Docking position measurement method for cabin sections based on non-fixed targets and docking surface features

Abstract

The present application relates to large cabin section docking, and in particular to a cabin section docking pose measurement method based on a non-fixed target and a docking surface feature, to solve the low precision, slow speed and poor operation stability of the prior art when docking manually, the measurement method acquires images of the target tooling arranged on the cabin docking surface in real time, combines the pre-calibrated target tooling three-dimensional coordinates, accurately measures the positioning structure coordinates, obtains the rigid body transformation matrix M of the movable cabin section relative to the fixed cabin section, and then calculates the pose adjustment value of the movable cabin section relative to the fixed cabin section by solving M.

Description

Technical Field

[0001] This invention relates to the docking of large modules, and more specifically to a method for measuring the docking posture of modules based on non-fixed targets and docking surface characteristics. Background Technology

[0002] The production and research of equipment in the aviation, aerospace, and shipbuilding fields involve the docking and assembly of modules, which is a crucial link in the manufacturing process and a complex engineering project with high technical difficulty and multiple fields involved. The quality of module docking significantly affects the overall performance. Traditional module docking and assembly uses rigid tooling for positioning and manual hole drilling for connection. It is difficult to quickly adjust the coaxiality error between modules and the alignment deviation of pins and positioning grooves in the circumferential direction to the required range by visual inspection. This method results in high labor intensity, low work efficiency, and long assembly cycles for operators. Moreover, the docking effect of this method depends on the experience and skill level of the operators, resulting in low docking accuracy, slow speed, and poor operational stability. Therefore, achieving automated module docking is the goal and trend of development in the module assembly field. Module docking requires high precision to ensure production quality, and improved docking efficiency can reduce input costs. Therefore, a non-contact automated method for measuring module position and attitude is needed to achieve automated docking. Summary of the Invention

[0003] The purpose of this invention is to address the shortcomings of existing technologies, such as low accuracy, slow speed, and poor operational stability during manual docking, and to provide a method for measuring the docking posture of compartments based on non-fixed targets and docking surface features.

[0004] To achieve the above objectives, the technical solution provided by this invention is as follows:

[0005] A method for measuring the docking attitude of a module based on a non-fixed target and docking surface features, characterized by the following steps:

[0006] S1, Equipped with a docking posture device: The two modules to be docked are defined as a fixed module and a movable module. An attitude adjustment mechanism is set below the movable module and mounted on the mounting platform. At least three positioning structures and at least two target fixtures are respectively set on the docking surfaces of the movable module and the fixed module. The number of positioning structures on the two docking surfaces is the same and corresponds one-to-one, and the number of target fixtures is the same and corresponds one-to-one. The target fixtures are provided with target feature points and mounting holes, and are connected to the positioning structures through the mounting holes. The plane where the target feature points are located is perpendicular to the docking surface. A monocular vision system is set to acquire images of the target fixtures to ensure that all target fixtures are within its field of view.

[0007] S2, a monocular vision system captures images of the docking status, including all target fixtures;

[0008] S3, process the image and extract the image coordinates of all target feature points in the target tooling;

[0009] S4. Based on the camera intrinsic parameter matrix, the image coordinates and three-dimensional coordinates of the target feature points, calculate the rotation matrix for transforming the coordinate system of the measuring equipment to the camera coordinate system under the docking state. Translation matrix The camera intrinsic parameter matrix is ​​obtained by calibrating the monocular vision system, and the three-dimensional coordinates are the coordinates in the coordinate system of the measuring device obtained by measuring the feature points of the target using the measuring device.

[0010] S5, based on the rotation matrix and translation matrix The target feature point and the mounting hole position are calculated using the three-dimensional coordinates of the target feature point or the three-dimensional coordinates of the mounting hole position; the three-dimensional coordinates of the mounting hole position are the coordinates in the coordinate system of the measuring equipment obtained by measuring the mounting hole position using the measuring equipment.

[0011] S6. Rotation matrix based on the camera coordinate system to the attitude adjustment mechanism coordinate system Translation matrix The coordinates of the target feature point and the mounting hole position in the attitude adjustment mechanism coordinate system are calculated respectively, and the coordinates of the mounting hole position are its corresponding positioning structure coordinates.

