CN105651211A - Mirror surface out-plane displacement measurement device and method based on geometrical optics - Google Patents

Abstract

The invention discloses a measuring device and a measuring method for out-of-plane displacement of a mirror surface based on geometric optics. The present invention provides light information through a point lighting system, multiple reflections of light on two mirror surfaces, and uses an image acquisition device to obtain a digital image with mirror surface displacement information, replaces the objective mirror, and collects multiple digital images, which can be compared The change of the light point position on these digital images is analyzed, and then the out-of-plane displacement of the mirror surface is obtained. The invention provides a novel flatness monitoring device, which can complete high-precision flatness detection and has the characteristics of full-field detection, flexible and convenient use, and high detection speed.

Description

A device and method for measuring out-of-plane displacement of a mirror surface based on geometric optics

technical field

The invention belongs to the field of flatness error measurement, and in particular relates to a geometric optics-based measuring device for out-of-plane displacement of a mirror surface and a measuring method thereof.

Background technique

With the rapid development of scientific research, the demand for high-precision large-size glass workpieces is increasing, and the requirements for the measurement accuracy of workpieces and flatness errors in the manufacturing industry are also getting higher and higher, which leads to the creation of an engineering practice. The easy-to-apply out-of-plane displacement detection method for medium and large flat glass is of great significance.

At present, there are many types of glass flatness testing instruments, which can be basically divided into mechanical measurement and optical measuring instruments. Among them, optical measuring instruments are widely used and have high precision, but the current measurement method mainly adopts point-by-point scanning. Checking is time consuming. In contrast, using this device to measure the out-of-plane displacement of the mirror surface does not require point-by-point scanning. It has the characteristics of full-field detection and flexible and convenient use. It can effectively shorten the measurement time and reduce the measurement cost, which has certain practical significance.

Contents of the invention

The object of the present invention is to provide a practical and easy-to-install device for measuring out-of-plane displacement of a mirror surface based on geometric optics. The object of the present invention also includes providing a method for measuring out-of-plane displacement of a mirror surface based on geometric optics with high measurement accuracy.

A device for measuring out-of-plane displacement of a mirror surface based on geometric optics, comprising an objective mirror, a monitoring mirror, two frames, a camera, an optical platform, two pull rods, four uprights, tie rod and upright connectors, frame connectors, upright bases and a computer ;

The four columns are respectively installed on the four corners of the optical table through a column base, and the two pull rods are located on both sides above the optical table. Between the two pull rods, the two sides of the frame of the objective mirror are respectively connected to the corresponding pull rods through a frame connector, the monitoring mirror is installed between the two pull rods through the frame, and the two sides of the frame of the monitoring mirror are respectively connected to each other through a frame connector. The corresponding rods are connected, the target mirror and the monitoring mirror are center-to-center, and the surfaces are parallel to each other. The frame includes an inner frame and an outer frame. The inner frame of the monitoring mirror is equipped with a point light source arranged in a square, and the camera is installed on the monitoring mirror. On the outside, the camera lens is parallel to the mirror surface of the monitoring mirror, and the camera is connected to the computer through a data cable.

A kind of geometric optics-based measuring device for out-of-plane displacement of the mirror surface of the present invention may also include:

It also includes a camera adjusting position device, the camera adjusting position device is installed on the outer frame of the monitoring mirror, and the camera is installed on the camera adjusting position device.

A method for measuring out-of-plane displacement of a mirror surface based on geometric optics, comprising the following steps,

Step 1: The objective mirror and the monitoring mirror are placed in parallel, and the surfaces are required to be parallel to each other, and there is no twist angle between them;

Step 2: Turn on the electric light source, the light of the electric light source reflects on the two mirrors to generate a multi-level lattice, save it as an information collection point, and obtain digital images of different target mirrors. If the image does not change, there will be no out-of-plane displacement. If The out-of-plane displacement occurs when the digital image changes;

Step 3: The camera collects a digital image with information about the out-of-plane displacement of the mirror surface, and transmits it to the computer to obtain the displacement change Δy of the light point on the image, taking z as the out-of-plane displacement, and expanding it at a fixed point _y0 based on the Taylor series as:

