IMU Placer tool (APDM)

[Ali Forouzanfar]

Hi everyone,

I'm new to using OpenSense, and I'm currently working with gait data captured using APDM sensors. I'm encountering some difficulties in understanding how to properly utilize the IMU Placer tool within OpenSim.

Specifically, I'm struggling with the following:

How do I determine the appropriate settings for sensor heading correction and sensor rotation for APDM sensors within the IMU Placer tool?

I'm unsure about the best approach to configure these settings for accurate marker placement based on my APDM data.

I have loaded the OpenSim example related to IMU data without rotation. However, when I visualize the IMU coordinate frame, I observe the following:

without rotation

IMU.jpg (577.37 KiB) Viewed 399 times

Heading (Z-axis) is pointing in a different direction than expected.
Rotation around the X-axis is -90 degrees, which also doesn't align with my expectations.
As a result, the IMU coordinate frame doesn't overlap with the expected orientation in the figure below.

-90 rotation X

IMU_2.jpeg (509.93 KiB) Viewed 399 times

Any guidance or resources that could assist a beginner in comprehending these concepts would be incredibly helpful.

Thank you in advance for your time and expertise!

[C.J. Kennett]

We have the same issue and are trying to resolve it ourselves. If no replies are posted in a couple weeks, maybe we can try to collaborate on a solution.

Thanks,
C.J.

[Ge Cos]

Hi,

I have the seem problem, I used Movesense to collect the data, but it seems the coordination of my IMU9 sensor doesn't correspond that of the OpenSim, I have tried to set the initial .sto file to keep the rotation as x:-90, y:0,z:90. But seems not right. If you have solved this problem, please contact me.