阅读说明：本技术 一种基于迈克尔逊结构的高精度测角装置及测角方法 (High-precision angle measuring device and method based on Michelson structure ) 是由 赵怀学 周艳 田留德 刘锴 潘亮 曹昆 于 2019-09-12 设计创作，主要内容包括：本发明涉及一种基于迈克尔逊结构的高精度测角装置及测角方法,解决现有测角装置测量精度较低的问题。该测角装置包括激光光源、会聚镜、缩束镜、分光棱镜、第一准直镜、第一平面反射镜、第二准直镜、第二平面反射镜、探测器和计算机；激光光源经会聚镜整形后,通过星点板入射至缩束镜,再经分光棱镜分为两路,一路被分光棱镜反射会聚于第一准直镜焦面；另一路被分光棱镜透射至第一平面反射镜,透射光经第一平面反射镜反射后,再次经分光棱镜反射至第二准直镜,反射光通过第二准直镜后入射至第二平面反射镜,经第二平面反射镜反射后,成像于第一准直镜焦面,第一平面波和第二平面波在探测器靶面干涉,计算机及与探测器连接。(The invention relates to a high-precision angle measuring device and method based on a Michelson structure, and solves the problem that the existing angle measuring device is low in measuring precision. The angle measuring device comprises a laser light source, a converging mirror, a beam shrinking mirror, a beam splitting prism, a first collimating mirror, a first plane reflector, a second collimating mirror, a second plane reflector, a detector and a computer; after being shaped by the converging lens, the laser light source is incident to the beam-shrinking lens through the star point plate and then is divided into two paths through the beam-splitting prism, and one path is reflected by the beam-splitting prism and converged on the focal plane of the first collimating lens; the other path of the transmitted light is transmitted to a first plane reflector by a beam splitter prism, the transmitted light is reflected to a second collimating mirror by the beam splitter prism after being reflected by the first plane reflector, the reflected light is incident to the second plane reflector after passing through the second collimating mirror, and is imaged on a focal plane of the first collimating mirror after being reflected by the second plane reflector, the first plane wave and the second plane wave are interfered on a target surface of a detector, and the computer is connected with the detector.)

1. The utility model provides a high accuracy angle measuring device based on michelson structure which characterized in that: the device comprises a laser light source (1), a converging mirror (2), a beam shrinking mirror (3), a beam splitting prism (4), a first collimating mirror (5), a first plane reflecting mirror (7), a second collimating mirror (8), a second plane reflecting mirror (9), a detector (6) and a computer (10);

the laser light source (1) is shaped by the converging lens (2), then enters the beam reducing lens (3) through the star point plate, is divided into two paths by the beam splitting prism (4), one path is reflected by the beam splitting prism (4) and converged on a focal plane of the first collimating mirror (5), and is converted into a first plane wave after passing through the first collimating mirror (5); the other path of the reflected light is transmitted to a first plane reflector (7) by a beam splitter prism (4), the transmitted light is reflected by the first plane reflector (7), then reflected by the beam splitter prism (4) to a second collimating mirror (8), the reflected light is incident to a second plane reflector (9) after passing through the second collimating mirror (8), reflected by the second plane reflector (9), imaged on a focal plane of the first collimating mirror (5), converted into a second plane wave after passing through the first collimating mirror (5), the first plane wave and the second plane wave are interfered on a target surface of a detector (6), a computer (10) is connected with the detector (6), and interference fringes are processed to obtain an included angle between the optical axes of the second plane reflector (9) and the second collimating mirror (8).

2. The michelson structure-based high-precision angle measurement device according to claim 1, wherein: the detector (6) is a CCD or a CMOS.

