Drexel Rock SAT Critical Design Review Kelly Collett

Drexel Rock. SAT Critical Design Review Kelly Collett • Christopher Elko • Danielle Jacobson December 8, 2011

PDR Presentation Contents • Section 1: Mission Overview • • • Mission Statement Mission Requirements Mission Overview Concept of Operations Expected Results 2

PDR Presentation Contents • Section 2: Design Description • • Off-ramps Physical Model Mechanical Design Electrical and Software Design • Section 3: Prototyping and Analysis • • Mechanical Subsystems Electrical Subsystems Mass Budget Power Budget 3

PDR Presentation Contents • Section 4: Manufacturing Plan • Mechanical Elements • Electrical and Software Elements • Section 5: Testing Plan • • PEA Subsystem EPS Subsystem VVS Subsystem Total System Testing 4

PDR Presentation Contents • Section 6: Prototype Risk Assessment • PDR Risk Walk-down • Top CDR Risks • Section 7: User’s Guide Compliance • Section 8: Project Management • • Organizational Chart Schedule Budget Sharing Logistics 5

Mission Overview Drexel Rock. Sat 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. 7

Mission Requirements Number Requirement MIS-REQ-1000 Must be able to convert vibrational energy to electrical energy MIS-REQ-2000 Must be able to withstand launch environments MIS-REQ-3000 Final design must meet Rock. SAT specifications MIS-REQ-4000 Must be functional during flight MIS-REQ-5000 Must not interfere with canister partner’s design 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 Rock. SAT and Cube. SAT missions as a potential source of power • Data will be used for feasibility study 9

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 on piezo 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 10

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 11

Expected Results • Piezoelectric beam array will harness enough vibrational energy to generate and store voltage sufficient to power satellite systems • Anticipate output of 130 m. V 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 12

Design Description Christopher Elko

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 14

Off-Ramps VVS • Main concern: Camera activation • Relaying the camera to the g-switch for activation after launch will likely prove difficult. • If this cannot be achieved on time, the VVS will be removed from the payload. • This will drop the mass of the payload significantly, and will require additional ballast in its place. 15

Physical Model Accelerometer Array Microcontroller Power Supply G-Switch Bridge Rectifiers Flight Decks Camera Standoff Supports Verification LED Piezo Arrays 16

Canister Fitment Canister Partner’s Space Allowance 10. 0” 4. 313” 17

Mechanical Design STR Stainless Fasteners Clear Acrylic Flight Decks 8 -32 thread x 3/8” long QTY = 10 ¼” thick 9. 29” dia. QTY = 2 Aluminum Standoffs 5/16” hex x 2 ¼” long QTY = 5 Fifth standoff column included to provide support for EPS electronics mounted to top deck. 18

Mechanical Design PEA Piezoelectric Strip PZT Ceramic 40 mm x 10 mm 5 mm thick Fasteners Support Block Aluminum Cantilever 2 ¼” x ½” 0. 040” thick Different orientations account for vibrations in multiple planes. 19

PEA Design continued Mounted to Lower Deck Use 4 -40 x 3/8” Screws 20

Electrical Design LED High-G Accelerometer Piezoelectric Power Output Rectifier Arduino Microcontroller G-Switch LED Camera Low-G Accelerometer Power Supply 21

Electrical Design continued Piezoelectric Wire Output LED EPS Camera Power Supply 22

Electrical Elements • Powered by 4 AA batteries • Connects directly to microcontroller • Modified to incorporate Gswitch G-Switch To Bridge Rectifier Piezo Arrays (Battery) LED Battery Pack Microcontroller To Bridge Rectifier PEA-VVS Circuit Diagram G-switch interface with EPS 23

Electrical Elements continued Low-G Accelerometer High-G Accelerometer 24

Electrical Elements continued Bridge Rectifier #1 Piezo Array 1 Bridge Rectifier #2 Piezo Array 2 25

Electrical Elements continued • Breadboard used for SD card and Arduino microcontroller integration http: //www. electronicslab. com/blog/? m=200806 26

Electrical Elements continued • Two breadboards • LED circuit • SD card integration • Allowance of 15 -20 iterations to debug electronics • Limited previous exposure to programming microcontrollers and EE in general • All electrical elements have been procured • Four dual-axis accelerometers have been replaced with two three-axis accelerometers 27

