CN201522266U - A computer binocular vision denture scanning device - Google Patents

Abstract

The utility model relates to a computer binocular vision denture scanning device, a line structured light vision collection part, a rotating measuring table and its control part and a box body, wherein: the line structured light vision collection part includes two high-resolution digital CCD cameras , a line-structured light laser, and two high-resolution digital CCD cameras are located above the center side of the rotating measuring table and its control part, symmetrically distributed with the line-structured light laser as the center; the rotating measuring table and its controlling part include the rotating measuring table and its The driving mechanism and the 1st and 2nd accessories, the 1st and 2nd accessories are set on the rotating measuring platform, the 1st accessory is a platform for placing and clamping the denture dental model, the 2nd accessory is provided with marking points, and the rotating measuring platform is driven by The mechanism rotates; the above structure is installed in the box. The mechanical structure and control method of the utility model do not require variable speed control, and have no precision requirements for the rotation of the main shaft of the motor, are easy to operate, and have high scanning precision.

Description

A computer binocular vision denture scanning device

technical field

The utility model relates to a denture scanning technology in the technical field of measurement and testing, in particular to a denture scanning device with computer binocular vision.

Background technique

The development of computer vision technology provides strong technical support for the application of non-contact 3D measurement technology in reverse engineering, industrial inspection and quality control. At the same time, the increasingly wide application in these fields also promotes the development of visual 3D measurement technology. . Such as structured light measuring instrument, triangulation method using line laser or spectral laser. Computer vision measurement technology has been widely used in denture scanning equipment due to its convenience, speed and accuracy. At present, denture scanning equipment using non-contact computer vision three-dimensional measurement technology mainly adopts two methods. One is to project a surface grating onto the surface of the denture when measuring the denture, and a CCD camera captures the image to extract three-dimensional points on the denture surface. The data is sampled, neither the denture nor the camera moves during the measurement, and this method requires complex raster projection setups. Another method is to project linear structured light onto the surface of the denture, and then take an image with a CCD camera to extract the three-dimensional sampling points of the light strip on the surface of the denture. Three-dimensional point sampling point data, a CCD camera takes an image every time it rotates at a certain angle, and all the data are fused together through the rotation angle precisely controlled by the computer. The cost is also high.

Utility model content

Aiming at the shortcomings of current denture scanning equipment with complex structure and high price, the technical problem to be solved by this utility model is to provide a computer binocular vision denture scanning device and its three-dimensional rebuild method.

In order to solve the problems of the technologies described above, the technical solution adopted in the utility model is:

The utility model computer binocular vision denture scanning device comprises: a linear structured light vision acquisition part, a rotating measuring table and its control part and a box body, wherein:

The line-structured light vision acquisition part includes 2 high-resolution digital CCD cameras and a line-structured light laser. The 2 high-resolution digital CCD cameras are located above the center side of the rotating measuring table and its control part, symmetrical to the line-structured light laser. distributed;

The rotating measuring table and its control part include the rotating measuring table and its driving mechanism and the first and second accessories. The first and second accessories are set on the rotating measuring table. The first accessory is a platform for placing and clamping the denture model , the second accessory is installed on the rotating measuring platform through fasteners, the second accessory is provided with marking points, and the rotating measuring platform is rotated by the driving mechanism; the above-mentioned structure is installed in the box; the data output end of the above-mentioned CCD camera and lens, The control terminal of the line laser and the control terminal of the rotating measuring table and its control part are connected with an external control computer.

The utility model also has a lighting part, which is installed on the top of the box body, and its control end is connected with an external control computer; the driving mechanism is an AC frequency conversion speed regulating motor; the box body is divided into two layers, and the upper layer accommodates the visual collection of line structured light Part, the lower layer accommodates the rotating measuring table and its control part, the 1st and 2nd accessories and the rotating measuring table and its control part are separated by a partition, and there is a door on the front of the box; the door corresponds to the 1st, 2nd accessories and the space of the rotating measuring table The location is closed glass.

