Measurement and algorithm for localization of aspheric lens in magnetorheological finishing

Unlike traditional machinery manufacturing generally using simple features of workpiece as the alignment reference, optical manufacturing, which prioritizes shape tolerances of the machining surface over position tolerances between workpiece geometry features, chooses the machining surface itself as the alignment reference. Thus, the manual alignment of workpiece in optical manufacturing could be very time-consuming when the machining surface is aspheric. Workpiece localization technology is able to automate the workpiece alignment and improve its efficiency. However, there are no relevant reports about application of this technology in the field of optical manufacturing. In this work, the workpiece localization problem for aspheric surface in magnetorheological finishing (MRF) is investigated from aspects of measurement and algorithm. The probe radius error is compensated by applying the polynomial fitting method. A new localization algorithm is proposed in order to improve the computational efficiency for the localization of aspheric surface. Simulation and experiment results verify the validity of the proposed methods. The accurate and efficient workpiece localization in MRF has been achieved and applied in real application which proves its practicability.