I have tried to perform inverse dynamics with motion capture data and simulated external forces. I have followed the OpenSim tutorials to include external data, but I am experiencing problems with forces visualization. I detail the steps followed with screen captures:
1) In the "Inverse dynamics tool", the movement of the model is specified.
2) The file "forces_test.mot" attached includes 2 forces for test: a ground reaction force and a force applied to the femur. As seen in the image, the "femur_force_v" is applied to "femur_r" and expressed in its frame.
3) Once the ID is computed, I add a motion file to IDResults ("forces_test.mot"). The image shows that all forces are expressed in the ground frame. However, the "femur_force_v" was previously expressed in "femur_r" frame. I have tried to replace in this window the frame, but once it is changed to a different frame from the ground, the forces are not displayed.
I do not know if there could be a bug in OpenSim GUI or if I am making some mistake. Any suggestions would be great. Thank you.
1)
- kinematics especification.jpg (112.24 KiB) Viewed 194 times
2)
- external forces config.jpg (76.86 KiB) Viewed 194 times
3)
- forces in ground frame.jpg (158.45 KiB) Viewed 194 times