Issues using version 1.5.5 motion data on version 3.3

[Jin Z]

Hi,
I am studying the effects of wearing an ankle exoskeleton (a biarticular spring) on the calf muscles and would like to simulate this for multiple walking speeds. I would like to use available motion capture data from the SimTk website, such as the ones from this study by Liu et al (https://simtk.org/projects/mspeedwalksims ). However these sets of motion data were run on OpenSim 1.5.5 and don't seem to work on version 3.3 .For example when loading the .osim model, the bodies do not appear in the list of bodies and I get an error from the scaling function on the generic 3.3 version 2392 model with the GIL11 or GIL01 motion data.

I've also tried downloading the OpenSim 1.5.5 version (onto my 64-bit computer) to run these motions however I get an error when trying to open the application (for the first time after downloading is complete) saying "A java.lang.NullPointerException exception has occurred (...)".

I'd appreciate any suggestions as to what I might be missing, or if there is another set of motion data (of more than 1 gait speed for the same subject) available that I could use for my study.

Thanks a lot,

JZ
University of Ottawa

[jimmy d]

You will need to convert the models using an intermediate version of OpenSim. Load and save the models in OpenSim 2.4, then load and save in 3.3.

[Jin Z]

Hi James, thanks for your reply. I downloaded OpenSim 2.4 and tried to open the v1.5.5 osim file however after prompting me to update the version 1.5.5 model, it displayed a pop-up saying "Error updating model files.". In the messages window (copied below) it says the model was migrated to version 1.8 and copied and renamed into my folder however this new file wasn't actually written and doesn't exist in my files.

Code: Select all

Updating Model file to latest format...
Executing [migrate15to18.exe "C:\Program Files\OpenSim 3.3\Models\GIL11\GIL11\GIL11_gait2392_simbody_adjusted.osim" "C:\Program Files\OpenSim 3.3\Models\GIL11\GIL11\GIL11_gait2392_simbody_adjusted_v18.osim"]migrate15to18, version 1.9.0, build date 13:52:50 Nov 10 2009
Version migrating an object of type SimbodyEngine to latest version.
Created model GIL11 from file C:\Program Files\OpenSim 3.3\Models\GIL11\GIL11\GIL11_gait2392_simbody_adjusted.osim
Model GIL11 migrated to version 1.8 and written to file C:\Program Files\OpenSim 3.3\Models\GIL11\GIL11\GIL11_gait2392_simbody_adjusted_v18.osim

I also downloaded v1.8 to try converting the model there but wasn't able to open the application and got the same error as I did with trying to open v1.5.5 after installation:"A java.lang.NullPointerException exception has occurred (...)".