3. An angle measurement method using the michelson structure-based high-precision angle measurement device according to claim 1 or 2, comprising the steps of:

step one, a detector collects an interference fringe image to obtain the width e of the interference fringe;

step two, calculating the distance d between the laser focal spot of the reflecting light path of the beam splitting prism and the focal spot of the transmitting light path;

d＝λ×f′×e

in the formula, e-interference fringe width, lambda-laser light source wavelength and f' -first collimating mirror focal length;

calculating an included angle theta between the normal of the second plane reflector and the optical axis of the second collimating mirror;

d＝f_col·tan(θ)

in the formula (f)_colIs the focal length of the second collimating mirror.

Technical Field

The invention relates to the field of high-precision angle measurement, in particular to a high-precision angle measurement device and method based on a Michelson structure.

Background

At present, the traditional photoelectric autocollimator has more manufacturers and models. The typical domestic test is LDA803 developed by Tianjin university and SZY-99 II model of Jiujiang 6354 of Zhonghai, the angle measurement precision is 1', the principle of the angle measurement device is basically the auto-collimation imaging principle, namely the optical auto-collimation principle is utilized, the position of a target image is judged and read, and the tangent principle of an optical system is utilized to realize small-angle measurement, but the device is influenced by pixel resolution, optical system distortion and auto-collimation imaging quality, and the high-precision test below arc second cannot be further improved or realized. Therefore, with the requirement of higher angle measurement accuracy, the existing autocollimator can not completely meet the requirement of technical development.

Disclosure of Invention

The invention aims to solve the problem of low measurement precision of the existing angle measuring device and provides a high-precision angle measuring device and method based on a Michelson structure.

The technical scheme of the invention is as follows:

a high-precision angle measuring device based on a Michelson structure comprises a laser light source, a converging mirror, a beam shrinking mirror, a beam splitting prism, a first collimating mirror, a first plane reflecting mirror, a second collimating mirror, a second plane reflecting mirror, a detector and a computer; the laser light source is shaped by the converging mirror, then enters the beam-shrinking mirror through the star point plate, is divided into two paths by the beam-splitting prism, one path is reflected by the beam-splitting prism and converged on the focal plane of the first collimating mirror, and is converted into a first plane wave after passing through the first collimating mirror; the other path of the reflected light is transmitted to the first plane reflector by the beam splitter prism, the transmitted light is reflected to the second collimating mirror by the beam splitter prism again after being reflected by the first plane reflector, the reflected light is incident to the second plane reflector after passing through the second collimating mirror, the reflected light is imaged on the focal plane of the first collimating mirror after being reflected by the second plane reflector, the reflected light is converted into second plane wave after passing through the first collimating mirror, the first plane wave and the second plane wave are interfered on the target surface of the detector, the computer is connected with the detector, and the interference fringes are processed to obtain the included angle between the second plane reflector and the optical axis of the second collimating mirror.

Further, the detector is a CCD or a CMOS.

Meanwhile, the invention also provides an angle measuring method using the high-precision angle measuring device based on the Michelson structure, which comprises the following steps:

step one, a detector collects an interference fringe image to obtain the width e of the interference fringe;

step two, calculating the distance d between the laser focal spot of the reflecting light path of the beam splitting prism and the focal spot of the transmitting light path;

d＝λ×f′×e

in the formula, e-interference fringe width, lambda-laser light source wavelength and f' -first collimating mirror focal length;

calculating an included angle theta between the normal of the second plane reflector and the optical axis of the second collimating mirror;

d＝f_col·tan(θ)

in the formula (f)_colIs the focal length of the second collimating mirror.

Compared with the prior art, the invention has the following beneficial effects:

the method is based on the principle of light interference, the width of the interference fringe is obtained by analyzing the frequency spectrum information of the interference fringe, and then the included angle between the plane reflector and the optical axis of the collimating optical system is solved by the tangent theorem of the optical system, so that the high-precision angle test is realized.

Drawings

Fig. 1 is a schematic diagram of a high-precision angle measuring device based on a michelson structure.

Reference numerals: 1-a laser light source, 2-a converging mirror, 3-a beam shrinking mirror, 4-a beam splitting prism, 5-a first collimating mirror, 6-a detector, 7-a first plane reflector, 8-a second collimating mirror, 9-a second plane reflector and 10-a computer.

