A method of calibrating an automated three-dimensional laser scanner

Abstract

The application discloses a calibration method of an automatic three-dimensional laser scanner, and belongs to the technical field of calibration methods.The application solves the problem that the automatic three-dimensional scanner in the prior art is usually installed in a fixed environment, and the space and operation for calibration are limited and inconvenient for calibration.The calibration method of the application comprises the following steps: a plurality of target poses are preset; then an operator changes the pose of a calibration plate in hand, so that a perspective projection quadrilateral representing the current pose of the calibration plate in a computer screen coincides with a perspective projection quadrilateral representing the target pose of the calibration plate, the image of the calibration plate collected under the current pose and the image of laser line projection on the calibration plate are saved; the above steps are repeatedly executed until all the target poses are traversed; and the calibration of the visual laser detector is realized by using all the saved images.In the case that the space and operation for calibration are limited, the scanner does not need to be taken off from the installation station, and the visual laser detector and the motion track are quickly calibrated by using the same calibration plate.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of calibration methods, and particularly relates to a calibration method of an automatic three-dimensional laser scanner. BACKGROUND

[0002] For a long time, the accurate measurement of the geometric size of a real object mainly relies on the contact type manual measurement mode of a vernier caliper, a micrometer, an angle ruler and the like. This measurement mode cannot measure the surface of an irregularly shaped object and has technical bottlenecks for objects such as cultural relics and historical sites which require non-contact measurement. With the development of related disciplines and the driving of new technology and new needs, three-dimensional scanning technology emerges as the times require. This technology can calculate the spatial distribution of point clouds according to the collected object surface information without contacting the measured object, and through a series of surface reconstruction methods, the point cloud data is integrated into a triangular mesh model of the measured object in the computer. This technology is widely used in the fields of auxiliary manufacturing and inspection in the industrial design field, surgical positioning and rehabilitation in the medical field, real scene modeling and simulation in the game entertainment field, and site protection and restoration in the archaeological field.

[0003] With the advancement of industrial automation and intelligentization, the demand for automatic three-dimensional detection is increasing, and the sizes and shapes of measured objects are various, which requires that the automatic three-dimensional detection equipment can adapt to the detection needs of different objects as much as possible. At present, three-dimensional scanning equipment applied in the measurement field mainly includes a photographing type three-dimensional scanner based on grating projection and a handheld three-dimensional scanner based on multi-line laser. The photographing type three-dimensional scanner uses a projector to continuously project multiple bright and dark stripes with optical coding characteristics to the surface of a measured object, and uses a binocular camera to synchronously collect the reflection light of each bright and dark stripe on the object surface. Three-dimensional point cloud data is obtained by uniformly decoding all the collected images. This type of equipment requires that the position of the scanner and the measured object is relatively fixed during scanning, and only a fixed area size of the object can be scanned each time. When the size of the measured object exceeds the measurement range, the three-dimensional scanner needs to be redesigned. The handheld three-dimensional scanner using laser as a light source needs to paste a mark point on the surface of the measured object. In the scanning step, the operator holds the scanner to traverse the surface of the measured object to obtain complete point cloud data. Since this type of equipment needs to paste a mark point before scanning and the scanning step needs manual participation, it is only suitable for scanning large objects or sampling detection and cannot realize automation.

[0004] Automated 3D laser scanners combining visual laser detectors and guide rails can meet the compatibility requirements of the automated inspection industry. For objects of different sizes, only the travel distance of the guide rail needs to be adjusted. Among these, inspection accuracy is the most important indicator for a 3D scanner, and its calibration accuracy directly determines the inspection accuracy. However, automated 3D scanners are typically installed in fixed environments, and the space and operation for calibration are greatly limited, making calibration inconvenient. Summary of the Invention

[0005] The purpose of this invention is to provide an automated calibration method for a 3D laser scanner. In situations where calibration space and operation are limited, the 3D laser scanner can be calibrated without removing it from the installation station using the same calibration board. This includes rapid calibration of the visual laser detector and motion trajectory, enabling multi-functional reuse of the same calibration board and reducing the complexity of the calibration method.

[0006] The technical solution adopted by the present invention to achieve the above objectives is as follows.

