why does kinematic singularity arises in a simscape multibody that was imported from autocad inventor and how to fix it

hello,

I imported an autocad inventor model into simscape multibody. The simscape model works when there is not input angular velocity given but I do require to include the angular velocity. I don't undertand why the model work without any input angular velocties but it gives an error on rotational 8 when I add an angular velocity. Is ther a way in whihc I can fix it?

Answer 1

[Kautuk Raj]

I was facing the same error while carrying out a similar workflow in Simscape Multibody and found out that the issue was related to changing the "Consistency Tolerance" parameter in the Solver Configuration block. More about this parameter can be gathered from the following MathWorks documentation page: https://in.mathworks.com/help/simscape/ref/solverconfiguration.html#:~:text=off%20(default)%20%7C%20on-,Consistency%20tolerance,-%E2%80%94%20State%2Dbased

If the solver tolerance is too loose, meaning the tolerance value is too large, then it is possible that the simulation may overlook small errors and extend beyond the physical limits of the model. This can lead to larger errors and ultimately trigger a constraint violation error message.

If the solver tolerance is too tight, meaning the tolerance value is too small, then it is possible the solver time step will have to be decreased to a value that is too small to meet the tolerance requirements. This can then trigger a constraint violation error message.

Setting the parameter to its default value of 1e-09 solved the issue for me, I suggest you to try the same.