Abstract
The static and dynamic characteristics of the CNC end milling process were investigated to develop an ACC (adaptive control constraints) system for regulating spindle current. These characteristics were used to develop a new spindle current regulation algorithm composed of both adjustable proportional feedback control (adjustable P control) and fine control. For adjustable P control, a model of the entire plant was developed as a first-order system with time delay. Fine control was used to reduce the steady state error due to P control. The consequently developed spindle current regulation algorithm with a few appropriate parameters showed good global stability and applicability.