The three-dimensional reconstruction method adopted by the computer binocular vision denture scanning device of the present invention comprises the following steps:

Clamp the denture through the second attachment and place it within the effective shooting range of the CCD camera on the rotating measuring platform;

The line-structured light laser projects laser light to the denture, forming a curved light strip on the denture surface;

Start the driving mechanism to drive the rotating measuring table to rotate continuously;

Two CCD cameras capture images, and the image data is transmitted to an external control computer for processing through an image interface card to obtain three-dimensional point data of the entire denture surface.

Image processing by an external control computer includes the following steps

Extract the center of the mark point and the center line of the light bar from all the received images of the rotating measuring table for one revolution;

Using the binocular stereo vision method to calculate the three-dimensional coordinates of the center point of each frame image marker point and the center line of the light strip, and obtain the three-dimensional data point set of the light strip on the surface of the denture;

Use the feature vector of the three-dimensional coordinates of the center point of the marker point to obtain the corresponding relationship between the marker points, calculate the transformation matrix between the coordinate systems formed by each frame of image according to the above corresponding relationship, and transform the light bars under each coordinate system on the denture through the transformation matrix The three-dimensional data of the surface are fused in a coordinate system to obtain the three-dimensional sampling data of the complete surface of the denture.

The extraction of the center line of the light bar includes:

Use a median filter to eliminate isolated noise points in the images for all captured images;

Use the Otsu threshold method to obtain the threshold value of the binarization of the entire image, and perform binarization processing on the image;

The binarized image is thinned, and the improved OPTA thinning algorithm is used to construct 5-8 elimination templates and 4-6 retention templates to thin the light strips;

Thin the skeleton of the light strip obtained by pruning to obtain a rough line structure light strip skeleton;

Taking the thinned light strip skeleton as the center line, take n points on the light strip along the normal direction of each point on the skeleton to form a pixel point set;

Use the coordinates and gray values of the pixel point set to fit the quadratic curve equation; traverse other points on the skeleton in turn to find the sub-pixel center point of the entire light strip.

The calculation of the three-dimensional coordinates (X _W , Y _W , Z _W ) of the center of each frame image mark point and the center line of the light bar is realized by the following formula:

$\left\{\begin{array}{c}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 31</span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="11"\; label="m"\; filenames="H2009202479975E00011.png,H2009202479975E00012.png"\; state="\{\{state\}\}">m</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 11</span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; W</span>}}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 32</span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="12"\; label="m"\; filenames="H2009202479975E00011.png,H2009202479975E00012.png"\; state="\{\{state\}\}">m</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 12</span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; Y</span>}}_{\mathrm{<span\; class="notranslate">\; W</span>}}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 33</span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 13</span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; Z</span>}}_{\mathrm{<span\; class="notranslate">\; W</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 14</span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 34</span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}\\ <span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; v</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 31</span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; twenty\; one</span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; W</span>}}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; v</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 32</span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; twenty\; two</span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; Y</span>}}_{\mathrm{<span\; class="notranslate">\; W</span>}}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; v</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 33</span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; twenty\; three</span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; Z</span>}}_{\mathrm{<span\; class="notranslate">\; W</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; Z</span>}}_{\mathrm{<span\; class="notranslate">\; W</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; twenty\; four</span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; v</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 34</span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}\end{array}\right.<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>$

$\left\{\begin{array}{c}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 31</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="11"\; label="m"\; filenames="H2009202479975E00011.png,H2009202479975E00012.png"\; state="\{\{state\}\}">m</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 11</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; W</span>}}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 32</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="12"\; label="m"\; filenames="H2009202479975E00011.png,H2009202479975E00012.png"\; state="\{\{state\}\}">m</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 12</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; Y</span>}}_{\mathrm{<span\; class="notranslate">\; W</span>}}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 33</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 13</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; Z</span>}}_{\mathrm{<span\; class="notranslate">\; W</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 14</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 34</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}\\ <span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; v</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 31</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; twenty\; one</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; W</span>}}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; v</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 32</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; twenty\; two</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; Y</span>}}_{\mathrm{<span\; class="notranslate">\; W</span>}}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; v</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 33</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; twenty\; three</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; Z</span>}}_{\mathrm{<span\; class="notranslate">\; W</span>}}{<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; twenty\; four</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; v</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 34</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}\end{array}\right.<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span>$

Where (u ₁ , v ₁ ) and (u ₂ , v ₂ ) are the coordinates of points p ₁ and p ₂ in their respective images; m _ij ^k (k=1, 2; i≤3, j≤4) respectively is the i-th row and j-th column element of the 3×4 projection matrix M _k of the camera; M _k can be obtained from the calibration of the camera.

