution

Thank You

Dr. PhillipsDr. MathewKen SnyderJim Stefano

Jacob Slezak

Questions

?

Item Itemized Cost Qty. TotalInterface PCB (3 min. order) $17.00 1 $17.00

50 Pin Connector $1.47 2 $2.9434 Pin Connector $1.14 1 $1.14PCI-DAS1602/16 $715.50 1 $715.50

C100FF-2 (50 Pin Ribbon Cable) $44.10 1 $44.10

Total Cost Per Station $780.68

Complete Lab Station $780.68 8 $6,245.44

Single Computer Setup BOM

Two Computer Setup BOM

Item Itemized Cost Qty. TotalInterface PCB (3 min. order) $17.00 2 $34.00

50 Pin Connector $1.47 4 $5.8834 Pin Connector $1.14 2 $2.28PCI-DAS1602/16 $715.50 2 $1,431.00

C100FF-2 (50 Pin Ribbon Cable) $44.10 2 $88.20RS-232 Cable $8.00 1 $8.00

xPC Target License (One Year for Entire Lab) $600.00

Total Cost Per Pair $1,569.36

Total Cost for Lab (Hardware) $1,569.36 4 $6,277.44

Total Cost for Lab with Software $6,877.44

Production Plan

Week 1 Week 2 Week 3 Week 4 Week 5 Week 6

Order PCI Card from Measurement Computing

Receive PCI CardsInstall PCI Cards into PC'sOrder PCB BoardsReceive PCB BoardsPopulate PCB BoardsTest Setups

Documents

Project Sponsor: EE Department Team Members: Michael Abbott, Neil Burkell