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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.
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Drexel RockSAT Full Mission System Testing Report • Kelly Collett • Christopher Elko • Danielle Jacobson • April 24, 2012
FMSTR Presentation Contents • Section 1: Mission Overview • MissionStatement • Mission Objectives • Expected Results • System Modifications • Functional Block Diagrams
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
Mission Overview Drexel 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.
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
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
Changes Since ISTR • Implemented latching relay for g-switch • Added additional 9V battery to power camera
Mechanical Subsystems Christopher Elko
Integration PEA & STR • 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 • 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 • 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 Software Danielle Jacobson
Electrical Design LED Array PEA I PEA II PEA III PEA IV Rectifier + Capacitor Rectifier + Capacitor Rectifier + Capacitor Rectifier + Capacitor Camera Internal Memory Arduino Microcontroller Accelerometer I SD Card Memory Accelerometer II 9V Battery Legend 9V Battery Wallops G-Switch New / updated part Power connection Data connection
EPS test summary • 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 Conclusion A bit messy…let’s take a closer look…
Data piezoelectric output 5V Reference Input Pendulum beam generates highest voltage followed by diving board orientation; balance beam lowest (low G’s?) Observations
Data accelerometers High-load vibration testing needed to fully characterize correlation between voltage output and acceleration (Wallops) Conclusion
Data correlations Z-Axis Acceleration As acceleration in beam oriented direction increases, generated voltage also increases!!! It works!!! Observations
Battery Power • 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 • Software is running as planned • Data collection rates are solid • No inconsistencies
VVS Updates Kelly Collett
VVS on a serious note… • Camera wired to 9V Battery • Originally running from Arduino 5 V output • Moved so Arduino can have its own power source
VVS test summary • 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 • 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
Action Items • 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 • Camera • Latching relay • Spotty communication with Temple
Acknowledgements • Kyle Dooleyfor assistance with electronics and circuitry troubleshooting • Dan Lofaro for lending us his precision solder kit
Thank you! Questions?