[0012] S7. Calculate the coordinates of the remaining positioning structures without target fixtures in the attitude adjustment mechanism coordinate system;

[0013] S8. Using all the coordinates of the positioning structure, calculate the rigid body transformation matrix M of the moving section relative to the fixed section, solve M, and obtain the pitch angle θ, yaw angle ψ, roll angle φ, lateral displacement x, horizontal displacement y, and vertical displacement z of the moving section relative to the fixed section in the attitude adjustment mechanism coordinate system, thus completing the docking attitude measurement.

[0014] Furthermore, in step S1, two target fixtures are respectively set on the docking surface of the movable section and the docking surface of the fixed section.

[0015] Further, in step S5, the camera coordinates of the target feature points of the four target fixtures are denoted as P1. t , The following formulas are used to calculate:

[0016]

[0017] in, These are the rotation matrices for transforming the coordinate system of the measuring device to the camera coordinate system; These are the translation matrices used to transform the coordinate system of the measuring device to the camera coordinate system; These are the three-dimensional coordinates of the target feature points of the four target fixtures;

[0018] The coordinates of the cameras at the four mounting holes are denoted as P1. h , P3 h , The following formula is used to calculate:

[0019]

[0020] in, These are the three-dimensional coordinates of the mounting holes for the four target fixtures.

[0021] Furthermore, in step S6, the coordinates of the target feature points of the four target fixtures in the attitude adjustment mechanism coordinate system are denoted as P1, P2, P3, P4, P5, P6, P7, P8, P9, P1, P1, P1, P2, P1, P2, P1, P2, P3, P4, P1, P2 ... bt , The following formula is used to calculate:

[0022]

[0023] Furthermore, step S7 specifically includes:

[0024] S7.1. Calculate the plane equations of the docking surfaces of the movable and fixed sections;

[0025] S7.2. Calculate the linear equation of the line connecting any two positioning structures with target fixtures on the docking surface of the movable section, and the linear equation of the line connecting any two positioning structures with target fixtures on the docking surface of the fixed section.

[0026] S7.3. Based on the known positional relationships of all positioning structures on the docking surface of the movable section, obtain the coordinates of the remaining positioning structures without target fixtures; based on the known positional relationships of all positioning structures on the docking surface of the fixed section, obtain the coordinates of the remaining positioning structures without target fixtures.

[0027] Further, in step S7.1, the calculation of the planar equation of the docking surface of the active module is specifically as follows:

[0028] 1) Using the target feature point coordinates obtained in step S6, calculate the normal vector of the plane containing the target feature point of the target tooling set on the docking surface of the moving section.

[0029] 2) Based on the fact that the plane containing the target feature point is perpendicular to the docking surface, the normal vector of the docking surface of the moving section is obtained. Combined with the corresponding positioning structure coordinates obtained in step S6, the plane equation of the docking surface of the moving section is calculated.

[0030] Further, in step S4, the rotation matrix Translation matrix It was calculated using the PNP algorithm.

[0031] Furthermore, in step S1, the monocular vision system is fixed to the posture adjustment mechanism or the mounting platform;

[0032] In step S8, the rigid body transformation matrix M of the moving section relative to the fixed section is calculated by constructing an SVD function using all the coordinates of the positioning structure, and M is solved using Euler angles.

[0033] Furthermore, in step S1, at least one monocular vision system is added to perform error correction on the pitch angle θ, yaw angle ψ, roll angle φ, lateral displacement x, horizontal displacement y, and vertical displacement z obtained in step S8.

[0034] Furthermore, the target includes 5×9 dots of the same diameter and marking symbols set around the four corner dots.

[0035] The beneficial effects of this invention are:

[0036] 1. This invention acquires images of the target fixture set on the docking surface of the compartment in real time, combines them with the pre-calibrated three-dimensional coordinates of the target fixture, and obtains the coordinates of the positioning structure through precise measurement, thereby obtaining the rigid body transformation matrix M of the moving compartment relative to the fixed compartment. Then, by solving M, the pose adjustment value of the moving compartment relative to the fixed compartment is calculated.

[0037] 2. The target fixture of the present invention is suspended on the pin hole or pin shaft through the mounting hole. The suspension angle cannot be exactly the same each time it is used. However, as long as the plane where the target feature point is located is perpendicular to the mating surface, the coordinates of the positioning structure can be accurately obtained. Therefore, the installation requirements of the target fixture are not absolutely fixed, the accuracy requirement of the setting angle is low, the operation is simple, and the results obtained are highly accurate. The target fixture is flexible and convenient to use.

