whether the "effort" in "/joint_states" topic stand for the joint torques of UR?

[TianXu1991]

Summary

Introduction to the issue
Hi, fmauch.
In order to idetify the dynamic parameters of UR, I need to read the joint positions, joint velocities and joint torques of UR. I guess the "position" and "velocity" in the "sensor_msgs/JointState" stand for "joint positions" and "joint velocities" in the "/joint_states" topic, respectively. However, I'm not sure whether the meaning of "effort" stand for joint torques of UR.

Versions

• ROS Driver version: Melodic
• UR: UR10
• URCaps Software version(s): 1.0.4

Impact

What is the impact of the issue. Try to describe it well enough, in order for us to prioritise the issues.
Dynamic parameters of robot is necessary for designing the model-based observer, such as collision detection observer. In order to identify these parameters of UR, joint positions, joint velocities and joint torques of UR are needed to read.

Issue details

This part is important in order to clarify the severity of the issue.
I want to read the joint torques of UR, but I'm not sure whether the meaning of "effort" in "/joint_states" topic stand for joint torques of UR?
If the "effort" is not the joint torques, how can I get the joint torque readings from this driver? Maybe this issue can be related to #35.

Expected Behavior

What did you expect and why?
I expect to read the joint positions, joint velocities and joint torques of UR for dynamic parameter identification.

[fmauch]

Please see the discussion in #146