Improving the angle measurement accuracy of circular grating.

Circular grating usually served as the angle displacement feedback element in a precision turntable, and its measurement accuracy is very important. Installation errors always exist in the measurement system, which can cause angle measurement errors. Angle measurement errors are an impediment to improve the angle positioning precision of a turntable. It is necessary to reduce the effect of installation errors. In this paper, a novel method was proposed to improve the angle measurement accuracy of circular grating, which is based on compressed sensing and sparsity decomposition. An experimental system was built to verify the effectiveness of the proposed approach. The experimental results validate that the proposed method can effectively improve the angle measurement accuracy of circular grating.