Real-time width control of molten pool in laser engineered net shaping based on dual-color image

This paper introduces a real time control system for laser engineered net shaping, to improve the machining accuracy of workpiece. A coaxial CCD image system with a dual wavelength narrow-band filter is built to obtain the size information of molten pool. The width of molten pool is extracted by the minimum bounding rectangle method and used as the feedback for molten pool control. The experimental results show that the dimensional accuracy of the workpiece is significantly improved, especially for curved thin-walled workpieces.