A Coordinate Unification Method for Laser Positioning System Based on Calibration Plate

Abstract

This invention relates to a coordinate unification method for a laser positioning system based on a calibration plate, comprising: 1) constructing a coordinate unification device for laser transmitting stations; 2) measuring the coordinate values ​​of each measuring node (2-2) in the coordinate system of the measuring instrument using a measuring instrument, and calculating the distance between every two measuring nodes (2-2) and the angle between the lines connecting each pair of measuring nodes (2-2) using the coordinate values; 3) measuring the coordinate values ​​of four measuring nodes (2-2) in the coordinate system of the M laser transmitting stations (1) using M laser transmitting stations (1) respectively, based on the calculated distance and angle values; 4) achieving coordinate unification of the M laser transmitting stations (1) through a rotation matrix and a translation matrix of coordinate transformation based on the obtained coordinate values; 5) optimizing the obtained coordinate transformation matrix based on the distance constraints of the measuring nodes to achieve higher precision coordinate unification, which effectively reduces the reference position and improves calibration efficiency.

Description

Technical Field

[0001] This invention belongs to the field of electronic information calibration technology, and relates to a method for unifying the coordinates of a laser positioning system, specifically a method for unifying the coordinates of a laser positioning system based on a calibration board. Background Technology

[0002] Laser positioning systems are widely used in large-scale industrial measurement fields, and the coordinate unification of multiple laser emitting stations is a key technical problem currently facing laser positioning systems.

[0003] The most commonly used method for coordinate unification is the standard ruler method. This involves placing a standard ruler of known length at multiple locations in the measurement space, solving for the coordinates of the receivers at both ends of the standard ruler based on the length constraint of the standard ruler, and achieving coordinate unification of the laser transmitter coordinate system through coordinate transformation.

[0004] However, in order to achieve high calibration accuracy, this method requires the standard ruler to be distributed in many positions in the measurement space. In a space of 3.5m×4.0m×2.0m about 6m away from the two laser emission stations, 16 reference positions are needed to control the ruler length measurement error within 0.25mm. Therefore, this method is inefficient.

[0005] Given the aforementioned technical deficiencies of existing technologies, there is an urgent need to develop a new method for unifying coordinates in laser positioning systems. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a coordinate unification method for a laser positioning system based on a calibration plate, which can improve the efficiency of coordinate unification of laser transmitting stations.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A coordinate unification method for a laser positioning system based on a calibration plate, characterized by the following steps:

[0009] 1) Construct a laser emitting station coordinate unification device, which includes M laser emitting stations and a calibration plate, wherein M≥2. The calibration plate is set at a common visible position of the M laser emitting stations. The calibration plate includes a rectangular carbon fiber substrate and four measurement nodes fixed on the rectangular carbon fiber substrate, wherein one of the measurement nodes is not on the same plane as the other measurement nodes.

[0010] 2) Measure the coordinates of each of the measuring nodes on the rectangular carbon fiber substrate in the coordinate system of the measuring instrument, and use the coordinates to calculate the distance between each pair of measuring nodes and the angle between the lines connecting each pair of measuring nodes.

[0011] 3) Based on the distance and angle values ​​calculated in step 2), use the M laser emitting stations to measure the coordinate values ​​of the four measurement nodes in the coordinate system of the M laser emitting stations respectively;

[0012] 4) Based on the coordinate values ​​obtained in step 3), the coordinates of the M laser emission stations are unified through the rotation and translation matrices of coordinate transformation.

[0013] Preferably, the coordinate unification method for the laser positioning system based on the calibration plate further includes the following steps:

[0014] 5) Based on the coordinate unification achieved in step 4), the coordinate transformation matrix is ​​optimized by measuring the distance between nodes to achieve higher precision coordinate unification of the M laser emission stations (1).

