Actuators for SO

[Hafizur Rahman]

Hello everyone,

I am using "MoBL-ARMSDynamicUpperLimb-latest" shoulder model. The model has total 13 'Coordinates' and 13 'Constraints'. My questions are:

i) While running for SO, do I need to add extra actuators for each 'Coordinates' and 'Constraints' or for some particular 'Coordinates' and 'Constraints'? If particulars, how do I know this? Also, how this will effect the results of SO i.e. muscle forces?

ii) What value should I choose for the 'optimal_force' for reserve actuators?

iii) For point actuators, how do I select the point i.e. 'the Location of application point'?

Thanks in advance!

[Dimitar Stanev]

i) While running for SO, do I need to add extra actuators for each 'Coordinates' and 'Constraints' or for some particular 'Coordinates' and 'Constraints'? If particulars, how do I know this? Also, how this will effect the results of SO i.e. muscle forces?

Its a good practice since the simulation may fail. You can inspect which coordinates have large residuals afterwards. In any case muscle forces are preferred to residual actuators.

ii) It depends on the model, you can start doing this iteratively. After simulation you choose the acceptable values. There is a troubleshooting in the user manual.

http://simtk-confluence.stanford.edu:80 ... d+with+CMC

iii) You don't select a point but a direction

https://simtk.org/api_docs/opensim/api_ ... e96b46764f
https://github.com/opensim-org/opensim- ... uators.xml