# Varying the acceleration and deceleration in a movel command

**URL:** <https://forum.universal-robots.com/t/varying-the-acceleration-and-deceleration-in-a-movel-command/41183>\
**Category:** URScript\
**Created:** [September 17, 2025, 6:32pm UTC](https://forum.universal-robots.com/t/varying-the-acceleration-and-deceleration-in-a-movel-command/41183 "2025-09-17T18:32:26Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![federico.venturi](https://avatars.discourse-cdn.com/v4/letter/f/e5b9ba/32.png) [@federico.venturi](https://forum.universal-robots.com/u/federico.venturi)\
**Post date:** [September 17, 2025, 6:32pm UTC](https://forum.universal-robots.com/t/varying-the-acceleration-and-deceleration-in-a-movel-command/41183/1 "2025-09-17T18:32:26Z")

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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](https://forum.universal-robots.com/t/a-way-to-tell-movel-separate-acceleration-and-deceleration/35388/2) 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!

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**Author:** ![lxop](https://avatars.discourse-cdn.com/v4/letter/l/8491ac/32.png) [@lxop](https://forum.universal-robots.com/u/lxop)\
**Post date:** [September 17, 2025, 9:51pm UTC](https://forum.universal-robots.com/t/varying-the-acceleration-and-deceleration-in-a-movel-command/41183/2 "2025-09-17T21:51:20Z")

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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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<div class="post-metadata">

**Author:** ![federico.venturi](https://avatars.discourse-cdn.com/v4/letter/f/e5b9ba/32.png) [@federico.venturi](https://forum.universal-robots.com/u/federico.venturi)\
**Post date:** [September 18, 2025, 1:48am UTC](https://forum.universal-robots.com/t/varying-the-acceleration-and-deceleration-in-a-movel-command/41183/3 "2025-09-18T01:48:18Z")

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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?

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<div class="post-metadata">

**Author:** ![lxop](https://avatars.discourse-cdn.com/v4/letter/l/8491ac/32.png) [@lxop](https://forum.universal-robots.com/u/lxop)\
**Post date:** [September 18, 2025, 2:04am UTC](https://forum.universal-robots.com/t/varying-the-acceleration-and-deceleration-in-a-movel-command/41183/4 "2025-09-18T02:04:32Z")

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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!