Obtaining the corresponding relationship between the marker points by using the feature vector of the three-dimensional coordinates of the center of the marker points includes:

Use the three-dimensional coordinates of the center of the mark point to calculate the vector between the center of each mark point and the center of other mark points in each coordinate system, and calculate the feature vector formed by the vector product of each mark point;

The feature vectors of each marker point in each coordinate system are compared to obtain the corresponding relationship between marker points in each coordinate system.

The beneficial effects of the utility model are:

1. The mechanical structure and control method of the utility model are simple. The rotating measuring platform is only directly driven by a low-power frequency conversion speed regulating motor, and only needs to control the start and stop of the motor without variable speed control, and the main shaft of the motor There is no precision requirement for rotation.

2. The utility model is simple to use and easy to operate. Just put the denture to be tested into the scanner, click to start the measurement, and the measurement of a denture can be completed in less than 1 minute.

3. The utility model has high scanning precision for dentures, and the positional precision of three-dimensional points can reach 0.02mm.

Description of drawings

Fig. 1 is a front view of the structure of the utility model;

Fig. 2 is the top view of Fig. 1;

Fig. 3 is the structural representation of the first and second accessories in the utility model;

Fig. 4 is the utility model control principle schematic diagram;

Fig. 5 is the electrical control schematic diagram of the utility model rotary measuring platform;

Fig. 6 is the control method flowchart that the utility model adopts;

7A and 7B are schematic diagrams (1) and (2) of data fusion between different coordinate systems in the method adopted by the present invention;

Fig. 8 is a schematic diagram of extracting the center of the light bar in the method adopted by the utility model;

Fig. 9 is a schematic diagram of the principle of binocular stereo vision in the method adopted by the present invention.

Detailed ways

The utility model is a measurement device integrating optical, mechanical and electrical technologies, as shown in Figures 1 to 4, the device includes:

Line-structured light vision collection part 1, rotating measuring table and its control part 2, and box body 3, wherein: line-structured light vision collection part 1 includes two high-resolution digital CCD cameras 11, one line-structured light laser 12, two The high-resolution digital CCD camera 11 is located above the center side of the rotating measuring platform and its control part 2, and is distributed symmetrically with the line structured light laser 12 as the center;

The rotating measuring table and its control part 2 include a rotating measuring table 21 and its driving mechanism and the first and second accessories 22 and 23. The first and second accessories 22 and 23 are arranged on the rotating measuring table 21. On the platform where the denture dental model is placed and clamped, the second accessory 23 is installed on the rotating measuring platform 21 through fasteners, the second accessory 23 is provided with marking points, and the rotating measuring platform 21 is rotated by the driving mechanism; the above-mentioned structure is installed on the In the box 3, the data output end of the above-mentioned high-resolution digital CCD camera 11, the control end of the line laser 12, the control end of the rotating measuring platform and its control part 2 are connected to an external control computer.

The utility model also has a lighting part installed on the top of the box body, and its control end is connected with an external control computer.

The driving mechanism is an AC variable frequency speed regulating motor.

The box body 3 is a closed space, which is closed by two side panels, a top panel, a back panel and a bottom panel to shield the interference of stray light from the outside; the interior is divided into two layers, the upper layer accommodates the linear structured light vision collection part 1, and the lower layer accommodates the rotation measurement Table and its control part 2, the first and second accessories 22, 23 and the rotating measuring table and its control part 2 are separated by a partition, and the front of the box body 3 is provided with a door, which corresponds to the first and second accessories 22, 23 and The position of the space of the rotating measuring platform 21 is a closed brown glass for observation and measurement operations.

