Some Axes0 values for AnySeg may not work

Main Forum
1

Hi,

I modeled the two-link assembly in SolidWorks CAD system and tried to its AnyBody version model.

I attached its SolidWorks capture file and its AnyBody capture file.

Also I attached the zip compressed file for the AnyBody project.

But I could not reproduce the AnyBody model that has the same initial kinematic configuration of the SolidWorks CAD assembly.

I could find the reason that Axes0 values for ‘RTIB_1’ AnySeg in my example may not work. Its values are as follows:

Axes0={ {-1, 0, 0}, {0, 0, 1}, {0, 1, 0} };

Even if I commented out this line, it does not effect on the result.

I’d like to ask of you whether there are some special values for ‘Axes0’ that I should avoid to use.

Best regards,
Moonki

2

Hi Moonki,

I am not sure i understand the question.

I have tried to add these joints to the model



  AnyStdJoint fix={
  AnyFixedRefFrame &ref2=Main.EnvironmentModel.GlobalRef;
   AnyRefFrame &RefNode0=..Segs.RTHI_1.Joint0_RTHI_1_RefNode;
 };
   AnyKinEqSimpleDriver drv={
    AnyRevoluteJoint &ref1=.Joint0;
DriverPos={pi};
DriverVel={0};   
   };

and then it runs, but complains about gimbal lock …

Please if you can add more details on what is the issue.

Best regards

3

Hi Søren,

The intention of my question is that the initial position and orientation of AnySeg are determined by its ‘r0’ and ‘Axes0’ properties.

Besides drivers and constraints, I should think that the initial position and orientation of all AnySeg objects should represent their ‘r0’ and ‘Axes0’ values.

As I told in my first post, some Axes0 values like this may not work properly:
“Axes0={ {-1, 0, 0}, {0, 0, 1}, {0, 1, 0} };”

This means that initially the local x-axis of this AnySeg should be represented as (-1, 0, 0) with respect to the global coordinate system. And the local y-axis should be (0,0,1) and the local z-axis should be (0, 1, 0). But this may not work.

Thanks for your reply and I hope to get your additional help. :slight_smile:

Best regards,
Moonki

4

Hi Moonki,

Thanks for the extra explanation, this looks like a bug.
We will try to debug it and find the explanation.

Thanks for making us aware of it.

Best regards
Søren

5