Kinetics sampling/analysis frequency

New project for OpenCap, which is a new software package to estimate 3D human movement dynamics from smartphone videos. OpenCap strongly relies on OpenSim.
POST REPLY
User avatar
Herman van Werkhoven
Posts: 6
Joined: Wed Jan 28, 2009 3:41 pm

Kinetics sampling/analysis frequency

Post by Herman van Werkhoven » Thu Feb 22, 2024 8:00 pm

Hi there,

We collected data using Opencap at 240 Hz. The MarkerData file (*.trc) shows this 240 Hz sampling rate, and so does the OpenSimData Kinematics file (*.mot). However when we then run a kinetics analysis (to estimate GRF using code created similar to example_kinetics.py) our results (in OpenSimData Dynamics) *.mot file shows a sampling frequency of 100 Hz. Is this correct - does the sampling/analysis frequency change as output of the kinetics simulation?

I would appreciate your feedback!

Regards,
Herman
Top
User avatar
Antoine Falisse
Posts: 439
Joined: Wed Jan 07, 2015 2:21 am

Re: Kinetics sampling/analysis frequency

Post by Antoine Falisse » Fri Feb 23, 2024 9:32 am

Hi Herman,

You can select the mesh density of your simulation: see here https://github.com/stanfordnmbl/opencap ... #L140-L142 and here https://github.com/stanfordnmbl/opencap ... mAD.py#L84. The finer the mesh the larger the problem and the longer it will take to solve. But it might be more accurate.

Best,
Antoine
Top
POST REPLY