Movement of Detailed Hand Model

Main Forum
1

Hi,

I am new to AnyBody and try to get the detailed hand model move…
therefore I tried to combine two models:

  1. FreePostureHandSR (included Detailed Hand Model) and
  2. FreePostureMove (include Interpolation driver for movement).

My Goal is: Making Hands move by using Detailed Hand Model and InterpolationDriver

Therefore I have done the following steps.

Step1: Added IntitalPositionValue.any and InterpolationsFunctions.any into FreePostureHandSR.Main.

Steps2: Replaced in Mannequin.any and in JointsAndDrivers.Any the old values (i.e. Position, Velocity,…) from the FreePostureHandSR-Model with the values from FreePosturesMove-Model.

Intermediate Result: Get the model move with deactivated “Detailed Hand”. “Simple Muscles” activated.


Step3: Like in step 2 I extended Finger 1-5 in Mannequin.Any according to movement of other body parts.

Step4: Added movement functions for every finger into InterPolationFunctions.Any.

Step5: Added the Initial Position values for the fingers to the Mannequin.Any.

Step6: Adapted RightHandDrivers.any and LeftHandDrivers.Any for movement with Interpolation Drivers.

Final Result: If I activate the “Detailed Hand” and perform the Kinematic Analysis I will get following Error msg:

WARNING(OBJ.MCH.KIN1) : C:/P…)/A…y/A…3/AMMR/A…n/E…s/F…R/FreePostureHandSR.Main.any : Study : Model is kinematically indeterminate : Position analysis failed : 510 independent constraints and 511 unknowns
- attemps to continue (attempt no. 1)

Now here are my questions:

  1. Is this approach to combine the Detailed Hand Model with the Free posture Model possible and valid?
  2. How can I find the missing constraint?

Attached you will find the files.

Thanks a lot in advance.

Kind regards
Stefan

2

Hi Stefan,

Your approach is correct. In the coming version of the AMMR these models will be combined and we have done exactly what you are suggesting.

I tried to load your model with the AMMR1.5, but it failed. It seems that you may have changed something in the repository (e.g. HandSeg.any - it’s safer to use the original version). When I finished fixing the model (fingers 3-4-5 on the left side were not finished) - everything loads and runs well.

Regards,
Pavel

3

Hi Stefan,

I am sorry, the problem is not gone, but there was a typo:
In RightHandDrivers please modify the first 5 drivers as follows:

  //finger1
  AnyKinEqInterPolDriver CMC1Flexion={
    AnyKinMeasureOrg &CMC1= ...HumanModel.Right.ShoulderArm.Seg.Hand.Finger1.Jnt.CMCFlexion;
        Data=pi/180*{.JntPos.Right.Finger1.CMC1Flexion};  
 T=.JntPos.Right.Finger1.CMCTime;
    Type=PiecewiseLinear;
    
    Reaction.Type={Off};
    
  };
    AnyKinEqInterPolDriver CMC1Abduction={
    AnyKinMeasureOrg &ref= ...HumanModel.Right.ShoulderArm.Seg.Hand.Finger1.Jnt.CMCAbduction;
        Data=pi/180*{.JntPos.Right.Finger1.CMC1Deviation};  
 T=.JntPos.Right.Finger1.CMCTime;
    Type=PiecewiseLinear;
    
    Reaction.Type={Off};
    
  };
   AnyKinEqInterPolDriver MCP1Flexion={
    AnyKinMeasureOrg &ref= ...HumanModel.Right.ShoulderArm.Seg.Hand.Finger1.Jnt.MCPFlexion;
        Data=pi/180*{.JntPos.Right.Finger1.MCP1Flexion};  
 T=.JntPos.Right.Finger1.MCPTime;
    Type=PiecewiseLinear;
    
    Reaction.Type={Off};
    
  };
    AnyKinEqInterPolDriver MCP1Abduction={
    AnyKinMeasureOrg &ref= ...HumanModel.Right.ShoulderArm.Seg.Hand.Finger1.Jnt.MCPAbduction;
        Data=pi/180*{.JntPos.Right.Finger1.MCP1Deviation};  
 T=.JntPos.Right.Finger1.MCPTime;
    Type=PiecewiseLinear;
    
    Reaction.Type={Off};
    
  };

If you then try to switch on Right Shoulder Rhythm - it will fail too, but it seem to work for the Left Arm only. Please make things consistent between Right and Left side.

Regards,
Pavel

4

Hi Pavel,

thanks a lot for your help. Without muscle the model works now very well!

When I activate the simple muscle model I get the following error message:

ERROR(OBJ1) : C:/P…)/A…y/A…3/AMMR/Body/A…n/Arm/Muscle.any : Flexor_Digitorum_Produndus__Digit5.SPLine : Number of allowed iterations for contact solution has been exceeded in Main.HumanModel.BodyModel.Left.ShoulderArm.Mus.Flexor_Digitorum_Produndus__Digit5.SPLine

and I get warnings for all muscles:
WARNING(OBJ.MCH.MUS2) : C:/P…)/A…y/A…3/AMMR/Body/A…n/Arm/Muscle-parameters-shoulder.any : biceps_brachii_caput_longum : Muscle without strength : The muscle has been stretched too much
…

What is the reason for the error message? I assume changes in the repository (e.g. Muscle.any) should be avoided to solve the problem?!

Thanks in advance

Best regards,

Stefan

5

Hi Stefan,

This is related to the muscle wrapping. Try increasing SPLine.StringMesh number for those muscles to increase the accuracy of the wrapping algorithm.

And just a small recommendation: these kind of questions have been answered on the forum a few times. If you try searching - you may save time on waiting for us to answer (well, this one was luckily rather quick :))

Best regards,
Pavel