Problem with Articulation Controller

[pme1976]

Hello. I have a robot and its chassis looks like car chassis (Fig. 1).

Fig. 1

I have assembled the steering and I have two prismatic joint (left_servo_joint and right_servo_joint) for chassis steering. The coordinate frames of each prismatic joint are directed the same way (Fig. 2 and Fig. 3).

Fig.2

Fig.3

In the test model, I use a simple OmniGraph to set the positions of both joints equal to 0.025 (see Fig. 4).

Fig. 4

From start to start the directions of wheel rotation difference. Sometimes it looks like this (see Fig. 5).

Fig. 5

And sometimes everything works fine. At the same time, if the target positions of the joints are set not through the Articulation Controller (as I do), but with GUI (Property→Drive→Target Position), then the wheels always turn correctly (see Fig. 6).

Fig. 6

Do you have any idea why this is happened?

[arudich]

Hopefully your problem has a very easy fix. ArticulationController is applying joint targets in standard SI units radians meters etc. Setting targets through some sections of the GUI may be in degrees or stage units. So hopefully you just need to convert your units in ArticulationController.