Evolutionary grinding model for nanometric control of surface roughness for aspheric optical surfaces

Abstract

A new evolutionary grinding process model has been developed for nanometric control of material removal from an aspheric surface of Zerodur substrate. The model incorporates novel control features such as i) a growing database; ii) an evolving, multi-variable regression equation; and iii) an adaptive correction factor for target surface roughness (Ra) for the next machine run. This process model demonstrated a unique evolutionary controllability of machining performance resulting in the final grinding accuracy (i.e. averaged difference between target and measured surface roughness) of -0.2+/-2.3(sigma) nm Ra over seven trial machine runs for the target surface roughness ranging from 115 nm to 64 nm Ra.

Dynamic tool influence function on SiC mirror surfaces for space optical telescopes using orthogonal velocity tool

“…[4,5] To enhancing the quality of mirror surface installed on space telescopes, precision machining technology is essential. [6,8] In this study, we report on the dynamic Tool Influence Function (TIF) patterns on SiC surfaces using the Orthogonal Velocity Tool (OVT) machine. [6,7,8] TIF is a crucial function that improves optical performance by controlling material removal and the resulting surface volume.…”

“…[6,8] In this study, we report on the dynamic Tool Influence Function (TIF) patterns on SiC surfaces using the Orthogonal Velocity Tool (OVT) machine. [6,7,8] TIF is a crucial function that improves optical performance by controlling material removal and the resulting surface volume. [7,9] We observed the depth of material removal from dynamic TIF patterns.…”

Fabrication of small aspheric moulds using single point inclined axis grinding

“…Han et al specially designed an evolutionary grinding process for the fabrication of aspheric surfaces of a glass ceramic substrate [9]. Kim et al developed a new sub-micron control algorithm in order to interpolate tool path in grinding and polishing aspheric surfaces [10].…”