[0038] 3. This invention calculates the plane equation of the target feature points, and then obtains the docking surface equation based on its normal vector and the mounting hole position of the target tooling. This allows the coordinates of other positioning structures to be obtained, solving the problem that the spatial orientation of the compartment cannot be directly measured due to the limited surface features of the product during actual docking. It also minimizes the number of suspended target tooling, simplifies the operation steps, and shortens the docking time. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the module docking.

[0040] Figure 2 This is a schematic diagram of the target.

[0041] Explanation of reference numerals in the attached drawings: 1-Attitude adjustment mechanism; 2-Moving section; 3-Fixed section; 4-Positioning structure; 5-Target tooling; 6-Monocular camera; 7-Mounting platform. Detailed Implementation

[0042] Example 1

[0043] This invention addresses the large size of the compartments, where it is inconvenient to fix or set targets on the docking surface, and targets cannot be printed on the compartment surface. Therefore, a detachable target fixture 5 is provided on the docking surface. Figure 1 As shown, the compartment includes a fixed compartment 3 and a movable compartment 2. Positioning structures 4 are correspondingly provided on their mating surfaces. The positioning structures 4 consist of matching pins and pin holes, with at least three pins and pin holes in each. At least two target fixtures 5 are provided on the mating surfaces of the fixed compartment 3 and the movable compartment 2, respectively. The number of target fixtures 5 on the two mating surfaces is the same and they correspond one-to-one. Each target fixture 5 includes a target and a connector. The target has multiple target feature points. The target is suspended and installed on the pins or pin holes through mounting holes on the connector. The plane of the target is perpendicular to the plane of the mating surface. A monocular vision system is fixedly installed at one end of the fixed section 3 or the movable section 2 to ensure that all target fixtures 5 are within the field of view of the monocular vision system. The monocular vision system includes a monocular camera 6. An attitude adjustment mechanism 1 is installed below the movable section 2 to adjust its position. The docking attitude measurement ultimately requires converting the docking attitude data into the coordinate system of the attitude adjustment mechanism. The docking of the sections is achieved by moving the attitude adjustment mechanism 1. The attitude adjustment mechanism 1 is a six-degree-of-freedom attitude adjustment mechanism.

[0044] In this embodiment, four pins are provided on the docking surface of the fixed section 3, and four pin holes are provided on the docking surface of the movable section 2. Two target fixtures 5 are provided on both the fixed section 3 and the movable section 2. The section docking pose measurement method based on the non-fixed target and docking surface features of this invention is used to calculate the pose of the movable section 2 relative to the fixed section 3, including four steps: monocular vision system intrinsic parameter calibration, hand-eye calibration, target fixture calibration, and docking pose measurement.

[0045] Step 1: Intrinsic parameter calibration of monocular vision system.

[0046] Intrinsic parameter calibration of the monocular vision system is performed using a high-precision intrinsic parameter calibration board to obtain the camera's internal parameters. These parameters include the lens focal length, the coordinates of the intersection of the camera's optical axis and the imaging physical plane in the image pixel coordinate system, and the distortion coefficients. The intrinsic parameter calibration specifically includes the following steps:

[0047] 1.1. Within the camera's field of view, move the intrinsic parameter calibration plate freely (non-parallel) 8-12 times, covering as much of the field of view as possible. Take one image after each movement, ensuring all feature points on the intrinsic parameter calibration plate are included in the image. Extract the center coordinates of all feature points on the intrinsic parameter calibration plate in each image; these are the image coordinates of all feature points in the image pixel coordinate system. Then, establish a one-to-one correspondence between these coordinates and the calibration plate coordinates in the intrinsic parameter calibration plate coordinate system.

[0048] 1.2. Use the image coordinates of the feature points and the coordinates of the calibration board to calibrate the camera's internal parameters. For specific calibration, refer to the method in Zhang Zhengyou's paper "A flexible new technique for camera calibration. IEEE Transactions on Pattern Analysis and Machine Intelligence [J]. 2000, 22(11): 1330-1334".

