NASA University Student Launch Initiative (Sensor Payload) Final Design Review Payload Name: G.A.M.B.L.S. CPE496-01 Computer Engineering Design II Electrical and Computer Engineering The University of Alabama in Huntsville email:jgr0007@uah.edu
GAMBLS Members Jason G Renner - Project Manager Patrick R Williamson - Software development Michael A Bizanis Software development Tin T Tran Hardware development 2
Project Summary GAMBLS will measure rotation, acceleration, direction, and atmospheric pressure while ascending through the atmosphere, beginning at launch and ending at approximately 5280 feet (1 mile). The payload will sample sensor data at a minimum of 500 samples per second and store this data on board. After apogee, the rocket will begin transmitting all data to a ground station so that there will be two copies of acquired data, one on the rocket and one at ground station. GAMBLS will synchronize data sampling by use of a GPS time stamp, and transmit data to ground using an RF transmitter. 3
The Need Gather, store, and transmit data about flight characteristics from an accelerometer, magnetometer, gyroscope, barometer, and pitot probe pressure sensors. Data sampling rate at 500 Hz Lightweight payload with a 3.5 x4.5 footprint Who is affected and who will benefit? Charger Rocket Works (CRW) will have an off-theshelf payload for monitoring flight characteristics 4
NASA USLI Competition 20 universities involved in USLI competition Points awarded based on documentation, presentation, successful rocketry GAMBLS team worked as subteam of CRW Assisted with documentation and presentation 5
Marketing Requirements Shall operate under the under the rigors of flight Shall operate effectively for multiple launches Shall be able to idle on the launch pad for up to forty-five minutes and still be able to operate during flight Shall take data from an accelerometer, gyroscope, magnetometer, barometer, pitot probe pressure sensors and have the capability to add more sensors Shall store data on the rocket and transmit data to a ground station 6
Engineering Requirements The payload must contain the following instruments: 3-axis accelerometer (3 channels) 3-axis gyroscope (3 channels) 3-axis magnetometer (3 channels) One pressure sensor for ambient pressure (up to 15 psia) Develop a way to synchronize data between multiple copies of this payload in order to compare events between payloads. Five additional channels of data which may be used for sensors chosen by the USLI team 7
Engineering Requirements cont. The payload must also meet the following requirements: Minimum 500 Hz sampling rate Sensors and five additional channels must have a 12-bit minimum resolution Capable of making 5 voltage measurements (0-5 V) at up to four feet from the payload. These are the five additional channels. Noise tolerant digital or differential analog signaling required for the five additional channels and any other signals traveling more than five inches. System shall provide a minimum of 1W power to sensors and associated support components (e.g. ADCs, bus transceivers) for remote sensors 8
Engineering Requirements cont. Capable of operating under a 50g acceleration loading Capable of operating under vibration experienced during a rocket flight. Have a means of confirming operational state when the rocket is on the launch pad Have a means of powering on and off via an external switch when the payload is in the assembled rocket Must be capable of being integrated with the rest of the rocket, powered up, and operational within 45 minutes Must be ready for re-flight (new batteries installed, data transferred to ground station, and empty memory) within 45 minutes Capable of operating for up to one hour in the powered up (standby) state on the rocket pad Capable of fitting inside of a 3.5-inch cylinder with a 4 inch height Weigh under 1 kg Contain an independent power source (i.e. not require power from other systems in the rocket) 9
Initial System Design - October 2015 Use Raspberry Pi 2 Model B with ARMv7 quadcore with 1GB RAM with 64GB micro SD card Use Pre-built sensors from Adafruit Reuse Pitot Pressure Sensor from last year s design Raspberry Pi, Arduino, etc not capable of meeting 500Hz requirement 10
Final Design Strategy Redesign circuit boards from previous year for new requirements Refactor embedded code for new circuit board design Only change necessary hardware 11
Design Layout GAMBLS Payload: Sensor Board Transmitter Board Pitot Board Ground Station: XBee radio connected to a laptop Onboard transmitter will communicate with XBee radio at ground station 12 12
Interim Milestone December 2015 Demonstrated feasibility of design with pitot probe test Set goals for 2016 Design and fabricate new circuit boards Build on top of existing embedded code 13
CPE 496 - January 2016 Tin and Jason begin redesigning old board in Eagle Michael and Patrick work with old boards to rework embedded code GAMBLS team works with CRW to write NASA documentation 14
System Design Description Sensor Board 15
System Design Description RF-Power board 16
Pitot Board Schematic 17
PW/ RF Board Schematic 18
Sensor Board Schematic 19
Advantages Durable - Mounted to a 3d printed mounting bracket inside rocket. Battery enclosed by protective casing Light - 9.5 ounces Small - fits within 4 inch diameter footprint Data Fidelity - Capable of sampling at 500 Hz Value - Monitors flight characteristics including acceleration, rotation, orientation, airspeed, barometric pressure, and temperature 20
Disadvantages Cost - $362 to create one functional payload Usability - requires understanding of embedded code to modify sensor performance Maintainability - hardware changes require months of time to redesign and fabricate new circuit boards 21
Safety Analysis Soldering can create hot surfaces, fire, and smoke which can damage your eyes and skin. Fire risks during flight because of high speeds and fast temperature changes which can abrade the LiPo Battery also requires a precise charging profile to avoid damage which is accomplished with a LiPo charging circuit. Payload itself poses very little danger as the boards operate at 3.3 volts. 22
Circuit Board Fabrication 23
Finished Package Sensor Board RF/Power Board Pitot Board 24
Payload Integration GAMBLS Attached to mounting bracket on all thread Pitot board housed higher in nosecone 25
Difficulties Troubleshooting malfunctioning new sensor boards Porting embedded code to new hardware Radio transmission to ground station 26
Major Results and Problems Software Write data from sensors to flash memory Hardware problems cause software test difficulties Skeleton implementation of flight stages 27
Major Results and Problems Hardware Designed and fabricated 9 new circuit boards (3 sensor boards, 3 transmitter boards, and 3 pitot boards) New boards meet sensor requirements Fixed flash memory problem 28
Project Cost Total: 951.72 Tax: 85.65 Shipping: 47.59 Grand Total: 1084.96 Number of Payload Packages: 3 Cost of Each Payload: 361.65 Project Duration: 7 months (September - April) 29
Analysis Successfully competed in NASA s University Student Launch Competition Created three new copies of payload Began programming new sensor boards Practiced and learned about the design process 30
Lessons Learned Writing embedded software takes longer than designing and building circuit boards. Get boards made as soon as possible Check your circuit board footprint against the part you ordered. We lost time waiting for a component because we ordered the wrong size Designing software or hardware works better in pairs than as a group of four Finally, we learned vast amount of information about rocketry, PCB design, embedded programming, microcontrollers, and electronics. 31
General Conclusions and Future Implications Future users should be able to add new sensors to the payload, meet all the data sampling and storage requirements, and have an off-the-shelf solution to monitoring flight characteristics during rocket launches. 32
Special Thanks To Jason Winningham John Jetton Dr. Wells 33
Charger Rocket Works 2015/16 34
Thank You Questions? 35