In order to make the high-resolution digital CCD camera 11 can clearly capture the image of the marker point and keep the light source in the cabinet 3 stable and easy to observe, a 5W energy-saving lamp is installed on the top of the cabinet 3 .

The high-resolution digital CCD camera 11 adopts Canadian Prosilica EC1350, and configures a low-distortion CCD camera lens (Japan kowa LM12JCM); the line-structured light laser 12 adopts American SNF701 with good low-power focusing function. Two high-resolution digital CCD cameras 11 are placed at a certain angle (60°-90°), and are arranged symmetrically with the line-structured light laser 12 to ensure that images of the same area can be collected. The larger the size of the internal CCD of the high-resolution digital CCD camera 11, the clearer the image, and the better the image quality, but the price is also higher. Therefore, considering that the CCD size is 1/2 ", image resolution The ratio is 1360×1024; the lens is a standard lens of 2/3", f=12mm; the line-structured light laser 12 is a SNF laser, and when the designed object distance is 250mm, the laser line width is only 0.07mm and the power is 10mw. The angle between the optical axis of the high-resolution digital CCD camera 11 and the central axis of the line-structured light laser 12 is 30 degrees, the distance between the high-resolution digital CCD camera 11 and the center of the rotating measuring table 21 is 240mm, and the distance between the line-structured light laser 12 and the rotating measuring table 21 At 240 mm from the center, the distance between the high-resolution digital CCD camera lens 11 and the line-structured light laser 12 lens is 125 mm.

Rotary measuring table 21 is a disc type measuring table, its driving mechanism is AC variable frequency speed regulating motor and its control part; rotating measuring table 21 is used to directly place the denture to be tested during measurement, and the rotating shaft at the bottom of rotating measuring table 21 is in contact with the AC The output shaft of the variable frequency speed regulating motor is fixedly connected, and it rotates around the rotation axis of the rotating measuring table 21 under the drive of the AC variable frequency speed regulating motor; the speed of the AC variable frequency speed regulating motor is set to the speed of 360-degree scanning of the shape of the denture, and its angular velocity is 0.2 to 0.5 rad/s. The start and stop of the AC variable frequency speed regulation motor is controlled by the control program of the external control computer, which matches the start and stop of the high-resolution digital CCD camera 11 shooting. Connect the control program of the external control computer and the switching signal of the AC variable frequency speed regulating motor controller through the serial port RS232, add the serial port control program in the control program, specify a channel of the serial port (such as using DB9-7) and press the control program start button A high level is generated when the stop button is pressed, and a low level is generated when the stop button is pressed. Since the level generated by the RS232 serial port is not a standard TTL level, it is necessary to use a dedicated driver chip or circuit for signal conversion. This embodiment uses the conversion circuit shown in Figure 5. When DB9-7 is at a high level, the triode When it is turned on, the relay coil SSR is energized, and the control circuit of the AC variable frequency speed regulation motor is connected.

The three-dimensional reconstruction method adopted by the computer binocular vision denture scanning device of the present invention comprises the following steps:

(1) the denture is placed within the effective shooting range of the CCD camera 11 on the rotating measuring platform 21 by clamping the second annex 23;

The 2nd annex 23 is provided with more than 3 marking points (this embodiment adopts 4), the distance between the marking points can not be equal, and the marking point adopts a white dot with a diameter of 10mm;

(2) Line-structured light laser 12) projects laser light to the denture, forming a curved light strip on the denture surface;

(3) start the drive mechanism to drive the rotating measuring table 21 to rotate continuously;

(4) Two CCD cameras 11 capture images, and transmit image data to an external control computer through an image interface card for processing.