[0049] Let the coordinates of any feature point on the calibration plate be (X... w ,Y w Z w Given that the image coordinates on the image plane are (u,v), the camera perspective projection model is shown in the following equation:

[0050]

[0051] In the formula:

[0052] λ is an arbitrary, non-zero scaling factor;

[0053] A is the camera's intrinsic parameter matrix;

[0054] f x ,f y The effective focal length of the camera in the X and Y directions is the ratio of the physical size of a unit pixel in the row and column directions of the image pixel coordinate system to the focal length.

[0055] (u0,v0) are the image coordinates of the intersection of the camera's optical axis and the image plane;

[0056] (R,T) represents the camera's external parameters, indicating the transformation relationship between the intrinsic parameter calibration plate coordinate system and the camera coordinate system.

[0057] Step 2, camera extrinsic parameter calibration, that is, calibration of the camera coordinate system and the attitude adjustment mechanism coordinate system of the monocular vision system.

[0058] Camera extrinsic parameter calibration, also known as hand-eye calibration, involves mounting the attitude adjustment mechanism 1 on the mounting platform 7. In this embodiment, the mounting platform 7 is a vehicle body for easy movement. To guide the precise docking of the six-DOF attitude adjustment mechanism with the movable compartment 2, hand-eye calibration is required to calculate the transformation relationship between the camera coordinate system and the attitude adjustment mechanism coordinate system. Specifically:

[0059] 2.1. Install hand-eye calibration fixture

[0060] The external parameter calibration plate is attached to the hand-eye calibration fixture. The structure and installation position of the hand-eye calibration fixture are designed according to the installation method of the monocular camera 6. The monocular camera 6 is set at one end of the movable compartment 2. The monocular camera 6 can be installed on the vehicle body or the attitude adjustment mechanism 1. If the monocular camera 6 is installed on the vehicle body, the hand-eye calibration fixture is installed on the attitude adjustment mechanism 1. If the monocular camera 6 is fixedly connected to the attitude adjustment mechanism 1, the hand-eye calibration fixture can be installed at other fixed positions within the field of view of the monocular camera 6.

[0061] 2.2. Manually or automatically control the attitude adjustment mechanism 1 to move continuously to three positions along one of its X, Y, Z directions. During the movement, the external parameter calibration plate is always within the field of view of the monocular camera 6. Each time the plate moves to a new position, an image of the current external parameter calibration plate is captured.

[0062] 2.3. Repeat step 2.2, control the attitude adjustment mechanism 1 to move in another direction, and take a picture of the corresponding external parameter calibration plate;

[0063] 2.4. Represent the movement processes in steps 2.2 and 2.3 using rotation transformation B (containing rotation matrix and translation vector) in the attitude adjustment mechanism coordinate system, and represent this process using rotation transformation A (containing rotation matrix and translation vector) in the camera coordinate system. Let X be the transformation relationship from the camera coordinate system to the attitude adjustment mechanism coordinate system. Construct the hand-eye calibration equation: AX = XB, solve for X, and obtain the rotation matrix from the camera coordinate system to the attitude adjustment mechanism coordinate system. Translation matrix

[0064] Step 3, Calibration of Target Fixture 5

[0065] Each target fixture 5 was calibrated using a high-precision three-dimensional measuring device. The three-dimensional coordinates of the target feature points and the three-dimensional coordinates of the mounting hole positions in the target fixture 5 were recorded, thereby obtaining the three-dimensional coordinates of all feature points on the target fixture 5 in the coordinate system of the measuring device. and the three-dimensional coordinates of the mounting hole positions Where i is the sequence number of the four target tools 5, i = 1, 2, 3, 4.

[0066] Since the mounting holes on the connectors are installed on pin holes or pin shafts during docking, this calibration step can be used to obtain the positional relationship between the target feature points and the corresponding pin holes or pin shafts on the docking surfaces.

[0067] Step 4, Docking pose measurement

[0068] 4.1. An attitude adjustment mechanism 1 is installed below the movable section 2 and mounted on the mounting platform 7; a monocular vision system is installed on the attitude adjustment mechanism 1. Target fixtures 5 numbered 1 and 2 are installed on the docking surface of the fixed section 3, and target fixtures 5 numbered 3 and 4 are installed on the docking surface of the movable section 2. The target fixtures 5 on the two docking surfaces correspond one-to-one, and the plane where the target is located is perpendicular to its docking surface. Multiple target feature points are arranged on the target surface to determine the coordinates of the plane where the target is located and the corresponding pin holes or pin shafts, thereby calculating the pose of the fixed section 3 and the movable section 2. In the coordinate system of the measuring equipment, the three-dimensional coordinates of the target feature points of the four target fixtures 5 numbered 1, 2, 3, and 4 are denoted as follows: The three-dimensional coordinates of the mounting holes are denoted as follows: In other embodiments of the present invention, the monocular vision system can also be set at any position to ensure that the target tool 5 is within its field of view, and is usually set on the attitude adjustment mechanism 1 or the mounting platform 7.