[0015] Preferably, in step 1), the four measurement nodes fixed on the rectangular carbon fiber substrate (2-1) are Q1, Q2, Q3 and Q4, and one of the measurement nodes Q2 is located on a different plane from the other measurement nodes. When the rectangular carbon fiber substrate (2-1) is placed perpendicular to the ground, the line connecting the measurement nodes Q3 and Q4 is perpendicular to the ground.

[0016] Preferably, step 2) specifically involves: using the measuring instrument to measure the coordinate values ​​of the measuring nodes Q1, Q2, Q3, and Q4 in the measuring instrument's coordinate system, and then using the coordinate values ​​to solve for the coordinates of the measuring nodes Q1, Q2, Q3, and Q4. i With Q j The distance L between ij And the angle β between the line connecting nodes Q1 and Q2 and the line connecting Q3 and Q4.

[0017] Preferably, step 3) specifically comprises:

[0018] 3.1) Place the calibration plate (2) perpendicular to the ground. When the laser emitting station (1) scans the measurement node (2-2) on the rectangular carbon fiber substrate (2-1), the two laser fan surfaces of the laser emitting station (1) converge at the measurement node to form a ray pointing from the origin of the coordinates of the laser emitting station (1) to the measurement node. Let the direction vector of the two rays pointing to the measurement nodes Q3 and Q4 be r3 = [r 3x r 3y r 3z ], r4 = [r4x r 4y r 4z The pitch angle of Q3 was measured to be β3, and the pitch angle of Q4 was measured to be β4. The distance between the measurement nodes Q3 and Q4 was L. 34 The coordinate values ​​of measurement nodes Q3 and Q4 in the coordinate system of the laser emitting station (1) are obtained by solving according to the geometric relationship;

[0019] 3.2) When the laser emitting station (1) scans the measurement nodes Q1 and Q2, the elevation angle of Q1 is measured as β1, the elevation angle of Q2 is measured as β2, and the direction vector of the two rays pointing to the measurement nodes Q1 and Q2 is r1 = [r 1x r 1y r 1z ], r2=[r 2x r 2y r 2z The distance between nodes Q1 and Q2 is measured as L. 12 By combining the angle β between the line connecting Q1 and Q2 and the line connecting Q3 and Q4, the coordinate values ​​of the measurement nodes Q1 and Q2 in the coordinate system of the laser emission station (1) are obtained according to the geometric relationship.

[0020] Preferably, step 4) specifically involves: based on the coordinate values ​​of the measurement nodes on the rectangular carbon fiber substrate (2-1) obtained in step 3) under different coordinate systems of the laser emitting stations (1), applying formula (1) to unify the coordinates of the measurement nodes under the coordinate systems of the M laser emitting stations (1):

[0021]

[0022] In the formula, R ij and T ij Let Q be the rotation and translation matrix from the coordinate system of laser station i to the coordinate system of laser station j; ni For measuring node Q n The coordinates of Q in the coordinate system of the i-th laser emitting station; nj For measuring node Q n The coordinates of the j-th laser emission station in the coordinate system.

[0023] Preferably, step 5) specifically comprises:

[0024] The calibration board is placed at N commonly visible positions of the M laser emitting stations. At each position, the measurement nodes on the rectangular carbon fiber substrate are measured using each of the laser emitting stations. The coordinate system of any one of the M laser emitting stations is defined as the global coordinate system, and the coordinates of any measurement node on the rectangular carbon fiber substrate in the global coordinate system are defined as Q = [xyz].T When the k-th laser emitting station scans the measurement node with coordinates Q, the distance constraint from the measurement node to the laser plane is:

[0025]

[0026] In the formula, [a km b km c km d km (m=1,2) represents the plane coefficient when the m-th laser plane of the k-th laser emitting station scans the measurement node at coordinate Q. It is obtained based on the fixed intrinsic parameters of the laser emitting station and the rotation angle of the emitting station; R TXGk and T TXGk Let be the rotation and translation matrices from the global coordinate system to the coordinate system of the k-th laser transmitter station;

[0027] If Q is measured by M laser emission stations, then equation (2) is written as an overdetermined system of 2M equations, and the coordinate measurement value of Q is expressed by least squares solution.