$\mathrm{<span\; class="notranslate">\; z</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; the\; y</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; the\; y</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; the\; y</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>\frac{{\mathrm{<span\; class="notranslate">\; d</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; 2</span>}{\mathrm{<span\; class="notranslate">\; d</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; the\; y</span>}}{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; the\; y</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>\frac{{\mathrm{<span\; class="notranslate">\; d</span>}}^{\mathrm{<span\; class="notranslate">\; 3</span>}}\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; 6</span>}{\mathrm{<span\; class="notranslate">\; d</span>}}^{\mathrm{<span\; class="notranslate">\; 3</span>}}\mathrm{<span\; class="notranslate">\; the\; y</span>}}{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; the\; y</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; o</span>}{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; the\; y</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 4</span>}}$

Take the light point displacement change Δy as an unknown quantity:

$\mathrm{<span\; class="notranslate">\; z</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; the\; y</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; the\; y</span>}}\mathrm{<span\; class="notranslate">\; \&Delta;</span>}\mathrm{<span\; class="notranslate">\; the\; y</span>}<span\; class="notranslate">\; +</span>\frac{{\mathrm{<span\; class="notranslate">\; d</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; 2</span>}{\mathrm{<span\; class="notranslate">\; d</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; the\; y</span>}}{\mathrm{<span\; class="notranslate">\; \&Delta;y</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>\frac{{\mathrm{<span\; class="notranslate">\; d</span>}}^{\mathrm{<span\; class="notranslate">\; 3</span>}}\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; 6</span>}{\mathrm{<span\; class="notranslate">\; d</span>}}^{\mathrm{<span\; class="notranslate">\; 3</span>}}\mathrm{<span\; class="notranslate">\; the\; y</span>}}{\mathrm{<span\; class="notranslate">\; \&Delta;y</span>}}^{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; o\&Delta;y</span>}}^{\mathrm{<span\; class="notranslate">\; 4</span>}}$

y ₀ is a fixed point:

z=f(y)=a+bΔy+cΔy ² +dΔy ³ +οΔy ⁴

Initial condition: Δy=0, z=0, boundary condition: z=0 when y=h;

The displacement change Δy produced by the light spot corresponds to the out-of-plane displacement z.

Beneficial effect:

The invention provides a novel flatness monitoring device, which can complete higher-precision flatness detection, has the characteristics of full-field detection, flexible and convenient use, and high detection speed. The purpose of the present invention is to provide a low-cost, practical, and easy-to-install device for measuring out-of-plane displacement of a mirror surface based on geometric optics. The invention has a simple structure and is convenient for practical use. The out-of-plane displacement measurement of components is carried out by using the principle of plane geometric optics, so as to further analyze the strain or deflection of the object surface.

Description of drawings

Fig. 1 is the structural representation of patent of the present invention;

Fig. 2 is a schematic diagram of the device of the patent of the present invention;

Fig. 3 is the structural representation of target mirror and monitoring mirror inner frame;

Fig. 4 is the structural representation of target mirror and monitoring mirror outer frame;

Fig. 5 is a schematic diagram of the device for adjusting the position of the camera;

Fig. 6 is the structural representation of column base;

Fig. 7 is a structural schematic diagram of a tie rod column connector;

Fig. 8 is a schematic diagram of the connecting shaft of the frame.

detailed description

The purpose of the present invention is to provide a low-cost, practical, and easy-to-install device for measuring out-of-plane displacement of a mirror surface based on geometric optics.

The object of the present invention is achieved like this: in conjunction with Fig. 1, among the figure: 11-target mirror, 12-monitoring mirror, 13-illumination system, 14-camera, 15-computer), place a monitoring mirror in parallel with respect to target mirror 11 12. It is required that the surfaces are parallel to each other, and there is no twisting angle between them. This ensures that the light is reflected multiple times on the two mirror surfaces. Arrange the lighting system in a square. 13, ensure that at least four point light sources are installed at the corners, and the light source , the light is reflected multiple times in the two mirrors, and the camera 14 is used to shoot, and the multi-level lattice generated can be seen in the computer 15, and each level of lattice is on the corner of the same square, and these light points are used as mirrors The deformation information collection point is saved by computer to obtain digital images of different objective mirrors. If the image does not change, there will be no plane displacement. Corresponds to the out-of-plane displacement of the mirror.