[0007] The calibration method for the automated 3D laser scanner of the present invention comprises the following steps:

[0008] Step 1: Pre-set the poses of multiple targets on the calibration board in the coordinate system of the visual laser detector;

[0009] Step 2: Select a target pose. With the visual laser detector stationary, the operator moves the calibration plate towards the target pose. The computer screen displays the perspective projection quadrilateral of the calibration plate in the current pose and the perspective projection quadrilateral when the calibration plate reaches the target pose in real time. The operator uses the two perspective projection quadrilaterals on the computer screen as prompts. By changing the pose of the calibration plate in hand, the operator makes the perspective projection quadrilateral representing the current pose of the calibration plate on the computer screen coincide with the perspective projection quadrilateral representing the target pose of the calibration plate. After the coincidence, the computer saves the image of the calibration plate acquired by the visual laser detector in the current pose and the image of the laser line emitted by the visual laser detector projected onto the calibration plate.

[0010] Step 3: Repeat step 2 until all target poses preset in step 1 are traversed, and use all saved images to calibrate the visual laser detector.

[0011] The coordinate system of the visual laser detector takes the line connecting the centers of the binocular cameras of the visual laser detector as the Y-axis and the midpoint of the line connecting the centers of the binocular cameras of the visual laser detector as the origin. The Y-axis and the incident light axis of the binocular camera form the YOZ coordinate plane. The Z-axis is in the same direction as the incident light of the binocular camera. The X-axis is perpendicular to the YOZ coordinate plane. The directions of the X-axis, Y-axis and Z-axis conform to the right-hand rule.

[0012] The calibration plate is a flat plate with a plurality of feature points on the surface, the feature points are points that can be recognized by the visual laser detector, and the coordinates of all feature points on the calibration plate in the calibration plate coordinate system are known.

[0013] Further, the method for obtaining the perspective projection quadrilateral of the calibration plate at the current pose comprises the following steps:

[0014] 1) Recognize and extract the feature points on the calibration plate

[0015] The binocular camera of the visual laser detector synchronously collects the image of the calibration plate at the current pose and transmits it to the computer, the computer respectively recognizes all the feature points in the left and right view images, and calculates the coordinates of each feature point in the visual laser detector coordinate system according to the epipolar constraint and the triangulation principle;

[0016] 2) Calculate the rotation matrix and translation matrix between the current pose calibration plate coordinate system and the visual laser detector coordinate system

[0017] The rotation matrix and translation matrix between the current pose calibration plate coordinate system and the visual laser detector coordinate system are calculated by using the coordinates of the same group of feature points in the visual laser detector coordinate system and the coordinates in the current pose calibration plate coordinate system by using the least square method;

[0018] 3) Calculate the perspective projection points of the four corners of the calibration plate

[0019] The coordinates of the four corners of the current pose calibration plate in the visual laser detector coordinate system are calculated by using the rotation matrix and translation matrix between the current pose calibration plate coordinate system and the visual laser detector coordinate system, a perspective projection model is established in the visual laser detector coordinate system, the projection plane is XOY plane, the projection center is located on both sides of the calibration plate in the projection plane, according to the established perspective projection model, the coordinates of the four corners of the current pose calibration plate in the visual laser detector coordinate system are projected onto the projection plane to obtain the two-dimensional coordinate values of the four projection points, and the four projection points are connected in turn to obtain the perspective projection quadrilateral of the calibration plate at the current pose.

[0020] Further, in step 3), the distance from the projection center to the projection plane is set to the focal length of the binocular camera lens.

[0021] Further, the method for obtaining the perspective projection quadrilateral of the calibration plate at the target pose comprises the following steps:

[0022] 1) Calculate the rotation matrix and translation matrix between the target pose calibration plate coordinate system and the visual laser detector coordinate system

[0023] The coordinates of the same set of feature points in the visual laser detector coordinate system and the coordinates in the target pose calibration plate coordinate system are used to calculate the rotation matrix and the translation matrix between the target pose calibration plate coordinate system and the visual laser detector coordinate system by using the least square method.