[0028] Calculate the Euclidean distance ||Q between the measurement nodes based on the coordinate measurements. i Q j ||, then the distance constraint between measurement nodes on the rectangular carbon fiber substrate:

[0029] D = ||Q i Q j ||-L ij (3)

[0030] When the rotation matrix is ​​represented as The orthogonal constraint is of the form:

[0031]

[0032] Combining the above constraints, the optimization objective function is:

[0033]

[0034] In the formula, F nki The distance constraint equation for the k-th laser emitting station scanning to the i-th measurement node when the calibration plate is at the n-th position; D nij To constrain the distance between the i-th and j-th measurement nodes when the calibration board is at the n-th position; f k The orthogonal constraint corresponding to the rotation matrix from the coordinate system of the k-th laser emission station to the global coordinate system;

[0035] Finally, the rotation and translation matrices from step 4), that is, R, are... ij and Tij As the initial value for the objective function (5), a more accurate coordinate unification relationship is obtained by iteratively solving the nonlinear optimization algorithm.

[0036] Compared with the prior art, the coordinate unification method of the laser positioning system based on the calibration plate of the present invention has one or more of the following beneficial technical effects:

[0037] 1. When calibrating using a calibration plate, no other equipment is needed for auxiliary measurement, and the measurement method is simple.

[0038] 2. The four measurement nodes on its calibration plate are not on the same plane, which avoids the situation where the coefficient matrix of the linear equation system is not full rank when solving the coordinate transformation relationship.

[0039] 3. The transformation relationship of the laser emitting station coordinate system can be solved by placing the calibration plate at one position in the measurement space. The more reference positions the calibration plate moves to, the higher the system calibration accuracy. In a measurement area with a size of 6m×7m×2m, when the calibration plate is moved to 9 reference positions to calibrate 3 laser emitting stations, the average error of the length measurement is no more than 0.227mm.

[0040] 4. It provides a coordinate unification method for laser positioning systems based on calibration plates. Only four measurement nodes need to be fixed on the calibration plate. The coordinate unification of the laser transmitting station can be achieved by measuring the distance and angle information between the measurement nodes. Moreover, the more the calibration plate moves, the higher the coordinate unification accuracy, thus improving the efficiency of coordinate unification. Attached Figure Description

[0041] Figure 1 This is a flowchart of the coordinate unification method for a laser positioning system based on a calibration plate according to the present invention.

[0042] Figure 2 This is a schematic diagram of the laser emission station coordinate unification device of the present invention.

[0043] Figure 3 This is a diagram illustrating the geometric relationship of the measurement nodes when the calibration plate is placed vertically to the ground.

[0044] Figure 4 This is a schematic diagram of the coordinate calculation for measuring nodes Q1 and Q2.

[0045] Figure 5 This is a schematic diagram of the coordinate calculation for measuring nodes Q3 and Q4. Detailed Implementation

[0046] The present invention will be further described below with reference to the accompanying drawings and embodiments. The content of the embodiments is not intended to limit the scope of protection of the present invention.

[0047] To address the problem of unifying the coordinates of multiple laser emitting stations in existing laser positioning systems, this invention provides a coordinate unification method for laser positioning systems based on a positioning plate. This method only requires fixing four measurement nodes on a calibration plate, and the coordinates of the laser emitting stations can be unified by measuring the distance and angle information between the measurement nodes. Furthermore, the more the calibration plate moves, the higher the accuracy of coordinate unification, thus improving the efficiency of coordinate unification.

[0048] Figure 1 A flowchart of the coordinate unification method for a laser positioning system based on a calibration plate according to the present invention is shown. Figure 1 As shown, the coordinate unification method for a laser positioning system based on a calibration plate according to the present invention includes the following steps:

[0049] I. Construct a unified coordinate system for laser emission stations.

[0050] In this invention, such as Figure 2 As shown, the laser emission station coordinate unification device includes M laser emission stations 1 and a calibration plate 2, where M ≥ 2. Preferably, M = 2, that is, there are two laser emission stations 1 in total.

