My model cannot run inverse dynamic analysis

Hey, AnyBody support,

Please find the attached zipped file of my model. Based on the MaxForceNeck model, I created the surgery equipments (light and eye glasses) in the environment file. The imported equipments were attached to the head using two prismatic joints. I used neck motion text file to move the cervical spine part.

The model can run the kinematic analysis very well. However, it cannot run the inverse dynamic analysis at all, saying " muscle recruitment solver aborted after maximum number of line-search iterations".

I tried many other ways to modify this model, like to reduce the data points or size of the text file, reduce tEnd, change the directions of gravity, or turn on/off the reaction.type… Still failed!

Could you please help me with this problem, so that I can run the inverse analysis well?




Hi Cathy

I had a quick look on the script.

Please try to add an AnyReacForce on the two prismatic joints one at the time…

It could be that the direction of the LightStrap or GlassStrap pline’s do not correspond with the direction of the free dof in the prismatic joint.

If this is the case the reactions on these lines will not be able to carry the free dof of the joints.

Best regards