Winter 2023 End of Term Drivetrain Meeting

Goals

• Scope work for drivetrain for the end of Winter 2023 term into the spring 2023 term
• What is the drivetrain? Includes suspension, chassis, wheels, autonomy sensors (camera/gimbal, etc), battery mount. NOT: Ebox, arm, science (or mounting for those systems).
• Meeting members: Nico, David, Chan

Update & Action Items

New Tasks

General Drivetrain Notes: Direction for Spring 2023

Subsystem Integration

• Software and mechanical: Sensor mounting on drivetrain.
• Firmware and electrical: Figure out the jumper wire connections coming into the odrives (CAN bus and encoder breakout boards). The jumper wires were breaking during SAR. Can we modify odrives and add screw terminals? How can we make the connections more effective on the drivetrain? Define requirements very well for what needs to get done here (spacing concerns in ebox, reliable encoder).

Mech

• Make battery mount
• Make carbon fiber version of chassis and suspension. Change joints as necessary.
• Improve wheel mounting. Make sure motor is supported on both ends (not just one end).
• Reorganize CAD file directory in kenesto drive (coming from grab CAD).
• Comms mount (increase height of tube in Z axis).
• Clean the BOM
• Remachine encoder mounting if needed.

Electrical

LOGAN PLEADE ADD ON

• Finish PDB
• Improve ebox wiring

Software

• Sensors for rover autonomy on drivetrain. Determine which sensors are needed/wanted first (and autonomy requirements for the drivetrain).
• Finish CAN wrapper and hardware bridge for writing to the drivetrain (polish Colin's code)
• Implement ROS2 control and Andrew's differential drive train controller for writing to the drivetrain.
• Finish xbox controller for driving the drivetrain

Firmware

• Test a new encoder with drivetrain motors (test AMT encoder since we have used it before). Figure out if we are going to switch encoders (had some problems with the encoder magnets shearing off during SAR). Use a supported odrive encoder. Make sure the encoders are reliable; see if we can get rid of the breakout boards.

Unknowns to answer

• Figure out requirements for driver remotely driving the rover
• Determine our requirements/performance for drivetrain terrain
  • Flat terrain: Speed on flat surface? Turning radius? Braking distance at max speed?
  • Steep terrain: How steep of a slope can we climb?
  • Irregular steep terrain (bumpy steep terrain). Current draw of motors.
  • Going down hill
  • Getting into a ditch (think of it as a local minimum). Can we get in/get out?