[0024] 2) Calculate the perspective projection points of the four corners of the calibration plate

[0025] The coordinates of the four corners of the target pose calibration plate in the visual laser detector coordinate system are calculated by using the rotation matrix and the translation matrix between the target pose calibration plate coordinate system and the visual laser detector coordinate system, a perspective projection model is established in the visual laser detector coordinate system, the projection plane is XOY plane, the projection center and the calibration plate are located on both sides of the projection plane, and the coordinates of the four corners of the target pose calibration plate in the visual laser detector coordinate system are projected onto the projection plane according to the established perspective projection model to obtain the two-dimensional coordinate values of the four projection points. The four projection points are connected in turn to obtain the perspective projection quadrilateral of the calibration plate at the target pose.

[0026] Further, in step 2), the distance from the projection center to the projection plane is set to be the focal length of the binocular camera lens.

[0027] Further, in step two, the computer displays the target pose in a predetermined order, and when the image of the previous target pose is saved, the computer screen will automatically display the perspective projection quadrilateral of the next target pose.

[0028] Further, in step three, the saved all images are used to realize the calibration of the visual laser detector, including the following steps:

[0029] 1) The position coordinates of the feature points in the saved all images are extracted, the coordinates of the feature points in the calibration plate coordinate system are used, and the equivalent focal length of the binocular camera lens, the projection point coordinates of the optical axis of the binocular camera lens on the image and the distortion coefficient of the binocular camera lens are obtained by using Zhang Zhengyou calibration method, and the rotation matrix and the translation matrix between the binocular cameras are obtained by using double target calibration method;

[0030] 2) The position coordinates of the laser lines in the saved all images are extracted, and the plane equation of the laser lines is obtained by using double target calibration method.

[0031] Another automatic three-dimensional laser scanner calibration method of the application comprises the following steps:

[0032] Step one, adjust the guide rail to the motion zero position, place the calibration plate opposite to the visual laser detector, the visual laser detector recognizes and extracts the feature points on the calibration plate, and the rotation matrix and the translation matrix between the calibration plate coordinate system and the visual laser detector coordinate system are calculated by using the feature points;

[0033] Step two, keep the calibration plate in the original static state, start the guide rail, the guide rail drives the visual laser detector to move in a straight line, in the movement process of the visual laser detector, continuously calculate the coordinates of the coordinate system origin of the visual laser detector in the calibration plate coordinate system at each time, and obtain a set of three-dimensional coordinate data;

[0034] Step three, linear fitting is performed on the three-dimensional coordinate data to obtain a straight line direction vector, and the rotation matrix and the translation matrix between the calibration plate coordinate system and the visual laser detector coordinate system when the guide rail is located at the movement zero position are used to transform the direction vector from the calibration plate coordinate system to the visual laser detector coordinate system when the guide rail is located at the movement zero position, that is, the movement trajectory of the visual laser detector is obtained.

[0035] The visual laser detector coordinate system takes the center line of the binocular camera of the visual laser detector as the Y axis, takes the midpoint of the center line of the binocular camera of the visual laser detector as the origin, the Y axis and the incident light axis of the binocular camera form a YOZ coordinate plane, the Z axis is in the same direction as the incident light of the binocular camera, and the X axis is perpendicular to the YOZ coordinate plane, and the directions of the X axis, the Y axis and the Z axis comply with the right-hand rule.

[0036] The calibration plate is a flat plate with a plurality of feature points on the surface, the feature points are points that can be recognized by the visual laser detector, and the coordinates of all the feature points on the calibration plate in the calibration plate coordinate system are known.

[0037] Further, the automatic three-dimensional laser scanner comprises a visual laser detector, a guide rail, a support structure, a controller and a computer; the visual laser detector is composed of a binocular camera and a laser that can emit a laser line or a plurality of parallel laser lines, the visual laser detector is installed on the guide rail, the guide rail is installed on the support structure, the guide rail is connected with the detector, the computer is connected with the controller and the visual laser detector, the computer controls the start, stop and reset of the guide rail through the controller, the visual laser detector moves in a straight line along the guide rail, the visual laser detector collects images and transmits them to the computer, and the computer displays, saves and processes the collected images.

