Control TeamFaculty Advisors

Dr. Helen Boussalis

Dr. Khosrow Rad

Dr. Charles Liu

Student Assistants

Jessica AlvarengaAlok DesaiHarshit TarsariaKimberly CastroHeather RudowEric Diaz

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Outline

Background

Current Work

Integration of PPA to DSP

Multiple Sensor Calibration

Modeling of PPA to State-Space

Future Work

Timeline

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Background

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Bigger Viewing Dish6.5m Mirror PanelGold-plated Beryllium MirrorsSix times the collecting area

Deep Space No atmospheric interferenceLag time due to distance

Segmented SystemControl AlgorithmDecentralized System

Reconfigurable Fault Detection and IsolationMaintain Shape Control under Disturbance

IR DetectionStudies of Big Bang

NASA/JPL-Caltech/R. Hurt (SSC)

James Webb Space Telescope

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SPACE Telescope Testbed

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Control RequirementsShape Control

Hold nominal paraboloid shape

Pointing Control

Accuracy of 2 arc second

Vibration Suppression

100:1

Control Bandwidth

30HZ

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Current Work

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Ongoing Work

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Integration of Pointing Control into Shaping Control

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Objective

H-infinity controller to handle both Shaping and Pointing (Currently just demonstrates shaping)

Integrate the Peripheral Pointing Architecture (PPA) Control with the Digital Signal Processor (DSP)

Some hardware/software changes will need to be made

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Current Configuration

DSPDSP

PPA Motion

Controller

PPA Motion

Controller

Shape Control

Pointing Control

Shaping and

pointing control

are separate

Testbed

Pointing Architecture

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Desired Configuration

DSPDSP

Shape and

Pointing Control Shaping

and pointing control

are integrated

PPA Motion

Controller

PPA Motion

Controller

Testbed

Pointing Architecture

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Functional Block Diagram

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Communication from DSP to DAQ

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• Generate a sine wave digital test signal from DSP to free D/A channels

• From D/A channels, test signal will be converted to analog

• Converted analog signals will be input to USB-6251 DAQ

• The acquired data will be acquired by LabVIEW

DSP Board(Pentek 4285)

MIX-VME baseboard it has:40 MHz 68030 processor

4 processors used on the SPACE test-bed (numbered 0,1,4,5 or A,B,E,F)

Offers communication ports to the host computer and other modules such as the A/D & D/A

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Digital to Analog Converter (DAC)

Purpose:

Converts digital to analog voltage

High performance 8-channel, 16-bit converter

18 channels are currently used on the test-bed

16-bit resolution, sampling frequency up to 250 kHz

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Communication from LabVIEW to PPA

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• Voltage signals from DAQ must be converted into linear displacements for the two PPA actuators

• Displacement must then be converted to ASCII commands for the ESP

• Position of both PPA actuators may be queried and returned to LabVIEW for position verification and/or for feedback to the DSP

DSP-to-PPA GUIMust first establish a “home” position (a spatial origin of reference)Convert sampled voltage signal into a two-dimensional displacement

i.e. –

G1 and G2 are gains to be experimentally determined

Convert displacement into ASCII command and send to ESP to send to PPA

i.e. – 01MA0.03 -> tells ESP to move actuator 1 to an “absolute” position of 0.03mm

Retrieve actuator positions of PPA from ESP

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2222

1111

OffsetVGy

OffsetVGx

actuator

actuator

Sensor Network Calibration

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Calibration

Sensor linearity 8 volts/ 2 mm

Operate between +/- 10 Volt

Sensor Testing Module

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Target Caliper

Calibration Fixture

Sensors

18 collocated sensor

24 edge sensor

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Edge Sensors

Collocated Sensors

Sensor Holder

Single Sensor Calibration

LabVIEW GUI has been developed to aid with sensor calibration checks

Requires removal of sensor from holderProne to human errors when replacing

Maintain offset through entire procedureOriginal offsetDuring calibration checkPlacing back onto the structure

Tedious and time consuming

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Sensor Network Calibration Check

Eliminate the need for removal of the sensors from holders

Eliminate as much human error as possible

Being able to check multiple sensors at once

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Block Diagram

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LabView DAQ(Ao)

DAQ(AI)Panel

Sensors

TestbedActuators

PPA Structure Modeling

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Background

We know the dynamics of all the components of a segmented telescope testbed

Now, we will focus on model identification, implementation, and control design for the PPA

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Model Identification of A Segmented Telescope Testbed

Laser Platform

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FEMAP Platform Design

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Platform Design

Hexagonal Part Design

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Platform with Base Design

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Future Work

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Timeline

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  SPACE Laboratory Control Team Timeline: October 2010 - Jan 2011

  2010 2011

Student Name OCT NOV DEC JAN

JessicaAlvarenga

Sensor Calibration ProcedureConference Paper Preparation

PPA Laser Replacement and Alignment

H Infinity Team Supervision

AlokDesai

Sensor Calibration ProcedureConference Paper Preparation

PPA Laser Replacement and Alignment

Sensor Calibration GUI H Infinity

HarshitTarsaria

Ray Tracing LabVIEW GUIConference Paper Preparation

Sensor Calibration

Document GUI H Infinity

HeatherRudow

Testbed Training Determine Options for PPA to DSP Operation Develop LabVIEW Code to control PPA actuator

LabVIEW Training Familiarization with LabVIEW Signal Processing

PPA PPA Laser Replacement and Alignment

EricDiaz

Testbed Training Sensor Visualization Upgrade Optical Detector GUI

LabVIEW Training Sensor Calibration Develop LabVIEW Code to control PPA actuator

Sensor Calibration PPA Laser Replacement and Alignment

Kimberly Castro

Testbed Training DSP FamiliarizationDevelop LabVIEW Code to receive signals from DSP

DSP Training Upgrade DSP Software

PPA PPA Laser Replacement and Alignment

Timeline

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SPACE Laboratory Control Team Timeline: October 2010 - Jan 2011

  2011

Student Name FEB MAR APR MAY JUN

JessicaAlvarenga

Develop State Space Model of PPA Validation of PPA SS ModelDevelop H-Infinity for PPA and

Shaping SimulationIntegration of PPA to DSP

Simulations of PPA ControlTeam Supervision

AlokDesai

Develop of State Space Model of PPA Validation of PPA SS ModelDevelop H-Infinity for PPA and

Shaping SimulationFamiliarization with NASTRAN

Simulations of PPA ControlInitial control for PPA

HarshitTarsaria

Develop State Space Model of PPA Validation of PPA SS ModelDevelop H-Infinity for PPA and

Shaping SimulationFamiliarization with NASTRAN

Simulations of PPA ControlInitial control for PPA

HeatherRudow

Develop LabVIEW Code to control PPA actuator Testing of LabVIEW Code for PPA Actuator

Integration of PPA to DSP

Sensor Calibration CheckPPA to DSP

DSP C Code

EricDiaz

Sensor Calibration Check PPA to DSP

Integration of PPA to DSPDevelop LabVIEW Code to control PPA actuator Perform Homing of Structure

Begin Working on Homing Code DSP C Code

Kimberly Castro

Sensor Calibration Check Finalize Comm from DSP to LabVIEW

Integration of PPA to DSPInitial tests of DSP to LabVIEW Perform Homing of Structure

Homing Code PPA to DSP

Questions?

Thank You

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