A device for measuring out-of-plane displacement of a mirror surface based on geometric optics is characterized in that: white light-emitting diodes are installed around the target mirror as marking points, and machine vision is used to calculate the tiny out-of-plane displacement of the mirror surface. The frame adopts a split design, the outer frame is used to install the camera, and the inner frame is used to install the lighting source. A grinder is required to ensure that the contact position between the frame and the mirror surface is a plane, and that the direction of the lens installation out of the plane is in a state of no force, that is, no experiment The amount of error generated by the device is brought in, and the objective mirror can be easily disassembled and replaced, and the detection of a large number of glass mirrors can be completed conveniently and quickly. The multiple reflections of light on two mirror surfaces produce multi-level object images. The digital images with the out-of-plane displacement information of the mirror surfaces are collected by industrial cameras, and the multiple digital images with mirror surface shape information are compared and calculated. The same light point Multiple reflections generate a multi-level lattice. Based on the displacement of the light point, the Taylor series is used to calculate the out-of-plane displacement of the target mirror.

When the measurement device obtains the displacement change Δy of the light point on the digital image with the information of the out-of-plane displacement of the mirror surface, take z as the out-of-plane displacement, which is known to be expanded at a fixed point y ₀ based on the Taylor series, which can be written as:

$\mathrm{<span\; class="notranslate">\; z</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; the\; y</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; the\; y</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; the\; y</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>\frac{{\mathrm{<span\; class="notranslate">\; d</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; 2</span>}{\mathrm{<span\; class="notranslate">\; d</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; the\; y</span>}}{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; the\; y</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>\frac{{\mathrm{<span\; class="notranslate">\; d</span>}}^{\mathrm{<span\; class="notranslate">\; 3</span>}}\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; 6</span>}{\mathrm{<span\; class="notranslate">\; d</span>}}^{\mathrm{<span\; class="notranslate">\; 3</span>}}\mathrm{<span\; class="notranslate">\; the\; y</span>}}{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; the\; y</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; o</span>}{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; the\; y</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 4</span>}}$

At this time, the change of light spot displacement Δy is taken as an unknown quantity, and the above formula is rewritten as:

$\mathrm{<span\; class="notranslate">\; z</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; the\; y</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; the\; y</span>}}\mathrm{<span\; class="notranslate">\; \&Delta;</span>}\mathrm{<span\; class="notranslate">\; the\; y</span>}<span\; class="notranslate">\; +</span>\frac{{\mathrm{<span\; class="notranslate">\; d</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; 2</span>}{\mathrm{<span\; class="notranslate">\; d</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; the\; y</span>}}{\mathrm{<span\; class="notranslate">\; \&Delta;y</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>\frac{{\mathrm{<span\; class="notranslate">\; d</span>}}^{\mathrm{<span\; class="notranslate">\; 3</span>}}\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; 6</span>}{\mathrm{<span\; class="notranslate">\; d</span>}}^{\mathrm{<span\; class="notranslate">\; 3</span>}}\mathrm{<span\; class="notranslate">\; the\; y</span>}}{\mathrm{<span\; class="notranslate">\; \&Delta;y</span>}}^{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; o\&Delta;y</span>}}^{\mathrm{<span\; class="notranslate">\; 4</span>}}$

y ₀ is a fixed point, and the system of equations can be written as:

z=f(y)=a+bΔy+cΔy ² +dΔy ³ +οΔy ⁴

At this time, the initial condition (that is, when there is no deformation): Δy=0, z=0.

At this time, the boundary conditions (that is, no deformation of the four boundaries): z=0 when y=h.

If only one reflection of light on the objective mirror is considered, and only Δy ₁ and z ₁ are known, it can be written as z ₁ =f(y)=a+bΔy ₁ to solve b=z ₁ /Δy ₁ .

If considering the second reflection of light on the objective mirror, knowing Δy ₁ and z ₁ , Δy ₂ and z ₂ , z=f(y)=a+bΔy+cΔy ² can solve b, c.

If considering that light is reflected three times on the objective mirror, knowing Δy ₁ and z ₁ , Δy ₂ and z ₂ , Δy ₃ and z ₃ , z=f(y)=a+bΔy+cΔy ² +dΔy ³ can solve b, c and d.

It can be known from the above that the displacement change Δy generated by the light spot can correspond to obtain the extraction plane displacement z.

