Internal Model Control for DC Motor Using DSP Platform

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Internal Model Control for DC Motor Using DSP
Platform

• By Marcus Fair
• Advisor Dr. Dempsey

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Outline

•  
• Problem description
• Objectives
• Functional Specs
• Sub-system Overview
• Software
• Design

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Summary

• Design, build, and test IMC (Internal Model
  Control) system to control a DC motor
• 32-bit TMS320F2812 digital signal processor (DSP)
  
• Design for IMC controller built in Simulink
• Input to system uses graphical user interface
  (GUI) built in Matlab

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Preliminary Work

• DC Motor block diagrams from Senior Mini-project
• Also based on DC Motor Speed Control Demo
• M-files to run software
• Speed Measurement block in Simulink

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Common Problems in Control Systems

• Load Changes
• -Load shaft
• Plant Changes
• -Armature Resistor, Armature Inductor, Rotor
  Inertia, etc
• Power Supply Changes

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Objectives

• Build DSP/motor hardware interface
• Design and build (GUI)
• Design closed-loop controllers
• Compare conventional controller results with the
  IMC method

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Functional Requirements and Performance
Specifications

• Closed-loop operation Determine optimum gains
  for controllers
• Rise time 20 ms or less
• Settling time 100ms or less
• Overshoot lt or 5
• Steady state error or 5 RPM

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Equipment List

• GM9236C534-R2 Pittman DC motor
• Ezdsp F2812 Board
• LMD18200 H-bridge
• 3 - SN74LVC4245A voltage shifter
• 6-Pin DIP Opto-isolator
• 2N2222A BJT
• 2 - Diodes
• Agilent 30V power supply and HP 5V power supply
• Tektronix Oscilloscope

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Overall Block Diagram
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Overall Block Diagram
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Dsp board technical specs
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Inputs and Outputs
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H-bridge
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Pittman DC Motor
Motor Specs
Encoder Specs
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Pittman Motor Block Diagram
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Root Locus of Plant
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Bode Plot for Plant
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Software

• Matlab
• -Simulink
• -main m-files
• -Gui m-files
• Code Composer Studio 2.0
• -Auto-code generation
• -Communication with Dsp board

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Software flowchart
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Software flowchart
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Design Work

• Matlab GUI
• -Gui m-file
• Controller Design Iterations
• -Proportional Controller
• -Feed-forward Controller
• -IMC controller

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GUI
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Proportional Controller
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Proportional Controller
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Other Block diagrams
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Proportional Controller
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Proportional ControllerSimulink Results
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Proportional ControllerActual Results
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Proportional ControllerActual Results
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Feed-forward Controller

• Why Feed-forward Controller?
• Faster response to command changes than
  single-loop controllers
• Less overshoot More accurate than single-loop
  controllers
• Better system for Dc Motor control

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Feed-forward Controller
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Feed-forward Equations

• C/R (GcGp Gp) / (1 Gp)
• Desired C/R 1.0
• So Gc 1/Gp to get desired controller
• Gain K calculated based on DC gain of plant

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Feed-forward Controller
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Feed-forward Controller
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Feed-forward ControllerSimulink Results
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Feed-forward ControllerActual Results
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Feed-forward ControllerActual Results
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Internal Model Controller

• IMC uses a plant model for disturbance rejection
• More ideal control system
• Faster and more robust system

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Internal Model Controller
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IMC Equations

• C/R (GcGp)/(1 GcGp - GcGp)
• Desired C/R 1.0
• So Gc 1/Gp 1/Gp to get desired controller
• Gain K calculated based on DC gain of plant

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Internal Model Controller
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Internal Model Controller
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Internal Model ControllerSimulink Results
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IMC ControllerActual Results

• Hardware didnt support algebraic loops
• Unable to Run IMC from processor

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Conclusion

• Overall Hardware fully functional
• Functional parts of GUI work correctly/ extra
  features never implemented
• All Controllers work in Simulation
• Only proportional and feed-forward run off
  hardware

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Questions?
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Feed-Forward Equations

• C Gp(RGc E)
• E R - C
• C GcGpR GpR CGp
• C CGp GcGpR GpR
• C R(GcGp GP) / (1 GP)
• C/R (GcGp Gp) / (1 Gp)

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IMC EQUATIONS

• C EGcGp
• E R (EGcGp EGcGp)
• E EGcGp - EGcGp R
• E R / (1 GcGp - GcGp)
• C (RGcGp) / (1 GcGp - GcGp)
• C/R (GcGp) / (1 GcGp - GcGp)

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Spring Semester Schedule
Week Goals 1-7
Build and test single-loop controller, Design Gui
layout 8 Build and test feed-forward
controller 9-10 Implement IMC with
linear model 11 Final testing,
final Gui design 12-13
Final documentation
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Pinout
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Pinout