Robert

> A "large" Kp will not only produce high acceleration but also will

> overshoot (and over-correct). The longer the delay in reaching a stable

> speed after an applied correction, the worse the overshoot.

I really don't see that.

dP/dt (i.e. velocity) is self-perpetuating - hence momentum. Momentum gives

rise to overshoot in a P controller.

dV/dt (i.e. acceleration) is not self-perpetuating. There is no equivalent

of momentum for acceleration. Hence velocity cannot overshoot in a P

controller. (Assuming all the caveats in my last post about instant power

control and no sensor lag.)

Peter