Ultra-Precision Robotic Sub-Aperture Polishing Of Curved Mirrors

Industrial robots have great potential for efficient and flexible polishing of large optical components, but the low positioning accuracy and control stability limits the polishing form quality. A model is established to describe the pressure distribution at the edge based on FEA analysis, and the effects of form deviation between the workpiece and the polishing pad is also investigated, thus TIFs can be calculated reliably. Polishing paths are planned to avoid sharp turning angles and fast movement, which can lead to unstable material removal. The dwell time is calculated via deconvolution with the space-variant TIFs. Experiments are conducted and the results show that the edge-roll error is significantly reduced and the polishing time is saved by 80%. Hence the robotic polisher can be comparable to the conventional polishing machines, which has a great significance for the ultra-precision optical manufacturing.