On-machine measurement and compensation machining for ultra-precision cutting of optical aspheric surface

Abstract

An in-situ measurement device combining contact probe and capacitive displacement sensor is developed. An aspherical measurement and compensation machining software is also developed. The single point diamond ultra precision cutting experiments for C3604 brass spherical and aspherical surface are carried out. The in-situ measurement and compensation machining experiments are also carried out. After compensation machining, the spherical surface form accuracy PV reaches 231.4 nm, and the aspheric surface form accuracy PV reaches 206.3 nm. Compared with the off-line measurement results, the difference between the results is 3.0 nm, 7.0 nm respectively, the measuring accuracy of the in-situ measurement system and the validity of compensation machining are verified.

Keywords

• aspheric surface
• ultra-precision machining
• on-machine measurement
• compensation machining