As shown in Figure 6, the processing process of the external control computer is as follows:

(41) extracting the center of the mark point and the center line of the light bar for all images of the received rotating measuring platform 21 rotating one circle;

As shown in Figure 8, to extract the center line of the light strip, the median filter is firstly used to eliminate isolated noise points; then the Otsu threshold method is used to obtain the threshold value of the binarization of the entire image, and the image is binarized; The valued image is thinned, and the improved OPTA thinning algorithm is used to construct 5 to 8 (select 8 in this embodiment) templates for elimination and 4 to 6 (select 6 in this embodiment) templates for retention. Thinning the light strips; pruning the thinned light strip skeleton to obtain a rough line structure light strip skeleton; finally taking the thinned light strip skeleton as the center line, along the normal direction of each point on the skeleton Take n points on the light strip to form a pixel point set; use the coordinates and gray value of the pixel point set to fit the quadratic curve equation; traverse other points on the skeleton in turn to find the sub-pixel center of the entire light strip point.

(42) Using the binocular stereo vision method to calculate the three-dimensional coordinates of the center point of each frame image marker point and the center line of the light strip, and obtain the three-dimensional data of the light strip on the surface of the denture;

Both CCD cameras 11 have been calibrated, that is to say, the internal parameters of the two CCD cameras 11 are known. The 3D calculation based on dual CCDs belongs to the 3D reconstruction under stereo vision. It does not need to calibrate the line structured light laser 12, but it needs to know the image points p ₁ and p ₂ of any point P in the space on the two CCD cameras 11, such as As shown in Figure 9, it must be detected in advance that the two image points p ₁ and p ₂ are two corresponding points of the same point P in space, that is, the light points need to be matched, and then the projection matrices of the calibration cameras are set to M respectively according to the following formula ₁ and _M2 :

${{\mathrm{<span\; class="notranslate">\; Z</span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}}_{\mathrm{<span\; class="notranslate">\; i</span>}}\left[\begin{array}{c}{{\mathrm{<span\; class="notranslate">\; u</span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}}_{\mathrm{<span\; class="notranslate">\; i</span>}}\\ {{\mathrm{<span\; class="notranslate">\; v</span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}}_{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="i"\; filenames="H2009202479975E00011.png"\; state="\{\{state\}\}">i</figure-callout></span>}}\\ \mathrm{<span\; class="notranslate">\; 1</span>}\end{array}\right]<span\; class="notranslate">\; =</span>\left[\begin{array}{cccc}{{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="m"\; filenames="H2009202479975E00011.png"\; state="\{\{state\}\}">m</figure-callout></span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}}_{\mathrm{<span\; class="notranslate">\; 11</span>}}& {{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="m"\; filenames="H2009202479975E00011.png"\; state="\{\{state\}\}">m</figure-callout></span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}}_{\mathrm{<span\; class="notranslate">\; 12</span>}}& {{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="m"\; filenames="H2009202479975E00011.png"\; state="\{\{state\}\}">m</figure-callout></span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}}_{\mathrm{<span\; class="notranslate">\; 13</span>}}& {{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="m"\; filenames="H2009202479975E00011.png"\; state="\{\{state\}\}">m</figure-callout></span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}}_{\mathrm{<span\; class="notranslate">\; 14</span>}}\\ {{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="m"\; filenames="H2009202479975E00011.png"\; state="\{\{state\}\}">m</figure-callout></span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}}_{\mathrm{<span\; class="notranslate">\; twenty\; one</span>}}& {{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="m"\; filenames="H2009202479975E00011.png"\; state="\{\{state\}\}">m</figure-callout></span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}}_{\mathrm{<span\; class="notranslate">\; twenty\; two</span>}}& {{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="m"\; filenames="H2009202479975E00011.png"\; state="\{\{state\}\}">m</figure-callout></span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}}_{\mathrm{<span\; class="notranslate">\; twenty\; three</span>}}& {{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="m"\; filenames="H2009202479975E00011.png"\; state="\{\{state\}\}">m</figure-callout></span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}}_{\mathrm{<span\; class="notranslate">\; twenty\; four</span>}}\\ {{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="m"\; filenames="H2009202479975E00011.png"\; state="\{\{state\}\}">m</figure-callout></span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}}_{\mathrm{<span\; class="notranslate">\; 31</span>}}& {{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="m"\; filenames="H2009202479975E00011.png"\; state="\{\{state\}\}">m</figure-callout></span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}}_{\mathrm{<span\; class="notranslate">\; 32</span>}}& {{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="m"\; filenames="H2009202479975E00011.png"\; state="\{\{state\}\}">m</figure-callout></span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}}_{\mathrm{<span\; class="notranslate">\; 33</span>}}& \mathrm{<span\; class="notranslate">\; 1</span>}\end{array}\right]\left[\begin{array}{c}{\mathrm{<span\; class="notranslate">\; x</span>}}_{{\mathrm{<span\; class="notranslate">\; W</span>}}_{}}\\ {\mathrm{<span\; class="notranslate">\; Y</span>}}_{{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}\\ {\mathrm{<span\; class="notranslate">\; Z</span>}}_{{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}\\ \mathrm{<span\; class="notranslate">\; 1</span>}\end{array}\right]<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