[0051] The calibration plate 2 is positioned in a publicly visible location on the M laser emission stations 1. Furthermore, the calibration plate 2 includes a rectangular carbon fiber substrate 2-1 and four measurement nodes 2-2 fixed to the rectangular carbon fiber substrate 2-1, wherein one of the measurement nodes 2-2 is not on the same plane as the other measurement nodes 2-2.

[0052] Specifically, the four measurement nodes fixed on the rectangular carbon fiber substrate 2-1 are Q1, Q2, Q3, and Q4, with one of the measurement nodes, Q2, located on a different plane from the other measurement nodes. Furthermore, when the rectangular carbon fiber substrate 2-1 is placed perpendicular to the ground, the line connecting measurement nodes Q3 and Q4 is perpendicular to the ground.

[0053] 2. Measure the coordinate values ​​of each measurement node 2-2 on the rectangular carbon fiber substrate 2-1 in the coordinate system of the measuring instrument, and use the coordinate values ​​to calculate the distance between every two measurement nodes 2-2 and the angle between the lines connecting each pair of measurement nodes 2-2.

[0054] In this invention, any high-precision instrument in the prior art can be used to measure the coordinate values ​​of each measurement node 2-2 on the rectangular carbon fiber substrate 2-1 in the instrument coordinate system.

[0055] In this invention, since there are four measurement nodes, the coordinate values ​​of the four measurement nodes Q1, Q2, Q3, and Q4 in the coordinate system of the measuring instrument can be measured using the measuring instrument. After the coordinate values ​​are measured, the coordinate values ​​are used to solve for the coordinates of the measurement nodes Q1, Q2, Q3, and Q4. i With Q j The distance L between ij And the angle β between the line connecting nodes Q1 and Q2 and the line connecting Q3 and Q4.

[0056] Where i and j are natural numbers less than or equal to 4, L ij It is the distance between the i-th measurement node and the j-th measurement node.

[0057] Third, based on the distance and angle values ​​calculated in step two, the coordinate values ​​of the four measurement nodes 2-2 in the coordinate system of the M laser emission stations 1 are measured using the M stations (2 in this invention).

[0058] Specifically, first, the calibration plate 2 is placed perpendicular to the ground, and the geometric relationship between the measurement nodes is as follows: Figure 3 As shown, the angle between the line connecting Q1 and Q2 and the line connecting Q3 and Q4 is β, and the angle between the line connecting measurement nodes Q1 and Q2 and the ground is α. Then...

[0059] When the laser emitting station 1 scans the measurement node 2-2 on the rectangular carbon fiber substrate 2-1, the two laser sectors of the laser emitting station 1 converge at the measurement node to form a ray pointing from the origin of the coordinate system of the laser emitting station 1 to the measurement node, such as... Figure 4 As shown, when the laser emitting station 1 scans to measurement nodes Q1 and Q2, the measured pitch angle of Q1 is β1, the pitch angle of Q2 is β2, and the direction vectors of the two rays pointing to measurement nodes Q1 and Q2 are r1 = [r 1x r 1y r 1z ], r2=[r 2x r 2y r 2z The angle between r1 and r2 is θ. 12 The distance between nodes Q1 and Q2 is measured as L. 12 Let P1 and P2 be the projection points of measurement nodes Q1 and Q2 onto the xoy plane of the coordinate system of laser emission station 1, P3 be the intersection of the extension of the line connecting measurement nodes Q1 and Q2 with the xoy plane, and α be the angle between the line connecting measurement nodes Q1 and Q2 and the xoy plane. Then, based on the above geometric relationships, we have the following equation:

[0060]

[0061] In the formula, The Z-axis coordinates of measurement nodes Q1 and Q2 in the coordinate system of laser emitting station 1 can be obtained by solving the formula. The coordinates of measurement nodes Q1 and Q2 in the coordinate system of laser emitting station 1 can be obtained by combining r1 and r2.

