Problem with modified MoCapModel

Main Forum
1

Hi all

I am using AMMR v.1.6.5. I am doing inverse dynamic analysis using MoCap model. I am performing inverse dynamics on the body model of the MoCapModel by attaching ligaments, but I can not confirm the difference of the muscle Fm in the results. I just added tendon code in the MoCap_LowerBody.main.any. Could you tell me why?

2

Hi Bokku,

In the AnyBody Modeling System one needs to define a study with all relevant elements to be analysed and used for modelling. You define a ligament which is not related to any of the studies and is not taken into account.
What you need to do is to add this ligament to your actual model and study. Try wrapping your code with these pieces of code (see red):


Main.Studies.InverseDynamicStudy = {
    
    AnyViaPointLigament Lig = {
      AnyRefNode &Ori = Main.Studies.HumanModel.BodyModel.Trunk.SegmentsLumbar.L1Seg.L1L2JntNode;
      AnyRefNode &Via =Main.Studies.HumanModel.BodyModel.Trunk.SegmentsLumbar.SacrumSeg.SacrumContactNode;
      AnyRefNode &Ins =Main.Studies.HumanModel.BodyModel.Right.Leg.Seg.Thigh.KneeJoint;
        AnyLigamentModelPol &Model = .LigModel;
        AnyDrawPLine drw = {
          Thickness = 0.05;
          RGB = {1,0,0};
        };
      };
    
    AnyLigamentModelPol LigModel = {
      L0 = 0;   // Slack length
      eps1 = 0.2;  // Strain where F1 is valid
      F1 = 1000;   // Force in the ligament at strain eps1
      //a0 = 1;
    }; // LigModel
};
3

Thank you for your reply
But still it didn’t work. The error massage is

‘Muscle recruitment solver : solver aborted after maximum number of line-search iterations’

what does that mean? and How can I fix this problem?

Thank you very much :slight_smile:

4

Because your ligament definition generates a crazy force that no muscles can handle. Please specify something realistic.

Regards,
Pavel