[0069] 4.2. Use a monocular vision system to capture images of the docking state. The images include four target fixtures 5 and can display the target feature points.

[0070] 4.3. Process the acquired images and extract the image coordinates of the target feature points in the four target fixtures 5;

[0071] 4.4. Based on the camera intrinsic parameter matrix, the image coordinates and three-dimensional coordinates of the target feature points, the PNP algorithm is used to calculate the rigid body transformation relationship from the measurement equipment coordinate system to the camera coordinate system under the docking state. The rigid body transformation relationship includes the rotation matrix. Translation matrix

[0072] 4.5. The camera coordinates of the target feature points on the four target fixtures 5, numbered 1, 2, 3, and 4, are respectively denoted as P1. t , The following formulas are used to calculate:

[0073]

[0074] in, These are the rotation matrices used to transform the coordinate system of the measuring device to the camera coordinate system. These are the translation matrices for transforming the coordinate system of the measuring device to the coordinate system of the camera;

[0075] 4.6. The positional relationship between the target feature points and the mounting holes on the target fixture 5 is fixed. The camera coordinates of the mounting holes on the four target fixtures 5 with serial numbers 1, 2, 3, and 4 are respectively denoted as P1. h P2 h P3 h P4 h , The following formula is used to calculate:

[0076]

[0077] 4.7. The camera coordinates of the four target feature points of the four target fixtures 5 (numbered 1, 2, 3, and 4) are transformed to their corresponding coordinates in the attitude adjustment mechanism coordinate system using the following formula. The corresponding coordinates in the attitude adjustment mechanism coordinate system are denoted as P1. bt ,

[0078]

[0079] Similarly, the coordinates of the mounting holes of the four target fixtures 5 with serial numbers 1, 2, 3, and 4 in the coordinate system of the attitude adjustment mechanism can be obtained. These coordinates are also the coordinates of their corresponding pins or pin holes, denoted as P1. bh ,

[0080] 4.8. Calculate the plane equations of the docking surfaces of movable section 2 and fixed section 3 in the coordinate system of the attitude adjustment mechanism.

[0081] Mark the pins corresponding to the mounting holes of target fixtures 5 (numbered 1 and 2) as A and B, respectively, and mark the pin holes corresponding to the mounting holes of target fixtures 5 (numbered 3 and 4) as C and D, respectively. Then, A and B are located on the docking surface of the fixed section 3, and C and D are located on the docking surface of the movable section 2. Using the coordinates P1 of the coplanar target feature points in the attitude adjustment mechanism coordinate system... bt , Establish the corresponding target plane normal vectors for each, and then use the perpendicular relationship between the target and the docking surface to obtain the normal vectors of the docking surface of fixed section 3 and the docking surface of movable section 2. Then, based on the coordinates of A and B and the normal vector of the docking surface of fixed section 3, establish the plane equation of the docking surface of fixed section 3: A1x + B1y + C1z = 0. Based on the coordinates of C and D and the normal vector of the docking surface of movable section 2, establish the plane equation of the docking surface of movable section 2: A2x + B2y + C2z = 0.

[0082] 4.9. Establish the equations of the lines AB and CD respectively. Using the equation of the line AB and the plane equation of the docking surface of fixed section 3, and based on the known positional relationship of the four pins on the docking surface of fixed section 3, calculate the coordinates of the other two pins besides A and B; similarly, calculate the coordinates of the other two pin holes besides C and D on the docking surface of fixed section 3.

[0083] In other embodiments of the present invention, the target tooling 5 can be set in any two pins or pin holes on the same mating surface, and the straight line equation is the equation of the two pins corresponding to the target tooling 5 or the equation of the line connecting the two pin holes.

