1. P07202: Motor Module – Robotic Platform 100kg
Robert Saltarelli: Project Manager
Erich Hauenstein: Mechanical Member
Dustin Collins: Mechanical Member
Jasen Lomnick: Mechanical Member
Saul Rosa: Electrical Member
Derrick Lee: Electrical Member
Muhammad Moazam: Electrical Member
Vincent Capra: Electrical Member
Sponsor: Gleason Foundation

2. P07202: Functionality

3. P07202: Mechanical Design

4. Machining Very mechanically intense design
Hours of machining each day since the beginning of January
Over 36 parts on each driven motor module
Over 30 of these parts were machined or modified

5. Machining
Machine shop staff was very helpful through out the entire process.
Advanced machining techniques were introduced and explained by Rob Kraynik, Dave Hathaway and Steve Kosciol.
Rob performed welding for several of the subassemblies

6. Machining The Brinkman CNC machining lab was needed on 3 parts.
The need for precision led to the use of CNC
Ease of mass production

7. Lessons Learned Price is usually a good measure of quality
Modification of COTS parts may save money, but does add time to manufacturing
Manufacturers models do not always match the actual product.
Easy to add to a CAD model ≠ Easy to Machine!! (i.e. precise round plates)

8. Mechanical Design Modifications
Extension of vertical driveshaft and addition of a supporting bearing to handle radial load exerted by spur gear
Change from retaining rings to spacers, threaded axles, and washers
Simplification of Yoke Sides
Simplification of Motor Cage
Change to smaller belt
Additional washers to support available hardware

9. Verifying COTS Motor Performance
Obtained dynamometer from Dave Krispinsky
Fabricated coupling and mounting for motor to attach to dyno
Applied several loading conditions to motor and took readings from dynamometer
Motor speed was found using timing gun provided by Dr. Kempski

10. P07202: The H-Bridge First revision prototype on etch board PCB
Cleaned copper is written over with sharpie marker. Then the holes for through-hole devices are tapped and drilled out
After the necessary leads are soldered on the components can be placed and the revision of the board is ready for testing.
Made use of simulated input signals and tested under loading conditions.
After several revisions for the steering and drive motors, aftermarket H-Bridges were purchased due to budget constraints.
The design schematics, simulations, and PCB Layout files were well documented for possible future use and mass production.

11. No Longer Used Power Board
Originally design but not implemented. Included 6X 5V 1A lines, Battery Monitoring, Battery Indication, and Status Relay to P07302.
No Longer Used
(Rev A Power Board Layout)

12. Motor Control Board Xilinx FPGA processor JTAG Programming
CAN Communications
Interfacing to H-Bridge
Encoder Interpretation
Built in Multi Stage Regulation
Custom PCB design
Board Temperature Sensing 12

13. P07202: Control and Communications
Precise control over system allows for optimal efficiency designs
High speed
Power savings
Fully parallel driven and steering control systems achieves true simultaneous operation
CAN protocol is fully addressable and optimizes transmissions
Significant potential for future functionality
Incorporation of PIC soft core
Generic I/O headers for interfacing with additional circuitry (e.g. watchdog)
Easy to add additional devices over CAN

14. P07202: Error Protection and Failsafe Operation
CAN protocol provides robust protection against noise.
Errors of up to 5 consecutives bits can be identified and corrected
Differential signal is more immune to noise
Shielded, twisted pair cabling used to mitigate risk of interference
State encoding ensures that any errors are safely caught operation is returned to idle mode
Robust power up routines ensures integrity of system after booting
Sophisticated I/O synchronization protects components from errors or potential damage
Encoder inputs are properly measured
H-bridge lines never activated simultaneously

15. P07202: Digital Encoders
The US Digital optical encoders were ordered to measure the speed of the modules using the measured RPM from the drive motor shafts.
A different model US Digital optical encoder was used to measure the steering angle. An indexing function helped to read and convert the steering motor shaft’s RPM to an angular position.
Drive Encoder
Steer encoder
Pin-outs
Optical Ring

16. P07202: Testing 3 Phases Initial Semi-Integration
Baseline measurements
Signals, Voltage levels
Semi-Integration
Partial integration with Mechanical components
To show components operate efficiently together
Full Integration (Prototype)
Final measurements and stresses tested
Reconfirmation of desired specifications
Overall design assessed

17. P07202: Safety
Several different fail-safe algorithms are coded into the FPGA for a variety of disturbances:
No wheel contact with ground
Liquid disturbances
Collisions
Communication connection loss
Safety fuses are connected to the battery input to avoid burning out the motors and breaches of maximum speed.
Current sensors are employed to ensure proper functionality of critical signal lines.

18. Electrical Budget Driver production cost (electrical) $267.11 PCB
$17.13
Chips
$22.29
H-bridges (COTS)
$128.45
Encoders
$98.32
Cost of entire project $
Prototype cost
$334

19. Mechanical Budget Driver prototype cost Driver production cost
$651.14
Driver production cost
$598.49
Idler prototype/production cost
$121.82
Cost of entire project $
Difference from original cost projection
$140.70
All modules built

20. Looking Forward Total cost per driven module $985.85
Production cost per driven
$865.50

21. P07202: Questions ?