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hand and finger model

Posted: Wed May 13, 2020 2:37 pm
by kernalnet
Hi,

I was looking for a hand model with full DOF fingers and I found this model:
https://simtk.org/projects/moving-fingers

This is exactly what I was looking for but there are two limitations:
1) The muscles are Schutte1993. Are these muscles still practical?
2) There are no CMC_tasks/actuators/constraints files. I adjusted these files and built an ik.mot manually to check the CMC files (attached files), but CMC freezes at the beginning (with no error).
Modify_wrist_model.zip
(20.96 KiB) Downloaded 9 times
I would be greatly grateful if anybody would tell me where the problem is.

Regards

Re: hand and finger model

Posted: Tue May 19, 2020 4:45 am
by kernalnet
Dear Experts,

In the continuation of my previous post, I modified the CMC files and now it works, but the problem is the model disappeared in the first seconds of CMC (the right image).
17069.Image 295x395, Color.png
17069.Image 295x395, Color.png (19.25 KiB) Viewed 215 times
I wonder if anyone would tell me about the possibilities of disappearing the model during CMC.
The mass, center of mass, and inertia of each body in the model were set to zero. Can it be the source of this happening?

Any help would be greatly appreciated.

Regards

Re: hand and finger model

Posted: Wed May 20, 2020 3:42 pm
by tkuchida
The mass, center of mass, and inertia of each body in the model were set to zero. Can it be the source of this happening?
Yes: you cannot run a dynamic simulation with masses set to zero since any applied force will result in an infinite acceleration (F = ma).

Re: hand and finger model

Posted: Wed May 20, 2020 3:49 pm
by kernalnet
Dear Tom,

Thanks a lot for your help and I appreciate it.

Regards