RRA model falls through floor

Provide easy-to-use, extensible software for modeling, simulating, controlling, and analyzing the neuromusculoskeletal system.
POST REPLY
User avatar
Michael Dube
Posts: 6
Joined: Tue Jun 01, 2021 12:40 pm

RRA model falls through floor

Post by Michael Dube » Tue Jun 29, 2021 9:50 am

Hello,

When running RRA the model falls through the floor. I have been inputting GRF data for the left and the right but even when cropping the GRF data to the stance phase where there is a significant y vector force the model still falls through the floor. I was wondering if anyone could help with this.

Thank you.

Tags:

User avatar
Mohammadreza Rezaie
Posts: 407
Joined: Fri Nov 24, 2017 12:48 am

Re: RRA model falls through floor

Post by Mohammadreza Rezaie » Tue Jun 29, 2021 12:12 pm

Hi,

You must have all external loads, otherwise the residual forces and moments exceed the "GOOD" and "OKAY" range and thus, the model falls. Not only the residual forces and moments, but also, joint angle errors. See "Best Practices and Troubleshooting":
https://simtk-confluence.stanford.edu/d ... d+with+RRA
During the stance phase of walking (which I assume your task is), there are first double-limb support, single limb support, and second double-limb support sub-phases. Indeed, three floor embedded force plates or an instrumented treadmill with embedded force plates are needed to contain all external loads.
To keep the kinematics errors below the recommended ranges, you can increase the weight of pelvis_ty and other coordinates in the RRA_Tasks.xml file.

Best,
Mohammadreza

POST REPLY