[0038] Compared with the prior art, the automatic three-dimensional laser scanner has the following beneficial effects:

[0039] The calibration method of the automatic three-dimensional laser scanner of the present application can complete the calibration of the visual laser detector by the operator holding the calibration plate, and can complete the calibration of the running track by simply fixing the same calibration plate. Compared with the calibration method using a fixing device, the present application does not need the support structure of the calibration plate, and can set the target pose according to the actual situation, which is particularly suitable for the calibration of the working environment with limited space. Compared with the calibration method of the handheld scanner, although the handheld scanner can also realize the calibration by the operator holding the calibration plate, the handheld scanner takes the calibration plate coordinate system as the world coordinate system, the pose prompt in the computer and the movement direction of the operator are mirror images, and the operator is difficult to reach the target pose according to the prompt information. The present application takes the detector coordinate system as the world coordinate system, which is completely the same as the subjective direction of the operator, can effectively reduce the operation difficulty, and enables the operator to quickly realize the calibration of the whole system. BRIEF DESCRIPTION OF DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0041] Figure 1 The schematic diagram of the automatic three-dimensional laser scanner and the calibration plate in the present application;

[0042] Figure 2 The schematic diagram of the visual laser detector of the automatic three-dimensional laser scanner in the present application;

[0043] Figure 3 The perspective projection quadrilateral of the calibration plate at the current pose and the perspective projection quadrilateral of the target pose on the computer screen in the calibration method of the automatic three-dimensional laser scanner in the present application;

[0044] Figure 4 The structural schematic diagram of the calibration plate (with circular feature points pasted) in the calibration method of the automatic three-dimensional laser scanner in the present application;

[0045] Figure 5 The calibration plate image collected by the binocular camera of the visual laser detector in the calibration method of the automatic three-dimensional laser scanner in the present application;

[0046] Figure 6 The calibration plate image containing laser lines collected by the binocular camera of the visual laser detector in the calibration method of the automatic three-dimensional laser scanner in the present application;

[0047] In the figure: 1, visual laser detector, 1-1, binocular camera, 1-2, laser, 2, guide rail, 3, support structure, 4, controller, 5, computer, 6, calibration plate, 7, laser line, 8, perspective projection quadrilateral of the calibration plate in the current pose, 9, perspective projection quadrilateral of the calibration plate in the target pose. DETAILED DESCRIPTION

[0048] In order to further understand the present application, the preferred embodiments of the present application are described below, but it should be understood that these descriptions are only for further illustrating the features and advantages of the present application, but not for limiting the claims of the present application.

[0049] The calibration method of the automatic three-dimensional laser scanner of the present application is not limited in structure, and any automatic three-dimensional laser scanner containing the components used in the calibration method of the present application is suitable for the calibration method of the present application. In the present embodiment, the automatic three-dimensional laser scanner is a prior art, and the structure is as shown in Figure 1 and Figure 2 The automatic three-dimensional laser scanner mainly consists of a visual laser detector 1, a guide rail 2, a support structure 3, a controller 4 and a computer 5. The visual laser detector 1 consists of a binocular camera 1-1 and a laser 1-2 capable of emitting a laser line or multiple parallel laser lines. The visual laser detector 1 is installed on the guide rail 2, the guide rail 2 is installed on the support structure 3, the guide rail 2 is connected to the controller 4, the computer 5 is connected to the controller 4 and the visual laser detector 1. The computer 5 controls the start, stop and reset of the guide rail 2 through the controller 4. The visual laser detector 1 moves linearly along the guide rail 2, the visual laser detector 1 collects images and transmits them to the computer 5, and the computer 5 displays, saves and processes the collected images.

[0050] The calibration method of the automatic three-dimensional laser scanner of the present application is suitable for the calibration of the visual laser detector 1 and the calibration of the motion trajectory of the laser detector 1.

[0051] As shown in Figure 3 、 Figure 5 and Figure 6 For the calibration of the visual laser detector 1, the calibration method of the automatic three-dimensional laser scanner of the present application has the following steps:

[0052] Step one, pre-set multiple target poses of the calibration plate 6 in the coordinate system of the visual laser detector 1 (the target poses are uniformly distributed in the measurement area of the visual laser detector);