[0084] 4.10. Construct an SVD function using the coordinates of the four pin holes of the movable section 2 and the four pin axes of the fixed section 3, and calculate the rigid body transformation matrix M of the movable section 2 relative to the fixed section 3, as shown below;

[0085]

[0086] Where R and T are the rotation and translation matrices of the movable section 2 relative to the fixed section 3, respectively, and r 11 -r 33 t1 represents the rotation matrix, and t1-t3 represent the translation matrix.

[0087] In other embodiments of the present invention, the rigid body transformation matrix M can also be calculated by nonlinear optimization.

[0088] 4.11. Using the relationship between Euler angles and M, solve for M to obtain the attitude adjustment values ​​of the moving section 2 relative to the fixed section 3 in the attitude adjustment mechanism coordinate system, including pitch angle θ, yaw angle ψ, roll angle φ, lateral displacement x, horizontal displacement y, and vertical displacement z.

[0089] Then, based on the pitch angle θ, yaw angle ψ, roll angle φ, lateral displacement x, horizontal displacement y, and vertical displacement z calculated in step 4.11, the attitude adjustment mechanism 1 is adjusted in sequence to move the movable section 2 to dock with the fixed section 3.

[0090] In the above steps, steps 1 to 3 are system calibration tasks, which generally only need to be calibrated once. Subsequently, step 4 can be performed multiple times for different active modules 2 to measure the pose. Steps 4.4 to 4.11 are to solve the space docking pose of the two modules in the docking state by using all target feature points in the acquired images.

[0091] The external parameter calibration plate and target used in the above methods can have the same or different structural shapes, number of feature points, and arrangement methods. For ease of use, the structural shape, number of feature points, and arrangement methods are the same in this embodiment, such as... Figure 2As shown, each has 5×9 dots of the same diameter, and there are marking symbols around the four corner dots.

[0092] Example 2

[0093] In this embodiment, two monocular vision systems are included, which independently calculate the pose adjustment value of the active module 2 relative to the fixed module 3. Then, the two pose adjustment values ​​are used for error correction and compensation to improve docking accuracy.

[0094] In other embodiments of the present invention, more monocular vision systems may be provided for error correction and compensation as needed.

Claims

1. A method for measuring the docking attitude of a module based on a non-fixed target and docking surface features, characterized in that, Includes the following steps: S1, Equipped with docking posture device: Define the two sections to be docked as fixed section (3) and movable section (2), set up posture adjustment mechanism (1) below movable section (2), and set up posture adjustment mechanism (1) on the mounting platform (7); set up at least three positioning structures (4) and at least two target fixtures (5) on the docking surface of movable section (2) and fixed section (3) respectively; the number of positioning structures (4) on the two docking surfaces is the same and corresponds one-to-one, and the number of target fixtures (5) is the same and corresponds one-to-one; the target fixtures (5) are provided with target feature points and mounting holes, and are connected to the positioning structure (4) through the mounting holes, and the plane where the target feature points are located is perpendicular to the docking surface; set up a monocular vision system for collecting images of target fixtures (5) to ensure that all target fixtures (5) are within its field of view; S2, the monocular vision system captures an image of the docking state, which includes all target fixtures (5); S3, process the image and extract the image coordinates of all target feature points in the target tooling (5); S4. Based on the camera intrinsic parameter matrix, the image coordinates and three-dimensional coordinates of the target feature points, calculate the rotation matrix for transforming the coordinate system of the measuring equipment to the camera coordinate system under the docking state. Translation matrix The camera intrinsic parameter matrix is ​​obtained by calibrating the monocular vision system, and the three-dimensional coordinates are the coordinates in the coordinate system of the measuring device obtained by measuring the feature points of the target using the measuring device. S5, based on the rotation matrix and translation matrix The target feature point and the mounting hole position are calculated using the three-dimensional coordinates of the target feature point or the three-dimensional coordinates of the mounting hole position; the three-dimensional coordinates of the mounting hole position are the coordinates in the coordinate system of the measuring equipment obtained by measuring the mounting hole position using the measuring equipment. S6. Rotation matrix based on the camera coordinate system to the attitude adjustment mechanism coordinate system Translation matrix The coordinates of the target feature point and the mounting hole position in the attitude adjustment mechanism coordinate system are calculated respectively, and the coordinates of the mounting hole position are its corresponding positioning structure coordinates. S7. Calculate the coordinates of the remaining positioning structures (4) without target fixtures (5) in the attitude adjustment mechanism coordinate system; S8. Using the coordinates of all positioning structures (4), calculate the rigid body transformation matrix M of the moving section (2) relative to the fixed section (3), solve M, and obtain the pitch angle θ, yaw angle ψ, roll angle φ, lateral displacement x, horizontal displacement y and vertical displacement z of the moving section (2) relative to the fixed section (3) in the attitude adjustment mechanism coordinate system, and complete the docking attitude measurement.

