How to fix the position analysis problem?

Hi, I build a model of an exoskeleton like this. It is composed of seven parts.

These seven parts are connected by revolute joints as shown in the following figure.

Besides, I connect the human and exoskeleton models with two cuffs and one harness.

However, it always failed at step -Kinematic analysis failed in time step 0 : Position analysis is not completed. Here is the model
BenchPressTest (1).zip (505.5 KB)
Could you please give me some hints? Thank you!


Hi TJ,
I am unable to load your model. Can you please confirm which version of AMMR and AMS are you using?
Best wishes,

Hi, my anybody version is . (505.5 KB)
My AMMR version is 1.6.2.

Hi Taejun,

Before I look into your model, have you had a look at our wiki page concerning connecting an exoskeleton to the human model? It could be a good idea to follow the approach listed over there and build the model in incremental steps. Could you please have a look and let me know at what step are you on right now?

Could you also briefly summarize the changes that you have done in the model, specifically the drivers that you have added? I can see about the exoskeleton joints and the connection to human from your previous post, but how about the joints and drivers between between the weight and the human? Are you able to run the bench press motion without the exoskeleton?

Best wishes,

I build the model based on the official demo ---bench press model. So it works well without exoskeletons. The change I made on the demo includes:

  1. Bring the EXO into the model
  2. Adjust r0 and Axes0 of the EXO model to match the human position
  3. I build some connection between human and exoskeleton like this


Hi @Taejun

What you have made in the image are kinematic measures - but no connections.
You need to add constraints (AnyKinEq or derived classes) that utilize these measures.
Try to complete our getting started tutorials - that will take you through the different objects and how to construct what you need. Lesson 3: Connecting Segments by Joints — AnyBody Tutorials v7.4.0

Best regards,

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