Harbin Institute of Technology

Jian Shi

Jiubin Tan

Yang Yu

The disclosure belongs to the technical field of precision test and measurement, and provides a two-dimensional photoelectric autocollimation method and device based on wavefront measurement and correction. According to the disclosure, a link of wavefront measurement and correction of a reference light path is added to a traditional autocollimator measuring method. By using wavefront distortion information of the reference light path in the instrument and driving a deformable mirror to compensate for phase distortion of a beam, the link realizes measurement and control on aberration of the optical system of the autocollimator and improves the imaging quality and spot positioning accuracy of the optical system, thereby improving the angle measurement accuracy of the autocollimator. At the same time, by introducing the link, the autocollimator has the ability to resist interference from the external environment, so that the resolution and stability of angle measurement of the autocollimator are further improved. The method makes the traditional autocollimator have a nano-radian order (5×10rad, that is 0.001″) angle resolution and a sub-microradian order (10rad, that is 0.02″) angle measurement accuracy. The disclosure has the technical advantage of realizing angle measurement with high resolution, high accuracy and high stability under the same conditions, and has the abilities to resist environmental disturbances and compensate for errors caused by the disturbances.

Two-dimensional photoelectric autocollimation method and device based on wavefront measurement and correction

Disclosed is a high-stability nano-radian-order angle measuring method and device based on drift value feedback, belonging to the technical field of precision measurement and the field of optical engineering. The device consists of LED light sources, convex lenses, multi-slit diaphragms, beam splitters, deflecting mirrors, steering mirrors, a collimator objective set, linear array CCDs, a four-quadrant position detector and a plane mirror. The method includes: enabling two paths of measuring light beams to carry angle change information of a measured object, respectively forming respective images on two sensors, and calculating a pitch angle and a yaw angle of the measured object relative to an optical axis by using positions of the two images so as to achieve the detection capability on the angle change of the measured object. While a focal distance of the objective is greatly improved by using the collimator objective set, the linear array CCDs are used as sensors to improve a measuring range. Therefore, the technical advantage of nano-radian-order angle limit resolution is achieved under the condition of the same measuring range. The LED light sources, the convex lenses and the multi-slit diaphragms are used, and at the same time, drift value feedback is performed by using the four-quadrant position detector and the steering mirrors, and the system stability is improved to 10 nano-radian order, thus solving the problem of limitation of light beam drift value to limit resolution of an autocollimator. Additionally, a system device designed by the present disclosure has the technical advantages of small structure size, high measurement precision and high measurement frequency response.

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Harbin, China

Jian Shi