simtk.org

We are working with data created with the Vicon system and forceplate and the gait2354 model. I can create a scaled model and perform inverse kinematics. I can see the green ground reaction force vector when animating the model. However, the inverse dynamics tool always stops with the message "Tool execution failed. Check Messages window for details." The Messages window only contains the message "Creating states from motion storage" and no other details. The inverse dynamics tool finishes with no errors when I do not use external forces.

Does anyone know how I can get more information about what is causing the problem and what might be wrong with my ground forces?

Thank you -
Christine Buffinton
Dept. Mechanical Engineering
Bucknell University

Hi Christine,

What version are you using? Please try 2.1.0 Beta to see if the problem persists (recreate the external forces.xml file from the GUI and make sure column labels are unique in your grf.mot file). If that doesn't work, please report a bug and attach your model, setup and data files and we'll investigate.

Good luck,
-Ayman

Hello,

I've tried the new version and had no luck, in fact the program shuts down when I try to use the tool in the GUI to create the forces xml file. I am hesitant to say it is a bug because this is the first that we have tried to use the Inverse Dynamics so I have never had files that worked. I took a recording and reduced it down to just 10 frames to try to see the problem more clearly, but that did not help. I am sending all the files from the model along with the static pose and the scaled model (Bucknell_simbody.osim) in the hopes that perhaps someone there can find what is wrong; I know that you do not normally give this kind of support but perhaps someone will have sympathy for us and take a look since the files are so short. Since the beta release did not solve the problem, we went back to using v2.0 since the example gait2354 file are written for this version. By the way, the overall project is for development of a bipedal robot. We want to eventually study stepping for push-recovery and want to look at joint torques in a human to compare them to the robot.

Thank you!
Christine Buffinton

Christine,

The ID in 2.0 is not stable and crashes when you edit using the GUI. What I suggest to you is to report the bug, and then create all of your XML files using the GUI and save them (without running them), then close your model, reopen your model and then you can load ID setup files for your simulation and they should run w/o crashing (so long as you don't edit anything after you load them)...

Becca

Thanks Rebecca, really smart reminder.

Just load and run, no problem, thanks!