[0062] like Figure 5 As shown, let the direction vectors of the two rays pointing to measurement nodes Q3 and Q4 be r3 = [r 3x r 3y r 3z ], r4 = [r 4x r 4y r 4z The pitch angle of Q3 was measured to be β3, and the pitch angle of Q4 was measured to be β4. The distance between the measurement nodes Q3 and Q4 was L. 34 The projection point of measurement nodes Q3 and Q4 onto the xoy plane is P4. The coordinate values ​​of measurement nodes Q3 and Q4 in the coordinate system of the laser emitting station 1 are obtained by solving according to the geometric relationship.

[0063]

[0064] In the formula,

[0065] Thus, the coordinate values ​​of the four measurement nodes Q1, Q2, Q3 and Q4 in the coordinate system of each laser emitting station 1 were obtained.

[0066] Fourth, based on the coordinate values ​​obtained in step three, the coordinates of the M laser emission stations 1 are unified through the rotation and translation matrices of coordinate transformation.

[0067] In this invention, formula (1) can be used to achieve coordinate unification of the measurement nodes in the coordinate system of the M laser transmitting stations 1:

[0068]

[0069] In the formula, R ij and T ij Let Q be the rotation and translation matrix from the coordinate system of laser station i to the coordinate system of laser station j; ni For the nth measurement node Q n The coordinates of Q in the coordinate system of the i-th laser emitting station; nj For the nth measurement node Q n The coordinates of the j-th laser emission station in the coordinate system.

[0070] Thus, the coordinates of the four measurement nodes Q1, Q2, Q3 and Q4 in the coordinate systems of the two laser emission stations 1 were unified.

[0071] Through the above steps, the coordinates of different laser emitting stations in the laser positioning system have been unified; however, the accuracy is still insufficient. Therefore, in this invention, the coordinate unification method for the laser positioning system based on a calibration plate further includes the following steps:

[0072] Fifth, based on the coordinate unification achieved in step four, the coordinate transformation matrix is ​​optimized by measuring the distance between nodes to achieve higher precision coordinate unification for the M laser emission stations 1.

[0073] Specifically, the calibration plate 2 is placed at N publicly visible locations on the M laser emission stations 1. Preferably, N = 9.

[0074] Specifically, at each location, each laser emitting station 1 measures the measurement nodes on the rectangular carbon fiber substrate 2-1. The coordinate system of any one of the M laser emitting stations is defined as the global coordinate system, and the coordinates of any measurement node on the rectangular carbon fiber substrate 2-1 in the global coordinate system are defined as Q = [xyz]. T When the k-th laser emitting station 1 scans the measurement node with coordinates Q, the distance constraint from the measurement node to the laser plane is:

[0075]

[0076] In the formula, [a km b km c km d km R (m=1,2) is the plane coefficient when the m-th laser plane of the k-th laser emitting station scans the measurement node with coordinates Q, which is obtained based on the fixed internal parameters of the laser emitting station and the rotation angle of the emitting station; TXGk and T TXGk Let be the rotation and translation matrix from the global coordinate system to the coordinate system of the k-th laser transmitter. M laser transmitters jointly measure Q. Equation (2) is written as an overdetermined system of 2M equations, and the coordinate measurement value of Q is expressed by least squares solution. The Euclidean distance ||Q| between the measurement nodes is calculated based on the coordinate measurement values. i Q j ||, then the distance constraint between the measurement nodes on the rectangular carbon fiber substrate (2-1) is:

[0077] D = ||Q i Q j ||-L ij (3)

[0078] When the rotation matrix is ​​represented as The orthogonal constraint is of the form:

[0079]

[0080] Combining the above constraints, the optimization objective function is:

[0081]

[0082] In the formula, F nki The distance constraint equation for the calibration plate (2) at the nth position, from the kth laser emitting station to the i-th measurement node; D nij To constrain the distance between the i-th and j-th measurement nodes of the calibration board (2) at the n-th position; f k The orthogonal constraint corresponding to the rotation matrix from the coordinate system of the k-th laser transmitter to the global coordinate system.

