Detailed Design Review

P10231 - UAV Telemetry

Chris Barrett Project Manager

Gregg Golembeski Interface Manager

Alvaro Prieto Radio Concepts

Cameron Bosnic Software Concepts

Daron Bell Power Concepts

R09230 Project Family

Mission Statement

Customer Needs

Deliverable Summary

System Architecture

Subsystem Design

Bill of Materials

Risk Assessment

Outline

Mission StatementThe goal of this project is to create an open source, multi platform, bidirectional telemetry system.

Carried on UAV Airframe C

Interface with Control System(P10236)

Send flight data to ground

Remotely Trigger On-Board Camera

Deliverables

Wireless System for Bidirectional Communicationbetween control system and ground PC

GUI Application that displays flight datamulti platform, open-source, in real-time

System Design

RadioGoals:

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.

RadioComponents

Radio: 2 Digi Xtends PKG 900 MHz.

Ground Antenna: 65’’ 8.1 dBi Omni-directional antenna.

UAV Antenna: 6’’ 2.1 dBi Omni-directional antenna.

Specifications

Engineering Specifications

Ideal Value Marginal Value

Range 3000 2000

Refresh Rate (Hz) 10 5

Analysisc 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

AnalysisCalculated Values

Range 115200

bps

Range 9600 bps

Refresh Rate 115200 bps

Refresh rate9600 bps

Max Packet size

1400 4600 137 11

Min Packet Size

1400 4600 320 26

TestingTransfer 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

TestingRange:

• 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.

InterfaceRadio >> Controller

• DB 9 M/F cable Molded

Radio >> Computer

• Serial Cable

• USB to Serial Adapter

Power SupplyPower solution must...

not interfere with other on-board power systems.

sustain radio communication throughout flight time.

Components:Battery: 11.1V 5500mAh Li-Poly Lipo

Battery Pack

SpecificationsEngineering Specifications

Ideal Value Marginal Value

Flight Time (min) 45 30

Design SpecsMin. Battery Charge rating (mA-

h)900

AnalysisCurrent requirement for radio:

Battery Current mA x Time hours=mAh900 mA x 1 Hour=900 mAH

Battery Life:

Battery Current Rating /Current Draw = Run Time 5500 mAh/900 mA=6.11 hours

Testing•Battery Life:

• 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

InterfaceBattery >>Radio:

•Barrell power connector , size type M (5.5mm x 2.1mm barrell type connector)

•Battery output cables will be soldered to connector

Mounting and PackagingThe 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

1.5 in in

2 in.

1.13 in.

0.125 in

SpecificationsEngineering Specifications

Ideal Value Marginal Value

Weight (kg) 0.5 2.27

Size (cm) 15.25x15.25x15.25 17.75x17.75x17.75

Flight Time (min) 45 30

Max Acceleration(m/s2)

567 56.7

Design Specifications

Associated ES

Max Stress (kPa) 2.82e5 Max Acceleration

Max Weight (kg) 2.27 Weight

Max Size (cm) 17.75x17.75x17.75

Size

Max Temp.(ºC) 80 Flight time

Analysis

•Assumptions:o Motion of system is considered to be free vibrationoFoam acts a linear springoPCB in radio is analogous to PCBs used in phonesom1 and m2 are homogenousoDamping can be neglectedoCan simplify to a system with two degrees of freedom

m1 = 0.2 kgm2 = 0.364 kgk1 = 1310 N/mmk2 = 592 N/mmVi = 6 m/s

AnalysisFBD 1 FBD 2

Equations of motion Mass and stiffness Matrices

Kt = M-1/2KM-1/2

Normalized stiffness Matrices

w = [w1 w2]T

Natural Frequency Matrix Eigenvector Matrix

P = [v1 v2]

Analysis. Initial conditions for modal coordinates

Displacement of modal coordinates

Displacement ResponseDisplacement Response

Analysis.

Eg=2700 Jmradio=0.2kgmax=42.2 C

Eg = mcpT

Radio

Eg

Max Temperature:

Assumptions:

o Radio is well insulated

o Energy usage is 1 Watt

o Ambient Temperature is 37.8 C

o Run time is 45 minutes

Insulation

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

SoftwareSoftware application must...

track and log UAV control variables.

support multiple computing platforms.

report all flight data through a visual interface.

maintain open source concepts.refresh at acceptable rate.

transmit remote shutter command.

Software Design

GUI Design

Flight Plan

GUI Design

Flight Info

GUI Design

Data View

Bill of Materials

Bill of Materials

Risks

Risk Management