i want to inverse dynamics analysis

My Nickname is 7upneo2.
Recently, I started using Anybody.
I want to InverseDynamics analysis.
But I have problems. Please help me.

I want to analyze c3d data.
So I tried writing a program with reference to arm2d.any.
However, there were two problems.

First, it causes an error in InverseDynamics.
I think the problem is that many constraints.
but, I don’t know how to reduce it.

Second, I want to cut “Axis = y” at “AnyRevoluteJoint”.
but, get an error in Kinematics.

Please help me to solve these problem.

thank you.

Hi Satoshi

I think you do NOT have enough muscles in your setup, at the moment you have only muscles in there to bend the arm.
PLease look at the Tutorial: Getting started with ANyScript: Lesson5: Definition of muscles and external forces and see what muscles are necessary…

I also made a quick sketch.

Hi aalmunajjed

Thanks for the reply.
Able to run the InverseDynamics, thanks to you.
The problem is solved by adding muscle.

But I have a question.
Existing models for the analysis of only the arms are available?
It may be simple if possible.
Please let me know if you are.

thank you.

Hi Satoshi,

There is no example of a mocap(c3d) driven arm alone. You need to use the spine in order to get the muscles for using the arm. You can start with either using the GaitFullBody or maybe better, with the WheelchairRancho example.You have to take out the markers that will not be used, change the names of the remaining markers, and insert drivers instead.

hi aalmunajjed

Thanks for quick reply.

Previously, I tried out GaitFullBody.
But my c3d data did not work because there was no force plate data and analog data.
WheelchairRancho, I hope it is successful.

Thanks for your advice.

Please tell me that I have one more question.

Shoulder joint, I changed to AnySphericalJoint from AnyRevoluteJoint.
I get an error in InverceDynamics.

ERROR(OBJ.MCH.MUS4) : C:/Users/MoCap/D…s/An…y/forum/20120127_2.any : ArmStudy.InverseDynamics : Muscle recruitment solver : maximum number of setbacks occured

I don’t know the meaning of this error.
and how to resolve.

Please help me.

Thank you.

Hi Satoshi,

I think it is the same problem again, you don’t have enough muscles in the setup.
Going form a revolute joint to a spherical leads to more DOF and more possible motions. However, you will need muscles that are capable of creating this motion.

hi aalmunajjed

Thanks for reply.
I attached the muscles in the axial direction Z.
As a result, I now can inverceDynamics!
I hope that this approach can be parsed correctly.

Thank you