${{\mathrm{<span\; class="notranslate">\; Z</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}_{\mathrm{<span\; class="notranslate">\; i</span>}}\left[\begin{array}{c}{{\mathrm{<span\; class="notranslate">\; u</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}_{\mathrm{<span\; class="notranslate">\; i</span>}}\\ {{\mathrm{<span\; class="notranslate">\; v</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}_{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="i"\; filenames="H2009202479975E00011.png"\; state="\{\{state\}\}">i</figure-callout></span>}}\\ \mathrm{<span\; class="notranslate">\; 1</span>}\end{array}\right]<span\; class="notranslate">\; =</span>\left[\begin{array}{cccc}{{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="m"\; filenames="H2009202479975E00011.png"\; state="\{\{state\}\}">m</figure-callout></span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}_{\mathrm{<span\; class="notranslate">\; 11</span>}}& {{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="m"\; filenames="H2009202479975E00011.png"\; state="\{\{state\}\}">m</figure-callout></span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}_{\mathrm{<span\; class="notranslate">\; 12</span>}}& {{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="m"\; filenames="H2009202479975E00011.png"\; state="\{\{state\}\}">m</figure-callout></span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}_{\mathrm{<span\; class="notranslate">\; 13</span>}}& {{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="m"\; filenames="H2009202479975E00011.png"\; state="\{\{state\}\}">m</figure-callout></span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}_{\mathrm{<span\; class="notranslate">\; 14</span>}}\\ {{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="m"\; filenames="H2009202479975E00011.png"\; state="\{\{state\}\}">m</figure-callout></span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}_{\mathrm{<span\; class="notranslate">\; twenty\; one</span>}}& {{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="m"\; filenames="H2009202479975E00011.png"\; state="\{\{state\}\}">m</figure-callout></span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}_{\mathrm{<span\; class="notranslate">\; twenty\; two</span>}}& {{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="m"\; filenames="H2009202479975E00011.png"\; state="\{\{state\}\}">m</figure-callout></span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}_{\mathrm{<span\; class="notranslate">\; twenty\; three</span>}}& {{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="m"\; filenames="H2009202479975E00011.png"\; state="\{\{state\}\}">m</figure-callout></span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}_{\mathrm{<span\; class="notranslate">\; twenty\; four</span>}}\\ {{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="m"\; filenames="H2009202479975E00011.png"\; state="\{\{state\}\}">m</figure-callout></span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}_{\mathrm{<span\; class="notranslate">\; 31</span>}}& {{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="m"\; filenames="H2009202479975E00011.png"\; state="\{\{state\}\}">m</figure-callout></span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}_{\mathrm{<span\; class="notranslate">\; 32</span>}}& {{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="m"\; filenames="H2009202479975E00011.png"\; state="\{\{state\}\}">m</figure-callout></span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}_{\mathrm{<span\; class="notranslate">\; 33</span>}}& \mathrm{<span\; class="notranslate">\; 1</span>}\end{array}\right]\left[\begin{array}{c}{\mathrm{<span\; class="notranslate">\; x</span>}}_{{\mathrm{<span\; class="notranslate">\; w</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}\\ {\mathrm{<span\; class="notranslate">\; Y</span>}}_{{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}\\ {\mathrm{<span\; class="notranslate">\; Z</span>}}_{{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}\\ \mathrm{<span\; class="notranslate">\; 1</span>}\end{array}\right]<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$

