Disturbance Correction

1
Disturbance Correction

• Final Design Review
• Team 5
• February 25, 2003
• By Tyler Ferman
• Matt DiLeo
• Jack Damerji

2
Laser Deflection System

• Project Overview
• User supplies changing input.
• Goal is to compensate for measured input
  disturbance.
• Controller angles mirror to performs disturbance
  correction.
• Objectives
• Develop accurate controller in order to keep a
  laser communication link.
• Develop controller to correct for all disturbance.

3
Approach

• Input
• Measure the laser pen pan/tilt angles.
• Measure the mirror pan/tilt angles.
• Controller
• Determination of desired mirror pan/tilt angles.
• Develop controller to achieve performance
  specifications.
• Output
• Specified target (dot on wall)

4
Specifications Positioning
5
Specifications Cont.

• Input range of motion 43o
• Mirror 5 dia _at_ 55g ( 45g mount)
• Output Range of motion 26o
• Controller Speed gt6rad/s
• Overshoot Error lt 1
• Target -0.4
• Encoder Gearing 14 (4X accuracy)

6
Math Model (Angle Calc.)
Pan/Tilt Mirror Design
Motor Gear Selection
Mass Inertia Calc.
Simulation Controller Design
2/19
System Analysis
Input Pan/Tilt Considerations
Order parts
2/26
Building Input Pan/Tilt
Build Control Pan/Tilt
Input Pan/Tilt DSP
DSP Control of Pan/Tilt
Input Testing
Testing and Fine Tuning
4/1
Develop Full Interaction
4/9
Testing, Tolerance Analysis Fine Tuning
7
Math Model (Angle calc.)

• Approach
• Direct
• Solve by equating desired reflected unit vector
  with received reflected unit vector
• Solve using parametric equations
• Indirect
• Solve using Coordinate Transformations
• Solve using fminsearch foreword equation

Find foreword Equation (Maple)
Solve For Mirror Angles (Maple)
Create Math Model (MATLAB)
Find foreword Equation (Maple)
Educated Angles Guess (MATLAB)
Iterate Until Guess Converges
8
Math Model (Angle Calc.)
Pan/Tilt Mirror Design
Motor Gear Selection
Mass Inertia Calc.
Simulation Controller Design
2/19
System Analysis
Input Pan/Tilt Considerations
Order parts
2/26
Building Input Pan/Tilt
Build Control Pan/Tilt
Input Pan/Tilt DSP
DSP Control of Pan/Tilt
Input Testing
Testing and Fine Tuning
4/1
Develop Full Interaction
4/9
Testing, Tolerance Analysis Fine Tuning
9
Motor Gears Selection

• Center Of Gravity and Inertia were obtained from
  Solid Work Models
• Simulate a number of motors Examples Tested
  number of GM8000 series Needed more
  Torque Speed Motor ChosenPittman
  GM9234S016Gear Ratio 41

10
Math Model (Angle Calc.)
Pan/Tilt Mirror Design
Motor Gear Selection
Mass Inertia Calc.
Simulation Controller Design
2/19
System Analysis
Input Pan/Tilt Considerations
Order parts
2/26
Building Input Pan/Tilt
Build Control Pan/Tilt
Input Pan/Tilt DSP
DSP Control of Pan/Tilt
Input Testing
Testing and Fine Tuning
4/1
Develop Full Interaction
4/9
Testing, Tolerance Analysis Fine Tuning
11
Input Considerations

• Input trajectory accuracy is critical
• S1 Optical Shaft Encoder
• 1024 CPR ? 3600/1024 .350 per tick
• S2 Optical Shaft Encoder
• 2048 CPR ? 3600/2048 .1760 per tick
• Geared S1 Encoder
• 10244 CPR ? 3600/4096 .090 per tick

12
Error Induced
gtgt r,u,pfind_reflected(0,-2.5,6,
0,.178543307087,-1, 0,0,1) gtgt
x,y,zvec_plane_int(p,u,0,0,-1,0,0,36) x
0 y 4.9988 z 36 gtgt
r2,u2,p2find_reflected(0,-2.5,6,
0,.180344836659,-1, 0,0,1) gtgt
x2,y2,z2vec_plane_int(p2,u2,0,0,-1,0,0,36)
x2 0 y2 5.0745 z2 36

• Output error due to input measurement accuracy
• 0.10 input error ? 0.0745 output error

13
Ordering Parts

• Project Budget
• List of Parts
• List of Materials
• Machine shop service

14
List of Parts
15
List of Materials
Machine Shop Service
16
Project Budget Summary
Total Cost
17
Tin1
DSP I/O
Trajectory Calculator
State Estimator
Tin2
Desired States (T1, T2, T1dot, T2dot)
Mirror Position Calculator
Angle Saturation
Controller
Torque
T1
Estimated States (T1, T2, T1dot, T2dot)
State Estimator
T2
Torque ? Motor Control
Voltage for Motors
18
Math Model (Angle Calc.)
Pan/Tilt Mirror Design
Motor Gear Selection
Mass Inertia Calc.
Simulation Controller Design
2/19
System Analysis
Input Pan/Tilt Considerations
Order parts
2/26
Building Input Pan/Tilt
Build Control Pan/Tilt
Input Pan/Tilt DSP
DSP Control of Pan/Tilt
Input Testing
Testing and Fine Tuning
4/1
Develop Full Interaction
4/9
Testing, Tolerance Analysis Fine Tuning