Handling Precision Errors in RAPID

nolanmaris

Hello

One common challenge in RAPID programming is dealing with slight precision errors in robotic movement. You set an exact target position; but the robot’s tool doesn’t always land perfectly where expected. Is it due to floating-point precision limits, TCP calibration errors / mechanical backlash? Even small deviations can cause major issues in applications like welding, pick-and-place/ assembly. Understanding the root cause is crucial for improving accuracy.

There are several ways to tackle this. Checking and refining your work object calibration; optimizing zone da ta settings, and adjusting speed/acceleration parameters can help minimize deviations.

Have you tried different motion instructions like MoveL vs. MoveJ and noticed a difference? Could using fine-point positioning instead of approximate (z0 vs. z1) help?   Sometimes, adding error correction logic using feedback sensors or external vision systems can improve accuracy significantly. checked https://new.abb.com/news/detail/96221/10-ways-that-abbs-robotstudior-software-can-help-you-optimize-your-robots-performance-MongoDB Training guide related to this and found it quite informative.

If you’ve encountered precision issues in RAPID, let’s discuss how to solve them! What adjustments have worked for you? Have you used Offs(), RelTool(), or other fine-tuning techniques?

Thank you !!

matti

Hallo,

my practical expierence is:

- there are no accuracy issues when working with teached points on a single robot.

If inaccurate, check TCP, calibration or workobject definitions

- there are accuracy issues sometimes when the robot is moved by a cinematic (Track or Gantry).

Check calibration and base-frames. It is worth to update the gear-ratio of the external drives, so measure the real distance the cinematic moves in comparison to the set value and recalculate the ratio.

There are also dynamic inaccuracies, so robot stays not on path when accelerating or deaccelerating.

Set FFW_Mode to 1 or 2 in that case.

- there are definitely inaccuracies for the internal axes when working with offline generated positions.

Even with proper workobject and tool definitions, you will not get the same accuracy as for teached positions, especially when there are configuration changes (confdata). Absolute Accuracy is the way to go then.