Implementing Data

[Orkun Özkurtul]

Hello,

I`m new in using OpenSim. Since a while I`m trying to find out how to get vicon motion data into opensim. What I have are .mot-files exported by the vicon own software nexus. i tried to load them, but get the message `could not associate motion to current model`. I thought the problem could be that I don`t have the marker positions in a trc file. I have c3d-files from the same data. I tried to convert them into mot and trc files with the GaitExtractToolbox, but wasn`t successful. don`t know why. Get a message that it can`t find the marker. What i found in the forum is a vicon plugingait-model for opensim. Tried to load the model and my motion data. Didn`t work. Do I have to scale it like described in chapter 14? I`m thankful for any kind of help.

Regards
Orkun

[Ruoli Wang]

Hi Orkun,

I am also a Vicon user, but still with workstation. If nexus has similar function, it could export c3d as trc and grf.mot. In workstation, they are in the pipeline-export data as ASCII file (advance), where you can choose the option to save as .trc or ground-reaction force.mot. Just one thing, if you have different frequencies in camera collecting and force plate, you have to sync yourself.

Hope it helps,

Ruoli

[Orkun Özkurtul]

Hello,
I'm not sure what to do, but for any purpose I can't drive an ID simulation. To scale Tim Dorn’s Full-Body-PiG-Model I modified the markerset so that it matched with my data. It wasn't possible to add markers from the extracted c3d files. So I placed the markers manually on the model, saved it, opened the model with notepad++ and extracted the markerset, saved these markerset in an xml file, reconfigured the scale factors manually (which fit to my markerset) and then I retried to scale. After that I tried to implement the motion data (IK). It worked. When I try to build the ID model OpenSim give an error message: “Tool execution failed…”
Message:
Creating states from motion storage

Loading external loads kinematics from file C:\Applications \Frank 01 R_MarkerGUT\Frank modified_coordinates.mot ...
Storage: file=C:\Applications \Frank 01 R_MarkerGUT\Frank modified_coordinates.mot (nr=137 nc=56)
Model::formCompleteStorages(): WARNING- Did not find column pro_sup_l in storage object.
Model::formCompleteStorages(): WARNING- Did not find column wrist_flex_l in storage object.
Model::formCompleteStorages(): WARNING- Did not find column wrist_dev_l in storage object.
Model::formCompleteStorages(): WARNING- Did not find column scapula_weld_r in storage object.
Model::formCompleteStorages(): WARNING- Did not find column clavicle_weld_r in storage object.
Model::formCompleteStorages(): WARNING- Did not find column scapula_weld_l in storage object.
Model::formCompleteStorages(): WARNING- Did not find column clavicle_weld_l in storage object.
Low-pass filtering external load kinematics with a cutoff frequency of 6...

Exception:
Storage: ERROR- failed to open file Frank modified_kinetics.mot


What is my mistake?

Thanks a lot in advance.

Best regards,
Orkun

[Ayman Habib]

Hi Orkun,

This could be related to having spaces in the file names. There's an outstanding bug related to that. Can you try with paths that do not contain spaces and let us know how it goes?

Thanks,
-Ayman

[Orkun Özkurtul]

Hello Ayman,

thank you for your help. Unfortunately it is still not working. I got the same messages. I tried to change the markerset, I reconfigured the ik dataset, I tried to intergrate the datas into the example gait2354 model and configuration, but nothing worked. Is it possible that ID doesn't work if you only have grf of one side?

Best regards,
orkun

[Ayman Habib]

Hi Orkun,

ID by itself doesn't require grf, it's just that the results you get will not be physically meaningful if grf (or any other forces that affect the motion) are not accounted for.

Please feel free to report a bug and attach all model/setup/data files to it and I will investigate. By the way, did you try previewing the motion data to see how the marker trajectories and grf line up?

Best,
-Ayman

[Orkun Özkurtul]

Hi Ayman, yes i tried previewing. Everything seems to be all right.