mini-cheetah-motor-driver-socketcan 0.2

A Python Driver for MIT Mini-Cheetah Actuator which uses SocketCAN for communication.

Python Motor Driver for Mini Cheetah Actuator: T-Motor AK80-6

Dependencies:

• bitstring
• numpy
• sockets

Install via:

pip3 install bitstring sockets numpy pandas

Documentation

• Useful videos:
  • From T-Motor
  • From Skyentific
• Datasheet
• Ben Katz Documentation

Pre-requisites:

• Setting up the CAN interface:

  • Run this command and make sure that can0 (or any other can interface depending on the system)shows up as an interface after connecting the USB cable to your laptop: ip link show

  • Configure the can0 interface to have a 1 Mbaud communication frequency: sudo ip link set can0 type can bitrate 1000000

  • To bring up the can0 interface, run: sudo ip link set up can0

  Note: Alternatively, one could run the shell script setup_caninterface.sh which will do the job for you.

• To change motor parameters such as CAN ID or to calibrate the encoder, a serial connection is used. The serial terminal GUI used on linux for this purpose is cutecom

Usage:

Testing Communication: To enable one motor at 0x01, set zero position and disable the motor, run: python3 can_motorlib_test.py can0

Use in Scripts: Add the following import to your python script: from canmotorlib import CanMotorController after making sure this folder is available in the import path/PYTHONPATH.

Example Motor Initialization: motor = CanMotorController(can_socket='can0', motor_id=0x01, motor_type='AK80_6_V2', socket_timeout=0.5)

Available Functions:

• enable_motor()
• disable_motor()
• set_zero_position()
• send_deg_command(position_in_degrees, velocity_in_degrees, Kp, Kd, tau_ff):
• send_rad_command(position_in_radians, velocity_in_radians, Kp, Kd, tau_ff):

All functions return current position, velocity, torque in SI units except for send_deg_command.

Performance Profiler: Sends and received 1000 zero commands to measure the communication frequency with 1/2 motors. Be careful as the motor torque will be set to zero.