Displacement Measurement Method Based on the Rotating Paraboloid Array.

Featured Application: In this study, a displacement measurement method based on the rotating paraboloid array with large range has been developed. The purposed system has potential applicability for detection of geometric errors, such as the position error and straightness error of multi-axis systems. According to the size of multi-axis systems, the number and size of rotating paraboloid in the array can be adjusted appropriately. Therefore, the presented method can be applied to a variety of occasions related to multi-axis systems. Using an optical freeform surface to realize the precision measurement of displacement has become a research focus in the present day. However, the measurement range of this method is limited by the size of the freeform surface processed. In order to overcome this difficulty, this paper presents a two-dimensional displacement measurement system with a large range, which is composed of a slope sensor and a rotating paraboloid array. The slope sensor utilizes the optical structure of an autocollimator with minor optimization, and the rotating paraboloid array expands the measurement range of the system in a discrete manner. The experimental results showed that the optimized optical system enhanced the measurement accuracy to ±0.4 μm within the range of 1500 μm and the overall measurement error was approximately ±2 μm when measured within the range of 450 mm. The developed measurement system has potential applicability for detection of errors, such as the position error and straightness error of multi-axis systems. [ABSTRACT FROM AUTHOR]