[0053] Step two, when calibrating, a target pose is selected, the visual laser detector 1 is in a static state, the operator holds the calibration plate 6 and moves towards the target pose, the computer 5 screen displays the perspective projection quadrilateral 8 of the calibration plate 6 at the current pose in real time, and when the calibration plate 6 reaches the perspective projection quadrilateral 9 of the target pose, the operator uses the two perspective projection quadrilaterals on the computer 5 screen as prompt information, changes the pose of the calibration plate 6 in hand, so that the perspective projection quadrilateral 8 representing the current pose of the calibration plate 6 on the computer 5 screen coincides with the perspective projection quadrilateral 9 representing the target pose of the calibration plate 6, after the coincidence, the computer 5 saves the image of the calibration plate 6 collected by the visual laser detector 1 at the current pose and the image of the laser line projected on the calibration plate 6 by the visual laser detector 1, when the image of the previous target pose is saved, the computer 5 screen will automatically display the perspective projection quadrilateral 9 of the next target pose;

[0054] Step three, repeat step two until all target poses preset in step one are traversed;

[0055] Step four, the position coordinates of the feature points in all saved images are extracted, the coordinates of the feature points in the calibration plate 6 coordinate system are used, and the Zhang Zhengyou calibration method is used to obtain the equivalent focal length of the binocular camera 1-1 lens, the projection point coordinates of the binocular camera 1-1 lens optical axis on the image, and the distortion coefficient of the binocular camera 1-1 lens, and the double-object calibration method is used to obtain the rotation matrix and translation matrix between the binocular cameras 1-1;

[0056] Step five, the position coordinates of the laser line 7 in all saved images are extracted, and the double-object calibration method is used to obtain the plane equation of the laser line 7.

[0057] For the motion trajectory calibration of the visual laser detector 1, the calibration method of the automatic three-dimensional laser scanner of the application comprises the following steps:

[0058] Step one, adjust the guide rail 2 to the motion zero position, place the calibration plate 6 in front of the visual laser detector 1, identify and extract the feature points on the calibration plate 6 by the visual laser detector 1, and calculate the rotation matrix and translation matrix between the calibration plate 6 coordinate system and the visual laser detector 1 coordinate system;

[0059] Step two, keep the calibration plate 6 in the original static state, start the guide rail 2, and drive the visual laser detector 1 to move in a straight line, in the movement process of the visual laser detector 1, continuously calculate the coordinates of the coordinate system origin of the visual laser detector 1 in the calibration plate 6 coordinate system at each time, and obtain a set of three-dimensional coordinate data;

[0060] Step 3: Perform linear fitting on the three-dimensional coordinate data to obtain the linear direction vector. Using the rotation and translation matrices between the coordinate system of calibration plate 6 and the coordinate system of visual laser detector 1 when guide rail 2 is at the zero position of motion, which were calculated earlier, the direction vector is transformed from the coordinate system of calibration plate 6 to the coordinate system of visual laser detector 1 when guide rail 2 is at the zero position of motion, thus obtaining the motion trajectory of visual laser detector 1.

[0061] In the above technical solution, the coordinate system of the visual laser detector 1 takes the line connecting the centers of the binocular cameras 1-1 of the visual laser detector 1 as the Y-axis, the midpoint of the line connecting the centers of the binocular cameras 1-1 of the visual laser detector 1 as the origin, the Y-axis and the incident light axis of the binocular camera 1-1 form the YOZ coordinate plane, the Z-axis is in the same direction as the incident light of the binocular camera 1-1, the X-axis is perpendicular to the YOZ coordinate plane, and the directions of the X-axis, Y-axis and Z-axis conform to the right-hand rule;

[0062] In the above technical solutions, such as Figure 4 As shown, calibration plate 6 is a flat plate with multiple feature points on its surface. The feature points are points that can be identified by the visual laser detector 1. The coordinates of all feature points on calibration plate 6 in the coordinate system of calibration plate 6 are known.

[0063] In the above technical solution, the method for obtaining the perspective projection quadrilateral 8 of the calibration plate 6 in the current pose includes the following steps:

[0064] 1) Identify and extract feature points on calibration plate 6

[0065] The binocular camera 1-1 of the visual laser detector 1 synchronously acquires the image on the current pose calibration plate 6 and transmits it to the computer 5. The computer 5 identifies all feature points in the left and right viewpoint images respectively, and calculates the coordinates of each feature point in the coordinate system of the visual laser detector 1 according to the epipolar constraint and triangulation principle.

[0066] 2) Calculate the rotation and translation matrices between the current pose calibration board's 6-coordinate system and the visual laser detector's 1-coordinate system.

