Hi all,
I'm currently testing on PR2, with the "move_arm to joint position" client, the motion's stability when stopping. In order to find the highest speed which ensure a smooth stop, I need to change arm's speed. Does anyone knows how to do that ?
Guido
Originally posted by Guido on ROS Answers with karma: 514 on 2011-04-07
Post score: 2
Hi Guido,
pr2_arm_navigation/pr2_arm_navigation_config/config/joint_limits.yaml contains the actual velocity and acceleration limits that are used. If you are using the trajectory filter (which you will be if you are using the launch files in pr2_3dnav), it will use these values to determine the maximum velocities and set appropriate times for each waypoint in the trajectory so that these limits are always obeyed.
The "Moving the arm through a Cartesian pose trajectory" tutorial does not use the trajectory filter though. It assigns the times to each waypoint individually. It computes the time between waypoints assuming a linear segment between waypoints.
The behavior of the underlying joint trajectory controller is described here: http://www.ros.org/wiki/robot_mechanism_controllers/JointSplineTrajectoryController
Hope this helps,
Originally posted by Sachin Chitta with karma: 1304 on 2011-04-08
This answer was ACCEPTED on the original site
Post score: 2
Comment by Sachin Chitta on 2011-04-13:
Probably because one of us changed it for the right and forgot to make the corresponding changes for the left :-)
Comment by Guido on 2011-04-10:
Thank you for your answer, this is what I needed to know. By the way, I don't think it is worth a new question so i post it in this comment: why does the left arm have smaller velocity and acceleration values than the right arm ?
Hi,
If you're using the pr2 arms, I think those limits should be in the joint_limits.yaml file. Not sure which of those 3 is used but you should be able to check which one is loaded in your launch file.
Cheers,
Originally posted by Ugo with karma: 1620 on 2011-04-07
This answer was NOT ACCEPTED on the original site
Post score: 1
Comment by Guido on 2011-04-07:
Thank you for your answer. These files describe the speed limits, but is the PR2 always trying to reach maximum speed ? For exemple, in the "Moving the arm through a Cartesian pose trajectory" tutorial, speed is regulated by giving a time to reach each position fo the trajectory.