The object of the present invention is to provide a kind of measuring device based on geometric optics out-of-plane displacement of mirror surface, and this device is made up of target mirror, monitoring mirror, illumination system, and image acquisition equipment (comprising camera and computer). The present invention provides light information through a point lighting system, multiple reflections of light on two mirror surfaces, and uses an image acquisition device to obtain a digital image with the plane displacement information of the mirror surface, replaces the objective mirror, and collects multiple digital images, which can be compared The change of the light point position on these digital images is analyzed, and then the out-of-plane displacement of the mirror surface is obtained. The measurement method of this device is carried out in the following way: first, place a monitoring mirror parallel to the objective mirror, requiring that the surfaces are parallel to each other, and there is no twist angle between each other; then, turn on the lighting system, and the lighting system can be seen in the acquisition system The multi-level lattice generated by the reflection of light in the system on the two mirrors is saved as an information collection point to obtain digital images of different objective mirrors. If the image does not change, there will be no plane displacement. If the digital image changes, it will The out-of-plane displacement is generated; finally, by comparing and analyzing the images, the out-of-plane displacement of the mirror surface is calculated using a computer. The invention provides a novel flatness monitoring device, which can complete higher-precision flatness detection, has the characteristics of full-field detection, flexible and convenient use, and high detection speed.

Through multiple reflections of light on two mirror surfaces, a multi-level lattice is generated, and multiple digital images with mirror surface information are compared and analyzed, and the light point movement information is used as the collection point. If the image does not change, there will be no out-of-plane displacement. If there is a change in the digital image, the out-of-plane displacement occurs. By comparing and analyzing the image changes, the computer is used to calculate the out-of-plane displacement of the mirror surface.

The frame of the objective mirror and the monitoring mirror adopts a split design, in which the outer frame is used to install the camera, and the inner mirror frame is used to install the lighting source. A grinder is required to ensure that the contact position between the frame and the mirror surface is a plane, and the direction out of the plane where the lens is installed is free. In the stressed state, the objective lens can be easily disassembled and replaced.

An identification point, white light-emitting diodes are installed on the inner frame of the monitoring mirror as an identification point. There are at least four identification points arranged in a square.

Based on the displacement of the light spot in the digital image, the out-of-plane displacement of the objective mirror is calculated by Taylor series.

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments It is an embodiment of a part of the present invention, but not all embodiments.

In conjunction with Fig. 2, the present invention includes: 20-optical platform, 21-objective mirror, 22-monitoring mirror, 23-mirror inner frame, 24-mirror outer frame, 25-tie rod column connector, 26-column base, 27-camera , 28-camera adjustment position device, 29-frame connecting shaft, 210-computer. The optical table is evenly distributed with a large number of orderly bolt holes, and the base of the column is 26, as shown in Figure 6, including: 61-column connection hole, 62-screw hole for fixing the optical table, connect the device to the optical table through 4 screw holes, and connect the column Installed in the column connecting hole. Through the tie rod column connector 25, see Fig. 7, including: 71-the tie rod column connection hole, 72-fixing screw hole, the pull bar is connected with the column, and the frame of the target mirror 21 and the monitoring mirror 22 is determined to be installed at the position.

The frame consists of an inner frame and an outer frame. Inner frame 23, see Fig. 4, includes: 41 installation point light source position, 42 inner and outer frame fixing screw holes, the installation point light source position of inner frame 23 is arranged with white light-emitting diodes according to the square, at least 4 corners are arranged as marking points , as the information collection point of the experiment, the collection point should have a certain luminosity, so that the object image can still be recognized by the camera after multiple reflections. Outer frame 24, see Fig. 3, includes: 31 frame connecting shaft positions, 32 inner and outer frame fixing screw holes, frame connecting shaft positions are used for installing frame connecting shafts 29, as shown in Fig. 8, connected by frame connecting shafts 29 and tie rod columns Part 25 can connect the picture frame with the pull rod. The outer frame and the inner frame are reinforced by inner and outer frame fixing screws. During installation, ensure that the planes where the two frames of the target mirror 21 and the monitoring mirror 22 are formed are parallel, the center is opposite to the center, and there is no twisting angle between them.

