I am going to drive the MoCap lower extremity model with our C3d files with a different marker and force plate setup.
I have changed the marker, force plate and coordinate system setup as described in wiki and I could load the model so far, but the coordinate systems seems to be inconsistent as you can see in the figure. I cannot run the optimization analysis as well.
here are some more details:
we have 21 markers in lower extremity tracked by VICON system.
the markers are attached to a exoskeleton system.
2 type 2 force plate in a treadmill are used to record GRFs. there is no calibration matrix for them in the files.
I have added a sample of the c3d files in the input folder of the attachement, named “FenteCD01” and “MarcheCD1”.
I defined the center of 3 markers next to pelvis as the origin of the model to debug an error during loading, but I cannot find and change the parameters anymore
I use AMS version 6.0 and AMMR V 1.6.1
first step is to change the initial position of the subject. Change the pelvis rotations in the trialspecific file until the virtual (red) markers on the body model match roughly the recorded (blue) markers form the C3D.
I did change the initial position of the body and make some other changes but still it is not working. I think the reason is that we have only markers on the right leg and left foot. I would like to know how I can exclude the left foot from the model as you did in your recent grand challenge model.
actually I need to change the MoCap model to a one leg model. I changed the last two lines of following script in the BodyPartsSetup.any file but it was not effective (maybe because it is not included in the model).
I would be thankful if I can have your comment about my problem.
// RightLeg: 1 included, 0 not included
// ************************************
#define RIGHT_LEG 0
// This is just the bones,
// Choose one of the following options to add muscles
#define RIGHT_LEG_SIMPLE_MUSCLES 0
#define RIGHT_LEG_MUS_3E 0
// LeftLeg: 1 included, 0 not included
// ***********************************
#define LEFT_LEG 0
// This is just the bones,
// Choose one of the following options to add muscles
#define LEFT_LEG_SIMPLE_MUSCLES 0
#define LEFT_LEG_MUS_3E 0
// RightLegTD: 1 included, 0 not included
// ************************************
#define RIGHT_LEG_TD 1
// This is just the bones,
// Choose one of the following options to add muscles
#define RIGHT_LEG_TD_SIMPLE_MUSCLES 1
#define RIGHT_LEG_TD_MUS_3E 0
// LeftLegTD: 1 included, 0 not included
// ***********************************
#define LEFT_LEG_TD 0
// This is just the bones,
// Choose one of the following options to add muscles
#define LEFT_LEG_TD_SIMPLE_MUSCLES 0
#define LEFT_LEG_TD_MUS_3E 0
It seems that there are also no markers on the upper body, so please have a careful look at the end of the trialspecific file for defining extra markers.
Thanks, I made some changes to the model and it works now. your help was inspiring.
Now, the model correspond each body marker to a relevant external marker and perform the optimization on all the parameters including the positioning of the markers independently. Thus, the position of the markers change with respect to each other after the optimization procedure.
Since the markers that we use are installed on a exoskeleton device and they do not move relative to each other in different segments, is there any way to define a constraint for each group of the body markers (e.g each 3 markers) so that they move and be optimized in a way as they are fixed on a rigid segment?
Is that enough to turn off the optimization on the length of the specific segment (eg. Tibia) for that purpose? (we have the geometry from imaging data)
