HIGH-SPEED AND HIGH-PRECISION MOTION CONTROL WITH AN OPTIMAL HYBRID FEEDFORWARD CONTROLLER

An optimal feedforward controller which makes a hybrid usage of the sh ift (q) and delta (delta) operators is proposed for high-speed and hig h-precision digital motion control systems, Uncancellable discrete-tim e zeros arising from sampling the continuous-time plant at high rates, which make the mathematical inverse unstable, are handled in a natura l way. The controller is optimized to have good performance in both lo w and high frequency ranges, and it is able to handle uncancellable di screte-time zeros in the right half plane, The optimization problem is generalized to an H-infinity problem. Convex minimization is used to find the solution to the optimization problem, Simulation results and experiments carried out on an MC-510V Matsuura vertical machining cent er show superior performance of the proposed optimal hybrid feedforwar d controller.