Design of Disturbance Rejection Controllers for a Magnetic Suspension System

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Design of Disturbance Rejection Controllers for a
Magnetic Suspension System

• By Jon Dunlap
• Advisor Dr. Winfred K.N. Anakwa
• Bradley University
• December 6, 2005

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Summary

• Multiple Controllers for Multiple Disturbances
• Created In Simulink
• xPC Target Box Serving as Controller Container

• Minimize Steady-State Error, Overshoot and
  Setting Time
• Develop Controller Switching Method

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Summary

• Goals
• Functional Description
• Block Diagram
• Datasheet
• Preliminary Lab Work
• Schedule of Tasks
• Additional Goals

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Goals

• Previous Work
• Classical Controller Without Rejection
• Works With Step

• To Do
• Multiple Controllers For Various Inputs
• Use Internal Model Principle
• Automatic Controller Selection

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Functional Description

• Host PC using Simulink and xPC software
• xPC Target Box with Controllers
• Magnetic Suspension System

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Block Diagram

• Magnetic Suspension System
• xPC Target Box

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Magnetic Suspension System

• Control and Disturbance Drives Current
• Current Induces Magnetic Field
• Field Suspends Ball
• Sensor Translates Location into Voltage

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xPC Target Box and Host PC

• Using 10 V ADC and DAC
• Download Controllers, Upload Commands
• Process Position Data and Passes Control

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Datasheet

• Disturbance Classes
• Step
• Ramp
• Sinusoidal
• Square Triangular
• Steady-State Error
• 50mv

• Overshoot
• 18
• Settling Time
• 60ms

Previous Work Shows Useable Values
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Preliminary Lab Work
Disturbance State Space Equation
kCos(aT)
kSin(aT)
k-unit step
k-unit ramp

• Disturbance Classes with Plant SS Equations
• Using Controller Canonical Form

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Preliminary Lab Work

• Tested Classical Controller With Disturbance
• Researched Internal Model Principle with
  Disturbance Rejection Focus

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Major Tasks List

• Utilize Internal Model Principle To Design
  Controllers
• Implement Controllers In Simulink
• Process Simulink Controllers On xPC Target Box
• Fine Tune Controllers To Optimize Stability
  Specifications

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Schedule Of Tasks

• 12/8/2005 - 1/15/2006
• Develop Paper Controllers
• Implement Controllers In Simulink
• 1/19/2006 - 2/9/2006
• Research xPC Implementation
• Test Controllers on MSS
• Fine Tune Controllers

• 2/16/2006 - 3/9/2006
• Continue Development of Additional Controllers
• Documentation of Controller Methods
• Research Disturbance Detection Methods
• 3/11/2006 - 3/19/2006
• Spring Break
• Begin Final Presentation

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Additional Goals

• Design Disturbance Detection Hardware/Software
  For Automation Of Controller Usage
• Simulink using FFT
• Determine Maximum Time Delay Allowable for
  Stability
• Implement on xPC?

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Questions?