Gravity Compensation for a UR10e controller with the UR ROS package

[ansaarf]

Hi everyone,

We're using the Universal Robots ROS package from Github for our project, with Gazebo simulating UR robots. Each joint has an Effort Controller following a predefined trajectory. However, gravity affects the robot arm as it nears the desired position, preventing it from reaching it fully. That's why we want to add a gravity compensation torque to the existing PID control torque for the joints.

Where in Gazebo are the PID parameters of individual joints used to calculate joint positions and velocities? Also, how can we intervene to implement Gravity Compensation in the Effort Controller?

It seems that the PID controllers in Gazebo are responsible for controlling the joint positions and velocities. At what point can the gravity compensation term be implemented? Be it in the form of a vector with 6 entries or separately.

Any insights on the implementation details in ROS/Gazebo would be greatly appreciated. Thank you!