drexel rocksat
DESCRIPTION
Drexel RockSAT. Full Mission System Testing Report. Kelly Collett • Christopher Elko • Danielle Jacobson April 24, 2012. FMSTR Presentation Contents. Section 1: Mission Overview Mission Statement Mission Objectives Expected Results System Modifications Functional Block Diagrams. - PowerPoint PPT PresentationTRANSCRIPT
Drexel RockSAT Full Mission System Testing Report
Kelly Collett • Christopher Elko • Danielle JacobsonApril 24, 2012
FMSTR Presentation Contents
• Section 1: Mission Overview• Mission Statement• Mission Objectives• Expected Results• System Modifications• Functional Block Diagrams
2
FMSTR Presentation Contents
• Section 2: Subsystem Test Reports• Subsystems Overview• Structural System (STR)• Piezoelectric Actuator System (PEA)• Electrical Power System (EPS)• Visual Verification System (VVS)
• Section 3: Conclusions• Plans for Integration• Lessons Learned
3
Mission OverviewDrexel RockSat Team 2011-2012
Mission Statement
Develop and test a system that will use piezoelectric materials to convert
mechanical vibrational energy into electrical energy to trickle charge on-board power
systems.
5
Mission Overview• Demonstrate feasibility of power generation
via piezoelectric effect under Terrier-Orion flight conditions
• Determine optimal piezoelectric material for energy conversion in this application
• Classify relationships between orientation of piezoelectric actuators and output voltage
• Data will benefit future RockSAT and CubeSAT missions as a potential source of power
• Data will be used for feasibility study
6
Expected Results• Piezoelectric beam array will harness enough
vibrational energy to generate and store voltage sufficient to power satellite systems• Anticipate output of 130 mV per piezo
strip, based on preliminary testing.• Success dependent on following factors:• Permittivity of piezoelectric material• Mechanical stress, which is related to the
amplitude of vibrations• Frequency of vibrations
7
Changes Since ISTR
8
• Implemented latching relay for g-switch• Added additional 9V battery to power camera
Mechanical SubsystemsChristopher Elko
Integration full payload
10
Integration PEA & STR
11
• All PEA subsystem components fit successfully on lower flight deck
• No interference with VVS components• Electronics fit successfully on upper flight deck
Physical Specs full payload
12
• Overall Height: 4.5 inches• Overall Weight (including electronics): 2.42 lb• CG: X = -0.01, Y = 0.27, Z = 0.10 in.
Canister Sharing with Temple• Method of Integration: standoffs• Min. Required Standoff Clearance: 1.0 inch• Combined Weight: 7.06 lb (based on designs)• Combined CG: pending final designs from
Temple• CG to be adjusted with systematic ballast placement
Prepare for Takeoff
13
• Written integration procedure: in progress• Full parts list: compiled• Spare parts: procurement in progress
Action Items• More regular interface with Temple• Final construction of BETA
EPS and SoftwareDanielle Jacobson
15
PEA I
Camera
Rectifier + Capacitor
PEA II
Rectifier + Capacitor
Accelerometer II
Rectifier + Capacitor
Rectifier +Capacitor
PEA III PEA IV
Electrical Design
9V Battery G-SwitchWallopsNew / updated part
InternalMemory
LED Array
9V Battery
SD CardMemory
Accelerometer IArduino
Microcontroller
Power connectionData connection
Legend
EPS test summary
16
• All electronics performed favorably• Integration went smoothly• Activation system still in need of latching
relay• Mechanical solution introduces a troubling
single point of failure• Once activated, closes circuit until reset• Currently on order
Data as collected
17
A bit messy…let’s take a closer look…
Conclusion
Data piezoelectric output
18
Pendulum beam generates highest voltage followed by diving board orientation; balance beam lowest (low G’s?)
5V Reference Input
Observations
Data accelerometers
19
High-load vibration testing needed to fully characterize correlation between voltage output and acceleration (Wallops)
Conclusion
Data correlations
20
As acceleration in beam oriented direction increases, generated voltage also increases!!! It works!!!
Z-Axis Acceleration
Observations
Battery Power
21
• Before full system test: ~ 9.3 V• Voltage after full system test: ~ 8.1 V• ΔV over 30-minute test: ~ 1.2 V• Estimated operation time until failure: 1.5+
hr
Software
22
• Software is running as planned• Data collection rates are solid• No inconsistencies
VVS UpdatesKelly Collett
VVS status update
24
VVS on a serious note…
25
• Camera wired to 9V Battery• Originally running from
Arduino 5 V output• Moved so Arduino can
have its own power source
VVS test summary
26
• Camera will not function on auxiliary battery• Works when hooked up to the Li-Ion battery,
but not the 9V• Odd, since it worked with the 9V power
supply during ISTR testing
VVS troubleshooting
27
• Attempted changing resistors in the voltage regulator circuit• Resistor ratio (R2/R1) = 1.96
• 2.2/1.2, V = 3.7 V (It worked this time!)• 3.5/1.5, V = 4.5 V (It worked for a little while this
time)• 7.35 / 3.7, NOTHING
• Voltage going into circuit is too high?• 9 V, perhaps drop to 5 V?
• Currently coming out of circuit at 4.5 V or higher
Conclusions
Action Items
29
STR & PEA• Finish any machining for BETA supports, mounts, etc.• Laser-cut BETA decks• Reconstruction – estimated completion date: 4/29/2012
EPS• Vibe testing at Wallops to determine actual accelerations
from test data • Latching relay to be integrated this week; clean up wiring
VVS• Don’t burn the camera…yet• Determine voltage issue
Integration• Communicate with Temple…
Issues and Concerns
30
• Camera• Latching relay• Spotty communication with Temple
Final Thoughts
Acknowledgements• Kyle Dooley for assistance with electronics and
circuitry troubleshooting• Dan Lofaro for lending us his precision solder
kit
32
Thank you!Questions?