2. The method for measuring the docking attitude of a module based on a non-fixed target and docking surface characteristics according to claim 1, characterized in that: In step S1, two target fixtures (5) are respectively set on the docking surface of the movable section (2) and the docking surface of the fixed section (3).

3. The method for measuring the docking attitude of a module based on a non-fixed target and docking surface characteristics according to claim 2, characterized in that: In step S5, the camera coordinates of the target feature points of the four target fixtures (5) are recorded as P1 respectively. t , The following formulas are used to calculate: in, These are the rotation matrices for transforming the coordinate system of the measuring device to the camera coordinate system; These are the translation matrices for transforming the coordinate system of the measuring device to the coordinate system of the camera; These are the three-dimensional coordinates of the target feature points of the four target fixtures (5); The coordinates of the cameras at the four mounting holes are denoted as follows: The following formula is used to calculate: in, These are the three-dimensional coordinates of the mounting holes of the four target fixtures (5).

4. The method for measuring the docking attitude of a module based on a non-fixed target and docking surface features according to claim 3, characterized in that: In step S6, the coordinates of the target feature points of the four target fixtures (5) in the attitude adjustment mechanism coordinate system are respectively denoted as: The following formula is used to calculate:

5. The method for measuring the docking attitude of a module based on a non-fixed target and docking surface features according to any one of claims 1-4, characterized in that: Step S7 is as follows: S7.

1. Calculate the docking plane equations for the movable section (2) and the fixed section (3); S7.

2. Calculate the linear equation of the line connecting any two positioning structures (4) with target fixtures (5) on the docking surface of the movable section (2), and the linear equation of the line connecting any two positioning structures (4) with target fixtures (5) on the docking surface of the fixed section (3). S7.

3. Based on the known positional relationship of all positioning structures (4) on the docking surface of the movable section (2), obtain the coordinates of the remaining positioning structures (4) without target fixtures (5); based on the known positional relationship of all positioning structures (4) on the docking surface of the fixed section (3), obtain the coordinates of the remaining positioning structures (4) without target fixtures (5).

6. The method for measuring the docking attitude of a module based on a non-fixed target and docking surface features according to claim 5, characterized in that: In step S7.1, the calculation of the docking surface plane equation of the active module (2) specifically involves: 1) Using the target feature point coordinates obtained in step S6, calculate the normal vector of the plane containing the target feature point of the target tooling (5) set on the docking surface of the active section (2); 2) Based on the fact that the plane where the target feature point is located is perpendicular to the docking surface, the normal vector of the docking surface of the active compartment (2) is obtained. Combined with the coordinates of the corresponding positioning structure (4) obtained in step S6, the plane equation of the docking surface of the active compartment (2) is calculated.

7. The method for measuring the docking attitude of a module based on a non-fixed target and docking surface features according to claim 6, characterized in that: In step S4, the rotation matrix Translation matrix It was calculated using the PNP algorithm.

8. The method for measuring the docking attitude of a module based on a non-fixed target and docking surface features according to claim 7, characterized in that: In step S1, the monocular vision system is fixed on the posture adjustment mechanism (1) or the mounting platform (7); In step S8, the rigid body transformation matrix M of the active section (2) relative to the fixed section (3) is calculated by constructing the SVD function using the coordinates of all positioning structures (4), and M is solved using Euler angles.

9. The method for measuring the docking attitude of a module based on a non-fixed target and docking surface features according to claim 8, characterized in that: In step S1, at least one monocular vision system is added to perform error correction on the pitch angle θ, yaw angle ψ, roll angle φ, lateral displacement x, horizontal displacement y, and vertical displacement z obtained in step S8.

10. The method for measuring the docking attitude of a module based on a non-fixed target and docking surface features according to claim 9, characterized in that: The target consists of 5×9 dots of the same diameter and marking symbols placed around the four corner dots.

Images