Embed Size (px)
DESCRIPTION
Magnetic Suspension System Control Using Position and Current Feedback. Team: Gary Boline and Andrew Michalets Advisors: Dr. Anakwa and Dr. Schertz. Applications of a Magnetic Suspension System. Electromagnetic Suspension Train. Frictionless Magnetic Bearings. Summary. - PowerPoint PPT Presentation
Citation preview
Magnetic Suspension System Control Using Position and
Current Feedback
Team: Gary Boline and Andrew Michalets
Advisors: Dr. Anakwa and Dr. Schertz
Applications of a Magnetic Suspension System
Electromagnetic Suspension Train
Frictionless Magnetic Bearings
Determine if Current Feedback can be utilized to improve performance No success with Current Feedback
Develop New Position Controller Design Methods Implement: xPC & Coldfire
Summary
Outline Magnetic Suspension System Overview High Level Block Diagram Current Modeling Current Controller Attempts Position Controller Development Microcontroller Implementation Future Suggestions References Questions
System Overview
Outline Magnetic Suspension System Overview High Level Block Diagram Current Modeling Current Controller Attempts Position Controller Development Microcontroller Implementation Future Suggestions References Questions
High Level Block Diagram
Control System
Magnetic Suspension
Plant
Photo Sensor
Current Sensor
Set Point
Reference Signal
A/D Converter D/A Converter
Outline Magnetic Suspension System Overview High Level Block Diagram Current Modeling Current Controller Attempts Position Controller Development Microcontroller Implementation Future Suggestions References Questions
Current Modeling Experimental Simulink
Transfer Function Rate Limiter
(nonlinear)
Outline Magnetic Suspension System Overview High Level Block Diagram Current Modeling Current Controller Attempts Position Controller Development Microcontroller Implementation Future Suggestions References Questions
Current Controller Attempts State-space Current with Lag, Lead, or Lag/Lead
Noise Problems Current Feed-forward Current Error Feed-forward
Based on Proportion to Position Position Integrator ‘integrates’ current
term out
Outline Magnetic Suspension System Overview High Level Block Diagram Current Modeling Current Controller Attempts Position Controller Development Microcontroller Implementation Future Suggestions References Questions
Position Controller Development
Root Locus Attempts Block Diagram Simulation Data Scope Plots Performance Data vs. Specs
Position Controller Development
Root Locus Open Loop Poles:
1.0321, 0.9689 Closed Loop
Poles: 0.9704+/-0.0077j, 0.8550, 0.3888
Expanded
Position Controller Development
Block Diagram
Position Controller Development
StepResponse
(simulation)
28% OS
Position Controller Development
StepResponse
(xPC) ~30% OS
Outline Magnetic Suspension System Overview High Level Block Diagram Current Modeling Current Controller Attempts Position Controller Development Microcontroller Implementation Future Suggestions References Questions
Microcontroller Implementation
Improvements Input/Output Configuration System Timing
Scope Plots Performance Data vs. Specs
Input/Output Configuration
A/D
MicroController
Con
trol
Sig
nal
D/A
Error Signal
D/A Converter Setup
Volts (mV) Controller Output +2047 FFF
: : 0 800 -1 7FF
: :-2047 000
Software Flowchart Initialize Timer
Read in A/D Error Signal
Scale A/D
Controller Implementation
Scale D/A
Timer Overflow at 1ms?
Write Data from D/A to Control Signal
Yes
Reset Timer Overflow
No
Start
Timing Improvements
Step Response
Our Controller Past Controller
Step Response Results
Our ControllerMax Amplitude : 0.2VppOvershoot : 47%Settling Time : 240 ms
Past ControllerMax Amplitude : 0.5VppOvershoot : 36%Settling Time : 560 ms
Advantages: Faster System
Disadvantages: Larger overshoot, Less input amplitude, Less stability
Outline Magnetic Suspension System Overview High Level Block Diagram Current Modeling Current Controller Attempts Position Controller Development Microcontroller Implementation Future Suggestions References Questions
Future Suggestions
Lab bench space Modularize Code Design to realistic specs Anti-aliasing filters Design System Bottom Up, Current
and Voltage Control Independently
References Jose A Lopez and Winfred K. N. Anakwa, “Identification and Control of a Magnetic Suspension System using
Simulink and Dspace Tools”, Proceedings of the ASEE Illinois/Indiana 2003 Sectional Conference, March 27, 2004, Peoria, Illinois, U.S.A.
Feedback Inc., 437 Dimmocks Mill Road, Hillsborough, North Carolina 27278. http://www.fbk.com
Simulink, Version 6.1 (R14SP1), The MathWorks Inc., Natick, MA 01760, 2004.
xPC Target Box, The MathWorks Inc., Natick, MA 01760, 2003.
Conclusion Determined Current Feedback not viable
State Space Classical
Designed New Position Controller Root Locus Simulation and xPC
Implemented Design on Microcontroller Timer Driven Faster System
Bring back focus Step back up from lower level Project importance at beginning Balance additional content
Conclusion
Questions?
