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Drexel RockSAT

Drexel RockSAT. Preliminary Design Review. Kelly Collett • Christopher Elko • Danielle Jacobson October 26, 2011. PDR Presentation Contents. Section 1: Mission Overview Mission Statement Mission Requirements Mission Overview Theory and Concepts Literature Review Concept of Operations

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Drexel RockSAT

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  1. Drexel RockSAT Preliminary Design Review • Kelly Collett • Christopher Elko • Danielle Jacobson • October 26, 2011

  2. PDR Presentation Contents • Section 1: Mission Overview • MissionStatement • Mission Requirements • Mission Overview • Theory and Concepts • Literature Review • Concept of Operations • Expected Results

  3. PDR Presentation Contents • Section 2: System Overview • Physical Model • Critical Interfaces • Requirement Verification • User Guide Compliance • Section 3: Subsystem Design • Energy Harvesting Subsystem • Structural Subsystem • Electrical Subsystem • Visual Verification Subsystem

  4. PDR Presentation Contents • Section 4: Prototyping Plan • Projected Prototyping Process • Prototype Risk Assessment • Section 5: Project Management Plan • Organizational Chart • Schedule • Budget • Work Breakdown Schedule • Sharing Logistics

  5. Mission Overview Drexel RockSat Team 2011-2012

  6. 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.

  7. Mission Requirements

  8. 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

  9. Theory and Concepts • Piezoelectric Material • substance with linear electromechanical interaction between mechanical and electrical states in crystalline materials • Piezoelectric Effect • electrical potential (voltage) developed within a piezoelectric material in response to an applied pressure or stress.

  10. Theory and Concepts continued • Where D is electric displacement, ε is permittivity,and E is electric field strength • Where S is mechanical strain, s is compliance,and T is mechanical stress • Superscript e denotes a zero/constant electric field;Superscript t denotes a zero/constant stress field;d indicates piezoelectric constants

  11. Theory and Concepts continued • Array of piezoelectric actuators • Bonded to cantilevered aluminum strips with mass attached to free end • Dynamic deflection under vibration andg-loading will create voltage potential • Various orientations will account for vibrations in multiple directions http://en.wikipedia.org/wiki/Euler-Bernoulli_beam_equation

  12. Theory and Concepts continued • Place mass at end of beam to achieve maximum deflection under vibration • Model with point load Top: Bending Moment, M(x) Middle: Shear Force, Q(x) Bottom: Deflection, δ(x) http://en.wikipedia.org/wiki/Euler-Bernoulli_beam_equation

  13. Theory and Concepts continued • Uniform, distributed load when subjected to g-forces during launch • Model with load acting along length of beam Top: Bending Moment, M(x) Middle: Shear Force, Q(x) Bottom: Deflection, δ(x) http://en.wikipedia.org/wiki/Euler-Bernoulli_beam_equation

  14. Theory and Concepts continued • Electric potential (voltage) developed throughout piezoelectric actuators in AC form • AC voltage conditioned using a full-bridge rectifier • Accumulated in a capacitor • Monitored using a voltmeter • Recorded using data acquisition system (DAQ) http://en.wikipedia.org/wiki/Diode_bridge

  15. Literature Review • Piezoelectric Generator Harvesting Bike Vibrations Energy to Supply Portable Devices • E. Minazara, D. Vasic, and F. Costa • Piezoelectric generator that • harvests mechanical vibration • energy and produces electricity • Determined optimal band to harvest energy 12.5Hz • Modeled piezoelectric beam as spring mass damper system • Produced ~3.5mW electricity • capable of powering LED

  16. Literature Review continued • Recent Progress in Piezoelectric Conversion and Energy Harvesting Using Nonlinear Electronic Interfaces and Issues in Small Scale Implementation • D. Guyomar and M. Lallart • Design of an efficient microgenerator must consider: • Maximization of input energy • Maximization of electromechanical energy • Optimization of energy transfer • Increase conversion abilities by: • Increase voltage • Reduce time shift between speed and voltage • Increase coupling term

  17. Literature Review continued • A Review of Power Harvesting Using Piezoelectric Materials • S. R. Anton and H. A. Sodano • PZT widely used • Extremely brittle • Piezoceramics prone to fatigue crack growth when subjected to high-frequency cyclic loading • PVDF exhibits considerable flexibility • Flexible materials more beneficial • Practical coupling modes • -31: Force applied perpendicular to poling direction • -33: Force applied in same direction as poling

  18. Literature Review continued • A Review of Power Harvesting Using Piezoelectric Materials • S. R. Anton and H. A. Sodano • High power output situations • Stack configurations most durable in high-force environments • When driving frequency is at resonant frequency of the system

  19. Literature Review continued • Comparison of Piezoelectric Energy Harvesting Devices for Recharging Batteries • H. A. Sodano and D. J. Inman • Researchers tested energy-harvesting qualities of three different piezoelectric materials • Lead-zirconate-titanate (PZT) • Quick Pack bimorph actuator material (QP) • Macro Fiber Composite (MFC) • Measured vibration of compressor, using piezo samples as accelerometers – output in volts • Full-bridge rectifiers used to condition signal from oscillating AC into DC to charge batteries

  20. Literature Review continued • Comparison of Piezoelectric Energy Harvesting Devices for Recharging Batteries • H. A. Sodano and D. J. Inman • Efficiencies varied by material • QP most effective for resonant frequencies (~8 to 9%) • PZT most effective for random vibrations (~4 to 4.5%) • MFC significantly less effective than PZT and QP • Low-current, high-voltage output lacks the strength to charge batteries and is easily dissipated by diodes in circuit • QP charged batteries fastest under resonant frequencies; PZT charged the best with random vibration.

