A Machining Error Compensation Method Using on-Machine Profile Measurement in 3-Axis Aspheric Grinding

Abstract

The causes of machining errors are very complicated and apt to mutual influence in aspheric grinding, so it is difficult to improve machining accuracy by control one cause. To compensate the machining error of large aspheric grinding, an error-compensation technique using on-machine profile measurement system in three axes grinding machine are presented. To verify the effectiveness of the compensation machining and the reliability of the measurement system, experiments on high-precision grinding machine were performed. Moreover, the compensation machining with the on-machine measurement substantially decreases the machining errors and improve machining accuracy by more than 45%, compared with the non-compensation machining.

Discussions on on-machine measurement of aspheric lens-mold surface

“…In 2011, Huang [3] proposed a machining error compensation method using OMM system in 3-axis aspheric grinding. It aimed to providing the compensating profile data for large aspheric grinding.…”

“…That is to say, the onmachine measurement (OMM) of aspheric lens mold should be highly efficient, accurate and universal. Up to now, there are two major kinds of OMM methods: probe contacting method [3][4][5][6][7][8][9][10][11][12][14][15][16] and laser-based non-contacting method [13,[17][18][19][20][21][22][23][24][25][26][27][28][29][30]. The contacting method uses the stylus or probe to scratch the surface of lens mold to achieve the section profile.…”

On-Machine Measurement of Profile and Concentricity for Ultra-Precision Grinding of Hemispherical Shells

“…OMM of the profile of HSRs is challenging because of the blocking of the surface normal caused by the anchor stem and the large curvature and sag of the HSRs. OMM is mainly categorized as contact or non-contact optical measurement, according to the type of sensors employed [ 10 ].…”