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Dynamic simulation is wobbly/shaky

Posted: 12 Feb 2013, 23:02
by chris
Hello,

My simulation of a robotic manipulator is very shaky, and wobbly at the same time. What am I doing wrong? The behaviour appears with both physics engines, but still slightly different.

Thanks for any help

-Chris

Re: Dynamic simulation is wobbly/shaky

Posted: 12 Feb 2013, 23:14
by coppelia
Hi,

You very probably have mal-adjusted the inertias and/or masses of your dynamic objects.

The physics engines require that you don't have too large differences in masses or inertias in a same mechanism. For instance, having a shape with mass 1kg attached via a joint to another shape with mass 1g, will have very bad simulation results. Also, too small inertias might trouble the physics engines too. Make sure you carefully read the user manual section on dynamic simulation design, specially the design considerations 6, 7 & 8!

Remember also that a physics engine will only do approximations, and that sometimes you have to "help" the engine by cheating a little bit (e.g. by adjusting the masses or inertias appropriately).

Cheers