[0083] The rotation and translation matrices from step four, i.e., R, are... ij and T ij As the initial value for the objective function (5), a more accurate coordinate unification relationship is obtained by iteratively solving the nonlinear optimization algorithm.

[0084] This invention pre-measures the distances and angles between measurement nodes on a calibration plate. During use, simply placing the calibration plate in a publicly visible location within the laser transmitter station achieves coordinate unification. Furthermore, placing the calibration plate at multiple reference positions improves the accuracy of coordinate unification. Compared to traditional standard ruler calibration methods, this invention effectively reduces the number of reference positions, improves calibration efficiency, and is suitable for coordinate unification in precision measuring equipment.

[0085] The above embodiments of the present invention are merely examples for clearly illustrating the present invention and are not intended to limit the implementation of the present invention. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is impossible to exhaustively list all possible implementations here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A coordinate unification method for a laser positioning system based on a calibration plate, characterized in that, Includes the following steps: 1) Construct a laser emitting station coordinate unification device, the laser emitting station coordinate unification device includes M laser emitting stations (1) and a calibration plate (2), wherein M≥2, the calibration plate (2) is set at a common visible position of the M laser emitting stations (1), the calibration plate (2) includes a rectangular carbon fiber substrate (2-1) and 4 measurement nodes (2-2) fixed on the rectangular carbon fiber substrate (2-1), wherein one of the measurement nodes (2-2) is not on the same plane as the other measurement nodes (2-2); 2) Measure the coordinate values ​​of each measurement node (2-2) on the rectangular carbon fiber substrate (2-1) in the coordinate system of the measuring instrument, and use the coordinate values ​​to calculate the distance between every two measurement nodes (2-2) and the angle between the lines connecting each pair of measurement nodes (2-2); 3) Based on the distance and angle values ​​calculated in step 2), the coordinate values ​​of the four measurement nodes (2-2) in the coordinate system of the M laser emission stations (1) are measured using the M laser emission stations (1); step 3) specifically involves: 3.1) Place the calibration plate (2) perpendicular to the ground. When the laser emitting station (1) scans the measurement node (2-2) on the rectangular carbon fiber substrate (2-1), the two laser fan surfaces of the laser emitting station (1) converge at the measurement node to form a ray pointing from the origin of the coordinates of the laser emitting station (1) to the measurement node. Let the direction vector of the two rays pointing to the measurement nodes Q3 and Q4 be r3 = [r 3x r 3y r 3z ], r4 = [r 4x r 4y r 4z The pitch angle of Q3 was measured to be β3, and the pitch angle of Q4 was measured to be β4. The distance between the measurement nodes Q3 and Q4 was L. 34 The coordinate values ​​of measurement nodes Q3 and Q4 in the coordinate system of the laser emitting station (1) are obtained by solving according to the geometric relationship; 3.2) When the laser emitting station (1) scans the measurement nodes Q1 and Q2, the elevation angle of Q1 is measured as β1, the elevation angle of Q2 is measured as β2, and the direction vector of the two rays pointing to the measurement nodes Q1 and Q2 is r1 = [r 1x r 1y r 1z ], r2=[r 2x r 2y r 2z The distance between nodes Q1 and Q2 is measured as L. 12 By combining the angle β between the line connecting Q1 and Q2 and the line connecting Q3 and Q4, the coordinate values ​​of the measurement nodes Q1 and Q2 in the coordinate system of the laser emission station (1) are obtained according to the geometric relationship. 4) Based on the coordinate values ​​obtained in step 3), the coordinates of the M laser emission stations (1) are unified through the rotation and translation matrices of coordinate transformation.

2. The coordinate unification method for a laser positioning system based on a calibration plate according to claim 1, characterized in that, Further steps include: 5) Based on the coordinate unification achieved in step 4), the coordinate transformation matrix is ​​optimized by measuring the distance between nodes to achieve higher precision coordinate unification of the M laser emission stations (1).