The camera 27 is installed at the center of the outer frame of the monitoring mirror, and the camera and the outer frame are adjusted by the camera position device 28, as shown in Figure 5, including: 51-camera installation pillar, 52-rotary platform mounting seat, 53-rotary platform, 54-translation platform and Turntable connection seat, 55-translation stage, 56-tilt stage, 57-tilt stage and translation stage connection seat, 58-camera, 59-lens, 510-camera mounting base. The camera position adjustment device ensures that the camera lens is parallel to the mirror surface, and the camera 27 is connected to the computer 210 through a data cable to adjust the aperture and focal length, so that the computer can collect digital images with mirror deformation information.

Obtain digital images of different objective mirrors. If the image does not change, there will be no out-of-plane displacement. If the digital image changes, out-of-plane displacement will occur. Find an image in which four light spots move the same displacement in the image. The center of the image is where the out-of-plane displacement occurs. Through the method of Taylor series, the distance of the light spot change is used as the known quantity to calculate the out-of-plane displacement of the mirror surface. .

Claims (3)

1. the minute surface out-of-plane displacement measuring device based on geometric optics, is characterized in that: comprise target mirror, monitoring mirror,At the bottom of two frameworks, camera, optical table, two pull bars, four columns, pull bar column connecting piece, framework connecting piece, columnSeat and computer;

Four columns are arranged on four jiaos of optical table by a upright post base respectively, and two pull bars are positioned at optical table topBoth sides, the two ends of each pull bar are connected with a column by a railing post connector respectively, target mirror is pacified by frameworkBe contained between two pull bars, the framework both sides of target mirror connect by a framework connecting piece pull bar corresponding with it respectively, monitoringMirror is by frame installation between two pull bars, and the framework both sides of monitoring mirror are respectively by draws corresponding with it of framework connecting pieceBar connects, and target mirror is relative with center with centered by monitoring mirror, and face is parallel with face, and framework comprises inner frame and outside framework, monitoringSpot light by arranged in squares is installed on the inner frame of mirror, and camera is arranged on the outside of monitoring mirror, camera lens and monitoring mirrorMinute surface is parallel, and camera is connected with computer by data wire.

2. a kind of minute surface out-of-plane displacement measuring device based on geometric optics according to claim 1, is characterized in that:Also comprise camera adjustment location means, camera is adjusted location means and is arranged on the outside framework of monitoring mirror, and camera is arranged on camera and adjustsIn whole location means.

3. the measuring method based on the minute surface out-of-plane displacement measuring device based on geometric optics claimed in claim 1, itsBe characterised in that: comprise the following steps,

Step 1: target mirror and monitoring mirror parallel placement, require face parallel with face, there is not windup-degree between mutual;

Step 2: open electric light source, the light of electric light source produces multistage dot matrix at two mirror-reflections, sets it as information gathering pointPreserve, obtain the digital picture of different target mirror, as image does not change without out-of-plane displacement, if digital picture has changeWhen change, produce out-of-plane displacement;

Step 3: collected by camera, with the digital picture of minute surface out-of-plane displacement information, sends computer to, obtains image glazingPoint produces displacement and changes Δ y, and getting z is out-of-plane displacement, based on Taylor series at a fixing point y₀Expand into:

$z=f\left(y\right)=f\left(y_0\right)+\frac{df\left(y_0\right)}{dy}(y-y_0)+\frac{d^{2}f\left(y_0\right)}{2d^{2}y}{(y-y_0)}^2+\frac{d^{3}f\left(y_0\right)}{6d^{3}y}{(y-y_0)}^3+o{(y-y_0)}^4$

Getting spot displacement change Δ y is unknown quantity:

$z=f\left(y\right)=f\left(y_0\right)+\frac{df\left(y_0\right)}{dy}\mathrm{\&Delta;}y+\frac{d^{2}f\left(y_0\right)}{2d^{2}y}{\mathrm{\&Delta;y}}^2+\frac{d^{3}f\left(y_0\right)}{6d^{3}y}{\mathrm{\&Delta;y}}^3+{\mathrm{o\&Delta;y}}^4$

y₀For fixing point:

z＝f(y)＝a+bΔy+cΔy²+dΔy³+οΔy⁴

Primary condition: Δ y=0, z=0, boundary condition: z=0 when y=h;

Produce displacement by luminous point and change the corresponding out-of-plane displacement z that obtains of Δ y.