msr team savi - university of colorado boulder of a sheet of paper) simulated telescoping camera...

MSR Team SAVI Satellite Active Vibration Inverter

Wasseem Bel Joseph Schmitz

Patrick Byrne Justin Tomasetti

Blake Firner Jackson Vlay

Corey Hyatt Benjamin Zatz

Project Purpose

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• Develop a Satellite Active Vibration Inverter (SAVI) mount system that will identify and cancel low frequency vibrations from a cryocooler that cause image smearing on a telescopic camera.

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Cryocoolers create Exported Forces and Torques (EFTs) • Frequencies dynamically range from 40 to 60 Hz • Amplitudes on the order of 20 microns (twice the

thickness of a sheet of paper)

Simulated Telescoping Camera Payload • 22 kg mass • 1 rad Pixel Resolution

Image Smearing • Pixel Movement

• Angular Displacements from EFTs

These EFTs will cause up to 150 pixel smear 1- Cryocooler 2- Simulated camera payload 3- SAVI system

Budget Manufacturing Schedule Overview

SAVI and Test Stand Details

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• Flexures placed on top and bottom of actuating legs to avoid shear stresses in piezoelectric actuators

• Flexures placed on top of solid leg to allow for plate rotation

• Accelerometers placed on top plate next to each leg and on bottom plate next to the two actuating legs

SAVI 2 Actuating Legs

Accelerometer

2 Solid Legs

Top Plate

Base Plate

Top Plate

Base Plate

Actuating Leg

Flexure

Test Stand

Solid Leg


Levels of Success

Level 1: • Pixel smear reduced by 60% to about 60 pixels of smear

Level 2: • Pixel smear reduced by 80% so that about 30 pixels or fewer are smeared

• Signal frequency has dwell time of 2 seconds

Level 3: • The system dimensions will not exceed 20 cm x 20 cm x 10 cm

• The system mass will not exceed 5 kg

• The system will use no more than 10 W of power

4 Budget Manufacturing Schedule Overview

Critical Project Elements

• Flexture • Longitudinally rigid

• Laterally flexible

• Mitigates shear stresses on Actuators

• Epoxy • Soluble

• Be able to bond all materials

• Negligible vibration damping in compression

• Modal Analysis • Modes must not exist in 40 – 60 Hz range

• DAQ Error • Possible aliasing

• Amplitude error is frequency dependent


Updates

• Accelerometer Calibration • Previously mentioned drop test in FFR has been discarded • Cannot be statically tested for accuracy • Borrowed accelerometers are being sent to PCB Piezotronics to be

recalibrated

• Recessed mount holes for struts on plates • Improved alignment of the struts (accuracy is critical) • Allows for increased flexure size -> Resonance modes of system are distanced

from the operating frequency range

• A laser will be used to verify the full system • Tests will be done at Ball Aerospace -> new noise test data is needed


Schedule of Major Milestones


Technical Breakdown Schedule


SAVI Communication


Early Electronics Integration


Plans for Final Circuit

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Two PCB boards stacked PCB Board 1 (Left): • 2 Banana clip panel mounts • 3 BNC surface mounts PCB Board 2 (Below) • 5 Resistors - 860Ω • 5 Capacitors – 2.2μF • 5 BNC surface mounts


Software Recap

• After Fall semester, many of the technical software elements were completed including: • EFT wave determination routines • Wave inversion and output • Simulink Model predicting software performance.

• What needed further development: • Interfacing with electronics

• Continuous DAQ input and output to capture accelerometer data and drive actuators, respectively.

• Real time computation of prediction wave using real sensor data

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To PDm’s

From C65’s


Software Development

• Software/Electronics Interfacing Developments: • Input and output infrastructure complete

• Software now capable of electronics integration with the following capabilities: • Account for individual electronics calibration and varying

sensitivities of parts

• Generate arbitrary output disturbance in real time

• Acquire accelerometer data in real time

• Compute EFT from accelerometer data in real time


Software and Electronics Demonstration

• To demonstrate software and electronics capabilities: • Constructed demonstration consisting of:

• Software • cDAQ with NI-9263 and NI 9205 • PDm200 • Unloaded piezo-electric stack • C65 Accelerometer

• Purpose is to demonstrate: • Continuous voltage output

• Properly drive Piezo-electric stack disturbance up to 100V

• Continuous sensor input • Sense micron level vibrations

• Real time calculation of EFT prediction using real accelerometer data being driven by micron level piezoelectric stack displacements. 14

PDm200

cDAQ Signal

Conditioner

Actuator C65

NI-9263 NI-9205


Demonstration Results

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• EFT prediction created in real time using accelerometer data.