[0067] Using the coordinates of the same set of feature points in the coordinate system of visual laser detector 1 and in the coordinate system of the current pose calibration board 6, the rotation matrix and translation matrix between the coordinate system of the current pose calibration board 6 and the coordinate system of visual laser detector 1 are calculated by the least squares method.

[0068] 3) Calculate the perspective projection points of the four corners of the calibration plate.

[0069] The rotation matrix and the translation matrix between the current pose calibration plate 6 coordinate system and the visual laser detector 1 coordinate system are used to calculate the coordinates of the four corners of the current pose calibration plate 6 in the visual laser detector 1 coordinate system, a perspective projection model is established in the visual laser detector 1 coordinate system, the projection plane is the XOY plane, the projection center and the calibration plate 6 are located on the two sides of the projection plane, the distance from the projection center to the projection plane is set to be the focal length of the binocular camera 1-1 lens (it can also be set to other values according to the display requirement, the value only affects the overall scaling ratio of the perspective projection quadrilateral, and does not affect the use effect of the present application), according to the established perspective projection model, the coordinates of the four corners of the current pose calibration plate 6 in the visual laser detector 1 coordinate system are projected onto the projection plane to obtain the two-dimensional coordinate values of the four projection points, and the four projection points are sequentially connected to obtain the perspective projection quadrilateral 8 of the calibration plate 6 at the current pose.

[0070] In the above technical solution, the method for obtaining the perspective projection quadrilateral 9 of the calibration plate 6 at the target pose includes the following steps:

[0071] 1) Calculate the rotation matrix and the translation matrix between the target pose calibration plate 6 coordinate system and the visual laser detector 1 coordinate system

[0072] The rotation matrix and the translation matrix between the target pose calibration plate 6 coordinate system and the visual laser detector 1 coordinate system are calculated by using the coordinates of the same group of feature points in the visual laser detector 1 coordinate system and the coordinates in the target pose calibration plate 6 coordinate system, and the least square method is used;

[0073] 2) Calculate the perspective projection points of the four corners of the calibration plate

[0074] The rotation matrix and the translation matrix between the target pose calibration plate 6 coordinate system and the visual laser detector 1 coordinate system are used to calculate the coordinates of the four corners of the target pose calibration plate 6 in the visual laser detector 1 coordinate system, a perspective projection model is established in the visual laser detector 1 coordinate system, the projection plane is the XOY plane, the projection center and the calibration plate 6 are located on the two sides of the projection plane, the distance from the projection center to the projection plane is set to be the focal length of the binocular camera 1-1 lens (it can also be set to other values according to the display requirement, the value only affects the overall scaling ratio of the perspective projection quadrilateral, and does not affect the use effect of the present application), according to the established perspective projection model, the coordinates of the four corners of the current pose calibration plate 6 in the visual laser detector 1 coordinate system are projected onto the projection plane to obtain the two-dimensional coordinate values of the four projection points, and the four projection points are sequentially connected to obtain the perspective projection quadrilateral 8 of the calibration plate 6 at the current pose.

[0075] Obviously, the above embodiments are merely example for clearly illustrating but not limitation to the embodiments. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, it is not necessary and also impossible to enumerate all the embodiments. The obvious changes or variations derived from the above should be still within the protection scope of the present application.

