reading force on pr2 arm joint
I have been reading the various packages that pr2 arm controls uses.
1)http://www.ros.org/wiki/pr2_mechanism_model
2)http://www.ros.org/wiki/pr2_mechanism/Tutorials/Coding%20a%20realtime%20Cartesian%20controller%20with%20KDL
3)http://ros.org/wiki/ee_cart_imped_control#
The API from the first link shows that you can get the measured force of the joint.
However, I can't find any of such members in the 2nd link(or in the KDL library). And from the 3rd link, it says that PR2 don't have force sensors on its joints.
Why do they contradict each other? Could someone clarify with me on this? Thank you in advance. :)
Also, if PR2 joints indeed cannot sense the force/torque on the joint. May I know what does "effort" mean in joint_states_listener Thanks!
EDIT: I'm running simulation on Gazebo if that makes any difference
