Universal Robots Forum

Error in get_inverse_kin, Runtime Error in URControl.log


we are receiving an error popup as a result of a get_inverse_kin function on one specific robot and one specific position, while it works properly in a simulator.
The position is not close to the robot reach limits and not close to any singularities either. It is a quite regular position and we don’t understand why we get this error.
We are able to reproduce the error in URSim when using the same physical calibration data from the robot.
In URControl.log we have discovered the following entries:

2021-03-08_11:37:17:95469 00:04:03:322 INFO - get_inverse_kin target pose: [-0.357042, 1.017627, -0.129022, -1.195682, -2.900253, 0.001485]
2021-03-08_11:37:17:95473 00:04:03:322 INFO - get_inverse_kin target pose norm: 1.086136
2021-03-08_11:37:17:95473 00:04:03:322 INFO - get_inverse_kin qnear: [0.512249, -1.096430, 2.621763, -3.590033, -1.434567, 0.651568]
2021-03-08_11:37:17:95474 00:04:03:322 INFO - get_inverse_kin qnear pose: [-0.391083, -0.474128, -0.089977, 2.236784, 2.014546, -0.783590]
2021-03-08_11:37:17:95474 00:04:03:322 INFO - get_inverse_kin qnear pose norm: 0.621159
2021-03-08_11:37:17:95475 00:04:03:322 INFO - get_inverse_kin pose/qnear dist: 1.492654
2021-03-08_11:37:17:95475 00:04:03:322 ERROR - Runtime error (3466:14): The robot cannot reach the requested pose. Script function get_inverse_kin is unable to find an inverse kinematics solution.

The last line with “Runtime error” might be relevant.
I can attach the physical calibration data on request.
Polyscope version is 5.9.4

Thanks for any comments, suggestions.


The error disappears when I change the parameters to
in get_inverse_kin().

Hi @csaba.mucsi,

Can you share the calibration file for the specific robot?

20205080096.zip (287.7 KB) attached is the calibration data of the robot where the error has been observed, thanks @Ebbe