skid_drive_effort

ROS 2 node that publishes a left/right drive effort proxy for skid-steer and differential-drive robots.

The node estimates an effective drive effort signal by inverting a simple, control-oriented body dynamics model using:

• wheel angular velocities (sensor_msgs/JointState.velocity)
• yaw rate from IMU (sensor_msgs/Imu.angular_velocity.z)

The resulting signal is useful for:

• actuation saturation detection
• command feasibility checks
• controller supervision / fallback logic
• resilient control on heavy robots

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Output interface

Publishes:

/drive_effort_lr std_msgs/Float32MultiArray data[0] = left drive effort data[1] = right drive effort

Units: model-consistent effective drive effort.
This is not guaranteed to be physical motor torque (Nm) unless the backend provides real torque telemetry.

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Tested platforms

• Clearpath Jackal (ROS 2)
  • /platform/joint_states.effort is NaN
  • wheel speeds + IMU yaw rate are available
  • node provides a consistent effort proxy for supervision logic

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Usage

Build

cd ~/ros2_ws
colcon build --packages-select skid_drive_effort
source install/setup.bash

Run

ros2 launch skid_drive_effort drive_effort_proxy.launch