Super-precise measuring method based on scanning of multiple sensors

Abstract

The invention relates to a super-precise measuring method based on scanning of multiple sensors. The super-precise measuring method includes the following steps that two sets of sensors with difference intervals are constructed, a successive two-point method is adopted by the two sets of sensors to reconstruct two sets of linearity contours, and the interval between the two sets of linearity contours is determined, so that same sampling points can be found in the front set of curves and the rear set of curves; if a certain curve in one set of curves and a certain curve in the other set of curves at least share two identical sampling points, relative displacement amount and inclination amount between the two curves are calculated according to the two identical sampling points, so that the position relation between the two curves is determined; as the mutual position relations between the first set of curves and a certain curve in the second set of curves in the first set of curves are respectively determined, the mutual position relation of the first set of curves is determined and therefore, linearity contours of a detected surface are accurately reconstructed on all the sampling points. The super-precise measuring method based on scanning of multiple sensors is high in measuring precision, high in measuring speed, and capable of eliminating errors of a sensor system and linearity errors of a scanning platform.

Description

technical field [0001] The invention mainly relates to the technical field of measurement application, in particular to an ultra-precision measurement method based on multi-sensor scanning, which is mainly suitable for the straightness, flatness, ultra-precision optical surface and even optical free-form surface of the surface of precision and ultra-precision workpieces. shape measurement. Background technique [0002] Optical surface topography errors can cause beam shift, resulting in blurred imaging, enlarged focus, and reduced wavefront accuracy, affecting optical system performance. In order to process the surface shape of optical surfaces with higher precision, it is very important for the development of optical systems to perform precise measurements. Especially for many high-tech fields that require nano-level precision, ultra-precision measurement of optical surfaces is very important. For example: synchrotron (accelerated) radiation optics, extreme ultraviolet lit...

AI Technical Summary

Problems solved by technology

[0006] When using a measuring instrument with a large number of sensors and a small interval, such as a compact interferometer (TRIOPTICSμphase1000, etc.) or a 2D laser profile scanner, each pixel can be used as a displacement sensor, which is equivalent to Multi-displacement sensors are used for scanning measurement. At this time, the interval between each pixel point is quite small (to the micron level), that is, the sensor interval is quite small. If the scanning step is equal to the sensor interval at this time (at this time, it can be reconstructed by the successive two-point method) There are quite a lot of points to be collected (there are quite a few data files, and one position corresponds to one data file), and due to the small interval and low signal-to-noise ratio, it will affect the final measurement result

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