Inverse dynamic analysis fails due to factorization of stiffness matrix for velocity analysis

Hello everyone,

I have just posted an issue in regards to kinematic analysis. I am still on the same mission, but this time I got an error while analysing inverse dynamics. I will repeat the background information of this task for you here:
Seventeen subjects have been recorded by Xsens MVN Awinda inertial motion capture system with 17 wireless motion trackers and an update rate set to 60 Hz.
I am interested in estimating the Ground Reaction Force out of the BVH files. Here, the Xsens T-pose is in the beginning of every BVH file I am going to analyse. Thus, I was loading the inverse dynamic model, running the BVH_PreProcess and started to run the analysis. Some estimations succeeded, others resulted in errors.
While running the analysis on one subject I got a failure in factorization of stiffness matrix for velocity analysis during inverse dynamic analysis.

Please find the corresponding screenshot attached.
I am happy about any help.

Many thanks and best regards,

Hi Anja,

I think you need to start off by cropping out the t-pose (in trialspecificdata.any) before you run the BVH_PreProcess, please see similar post:

best regards,

Hi Christine,

Thanks, cropping out the t-pose solved the issue.
In trialspecificdata.any I set the StartFrame to ‘2’ so that I excluded frame 1 which contains the t-pose.


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