Get four linear equations about the three-dimensional point (X _w , Y _w , Z _w ):

$\left\{\begin{array}{c}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 31</span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="11"\; label="m"\; filenames="H2009202479975E00011.png,H2009202479975E00012.png"\; state="\{\{state\}\}">m</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 11</span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; W</span>}}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 32</span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="12"\; label="m"\; filenames="H2009202479975E00011.png,H2009202479975E00012.png"\; state="\{\{state\}\}">m</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 12</span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; Y</span>}}_{\mathrm{<span\; class="notranslate">\; W</span>}}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 33</span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 13</span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; Z</span>}}_{\mathrm{<span\; class="notranslate">\; W</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 14</span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 34</span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}\\ <span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; v</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 31</span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; twenty\; one</span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; W</span>}}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; v</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 32</span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; twenty\; two</span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; Y</span>}}_{\mathrm{<span\; class="notranslate">\; W</span>}}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; v</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 33</span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; twenty\; three</span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; Z</span>}}_{\mathrm{<span\; class="notranslate">\; W</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; twenty\; four</span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 34</span>}}^{\mathrm{<span\; class="notranslate">\; 1</span>}}\end{array}\right.<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>$

$\left\{\begin{array}{c}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 31</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="11"\; label="m"\; filenames="H2009202479975E00011.png,H2009202479975E00012.png"\; state="\{\{state\}\}">m</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 11</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; W</span>}}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 32</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="12"\; label="m"\; filenames="H2009202479975E00011.png,H2009202479975E00012.png"\; state="\{\{state\}\}">m</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 12</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; Y</span>}}_{\mathrm{<span\; class="notranslate">\; W</span>}}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 33</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 13</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; Z</span>}}_{\mathrm{<span\; class="notranslate">\; W</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 14</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 34</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}\\ <span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; v</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 31</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; twenty\; one</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; W</span>}}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; v</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 32</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; twenty\; two</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; Y</span>}}_{\mathrm{<span\; class="notranslate">\; W</span>}}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; v</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 33</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; twenty\; three</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; Z</span>}}_{\mathrm{<span\; class="notranslate">\; W</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; twenty\; four</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; v</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 34</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}\end{array}\right.<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span>$

Where (u ₁ , v ₁ ) and (u ₂ , v ₂ ) are the coordinates of points p ₁ and p ₂ in their respective images; m _ij ^k (k=1, 2) are respectively the i-th row j of Mk Column elements; Formula (3) and Formula (4) each represent a straight line O ₁ p ₁ and a straight line O ₂ p ₂ , and the space point P is the intersection point of these two straight lines. To solve the four equations, the least square method can be used to find the three-dimensional point (X _W , Y _W , Z _W );

(43) Use the feature vector of the three-dimensional coordinates of the center point of the marker point to obtain the corresponding relationship between the marker points, calculate the transformation matrix between the coordinate systems formed by each frame image according to the above corresponding relationship, and transform the light in each coordinate system through the transformation matrix The three-dimensional data of the strip on the surface of the denture are fused in a coordinate system to obtain the three-dimensional sampling data of the complete surface of the denture.

The CCD camera 11 obtains an image every time it shoots, and calculates a sampling curve composed of light points on the surface of the denture. To obtain the sampling points on the complete surface of the denture, the rotating measuring table 21 must be rotated 360° for continuous scanning. The coordinate systems of the three-dimensional point coordinates of the laser bar on the denture surface calculated from the frame images are different, so the marker points set in each image must be used for data fusion.

