GaitLowerExtremity Initial condition errors

Main Forum
1

Hi,

I am facing some issues with Gait lower extremity initial conditions. My Mannequin and marker trajectories are facing perpendicular directions and also dont know how to deal if the data is in centimeters (scaling section???). I am only interested in optimizing movement. Thanks

regards,
Reetica

2

Hi Reetica,
in many cases the model will solve the initial conditions even if the model is not in the correct orientation. In case of trouble you can adjust the inital conditions in the TrailSpecificData.any file, set the Pevlis orientation like this:
AnyVar PelvisRotZ = -90;
AnyVar PelvisRotY = 0;
AnyVar PelvisRotX = 90;
If your data is in cm you can scale the data by setting the PointsScaleFactor, this is done in the ModelSetup.any file and is an option in the AnyInputC3d class.
Best Regards,
Sebastian

3

Hi,

I made up the suggested changes but it failed again with an erroras

ERROR(OBJ.MCH.KIN3) : D:/A…Y/A…2/A…n/R…y/GaitLowerExtremity.main.any : MotionOptimization.Kinematics : Kinematic analysis failed in time step 104

I would be happy if you can tell me what is wrong with it now. Thanks

Regards,
Reetica

4

Hi Reetica,

Please have a look at the following post:
http://forum.anyscript.org/showthread.php?t=2569

It deals with similar problems (right and left ASI markers fused together, foot markers misplaced, etc…).
In addition you can consider prescaling the model before the optimization.

Best regards, Sylvain.

5

Hi Dr. Sylvain,

You had said “It deals with similar problems (right and left ASI markers fused together, foot markers misplaced, etc…).
In addition you can consider prescaling the model before the optimization.”

What I understood was some problems were in c3d produced by XSENS MVN SOFTWARE.

  1. I did not understand how to prescale the model??? Kindly explain

  2. setting up srel properties is a headache, please explain how you do it???

  3. I tried with some camera marker system but new errors originated now could you kindly explain in detail.

onstraint no. #0 in ‘Main.Studies.KinematicStudyForParameterIdentification.HumanModel.BodyModel.Left.Leg.Jnt.PatellaMovement’ above error tolerance 0.000001, error = 0.001365.
Constraint no. #0 in ‘Main.Studies.KinematicStudyForParameterIdentification.ModelEnvironmentConnection.Drivers.SCDriverLeft’ above error tolerance 0.000001, error = 0.209293.
Constraint no. #0 in ‘Main.Studies.KinematicStudyForParameterIdentification.ModelEnvironmentConnection.Drivers.SCDriverRight’ above error tolerance 0.000001, error = 0.209293.
ERROR(OBJ.MCH.KIN3) : D:/A…Y/C…d/A…2/A…2/A…n/L…y/GaitFullBody.main.any : MotionOptimization.InitialConditions : Kinematic analysis failed in time step 0

Please find the model attached.