Software Elements 28

Software Elements continued Input Output Purpose G-Switch T/F True/False Write to SD when T Accelerometer 1 X Data Collection Accelerometer 1 Y Data Collection Accelerometer 1 Z Accelerometer 2 X Accelerometer 2 Y Accelerometer 2 Z Voltage Outputs All data output to SD card via “write to file” command Data Collection Bridge Rectifier 1 Data Collection Bridge Rectifier 2 Data Collection Time (>1000 s? ) True/False End write command when T 29

Accelerometer Pseudo-Code */ // these constants describe the pins. They won't change: const int groundpin = 18; // analog input pin 4 -- ground const int powerpin = 19; // analog input pin 5 -- voltage const int xpin = A 3; // x-axis of the accelerometer const int ypin = A 2; // y-axis const int zpin = A 1; // z-axis (only on 3 axis models) void setup() { // initialize the serial communications: Serial. begin(9600); // Provide ground and power by using the analog inputs as normal // digital pins. This makes it possible to directly connect the // breakout board to the Arduino. If you use the normal 5 V and // GND pins on the Arduino, you can remove these lines. pin. Mode(groundpin, OUTPUT); pin. Mode(powerpin, OUTPUT); digital. Write(groundpin, LOW); digital. Write(powerpin, HIGH); } void loop() { // print the sensor values: Serial. print(analog. Read(xpin)); // print a tab between values: Serial. print("t"); Serial. print(analog. Read(ypin)); // print a tab between values: Serial. print("t"); Serial. print(analog. Read(zpin)); Serial. println(); // delay before next reading: delay(100); 30

SD Card Data Storage Code: Complete #include <sd-reader_config. h> #include <sd_raw_config. h> int print_disk_info(); int sample(); int read. Disk(); byte incoming. Byte; void print. Welcome(); long int address; byte temp. Bytes[2]; void setup() { Serial. begin(9600); delay(1000); print. Welcome(); if(!sd_raw_init()) { Serial. println("MMC/SD initialization failed"); } print_disk_info(); }void loop() { int i; if(Serial. available()>0) {incoming. Byte=Serial. read(); switch(incoming. Byte) { case 114: read. Disk(); break; case 115: sample(); break; default: break; }} int sample() { int i, j; int temp; byte low; byte high; byte in. Byte; Serial. println(); Serial. println("Sampling. . "); for(i=0; i<500; i=i+2) { if(Serial. available()>0) {in. Byte=Serial. read(); if(in. Byte==113) return 0; } temp=analog. Read(0); Serial. print(temp, DEC); Serial. print(" "); //Convert int to 2 bytes low=temp&0 x. FF; high=temp>>8; // Serial. print(temp, DEC); //Serial. print(low, DEC); //Serial. print(high, DEC); temp. Bytes[0]=low; temp. Bytes[1]=high; if(!sd_raw_write(i, temp. Bytes, 2)) { Serial. print("Write error"); } //sd_raw_sync(); delay(5000); Serial. println(); } return 1; } int read. Disk() { byte low; byte high; byte info[2]; int i; int result; Serial. println(); for(i=0; i<50; i=i+2) {sd_raw_read(i, info, 2); //Serial. print(info[0], DEC); //Serial. print(" "); //Serial. print(info[1], DEC); low=info[0]; high=info[1]; result=high<<8; //result<<8; Serial. print(" "); Serial. print(result+low, DEC); Serial. print(" "); }} void print. Welcome() int print_disk_info() { Serial. println("------------"); Serial. println("Data sampling system"); Serial. println("send r to read disk"); Serial. println("send s to start sampling"); Serial. println("send q to stop sampling"); Serial. println("Ready. . . "); Serial. println("-------------"); } { struct sd_raw_info disk_info; if(!sd_raw_get_info(&disk_info)) { return 0; } Serial. println(); Serial. print("rev: "); Serial. print(disk_info. revision, HEX); Serial. println(); Serial. print("serial: 0 x"); Serial. print(disk_info. serial, HEX); Serial. println(); Serial. print("date: "); Serial. print(disk_info. manufacturing_month, DEC) ; Serial. println(); Serial. print(disk_info. manufacturing_year, DEC); Serial. println(); Serial. print("size: "); Serial. print(disk_info. capacity, DEC); {Serial. println(); Serial. print("copy: "); Serial. print(disk_info. flag_copy, DEC); Serial. println(); Serial. print("wr. pr. : "); Serial. print(disk_info. flag_write_protect_temp, DEC) ; Serial. print('/'); Serial. print(disk_info. flag_write_protect, DEC); Serial. println(); Serial. print("format: "); Serial. print(disk_info. format, DEC); Serial. println(); Serial. print("free: "); 31 return 1; }

