Varying the acceleration and deceleration in a movel command

Technical Questions URScript
1

Hello,

We have a UR3e and we have a specific movement that requires linear motion of the TCP, up and down, between two waypoints using the movel command. However, I would like to change the acceleration/deceleration in a way that is independent from one another. For the up motion, I want to accelerate slowly, but decelerate quickly. I would like to do the opposite for the downward motion. As far as I can tell, I cannot find a way for a change of the acceleration in the speed curve to not affect the deceleration.

So far, I have found this thread that discusses a workaround using the blend radius parameter in movel, but I wasn’t sure if there would be any issues with a straight line motion with this parameter involved, or if there was a better way to accomplish this. Otherwise, I have not found any more information. Thank you in advance for any help you can provide!

2

Using a blend radius for two collinear movements will not cause any issues with the straight line motion. You can also just try it to see for yourself.

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3

I didn’t have a good way to measure any deviation from a straight line, at least not immediately. Thank you for clearing that up though. So that option is the best way to implement this variation in acceleration/decelaration?

4

You can run a little RTDE-monitoring script to record the robot positions while it performs the movements, then plot the position to check for deviations.

This is the best/only way that I’m aware of, but I could be wrong!

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