1. MARSUPIAL Detailed Design Review
Carnegie Robotics LLC. #10 40th Street Pittsburgh, PA 15201
Jared Raby
Nico Gallardo
Chris Griffin
Sean Greenslade
Wesly Rice

2. Agenda Introduction Systems Design Risks MSD II Schedule Questions
Tracks/Suspension
Wireless Node Payload
Wireless Node Deployment
Electrical Systems
Risks
MSD II Schedule
Questions

3. Introduction MARSUPIAL Tracked Rover for CRL Scope Deliverables
Suspended Track System
Wireless Node System
Electrical Systems
Deliverables
Mesh Network Payload

4. Wes
Tracks and suspension

5. Tracked Suspension System
Rugged against impact shock
Various environmental areas
Climb obstacles
Self Contained
IP Rated seals
Drive-Train
Off the shelf motors
Meet speed and torque requirements
Simple gearing
Integrated electronics
Odometry

6. Tracked Suspension System
Suspension Design
Improved Christie
Volute Idea

7. Tracked Suspension System

8. Tracked Suspension System

9. Tracked Suspension System
Drive-Train
Required Speed
Min of 5mph on level ground
Require Torque
To move 150 lbs of robot and payload
Off the Shelf Motor
Reduce overall price
Realistic Gear Train
8.0:1 – 12.0:1
Planetary

10. Tracked Suspension System
Upper Christie Arm
Bronze Bearings
Retaining Rings
Ballend Spring Joints

11. Tracked Suspension System
Lower Christie Arm
Bronze Bearings
Press Fit Axel
Ball Bearings for Tensioning Wheels
Ballend Spring Joints

12. Tracked Suspension System
Dedicated Tensioner
Bronze Bearings
Press Fit Axel
Ball Bearings for Tensioning Wheels
Clock Spring For Preload

13. Tracked Suspension System
Undriven Wheel Top Assy
Ball Bearings
Preload
Grease Seal
O-Rings
Stock Pulley
Magnetic Encoder
Odometry

14. Tracked Suspension System
Motor Assembly
Sealed
Planetary Gearbox
Parking Brake

15. Tracked Suspension System
Tracks
Proper materials
Coef of friction
Material stretch
Outdoor resistant
Chemical and physical ruggedness
Ease to install and remove

16. Tracked Suspension System BOM

17. Tracked Suspension System BOM 2

18. Tracked Suspension System BOM 3

19. Sean
Wireless node payload

20. Wireless Node Payload Droppable Node Current Prototype
OLinuXino – 575 MHz ARM Core
Running Arch Linux with B.A.T.M.A.N. wireless mesh protocol
USB Wi/Fi adapter
Buck converter
Li-on battery providing upwards of 6 hours of runtime
Current Prototype
3D printed shell
Off-the-shelf antenna

21. Wireless Node Payload Block Diagram

22. Wireless Mesh Node BOM Component Cost Distributor Manufacturer
Manufacturer Part Number
Qty.
System
Price Est.
5 Volt Buck Converter
$6.71
Mouser
RECOM Power R 8
Puck
$53.68
Single Board Computer
$32.95
Olimex Ltd.
IMX233-OLINUXINO-NANO
$263.60
WLAN USB Adapter
$14.33
Amazon LLC
TP-Link
TP-LINK TL-WN722N
$114.64
Li-Ion Battery
$3.39
Battery Space
PL C 24
$81.36
Battery Protection Board
$5.87
PCB-LiS3A4
$46.96
Total
$560.24

23. Wireless node deployment
Jared
Wireless node deployment

24. Wireless Node Deployment System
Needs to readily deploy the node while keeping in place during high impact moments
High holding strength
Ability to drop the puck easily
Deployment system should be isolated from the outside to comply with IP standards
Dust / water prevention
Short circuit protection
Magnetic holding system developed
Magnetic slide in the track

25. Wireless Node Deployment System CAD

26. Wireless Node Deployment System Wiring Diagram

27. Wireless Node Deployment System PCB

28. Wireless Node Deployment System BOM
Index
Component
Cost
Distributor
Manufacturer
Manufacturer Part Number
Qty.
Price Est. 1
ALEL 1uF 50V
$0.23
Mouser
Nichicon
UVR1H010MDD1TD 3
$0.69 2
MLCC 0.1uF 50V X7R
$0.10
Kemet
C0603C104K5RACTU
ISP Connection Headers
$0.54
Molex 4
Servo Connections
$0.19 10
$1.88 5
Payload Microcontoller
$1.30
Atmel
ATTINY2313A-SUR 6
TTL to RS232 Converter
$3.84
Maxim Integrated
MAX232ACSE+ 7
12 MHz Crystal
$0.49
Vishay
XT9SNLANA12M 8
22 pF capacitor
$0.20
Digikey
Yageo
CC0402JRNPO9BN220
$0.40
Total
$9.24