Prototyping and Analysis Christopher Elko

Prototyping PEA • Preliminary test setup measured voltage levels from a single strip actuator under deformation using a digital voltmeter. • Results suggest adequate voltage potential for entire system, with an average of approximately 132 m. VAC generated by a single actuator. • Preliminary finite element analysis results in ABAQUS suggest aluminum is adequate for resistance to cyclic loading in this application. • Mechanical analysis, in conjunction with destructive testing of piezo actuators, will optimize dimensions of support cantilever dimensions. 33

Prototyping continued STR • Preliminary FEA results suggest a fifth aluminum standoff is desirable for added support of electronic components on upper deck. • Currently finalizing design and interactions with PEA mounting methods. EPS • SD card adapter to be integrated • Accelerometers integrated into microcontroller and tested for data output VVS • Tested LED circuit for functional interaction with PEA 34

Prototyping continued Preliminary piezo strip actuator voltage testing for PEA design Preliminary piezo strip actuator LED testing for PEA -VVS interaction 35

Analysis cantilever deflection Point Load Distributed Load • Maximum deformation at end of beam, where x = L • Combined loading during flight due to G-loading and mass at end of beam 36

Analysis FEA PEA Stress Analysis • Point load to simulate mass at end • Uniform load to simulate G-loading • Maximum stress does not exceed 2000 psi 37

Analysis FEA PEA Deformation Analysis • Point load to simulate mass at end • Uniform load to simulate G-loading • Maximum deformation: 0. 3 inches 38

Analysis FEA STR Stress Analysis • • • Point load at electronic elements Uniform load to simulate G-loading Maximum stress does not exceed 649. 6 psi 39

Analysis FEA STR Deformation Analysis • • • Point load at electronic elements Uniform load to simulate G-loading Maximum deformation: 0. 92 inches 40

Mass Budget Part Mass (lbf) Qty Subtotal (lbf) Comment Flight Deck 0. 84 2 1. 68 Aluminum Standoff 0. 02 5 0. 1 Piezoelectric Arrays 0. 01 4 0. 04 Includes actuator, cantilever, mounting block, fastener, and deflection limiter G-Swtich 0. 014 1 0. 014 Microprocessor 0. 089 1 0. 089 Bridge Rectifier 0. 012 2 0. 024 Accelerometers 0. 002 2 0. 004 AA Battery 0. 0178 4 . 0712 Includes battery holder LED N/A 1 0 Negligible weight Camera 0. 0691 1 0. 0691 Based on micro-camera, may change manufacturer TOTAL 2. 091 STR PEA EPS VVS 41

Power Budget Part Voltage (V) Current (A) Qty Time On (min) Amp-hours Comment Structure 0 0 0 10 0 Piezo. Electric Actuators 0. 13 V - 4 10 0 power generation part of project scope G-Swtich 250 VAC 5. 00 E+00 1 0. 02 1. 39 E-03 Microprocessor 5 V 4. 00 E-02 54 10 3. 60 E-01 Bridge Rectifier 20 1. 00 E+00 2 10 3. 33 E-01 Accelerometers 2. 2 -16 V 5. 00 E-04 2 10 1. 67 E-04 LED 0. 055 V 5. 00 E-05 2 10 1. 67 E-05 Camera 10 Self-Contained TOTAL 0. 69 STR PEA EPS VVS 42

Manufacturing Plan Choose your weapon

Mechanical Elements STR • Acrylic plate laser-cut to size/shape of flight decks • Flight decks among first components manufactured to ensure proper interaction with other subsystems PEA • Cantilevers cut to size from sheet aluminum upon determining optimum • Piezo actuators to be bonded to cantilevers • Mounting blocks and deflection limiters must be custommilled from aluminum stock 44

Electrical Elements 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 45

Software Elements Code to be finalized • Accelerometers • Voltage output from bridge rectifiers • SD card data recording Code to be developed • Power loop for camera • G-switch Code block dependencies • SD card code integrates all subroutines • All code dependent on “true” output from G-switch 46

Testing Plan Choose wisely.