3. The coordinate unification method for a laser positioning system based on a calibration plate according to claim 2, characterized in that, In step 1), the four measurement nodes fixed on the rectangular carbon fiber substrate (2-1) are Q1, Q2, Q3 and Q4, and one of the measurement nodes Q2 is located on a different plane from the other measurement nodes. When the rectangular carbon fiber substrate (2-1) is placed perpendicular to the ground, the line connecting the measurement nodes Q3 and Q4 is perpendicular to the ground.

4. The coordinate unification method for a laser positioning system based on a calibration plate according to claim 3, characterized in that, Step 2) specifically involves: using the measuring instrument to measure the coordinate values ​​of the measuring nodes Q1, Q2, Q3, and Q4 in the measuring instrument's coordinate system, and then using the coordinate values ​​to solve for the coordinates of the measuring nodes Q1, Q2, Q3, and Q4. i With Q j The distance L between ij And the angle β between the line connecting nodes Q1 and Q2 and the line connecting Q3 and Q4.

5. The coordinate unification method for a laser positioning system based on a calibration plate according to claim 4, characterized in that, Step 4) specifically involves: based on the coordinate values ​​of the measurement nodes on the rectangular carbon fiber substrate (2-1) obtained in step 3) under different coordinate systems of the laser emitting stations (1), applying formula (1) to unify the coordinates of the measurement nodes under the coordinate systems of the M laser emitting stations (1): In the formula, R ij and T ij Let Q be the rotation and translation matrix from the coordinate system of laser station i to the coordinate system of laser station j; ni For measuring node Q n The coordinates of Q in the coordinate system of the i-th laser emitting station; nj For measuring node Q n The coordinates of the j-th laser emission station in the coordinate system.

6. The coordinate unification method for a laser positioning system based on a calibration plate according to claim 5, characterized in that, Step 5) specifically involves: The calibration plate (2) is placed at N commonly visible positions of the M laser emitting stations (1). At each position, the measurement nodes on the rectangular carbon fiber substrate (2-1) are measured by each of the laser emitting stations (1). The coordinate system of any one of the M laser emitting stations is defined as the global coordinate system, and the coordinates of any measurement node on the rectangular carbon fiber substrate (2-1) in the global coordinate system are defined as Q = [xyz]. T When the k-th laser emitting station scans the measurement node with coordinates Q, the distance constraint from the measurement node to the laser plane is: In the formula, [a km b km c km d km (m=1,2) represents the plane coefficient when the m-th laser plane of the k-th laser emitting station scans the measurement node at coordinate Q. It is obtained based on the fixed intrinsic parameters of the laser emitting station and the rotation angle of the emitting station; R TXGk and T TXGk Let be the rotation and translation matrices from the global coordinate system to the coordinate system of the k-th laser transmitter station; If Q is measured by M laser emission stations, then equation (2) is written as an overdetermined system of 2M equations, and the coordinate measurement value of Q is expressed by least squares solution. Calculate the Euclidean distance ||Q between the measurement nodes based on the coordinate measurements. i Q j ||, then the distance constraint between the measurement nodes on the rectangular carbon fiber substrate (2-1) is: D=||Q i Q j ||-L ij (3) When the rotation matrix is ​​represented as The orthogonal constraint is of the form: Combining the above constraints, the optimization objective function is: In the formula, F nki The distance constraint equation for the calibration plate (2) at the nth position, from the kth laser emitting station to the i-th measurement node; D nij To constrain the distance between the i-th and j-th measurement nodes of the calibration board (2) at the n-th position; f k The orthogonal constraint corresponding to the rotation matrix from the coordinate system of the k-th laser emission station to the global coordinate system; Finally, the rotation and translation matrices from step 4), that is, R, are... ij and T ij As the initial value for the objective function (5), a more accurate coordinate unification relationship is obtained by iteratively solving the nonlinear optimization algorithm.

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