Claims

1. A method of calibrating an automated three-dimensional laser scanner, characterized by, The steps are as follows: Step one, pre-set multiple target poses of the calibration plate (6) in the coordinate system of the visual laser detector (1); Step two, select a target pose, the visual laser detector (1) is in a static state, the operator holds the calibration plate (6) and moves it to the target pose, the computer (5) screen displays the perspective projection quadrilateral (8) of the calibration plate (6) in the current pose in real time, and when the calibration plate (6) reaches the perspective projection quadrilateral (9) of the target pose, the operator uses the two perspective projection quadrilaterals on the computer (5) screen as prompt information, changes the pose of the calibration plate (6) in hand, so that the perspective projection quadrilateral (8) representing the current pose of the calibration plate (6) on the computer (5) screen coincides with the perspective projection quadrilateral (9) representing the target pose of the calibration plate (6), after the coincidence, the computer (5) saves the image of the calibration plate (6) collected by the visual laser detector (1) in the current pose and the image of the laser line projected on the calibration plate (6) by the visual laser detector (1); Step three, repeat step two until all target poses pre-set in step one are traversed, and use all saved images to realize the calibration of the visual laser detector (1); The coordinate system of the visual laser detector (1) takes the center line of the binocular camera (1-1) of the visual laser detector (1) as the Y axis, takes the midpoint of the center line of the binocular camera (1-1) of the visual laser detector (1) as the origin, the Y axis and the incident light axis of the binocular camera (1-1) form a YOZ coordinate plane, the Z axis is the same as the incident light of the binocular camera (1-1), and the X axis is perpendicular to the YOZ coordinate plane, the directions of the X axis, the Y axis and the Z axis comply with the right-hand rule; The calibration plate (6) is a flat plate with multiple feature points on the surface, the feature points are points that can be recognized by the visual laser detector (1), and the coordinates of all feature points on the calibration plate (6) in the calibration plate (6) coordinate system are known.

2. The method of calibrating an automated three-dimensional laser scanner of claim 1, wherein, The method for obtaining the perspective projection quadrilateral (8) of the calibration plate (6) in the current pose comprises the following steps: 1) Identify and extract the feature points on the calibration plate (6) The binocular camera (1-1) of the visual laser detector (1) synchronously collects the image of the calibration plate (6) in the current pose and transmits it to the computer (5), the computer (5) respectively identifies all feature points in the left and right view images, and calculates the coordinates of each feature point in the coordinate system of the visual laser detector (1) according to the epipolar constraint and the triangulation principle; 2) Calculate the rotation matrix and translation matrix between the coordinate system of the calibration plate (6) in the current pose and the coordinate system of the visual laser detector (1) Using the coordinates of the same group of feature points in the coordinate system of the visual laser detector (1) and in the coordinate system of the calibration plate (6) in the current pose, the least square method is used to calculate the rotation matrix and translation matrix between the coordinate system of the calibration plate (6) in the current pose and the coordinate system of the visual laser detector (1); 3) Calculate the perspective projection points of the four corners of the calibration plate The rotation matrix and the translation matrix between the current pose calibration board (6) coordinate system and the visual laser detector (1) coordinate system are used to calculate the coordinates of the four corners of the current pose calibration board (6) in the visual laser detector (1) coordinate system, a perspective projection model is established in the visual laser detector (1) coordinate system, the projection plane is XOY plane, the projection center and the calibration board (6) are located on both sides of the projection plane, according to the established perspective projection model, the coordinates of the four corners of the current pose calibration board (6) in the visual laser detector (1) coordinate system are projected onto the projection plane to obtain the two-dimensional coordinate values of the four projection points, and the perspective projection quadrilateral (8) of the calibration board (6) at the current pose is obtained by connecting the four projection points in turn.

3. The method of calibrating an automated three-dimensional laser scanner of claim 2, wherein, In the step 2), the distance from the projection center to the projection plane is set as the focal length of the binocular camera (1-1).

4. The method of calibrating an automated three-dimensional laser scanner of claim 1, wherein, The method for obtaining the perspective projection quadrilateral (9) of the calibration board (6) at the target pose comprises the following steps: 1) calculating the rotation matrix and the translation matrix between the target pose calibration board (6) coordinate system and the visual laser detector (1) coordinate system The rotation matrix and the translation matrix between the target pose calibration board (6) coordinate system and the visual laser detector (1) coordinate system are calculated by using the coordinates of the same group of feature points in the visual laser detector (1) coordinate system and the coordinates in the target pose calibration board (6) coordinate system; 2) calculating the perspective projection points of the four corners of the calibration board The rotation matrix and the translation matrix between the target pose calibration board (6) coordinate system and the visual laser detector (1) coordinate system are used to calculate the coordinates of the four corners of the target pose calibration board (6) in the visual laser detector (1) coordinate system, a perspective projection model is established in the visual laser detector (1) coordinate system, the projection plane is XOY plane, the projection center and the calibration board (6) are located on both sides of the projection plane, according to the established perspective projection model, the coordinates of the four corners of the target pose calibration board (6) in the visual laser detector (1) coordinate system are projected onto the projection plane to obtain the two-dimensional coordinate values of the four projection points, and the perspective projection quadrilateral (9) of the calibration board (6) at the target pose is obtained by connecting the four projection points in turn.