29. Power management and distribution
Nico and Chris
Power management and distribution

30. Electrical Diagram

31. Electrical Diagram – Batteries

32. Electrical Diagram – Power Train

33. Electrical Diagram – Peripherals

34. Power Budget Device Rail Voltage Power (W)
Efficiency (converters, drivers, etc)
Motor #1 24
100
Motor #2
Motor Controller #1 15
0.85
Motor Controller #2
Main Computer 5 10
Power Management uC
5.00E-02
Payload (Pucks)
1.68
Payload (Dispenser)
Lighting 40
Camera
1.2
Ethernet Switch
Level Shifter
1.44
E-Stop Comm Reciever
IMU 1
WLAN Radio
5V DC-DC
3.3V DC-DC
0.425
0.66
Rail
Power
Current
24V 5V
34.115
6.823
3.3V
0.825
0.25

35. Electrical Systems

36. Risks

37. System Risks Risk Severity Occurance Probability Mitigation Owner 1
Staffing/engineering ability 4
Consultation with advisor/customer Scale back of scope
Nico 2
Budget 5
Wes 3
Machine setbacks
Plenty of lead time
Shipping setbacks
Part setbacks
Jared 6
Incorrect Engineering Analysis
Thourough verification of analysis
Per subsystem 7
Ordering errors
Thourough verification of BOM 8
Catostrophic prototype failure
Proof of concepts Small scale tests befor large scale tests
Chris 9
Time constraints 10
Hardware failure
Thorough design verification Spare components 11
Mechanical failure 12
Software failure
Sean 13
Environmental factors
Review weather conditions 14
Technological limits
Review current technologies

38. Mechanical Risks Risk Severity Occurance Probability Mitigation Owner1
Unstable control of the robot while it's it's hanging from straps connected to mini- crane 5   0
Consultation with advisor/customer Scale back of scope
 Wes 2
Module being dropped  5  2
Reinforced chassis and shock absortion 4
Lose control of vehicle while it's descending from the ramp 1 
Manual brakes/emergency brakes Limited/no power to the motors -> -> "coasting function" or clutch
Limited slip to turn  3
Make sure motors are powerful enough to cause slipping

39. Electrical Risks Risk Severity Occurance Probability Mitigation Owner1
Visual inspection of robot is not adequate in identifying all malfunctions  5  2
Perform electrical self tests to identify other malfunctions
 Nico 2
Battery short circuits  1
Fuse to break circuit
 Chris 3
Emergency stop malfunction 1 
It doesn't. 4
Electrical noise in the system  4
Proper signal conditioning and isolation 5
Packet loss 5 
Apply failsafe
 Sean 6
Lighting malfunction 2 
Infrared / additional backup
 Jared 7
Fauly IMU readings
redundant IMU

40. Software Risks Risk Severity Occurance Probability Mitigation Owner 1
Packet loss 5   5
Apply software failsafe
 Sean / Jared 2
Wheel slippage causes bad odometry readings 3   4
Use GPS / Inertial sensors to correct odometry readings
 Jared 3
Poor / Unavailable GPS connectivity  3
Fall back on inertial sensors / odometry alone
 Jared / Sean 4
Fauly IMU readings 1 
redundant IMU 5
Unstable control loop  1
Vigorous control loop testing
Nico

41. Safety Risks Risk Severity Occurance Probability Mitigation Owner 1
Weight consideration when lifting the robot  5  1
>1 person is used to lift the robot
 Chris 2
Unstable control of the robot while it's it's hanging from straps connected to mini- crane 5 
There needs to be 3 hook points in order to saftely move the robot using a crane
 Wes 3
Safety to personnel 3 
Needs to meet military safety standard MIL 883E 4
Lose control of vehicle while it's descending from the ramp 4  1 
Manual brakes/emergency brakes Limited/no power to the motors -> -> "coasting function" or clutch

42. Schedule

43. To be accomplished EMF interference mitigation
Further node deployment development
Prototyping
Schematic and PCB design
Full BOMs
Detailed Design Review Slideshow
Final Detailed Design Review Slideshow
Continued EDGE Updates

44. Questions