I am working on a Simscape 3D model of a 2-wheels robot moving inside a rolling pipe:
Pipe is rotating along its own central axis (z);
Robot is also moving around (not along) pipe central axis (z);
Therefore, both robot and pipe are rotating along axis z;
The model is built using multibody and contact block
The contact forces between robot wheels and pipe are modeled using contact block (Sphere to Tube Contact Force (3D));
1_ The problem is that the robot is supposed to be moving only in the plain perpendicular to z axis so the velocity along z axis is supposed to be zero
However, there is some velocity along axis z(vAxis); The values are low but with high-frequency fluctuations. Since friction force is a function of relative velocities, it is also suffering from same fluctuations
2_ Penetration velocity (vrad) is also considered and it has low values but with high-frequency fluctuations. Normal force is defined as a function of pentation velocity and so it is also suffering from same fluctuations.
Has anyone had similar experince?
Any explanation or suggestions in this regard would be highly appreciated.