5. The method of calibrating an automated three-dimensional laser scanner of claim 4, wherein, In the step 2), the distance from the projection center to the projection plane is set as the focal length of the binocular camera (1-1).

6. The method of calibrating an automated three-dimensional laser scanner of claim 1, wherein, In the step two, the computer (5) displays the target pose in a predetermined order, and when the image of the previous target pose is saved, the computer (5) screen will automatically display the perspective projection quadrilateral (9) of the next target pose.

7. The method of calibrating an automated three-dimensional laser scanner of claim 1, wherein, In the step three, the saved all images are used to realize the calibration of the visual laser detector, comprising the following steps: 1) extracting the position coordinates of the feature points in the saved all images, using the coordinates of the feature points in the calibration board (6) coordinate system, and using Zhang Zhengyou calibration method to obtain the equivalent focal length of the binocular camera (1-1) lens, the projection point coordinates of the binocular camera (1-1) lens optical axis on the image and the distortion coefficient of the binocular camera (1-1) lens, and using double target calibration method to obtain the rotation matrix and the translation matrix between the binocular camera (1-1); 2) Extract the position coordinates of the laser line (7) in all saved images, and obtain the plane equation of the laser line (7) by using the double-target method.

8. A method of calibrating an automated three-dimensional laser scanner, characterized by, The method comprises the following steps: Step one, adjust the guide rail (2) to the motion zero position, place the calibration plate (6) in front of the visual laser detector (1), the visual laser detector (1) recognizes and extracts the feature points on the calibration plate (6), and calculates the rotation matrix and translation matrix between the calibration plate (6) coordinate system and the visual laser detector (1) coordinate system by using the feature points; Step two, keep the calibration plate (6) in the original static state, start the guide rail (2), and drive the visual laser detector (1) to move along the straight line direction, in the movement process of the visual laser detector (1), continuously calculate the coordinates of the origin of the coordinate system of the visual laser detector (1) in the calibration plate (6) coordinate system at each time, and obtain a set of three-dimensional coordinate data; Step three, perform straight line fitting on the three-dimensional coordinate data to obtain a straight line direction vector, and use the rotation matrix and translation matrix between the calibration plate (6) coordinate system and the visual laser detector (1) coordinate system when the guide rail (2) is located at the motion zero position to transform the direction vector from the calibration plate (6) coordinate system to the visual laser detector (1) coordinate system when the guide rail (2) is located at the motion zero position, that is, to obtain the motion trajectory of the visual laser detector (1); The visual laser detector (1) coordinate system takes the center line of the binocular camera (1-1) of the visual laser detector (1) as the Y axis, takes the midpoint of the center line of the binocular camera (1-1) of the visual laser detector (1) as the origin, the Y axis and the incident light axis of the binocular camera (1-1) form a YOZ coordinate plane, the Z axis is in the same direction as the incident light of the binocular camera (1-1), and the X axis is perpendicular to the YOZ coordinate plane, the directions of the X axis, the Y axis and the Z axis comply with the right-hand rule; The calibration plate is a flat plate with a plurality of feature points on the surface, the feature points are points that can be recognized by the visual laser detector (1), and the coordinates of all feature points on the calibration plate in the calibration plate coordinate system are known.

9. The method of calibrating an automated three-dimensional laser scanner of claim 1 or 8, wherein, The automatic three-dimensional laser scanner comprises a visual laser detector (1), a guide rail (2), a support structure (3), a controller (4) and a computer (5); the visual laser detector (1) is composed of a binocular camera (1-1) and a laser (1-2) capable of emitting a laser line or a plurality of parallel laser lines, the visual laser detector (1) is installed on the guide rail (2), the guide rail (2) is installed on the support structure (3), the guide rail (2) is connected with the detector (1), the computer (5) is connected with the controller (4) and the visual laser detector (1), the computer (5) controls the start, stop and reset of the guide rail (2) by controlling the controller (4), the visual laser detector (1) moves linearly along the guide rail (2), the visual laser detector (1) collects images and transmits them to the computer (5), and the computer (5) displays, saves and processes the collected images.

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