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Detailed Design Review P 10231 - UAV Telemetry R 09230 Project Family Chris Barrett Project Manager Gregg Golembeski Interface Manager Alvaro Prieto Radio Concepts Cameron Bosnic Software Concepts Daron Bell Power Concepts
Outline Mission Statement Customer Needs Deliverable Summary System Architecture Subsystem Design Bill of Materials Risk Assessment
Mission Statement The goal of this project is to create an open source, multi platform, bidirectional telemetry system. Carried on UAV Airframe C Interface with Control System(P 10236) Send flight data to ground Remotely Trigger On-Board Camera
Deliverables Wireless System for Bidirectional Communication between control system and ground PC GUI Application that displays flight data multi platform, open-source, in real-time
Radio Goals: Two radios that send and receive data with high throughput and data integrity. The radios should be transparent to both the control system and base station as if it were a physical connection. This “radio as a wire” concept allows interchangeability of various radios using different wireless technologies.
Radio Components Radio: 2 Digi Xtends PKG 900 MHz. Ground Antenna: 65’’ 8. 1 d. Bi Omnidirectional antenna. UAV Antenna: 6’’ 2. 1 d. Bi Omni-directional antenna.
Specifications Engineering Specifications Ideal Value Marginal Value Range 3000 2000 Refresh Rate (Hz) 10 5
Analysis c Speed of Light L Wavelength f Frequency Pr Power Received Pt Power Transmitted Gr Receiving Antenna Gain Gt Transmitting Antenna Gain R Distance Between Antennas
Analysis Calculated Values Range 115200 bps Range 9600 bps Refresh Rate 115200 bps Refresh rate 9600 bps Max Packet size 1400 4600 137 11 Min Packet Size 1400 4600 320 26
Testing Transfer of Serial Data: • • Connect computer to each radio Transmit data using simple terminal program Tester confirms data is accurate Repeat at both available baud rates to confirm proper orientation
Testing Range: • • • Place one radio in a high place and the another on a mobile platform Send data back and forth between the radios using an automated program Move away with the mobile radio until you can no longer receive data.
Interface Radio >> Controller • DB 9 M/F cable Molded Radio >> Computer • • Serial Cable USB to Serial Adapter
Power Supply Power solution must. . . sustain radio communication throughout flight time. not interfere with other on-board power systems. Components: Battery: 11. 1 V 5500 m. Ah Li-Poly Lipo Battery Pack
Specifications Engineering Specifications Ideal Value Flight Time (min) Marginal Value 45 30 Design Specs Min. Battery Charge rating (m. A-h) 900
Analysis Current requirement for radio: Battery Current m. A x Time hours=m. Ah 900 m. A x 1 Hour=900 m. AH Battery Life: Battery Current Rating /Current Draw = Run Time 5500 m. Ah/900 m. A=6. 11 hours
• Battery Life: • • Testing Connect battery across a ten ohm resistor and monitor its output voltage until it drops below the level that is accepted by the radio The time it takes the voltage to drop below the acceptable amount is the approximate run time of the battery
Interface Battery >>Radio: • Barrell power connector , size type M (5. 5 mm x 2. 1 mm barrell type connector) • Battery output cables will be soldered to connector
Mounting and Packaging The Mounting and Packaging solution must. . . securely attach the aerial radio and power systems to UAV C. provide protection to onboard components in the event of a hard landing. add minimal weight to the system. add minimal size to the system. allow for easy access to components.
Mounting and Packaging
Specifications Engineering Specifications Ideal Value Marginal Value Weight (kg) 0. 5 2. 27 Size (cm) 15. 25 x 15. 25 17. 75 x 17. 75 Flight Time (min) 45 30 Max Acceleration(m/s 2) 567 56. 7 Design Specifications Max Stress (k. Pa) Max Weight (kg) Max Size (cm) Max Temp. (ºC) 2. 82 e 5 2. 27 17. 75 x 17. 75 80 Associated ES Max Acceleration Weight Size Flight time
Analysis m 1 = 0. 2 kg m 2 = 0. 364 kg k 1 = 1310 N/mm k 2 = 592 N/mm Vi = 6 m/s • Assumptions: o Motion of system is considered to be free vibration o. Foam acts a linear spring o. PCB in radio is analogous to PCBs used in phones om 1 and m 2 are homogenous o. Damping can be neglected o. Can simplify to a system with two degrees of freedom
Analysis FBD 1 Equations of motion Normalized stiffness Matrices Kt = M-1/2 KM-1/2 FBD 2 Mass and stiffness Matrices Natural Frequency Matrix w = [w 1 w 2]T Eigenvector Matrix P = [v 1 v 2]
Analysis. Initial conditions for modal coordinates Displacement of modal coordinates Displacement Response
Analysis. Max Temperature: Assumptions: o o Radio is well insulated Energy usage is 1 Watt Insulation Radio Eg Ambient Temperature is 37. 8 C Run time is 45 minutes Eg = mcp. DT Eg=2700 J mradio=0. 2 kg DTmax=42. 2 C
Testing. Overheating: • • • Run the system in an environment that is insulated similarly to our system. Monitor the temperature of the radio while it is running. If the radio stays within its operating temperature for longer then the planned flight time we can be sure it will not overheat in the UAV.
Interfaces. • System >> UAV C • System will be attached to UAV C using Industrial strength Velcro. • Housing >>Battery/Radio • Industrial strength Velcro will be used to secure the battery/radio to the housing
Software application must. . . report all flight data through a visual interface. track and log UAV control variables. transmit remote shutter command. support multiple computing platforms. maintain open source concepts. refresh at acceptable rate.
GUI Design Flight Plan
GUI Design Flight Info
GUI Design Data View
Bill of Materials
Risks Risk Management