PEA Subsystem Piezo Actuator Tests Non-destructive Testing • Non-destructive testing will determine voltage output from piezo actuators. • Test Plan • Connect actuators to voltmeter, LEDs; flex actuators to generate current Destructive Testing • Will determine bending deformation limits of piezo actuators. • Test Plan • Use spindle micrometer to bend piezos until fracture. 48

PEA Subsystem continued Cantilever Tests Unrestricted Cantilever • Unrestricted cantilever testing will determine max deformation limits of cantilevers and whether or not a block is needed to restrict deformation. • Cantilevers will be designed so that they bend freely with only slight vibration. • Test Plan • Set up cantilever assembly on vibe table • Measure deflection using high speed camera 49

PEA Subsystem continued Cantilever Tests continued Restricted Cantilever • Restricted cantilever testing will ensure that designed block will restrict deformation as needed such that PEA won’t deform past piezo deformation limits. • Block will be designed to restrict deformation in the + and – axis. • Test Plan • Same as unrestricted tests except for use of block. 50

PEA Subsystem continued Thermal and Adhesive Tests • Thermal tests will be used to determine thermal expansion of the piezos once adhered to the cantilever. This will ensure that the piezos don’t crack once adhered. • Results will determine adhesive to be used. • Test Plan • Adhere piezo actuator to cantilever material • Subject assembly to cyclic thermal environment • Bake in oven, then put in freezer 51

EPS Subsystem and Software Arduino Sampling Rates • Tests will ensure Arduino board records at highest sampling rate possible. • Test will be completed after all subsequent electronics are tested. • Test Plan • Connect all systems to Arduino board, click system on with G-switch • Set resolution • Iteratively check data collection while increasing sampling rates 52

EPS Subsystem and Software Arduino Data Collection • Tests will ensure Arduino board records data as required. • Test will be completed after all subsequent electronics are tested. • Test Plan • Connect all systems to Arduino board, click system on with g-switch. • Check for data collection and storage. • Modify software as needed. 53

EPS Subsystem and Software G-switch Program Test • Tests will ensure that G-switch activates system with one click and does not deactivate the system on subsequent clicks. • Test Plan • Program G-switch, connect to any system • Will test with dummy system and with full EPS system once other tests are complete • Click system on, ensure function; click again, check that system did not shut off 54

VVS Subsystem Camera Activation • Tests will ensure camera relays function properly. • Power down requirement includes camera. Camera will be relayed to g-switch to be activated upon launch. • Test Plan • Connect camera to G-switch, click system on and check that camera turns on and records. • Check that video saves at the end. 55

Full System Testing Vibration Testing • Tests will ensure system is structurally sound during vibration. • Test Plan • Construct and connect full system • Use vibe table to simulate Terrier-Orion flight vibration conditions • Monitor system connections and structural integrity throughout test • Check for data collection on Arduino board and camera at end of tests 56

Full System Testing Spin Testing • Tests will ensure system is structurally sound during spin. • Test Plan • Construct and connect full system • Use spin table to simulate spin of Terrier-Orion rocket • Monitor system connections and structural integrity throughout test • Check for data collection on Arduino board and camera at end of tests 57

Prototype Risk Assessment Kelly Collett

Prototype Risk Assessment Subsystem Risk/Concern Action STR Concerns exist about clearance and component mounting Prototype all interfaces with STR to ensure integrity PEA Bond between PE actuators and aluminum must not fail Test various bonding materials and application methods EPS Functionality of microcontroller must be verified by CDR Prototype controller on bread board to verify function VVS LED must light, camera must not fail to record actions of LED Test LED with PEA to verify power draw; test camera to ensure functionality 59

Risk Walk-Down risks at PDR Consequence EPS. RSK. 2 EPS. RSK. 1 • STR. RSK. 1 – Clearance and component mounting • PEA. RSK. 1 – Bonds between PE actuators and cantilevers must not fail • PEA. RSK. 2 – PEA actuators cannot fracture • EPS. RSK. 1 – Functionality of Microcontroller • EPS. RSK. 2 – G-switch must not shut off system • VVS. RSK. 1 – LEDs must light • VVS. RSK. 2 – Camera must record LED light and cantilever deflection PEA. RSK. 2 STR. RSK. 1 PEA. RSK. 1 VVS. RSK. 2 Possibility Risk Matrix at PDR 60

