Constant Turning Force Adaptive Controller Design

Abstract

In the Constant Turning Force Adaptive Control system, the cutting process is nonlinear time-varying; besides, the stability cannot be assured by classical control theory since the cutting tools usually cut a workpiece at various cutting depths. In this paper, based on the small gain theorem, we propose a new method to design a PI controller with high robustness to stabilize the force feedback control system against the nonlinear time-varying gain perturbation in the cutting process. A simple design procedure will be presented and several illustrative simulation results are given. The practical experimental results of a converted lathe with the PI controller designed with this method also show a good robustness and good reliability.