  21. Literature Review continued • Piezoelectric Sea Power Generator • R. M. Dickson • Operating principle • Attempted to harness mechanical energy of waves as changes in pressure acting upon piezoelectric mats • Minimally intrusive to ecosystem • Important implications for this project • Studies show that static pressure alone does not induce a charge in piezoelectric materials • Piezo arrays must be continuously deformed to create an electric potential that can be harvested

  22. Concept of Operations • G-switch will trip upon launch, activating all onboard power systems • Batteries power Arduino microprocessor and data storage unit • Data collection begins • Vibration and g-loads onpiezo arrays create electric potential registered on voltmeter • Current conditioned to DC through full-bridge rectifier and run to voltmeter • Voltmeter output recorded to internal memory • Data gathered throughout duration of flight

  23. Concept of Operations • Data acquisition and storage will enable researchers to monitor input from multiple sources • XY-plane vibrational energy • Z-axis vibrational energy • Researchers will determine if amount of power generated is sufficient for the power demands of other satellites • Include visual verification of functionality • Use energy from piezo arrays to power small LED • Onboard digital camera will verify LED illumination

  24. Expected Results • Piezoelectric beam array will harness enough vibrational energy to generate and store voltage sufficient to power satellite systems • Success dependent on following factors: • Permittivity of piezoelectric material • Mechanical stress, which is related to the amplitude of vibrations • Frequency of vibrations

  25. System Overview Christopher Elko

  26. Physical Model Microcontroller Power Supply Camera Accelerometers Verification LED Piezo Arrays

  27. Subsystem Identification • EPS – Electrical Power Subsystem • Includes Arduino microprocessor, g-switch, accelerometers, voltmeter, battery power supply, and all related wiring • STR – Structural Subsystem • Includes Rocksat-C decks and support columns • PEA – Piezoelectric Array Subsystem • Includes piezoelectric bimorph actuators, cantilever strips, mounting system, rectifier, and related wiring • VVS – Visual Verification Subsystem • Includes digital camera, LED, and all related wiring

  28. Critical Interfaces

  29. Requirement Verification

  30. User’s Guide Compliance • Magnitude of mass to be determined by CDR • CG – to be determined based on design, dictated by pre-CDR testing and validation • Low voltage electrical components used • No ports required

  31. Subsystem Design Structural Subsystem Christopher Elko

  32. Structural Components Rigid Mounting Deck Support Column

  33. Subsystem Design Energy Harvesting Subsystem Christopher Elko

  34. Piezoelectric Actuators Fastener Piezoelectric Strip Support Block Aluminum Cantilever Mass Redundant Assembly for Multi-plane Vibration

  35. Piezoelectric Actuators Mounted to Lower Deck Attached with Fastener

  36. Subsystem Design Electrical Power Subsystem Danielle Jacobson

  37. Block Diagram LED LED Piezoelectric Power Output Piezoelectric Power Output Rectifier Rectifier Camera Low-G Accelerometer Arduino Microcontroller High-G Accelerometer High-G Accelerometer Low-G Accelerometer G-Switch Power Supply

  38. Microcontroller • Arduino ATMEGA328 Microprocessor (Open Source) • Record and store data on 2GB SD card • Vibration data from accelerometers • Voltage output from piezoelectric materials • Powered by four (4) AA replaceable batteries

  39. Accelerometers • Two (2) Low-G Accelerometers • Analog Devices ADXL206 Dual-Axis • Two (2) High-G Accelerometers • Analog Devices ADXL278 Dual-Axis

  40. Bridge Rectifier and G-Switch • Bridge Rectifiers • Four (4) Diode Schottky 1A 20V MBS-1 • G-Switch • One (1) Omron Basic Roll Lever Switch SS-5GL2

  41. Subsystem Design Visual Verification Subsystem Kelly Collett

  42. Block Diagram Piezoelectric Wire Output LED Camera EPS Power Supply

  43. Camera Specifications • Runs on 12VDC, 100mA • Size: 0.98” sq. x 0.8” Super B/W Microvideo Pinhole Camera http://www.supercircuits.com/Security-Cameras/Micro-Video-Cameras/PC180XP2

  44. LED Specifications • 5mm through-hole LED • 360-degree viewing angle • Low power consumption White 5mm LED http://www.superbrightleds.com/moreinfo/component-leds/5mm-white-led-360-degree-viewing-angle-4500-millilumens/341/1288

  45. Prototyping Plan Christopher Elko

  46. Prototyping Plan • STR • Structural Subsystem will be designed and analyzed primarily using CAD and FEM techniques • Prototype to be constructed and tested for fitment and mounting methods • PEA • Piezoelectric actuators will be tested to determine deformation limits and optimal deformation for energy harvesting • Mounting/bonding methods to be explored upon construction of first prototypes

  47. Prototyping Plan continued • EPS • Electronic interfaces will be table-tested with breadboard and reconfigurable components • Testing will help to determine system capabilities • VVS • Testing will help to determine system capabilities and effects on other subsystems

  48. Prototype Risk Assessment Subsystem Risk/Concern Action

  49. Project Management Plan Kelly Collett

  50. Organizational Chart

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