Detailed Description

The invention is described in further detail below with reference to the figures and specific embodiments.

In order to realize high-precision angle measurement of the autocollimator, the invention provides a high-precision angle measurement device and method based on a Michelson structure. The device and the method adopt an interference principle, obtain the width of the interference fringe by analyzing the frequency spectrum information of the interference fringe, and solve the included angle between the plane reflector and the optical axis of the collimating optical system by the tangent theorem of the optical system, thereby realizing high-precision angle test.

As shown in fig. 1, the high-precision angle measuring device based on the michelson structure of the present invention mainly comprises a laser light source 1, a converging mirror 2, a beam-contracting mirror 3, a beam-splitting prism 4, a first collimating mirror 5, a first plane mirror 7, a second collimating mirror 8, a second plane mirror 9, a detector 6 and a computer 10. After being shaped by a converging lens 2, a laser light source 1 is incident to a beam reducing lens 3 through a star point plate, emergent light passing through the beam reducing lens 3 is incident to a beam splitting prism 4 and is divided into two paths by the beam splitting prism 4, one path is reflected by the beam splitting prism 4 and converged on a focal plane of a first collimating mirror 5, and the first path is converted into a first plane wave after passing through the first collimating mirror 5; the other path of light is transmitted through the beam splitter prism 4 and is incident to the first plane reflector 7, after being reflected by the first plane reflector 7, the light is reflected by the beam splitter prism 4 again, the reflected light is incident to the second plane reflector 9 through the second collimating mirror 8, after being reflected by the second plane reflector 9, the light is imaged on a focal plane of the first collimating mirror 5, the reflected light is converted into second plane wave through the first collimating mirror 5, the first plane wave and the second plane wave are interfered on a target surface of the detector 6, Fourier change is carried out on interference fringes through the computer 10, an interference fringe frequency spectrum and an interference fringe width are obtained, an included angle between the optical axis of the second plane reflector 9 and the optical axis of the second collimating mirror 8 is further calculated, and high-precision angle testing is achieved. Assuming that the focal length of the first collimating mirror 5 is f', the focal length of the second collimating mirror 8 is f_colAnd the included angle between the normal of the second plane reflector 9 and the optical axis of the second collimating mirror 8 is theta, and the distance d between the laser focal spot of the reflection light path and the focal spot of the transmission light path of the beam splitter prism 4 is calculated as follows:

d＝f_col·tan(θ)

further calculating the width of the interference fringe, we can obtain:

in the formula, e is the width of interference fringe, and lambda is the wavelength of the laser light source 1;

in the actual high-precision angle testing process, the formula is adopted for resolving, firstly, an interference fringe image is collected through a detector 6, and frequency spectrum analysis is carried out on the interference fringes to obtain the width of the interference fringes; calculating the distance between the laser focal spot of the reflection light path and the laser focal spot of the transmission light path of the beam splitting prism 4 again; and finally, calculating an included angle theta between the normal of the second plane reflector 9 and the optical axis of the second collimating mirror 8, and completing the measurement of the high-precision angle.

Based on the process, the invention provides an angle measuring method using the high-precision angle measuring device based on the Michelson structure, which comprises the following steps:

step one, a detector 6 collects an interference fringe image to obtain the width e of the interference fringe;

step two, calculating the distance d between the laser focal spot of the reflection light path and the laser focal spot of the transmission light path of the beam splitter prism 4;

d＝λ×f′×e

in the formula, the e-interference fringe width, the lambda-wavelength of the laser light source 1 and the f' -focal length of the first collimating mirror 5 are defined;

step three, calculating an included angle theta between the normal of the second plane reflector 9 and the optical axis of the second collimating mirror 8;

d＝f_col·tan(θ)

in the formula (f)_colIs the focal length of the second collimating mirror 8.