ROS2 Package for ODrive Pro/S1

This repository contains the development of a ROS2 node intended for communication with ODrive Pro/S1 devices over the CAN interface.

For information about installation, prerequisites, and getting started, checkout the official ODrive ROS CAN Package Guide.

Interface

Nodes

odrive_can_node

This node is designed to interface with the ODrive Pro/S1 series of motor controllers over the CAN bus.

• subscribes to: /control_message (ControlMessage)

• publishes:

  • /odrive_status (ODriveStatus)
  • /controller_status (ControllerStatus)

• service: /request_axis_state (AxisState)

• parameters:

  • node_id: The node_id of the device this node will attach to
  • interface: the network interface name for the can bus

Messages

ControlMessage

Exposes the minimal set of inputs to use an ODrive.

important Make sure the ODrive returns to IDLE before changing the input_mode, changing this value during CLOSED_LOOP_CONTROL is not advised.

The ODrive will interpret the values of input_pos, input_vel and input_torque depending on the control mode.

For example: In velocity control mode (2) input_pos is ignored, and input_torque is used as a feedforward term.

ODriveStatus

Provides ODrive/system level status updates. Requires setting a non-zero period for the following cyclic messages

error_msg_rate_ms

temperature_msg_rate_ms

bus_voltage_msg_rate_ms

note Each published message will wait for a new value from these endpoints. Therefore, the largest period set here will dictate the period of the ROS2 message as well.

ControllerStatus

Provides Controller level status updates. Requires setting a non-zero period for the following cyclic messages

heartbeat_msg_rate_ms

encoder_msg_rate_ms

iq_msg_rate_ms

torques_msg_rate_ms

note Each published message will wait for a new value from these endpoints. Therefore, the largest period set here will dictate the period of the ROS2 message as well.

Services

AxisState

Sets the axes requested state. This service requires regular heartbeat messages to determine the procedure result and will block until the procedure completes, with a minimum call time of 1 second.

Datatypes

All of the Message/Service fields are directly related to their corresponding CAN message. For more detailed information about each type, and how to interpet the data, please refer to the ODrive CAN protocol documentation

Using Python Enums

Python Example Node coming soon!

In the meantime, here is how you can use the odrive python package to display the enums:

from odrive_can.msgs import ControllerStatus # remember to include odrive_can as a package dependency
from odrive.enums import ProcedureResult
... # Node setup
ctrl_stat = ControllerStatus()
... # receive message data
print(ProcedureResult(ctrl_stat.procedure_result))