Box2D Forums

Hi,

Is there a way to implement a stable PD controller in Box2D in the same spirit as CCD ? To further clarify, let's say in a time step t torque T is computed to be applied on the joint. But applying this torque for the entire length of time step will cause the joint to overshoot its target position, so we need to find a time t- t_p where the joint will cross the target position and compute the correct torque for this scenario ( since in real PD controllers torque decreases continuously with distance from the target angle, although they still might overshoot but they apply much less torque when closer to target locations ). I am already running my simulations at 4K hz and I don't think I can further reduce my time step to replicate the reducing torque in continuous case. Any suggestions ?

Thanks,
darkZ