simtk.org • Calibration using motion capture data

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Calibration using motion capture data

Posted: Fri Feb 28, 2020 4:50 am

by brunompinto

Note: OpenSim 4.1

Hi,

I'm trying to use opensense to get the athlete's movement just like the example provided. However, I have a question regarding a few questions regard calibration. My idea was to use the data obtained by motion capture. Is there a file that has this already implemented? If not, is there any documentation that can help me implement the code?
My other doubt is due to the fact that I am quite new to biomechanics: how do I determine opensim sensor rotation and base heading and axis?

Best Regards

Re: Calibration using motion capture data

Posted: Mon Mar 02, 2020 11:53 am

by aymanh

Hi Bruno,

You can use marker data is compute initial pose (using standard inverse kinematics workflow). If you have the IMU data collected simultaneously then you can use the same pose to calibrate the model (place imu objects on corresponding segments of the model) and from then on only track imu data as done in the example. Typically IMU systems define a reference frame, you need to specify how that maps to OpenSim (Y-up X-forward) by a rotation. What sensor data/manufacturer do you use?

Best regards,
-Ayman