Modified MoCapModel - Kinematic Analysis Failure

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AnyBody 6.0 w/ AMMR V1.6.3

I’ve modified the MoCap Model to focus on the Trunk, Head, and Right Arm. I’ve modified the marker set to match my experimental marker set. I’ve added drivers for the right upper limb. When I try to run my Kinematic Analysis, there is a failure at Step 0 with the following error:

2.0.0.0.0.1) …Load-time positions have been re-established.
WARNING! NAN reached!
Unexpected error in computational kernel
Constraint no. #0 in ‘Main.Studies.HumanModel.BodyModel.Right.ShoulderArm.Mus.ArtificialRake.LinCom2Drv’ above error tolerance 0.001000, error = 0.100000.
Constraint no. #0 in ‘Main.Studies.HumanModel.BodyModel.Left.ShoulderArm.Mus.ArtificialRake.LinCom2Drv’ above error tolerance 0.001000, error = 0.100000.
ERROR(OBJ.MCH.KIN3) : X:/D…n/A…s/C…s/S…3/A…n/E…s/M…l/M…l/Kinematics.any(23) : KinematicStudyForParameterIdentification.InitialConditions : Kinematic analysis failed in time step 0

5.0.0.1) …Load-time positions have been re-established.
WARNING! NAN reached!
Unexpected error in computational kernel
Constraint no. #0 in ‘Main.Studies.HumanModel.BodyModel.Right.ShoulderArm.Mus.ArtificialRake.LinCom2Drv’ above error tolerance 0.000001, error = 0.100000.
Constraint no. #0 in ‘Main.Studies.HumanModel.BodyModel.Left.ShoulderArm.Mus.ArtificialRake.LinCom2Drv’ above error tolerance 0.000001, error = 0.100000.
ERROR(OBJ.MCH.KIN3) : X:/D…n/A…s/C…s/S…3/A…n/E…s/M…l/M…l/Kinematics.any(74) : MotionOptimization.InitialConditions : Kinematic analysis failed in time step 0

I’ve determined that this is with the ArtificialRake that wraps the Deltoid around the humeral head. I have a feeling it is an issue with the drivers because 1) regardless of changes to the marker set or initial position of the model, the error values do not change, and 2) The left upper limb is not marker driven and throws the same error.

In attempts to correct the error, I temporarily changed the Lin2ComDrv DriverPos from {-0.1} to {0}. This eliminated the two constraint errors, but the model still failed kinematic analysis at Step 0, so I changed it back.

I’ve found potential solutions on the forums, but they seem to be related to older software versions. I’ve attached my model to this post. Any assistance in overcoming this error is greatly appreciated.

Thank you,
Christopher Moore

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I guess I hadn’t attached my model, but I did now. In the mean time, I also tried to attach the LBAK and RBAK markers to the ThoraxSeg instead of the Scapula to see if that would make any difference, and it did not.

Please assist. I’m lost. Thank you.

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Hi Christopher

Sorry for the late reply. I think you post got drowned in the forum.

I just took a quick look at your model. I think you need to disable the left arms since you only have markers on the right side.

You do it in two places. “BodyPartsSetup.any” and “BodyPartsSetupKinematics.any”


// LeftArm: 1 included, 0 not included
// ***********************************
#define LEFT_ARM 0

Finally, I just spotted that the markers on hands are swapped. That can also cause some issues for the solver

Regards/
Morten

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