ForceTorqueBroadcaster

A virtual FTS sensor which simulates a real FTS sensor based on the actuator torque measurements.

Usage

Create an entry in your controllers.yaml and add it to your launch file infrastructure. You may activate this controller on startup
Activate the controller -> You shall now see a /<controller_name>/wrench and /<controller_name>/torques topic

Configuration example

virtual_fts:
  ros__parameters:
    joints:
      - shoulder_rotation
      - shoulder_flexion
      - elbow_flexion
      - forearm_rotation
      - wrist_flexion
      - wrist_rotation
    endeffector_frame: "flange"
    use_svd_solver: true

Interaction

Activate the controller an subscribe to the following topics:

/<controller_name>/wrench - Reading a FTS sensor would produce at the corresponding frame location
/<controller_name>/torques - Torques without the gravity component (external force impact on the arm)

Parameters

Name	Description	Default	Bounds
`joints`	List of joints used by the controller	-	May not be empty
`endeffector_frame`	Name of the end effector frame in the URDF	/flange	-
`lambda_regularization`	Regularization parameter for DLS solver approach	0.0001	-
`use_svd_solve`	Use SVD solver instead of DLS solver	false	-

Notes

The quality of the reading vastly depends on the accuracy of the torque readings and especially of the URDF
During our tests the virtual FTS readings proved to be way less drifting around compared to direct measurement approaches
The SVD solver approach has proved more stable during our tests