Integration of On-machine Surface Measurement into Fast Tool Servo Machining

Fast tool servo (FTS) machining is a highly efficient approach to generate optical freeform surfaces and microstructures, where submicrometric form accuracy and nanometric surface finish are often required. The on-machine surface measurement (OMSM) is an enabling technology to improve the metrology efficiency and machining accuracy of FTS. However, the integration of the OMSM with FTS on an ultra-precision machine is a huge challenge due to the complexity of data processing and synchronization. In this paper, a dedicated controller is in-house developed with data processing algorithms for the integration. The effectiveness of the proposed method is demonstrated through the successful fabrication and measurement of a freeform lens array.