Human-exo model is kinematically over-constrained

[Felix (Kurt Felix)]

Hello,
I am trying to investigate the effect of exo on human motion. But there are some issues that confused me.

1. I have run the parameters indentification and kinematic successfully. But when i ran the inverse dynamic analysis, i got an error as follows

 Model is kinematically over-constrained

The example constrain i set

  AnyKinEqSimpleDriver RightSagittaljointConnection = 
  {
    AnyKinLinear lin = 
    {
      AnyRefFrame& base = Main.HumanModel.BodyModel.Right.Leg.Seg.Thigh.HipJoint;
      AnyRefFrame& target = Main.EnvironmentModel.exo.RightThigh___1.right_sagittal_joint_connect;
      Ref = 0;
    };
    DriverPos = {0,0,0};
    DriverVel = {0,0,0};
    Reaction.Type = {On,On,On};
    CType = {Soft,Soft,Soft};

  };

I tried to reduce the constranins and made it equals to the mechanism dofs, it indeed worked successfully. But I don't know why i have to do this when i have set CType Soft.

2. Second, I got nothing information about the dofs and constranins of coupled human-exo system, when i double clicked the study. But the provided example is normal. The Anybody version is 7. 1. 2.
   
   

Thank you in advance.

Best regards,
Felix

[Bjorn (Bjørn Keller Engelund)]

Hi @Felix

The default of the study is to use the KinSolDeterminate kinematic solver. This is for determinate systems. When you want to add more constraints and utilize the soft kinematics you need to switch to use the KinSolOverDeterminate solver instead.

The reason why the study information is not present is because you have selected the Studies folder which is of instance of the AnyFolder class. Try to open that folder and find one of the AnyKinStudy or derived classes.

Best regards,
Bjørn

[Felix (Kurt Felix)]

Hi @Bjorn
Thank you for the reply.
The model worked well now .

Best regards,
Felix