Risk Walk-Down top 3 risks at CDR EPS. RSK. 2 EPS. RSK. 1 PEA. RSK. 2 • Top 3 Risks Consequence • PEA. RSK. 2 PEA fracture • EPS. RSK. 2 G-switch • EPS. RSK. 1 Microcontroller • Will be walked down with testing Possibility Top 3 Risks Remaining 61

User’s Guide Compliance Kelly Collett

User’s Guide Compliance Magnitude of Mass • Approximately 2. 091 lbf (without ballast) CG • Lies within 1 in. 3 volume at center Power Requirements • Low voltage electrical components used • Batteries • 4 x 1. 5 -V AA = 6 V 63

Project Management Plan Kelly Collett

Organizational Chart Danielle Jacobson Christopher Elko Electrical Systems Lead Structural Lead Machining CAD Designer Dr. Jin Kang Faculty Advisor Kelly Collett Testing Lead Drexel Space Systems Lab Primary POC Project Support 65

Schedule December & January Testing Deliverables 12/1 Prelim. cantilever FEM 12/8 CDR Due 12/12 -22 G-Switch programming 12/13 CDR Teleconference Arduino software programming Temple CDR Teleconference Destructive piezo testing Cantilever tests 1/9 -24 Thermal / Adhesive Tests 1/9 Flights Awarded Software Iterations 1/30 Online Progress Report due VVS Camera Tests Preliminary EPS Integration Redesigns, if necessary 66

Schedule February & March Testing February VVS Testing Re-test of any redesigns Full system hook-up tests Deliverables February 2/6 Midterm Draft Report Due 2/13 Subsystem Test Reports Due 2/27 Progress Presentation to Faculty Advisor March 3/12 Online Progress Report due 3/19 Project Progress Report due 67

Schedule May Testing Subsystem and system testing, troubleshooting, and modifications as needed Deliverables 5/7 Weekly Teleconference 5/14 Weekly Teleconference Senior Design Project Report Due 5/21 Weekly Teleconference 5/21 -5/22 Final Senior Design Presentations 5/28 LRR Presentation Due 5/29 LRR Teleconference 5/30 Co. E Project Competition 68

Budget Spending to date: $238. 48 Estimated final total: $503. 23 Budget: $1, 000 Lookin’ Good! Major Cost Contributors Digital Camera: $140 Piezoelectric Components: $100 Major Time Contributors Piezoelectric Components: 7 -10 Days Accelerometers: 7 -10 Days RECEIVED! 69

Budget Ordered Parts ($238. 48) Item Subsystem Supplier Cost/Set or Unit Sets Subtotal Bridge Rectifier EPS Digi. Key $0. 62 2 $1. 24 Piezo Actuator PEA STEMInc. $19. 98 1 $19. 98 Piezo Actuator PEA STEMInc. $19. 98 2 $39. 96 STR Mc. Master $7. 23 2 $14. 46 EPS Pololu $14. 95 2 $29. 90 EPS Digi. Key $4. 39 2 $8. 78 EPS Spark. Fun $58. 95 1 $58. 95 STR Mc. Master $1. 05 5 $5. 25 STR Mc. Master $20. 00 allowance N/A $20. 00 12” x 12” Acrylic Sheet 3 -Axis Accelerometers G-Switch Arduino MEGA Microprocessor Aluminum Standoffs Miscellaneous Fasteners 70

Budget To Be Ordered ($290) • Camera ($140) • Circuitry Components ($100) • Parts for testing and installation • We have some spare parts, so orders will be made on an as-needed basis • Structural Materials ($50) • We have some spare materials, so orders will be made on an as-needed basis 71

Sharing Logistics Temple University • Plan for Collaboration • • • Email, phone, campus visits Full model designed in Solid. Works for fit check Drop. Box/Google Docs for file sharing • Structural interface • • Consider clearance Joining method 72

Conclusions What’s Next?

Next Steps 3 days’ worth of sleep for each member of the team • Prototype assembly • Testing testing! • 74

Thank you! Questions?