Transcript System Design Review

Detailed Design
Review
P10231 - UAV Telemetry
R09230 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(P10236)
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
System Design
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 dBi Omnidirectional 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
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: 11.1V 5500mAh Li-Poly Lipo Battery Pack
Specifications
Engineering Specifications
Flight Time (min)
Ideal Value
Marginal Value
45
30
Design Specs
Min. Battery Charge rating (mA-h)
900
Analysis
Current requirement for radio:
Battery Current mA x Time hours=mAh
900 mA x 1 Hour=900 mAH
Battery Life:
Battery Current Rating /Current Draw = Run Time
5500 mAh/900 mA=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
(5.5mm x 2.1mm 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
1.5 in
in
0.125 in
1.13
in.
2 in.
Specifications
Engineering 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
Max Stress (kPa)
Max Weight (kg)
Max Size (cm)
Max Temp.(ºC)
2.82e5
2.27
17.75x17.75x17.75
80
Associated ES
Max Acceleration
Weight
Size
Flight time
Analysis
m1 = 0.2 kg
m2 = 0.364 kg
k1 = 1310 N/mm
k2 = 592 N/mm
Vi = 6 m/s
•Assumptions:
o Motion of system is considered to be free vibration
oFoam acts a linear spring
oPCB in radio is analogous to PCBs used in phones
om1 and m2 are homogenous
oDamping can be neglected
oCan simplify to a system with two degrees of freedom
Analysis
FBD 1
Equations of motion
Normalized stiffness Matrices
Kt = M-1/2KM-1/2
FBD 2
Mass and stiffness Matrices
Natural Frequency Matrix
w = [w1 w2]T
Eigenvector Matrix
P = [v1 v2]
Analysis
.
Initial conditions for modal coordinates
Displacement of modal coordinates
Displacement Response
Displacement Response
Analysis
. Temperature:
Max
Insulation
Assumptions:
o
o
o
o
Radio is well insulated
Energy usage is 1 Watt
Radio
Eg
Ambient Temperature is 37.8 C
Run time is 45 minutes
Eg = mcpDT
Eg=2700 J
mradio=0.2kg
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
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.
Software Design
GUI Design
Flight Plan
GUI Design
Flight Info
GUI Design
Data View
Bill of Materials
Bill of Materials
Risks
Risk Management