Abstract
Although the Constant Turning Force Adaptive Control (CTF AC) system has been developed for many years, the control stability during cutting a workpiece at varied cutting depth is still a reliability problem. In this paper, we propose a new variable structure system (VSS) approach to adjust controller gain according to the sliding mode with high robustness in order to stabilize the CTF AC system against the nonlinear time-varying gain perturbation in the cutting process. A simple control algorithm of the VSS controller will be presented and several illustrative simulation results given. According to the practical experimental results of a converted lathe with the CTF AC system, this VSS controller is capable of good performance and good reliability. © 1988.