Laser-error-correction control unit for machine tools

An ultraprecision machining capability is needed to meet the requirements for aspherical, optical-quality surfaces for the laser fusion program. A minicomputer-based control system was developed to transform a measuring machine into a very accurate contouring machine tool. This control system is a marriage of the "stepping-motor," open-loop, positioning system and the interferometric-feedback system. An ll indiameter aluminum disc was machined to a 10 in-radius spherical contour. A contour error of 10 pin was observed.