Application of the laser displacement sensor in the large-diameter aspheric parabolic mirror detection

摘要

The aspheric parabolic mirror is used extensively; however, its surface measuring requires high speed, high precision, and online detection. Non-contact laser displacement sensor (LDS) is the best choice especially for aspheric parabolic mirror with diameter larger than 150?mm. A quantitative error compensation model is deduced according to the principle of laser triangulation in this paper. The model is used to improve the measurement accuracy of the LDS, and then, its effectiveness is verified using a standard ball. The collected data was corrected by the error model for LDS measuring aspheric parabolic mirror with 152?mm diameter. Comparison experiment shows that the measurement data are very close to the Taylor-Hobson PGI Profiler, which proves the reliability of the method. Accordingly, the method is applied to the detection of large-diameter aspheric parabolic mirror online or in grinding process; the manufacturing quality of large-diameter aspheric parabolic mirror can be significantly improved.