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How to control a joint with position and velocity using ros_control ?

asked 2017-05-17 06:27:00 -0600

msabur gravatar image

updated 2017-05-17 12:32:28 -0600

Right now I have postion controllers for all of my joints. I can set every joint to the position I want and It takes the velocity limit into account. But I can't get it to move slower then the limit. Im trying to move my robot to a position with a certain speed (less then limit). I tried something with safely limits and the combination of position and velocity controllers. I have also tried the trajectory controller but since I don't want to set a completion time, it didn't come to use to me.

My guess is that the solution should be fairly simple but cant see it atm... Any help is welcome! Thanks! Btw I need to do this without MoveIt unfortunately and I'm using latest ROS Kinetic.

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answered 2017-05-17 14:40:06 -0600

Dave Coleman gravatar image

If you are using a position controller, it will move to the commanded position as fast as possible (max velocity). If you want it to move slower than that, you can 1) set the velocity limit to be lower, 2) send incremental position commands that will ensure it arrives at the speed you want, or 3) use the velocity controller instead.

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Thank you so much!

msabur gravatar image msabur  ( 2017-05-17 14:42:41 -0600 )edit

Is it possible to have both position and velocity controller for the same joint? The velocity controller to move the joint at a specific speed and the position controller to hold the the joint's position once a desired position is reached and velocity controller is turned off.

thejose gravatar image thejose  ( 2020-08-04 08:46:18 -0600 )edit

Any update on this ? to have both position and velocity controller for the same joint?

amjack gravatar image amjack  ( 2020-12-02 12:56:20 -0600 )edit

I would also like to know if it is possible to use a position and velocity controller for the same joint.

SimonJ gravatar image SimonJ  ( 2022-04-18 04:37:20 -0600 )edit

It is difficult for the velocity controller to maintain the zero setpoint. Do you know if there is a good strategy to overcome this limitation?

CroCo gravatar image CroCo  ( 2022-05-25 01:09:48 -0600 )edit

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Asked: 2017-05-17 06:18:54 -0600

Seen: 1,872 times

Last updated: May 17 '17