Static Optimization Problem

[Gabriel Britcher]

This is my first time writing to the forum, but I am not sure what else I can do. I have been working on a right arm model for a while now and have successfully ran through scaling, inverse kinematics, and inverse dynamics. My professor has asked that I work on the static optimization with the model and I cannot seem to figure it out. I do not have specified any external loads, but for an upper extremity this should not be an issue. Whenever the Static Opt is set up and ran it does nothing. The filter will run and the file will load, but at the bottom right of the window the executing analysis bar pops up and nothing happens. No error pops up, it just looks like it is loading and never stops. I believe this is due to a problem with the actuators, but I have not been able to find any help online on how to create an actuators file for an arm model. If there is an example file or help with it, it would be much appreciated. Thank you!

[Nithin Kurup]

Hi,

Pls check the sample files in arm26 model

Nithin

[Gabriel Britcher]

Thank you. Does every coordinate in the model need to be specified in this document?

[Gabriel Britcher]

Whenever I run the static optimization this comes up:

Loading coordinates from file C:\OpenSim 3.2\Models\Original Files - UpperExtremityModel\inverse_kinematics.mot.
Storage: file=C:\OpenSim 3.2\Models\Original Files - UpperExtremityModel\inverse_kinematics.mot (nr=1005 nc=95)
Found 1005 state vectors with time stamps ranging from 0 to 2.09167.
No external loads will be applied (external loads file not specified).
Executing the analyses from 0 to 2.09167...

And the program never goes any farther. What could be the problem and how could I fix it?

[Spencer Savoies]

Have you tried adding a external load file with a force vector of magnitude 0 N?
I found at least with the dynamic shoulder simulator model that the static optimization will not run without an external load file.

Spencer

[Takuya Kato]

Hi Spencer,

Will you tell me how to create the external load file with magnitude 0 N?

Thank you!

[Giorgia Ercolini]

Hi,
I have the same problem. I create a 24 dof neck model, starting from Vasavada's model, but the static optimization never succeed. I have tried to insert gravity in external force, but nothing change. Do you know how to solve this problem?