• Tracking of frequency prediction during a frequency sweep

• Adjustment to a change in EFT disturbance in 1 8 dwell time


Demonstration Issues

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Sampling Rate: 4096 Hz Sampling Rate: 16304 Hz

• Sampling rate of the DAQ affects amplitude of the acceleration data it records • Frequency is unaffected • Sampling frequency must be at least 16kHz to achieve desired actuator displacements


Top and Bottom Plate

• Changes in design: • Small pockets created on all plates to

assist in vertical alignment • Depth: 0.254 cm • Diameter: 1.27 cm

• Flexures and legs will be epoxied into holes

• Manufacture: • Generated SolidCAM code for CNC mill

to machine top and bottom plates • Edges sanded for smooth surface

• Manufactured top and bottom plate


Cyberbond Apollo 2150

• Leg to Flexure Connection • 0.159 cm

• Leg to Plate Connection • 0.159 cm

• Plate to Plate Connection • 0.159 cm

• Surfaces will be treated and sand blasted in order to maximize bond strength


Flexures

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• Flexures to be manufactured with CNC Lathe • Lathe was inoperable due to wrong parts

• New parts have been installed and machine is almost operational. • Flexures should be machined this week

• Due to the hole recession of the plates, the flexures were able to be increased in length


1.27 cm

0.508 cm

0.381 cm

2.26 cm

0.254 cm

Flexures

Test Compression/Tension Moment

Structure SAVI Test Stand SAVI and Test Stand

Force Applied (N) 1.76703 -1.76703 6.8914 -6.8914 0.25

Max Stress (N/m2) 110299 110299 430163 430163 295936

Max Displacement (𝜇𝑚) -0.68533 0.68533 -2.67276 2.67276 4.85

Moment applied (N-cm) n/a n/a n/a n/a 0.5

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• Maximum moment

the actuator tips can handle is 8.0 𝑁 − 𝑐𝑚

• Largest manufacturing

tolerance was used when calculating the corresponding needed deflection of the flexures

Fixed Geometry Compression Tension Simulated Moment


Modal Analysis SAVI and Test Stand

Mode Frequency (Hz) and

Bandwidth Description

1 10.287±0.103 Top plate of SAVI pivoting about solid leg in the horizontal plane

2 27.042±0.270 SAVI and Test Stand swaying from side to side (Base Fixed)

3 28.609±0.286 SAVI and Test Stand twisting back and fourth (Base Fixed)

4 110.6±1.106 Center Plates moving side-to-side in the Horizontal Plane

5 114.93±1.149 Center Plates moving side-to-side in the Horizontal Plane (60 degree shift)


Financial Layout

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Item Quantity Item Cost ($) Shipping ($) Total Item Cost ($)

PDm200 3 230 30 720

P-820.20 3 646 50 1988.00

Laser and Safety Goggles 1 119.90 15 134.90

Building Material: Plates, Rods and Simulated Mass

1 147.91 24.95 172.86

AE0505D16F Actuator 1 88 30 118

Extra Plates 2 14.80 6.99 36.59

Replacement Plates 4 20.28 8.91 90.03

Misc. Supplies 41.08 0 41.08 Remaining Budget

Total Cost $ 3270.48 $ 1729.52


List of Components

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Items Received • Building materials: Plates, Rods

and Simulated Mass

• PDm200 Drivers

• AE0505D16F Actuator

Items Awaiting Delivery • P-820.20 Actuators

• Laser and Safety Goggles

Items Not Yet Ordered • Epoxy and Solvent


Backup Slides

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Critical Project Elements

• Data Input and Output from MATLAB Interface

• NI CompactDAQ

• Capable of communicating with MATLAB

• Queued data I/O directly into MATLAB

• For maintaining a processing speed to mitigate output signal phase error

• Characterize 20 𝜇m EFT Vibration

• Find frequency (𝑓), amplitude (𝐴) and phase (𝜃) from noisy accelerometer data

• Collected errors in frequency, phase and amplitude must meet residual requirements

• Accelerometers

• PCB C65 – Piezoelectric accelerometer

• Must be able to measure system level vibrations

• Actuators

• PI 820.2 – Piezoelectric actuator

• Must be able to have submicron resolution while under the payload

• Actuator Driver

• PDm200 – Voltage amplifier and signal conditioner

• Must be able to run actuator within specifications

• Must be compatible with DAQ system

• NI CompactDAQ with modules

• NI 9205 – Analog to digital voltage measurement

• Must be able to sample system level vibrations

• NI 9263 – Digital to analog voltage output

• Must be able to provide input voltage to PDm200

• Structural

• Flexure

• Longitudinally rigid and laterally flexible to allow flexibility and mitigate shear stresses

• Base/top plate and solid leg

• Sufficient stiffness to be approximated as a rigid element

• Electronic components

• Electronic mounting capability

• Connections

• Materials compatible with epoxy chosen

• Analysis

• Modeled in CAD (SolidWorks)

• Able to produce force and vibration analysis

• Able to confirm flexure deflection with system loads

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msr team savi - university of colorado boulder of a sheet of paper) simulated telescoping camera...

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