High performance ultra-precision turning of large-aspect-ratio rectangular freeform optics

摘要

Large-aspect-ratio rectangular freeform surfaces (LRFSs) are key components in optical scanning and widevision-field imaging systems. However, machining quality significantly affects the performance of LRFSs. This paper proposes a novel and effective machining approach that uses a position-optimized off-axis ultraprecision turning (UPT) strategy to eliminate traditional machining defects. The proposed method synthesizes the advantages of both ultra-precision milling and on-axis UPT to make the machining tool more flexible. The machining kinematic mechanism and optimal mounted position of the workpiece are first analyzed and experimental results presented. The results prove that the proposed method has the potential to realize the performance controllable goal in machining LRFSs with high efficiency. (C) 2018 Published by Elsevier Ltd on behalf of CIRP.