First accurately locate the image coordinates of the center of the marker point on each frame of image, then calculate the three-dimensional coordinates of the center of each marker point and calculate the feature vector of each marker point, and complete the corresponding matching of each rotation position with the marker point of the first image; calculation The transformation matrix converts the three-dimensional coordinates of the light bar calculated at each position into the coordinate system calculated for the first image, and completes the data fusion of the images taken at all positions.

Obtaining the corresponding relationship between the marker points by using the feature vector of the three-dimensional coordinates of the marker point centers is to use the three-dimensional coordinates of the marker point centers to calculate the vectors between each marker point center and other marker point centers in each coordinate system, and calculate each The feature vector formed by the vector product of each marker point; compare the feature vector of each marker point in each coordinate system to obtain the corresponding relationship between the marker points in each coordinate system.

As shown in Figures 7A and 7B, the four marker points V ₁ , V ₂ , V ₃ and V ₄ at position 1, after the rotating measuring platform 21 rotates, all the marker points become marker points P ₁ , P ₂ , P at position 2 ₃ and P ₄ ; each marker point and other three points can form three vectors, for example, V ₁ point has three vectors V ₁ V ₂ , V ₁ V ₃ and V ₁ V ₄ , P ₁ point has three vectors as P ₁ P ₂ , P ₁ P ₃ and P ₁ P ₄ respectively calculate the three vector products of V ₁ point and the three vector products of P ₁ point, if these two vector products are equal, then V ₁ and P ₁ is the corresponding point. It can also be seen that V ₂ and P ₂ , V ₃ and P ₃ , V ₄ and P4 are also corresponding points, and the transformation matrix from position 1 to position 2 can be calculated through these corresponding points, and this transformation matrix is also applicable to the extracted light bars 3D points, so that the 3D points of the light bar at all rotation positions are fused into a 3D point set data of the complete surface of the denture.

In summary, the utility model utilizes the principle of binocular vision of structured light, and adopts a sensor composed of a line structured light laser 12 and two CCD cameras 11 to form a geometric model of structured light imaging. The denture is continuously scanned and imaged, using visual image processing technology to calculate the three-dimensional point coordinates of the centerline of the light bar in each image, and then using the marker points to fuse the three-dimensional point coordinates of all images into one coordinate system to obtain the entire denture. Sample point set data.

Claims (5)

1. A computer binocular vision denture scanning device, characterized in that it comprises: line structured light vision collection part (1), rotating measuring platform and its control part (2) and casing (3), wherein: The line-structured light vision collection part (1) includes 2 high-resolution digital CCD cameras (11), a line-structured light laser (12), and 2 high-resolution digital CCD cameras (11) located on the rotating measuring platform and its control part (2) above the central side, symmetrically distributed with the line structured light laser (12) as the center; The rotating measuring table and its control part (2) include the rotating measuring table (21) and its driving mechanism and the first and second accessories (22, 23), and the first and second accessories (22, 23) are arranged on the rotating measuring table (21 ), the first attachment (22) is a platform for placing and clamping the denture model, the second attachment (23) is provided with marking points, and the rotating measuring table (21) is rotated by the driving mechanism; the above structure is installed in the box In (3): the data output end of the above-mentioned CCD camera and the lens (11), the control end of the line laser (12) and the control end of the rotating measuring table and its control part (2) are connected with the external control computer. 2. The computer binocular vision denture scanning device according to claim 1, characterized in that: it also has a lighting part installed on the top of the box body, and its control terminal is connected with an external control computer. 3. The computer binocular vision denture scanning device according to claim 1, characterized in that: the driving mechanism is an AC variable frequency speed regulating motor. 4. The computer binocular vision denture scanning device according to claim 1, characterized in that: the box body (3) is divided into 2 layers, the upper layer accommodates the line structured light vision collection part (1), and the lower layer accommodates the rotation measurement The table and its control part (2), the first and second accessories (22, 23) and the rotating measuring table (21) and its control part (2) are isolated by a partition, and the front of the box body (3) is provided with a door. 5. The computer binocular vision denture scanning device according to claim 4, characterized in that: the positions on the door corresponding to the spaces of the first and second accessories (22, 23) and the rotating measuring platform (21) are closed glass.

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