Geometrical Adaptive Controller for Tool Deflection Compensation in Helical End Milling Processes

Geometrical Adaptive Control (GAC) aims to maintain the stability of the geometrical quality of mechanical parts during production. GAC systems can effectively compensate for the machining error induced by cutter deflection during helical end milling processes. The existing GAC systems only deal with deflection compensation in machining of straight surfaces. Deflection in curved surface machining is more complicated, and the effect of surface curvature on deflection should be considered when designing the GAC compensation system. This paper intends to develop a GAC system for cutter deflection in end milling of curved geometries to account for deflection variation induced by workpiece curvature. In this paper, the influence of curved geometry on cutting forces is firstly analyzed; then, the deflection is calculated based on the cantilever beam model. The error space motion control methodology is utilized in GAC design for deflection compensation. Simulation studies are conducted on a two-axis milling system for circular surface, and the results validate the compensation strategy.