Calculation method and system for multi-plane position degree calibration

Abstract

The invention discloses a calculation method and system for multi-plane position degree calibration. The calculation method comprises the following steps that an image with a calibration block is collected through a 2D camera; calculating calibration data of different height planes of the image with the calibration block; calculating the relative position relation of the original points of different planes; and converting different planes into the same plane based on the relative position relationship between the calibration data and the original point, and correcting the position degrees of the different planes in the same plane. Calibration data of respective planes can be obtained according to different plane calibration block images collected by a 2D camera, then the relative coordinate relation of original points of the different planes is obtained through calculation, finally, the different planes are converted into a unified plane, and multi-plane position degree correction calculation is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of vision calibration, and in particular relates to a calculation method and system for multi-plane position calibration. Background Art

[0002] Calibration blocks are commonly used for camera calibration. They are objects with precise geometric patterns, and planes at different heights on them can be used to determine the spatial position and attitude of the camera. In robot vision systems, calibration blocks can help establish the mapping relationship between the camera coordinate system and the robot coordinate system, which is essential for accurate object positioning and grasping.

[0003] At present, for multi-plane objects in industry, each plane is calibrated separately, and then the calibration of each plane is performed separately, and the different planes are not unified into one plane. Only the calibration of each plane can be performed separately, and the relative coordinate relationship of multiple planes of the object is not established. When the object has multiple planes with a certain height difference, the relative position relationship between the height difference planes cannot be obtained. Summary of the invention

[0004] In order to solve the above technical problems, the present invention proposes a calculation method and system for multi-plane position calibration to solve the problems existing in the above prior art.

[0005] To achieve the above object, the present invention provides a calculation method for multi-plane position calibration, comprising the following steps:

[0006] Capture images with calibration blocks through a 2D camera;

[0007] Calculating calibration data of different height planes of the image with the calibration block;

[0008] Calculate the relative position relationship of the origins of different planes;

[0009] Based on the calibration data and the relative position relationship of the origin, different planes are converted into the same plane, and position correction of different planes is performed in the same plane.

[0010] Preferably, the image with the calibration block is a grayscale image, and the grayscale image includes two-dimensional data information of different planes.

[0011] Preferably, the method for calculating the calibration data includes:

[0012] The coordinates of the calibration block image coordinate points and the corresponding points in the real coordinate system are recorded during calibration, an affine transformation matrix is ​​obtained based on the coordinates of the calibration block image coordinate points and the corresponding points in the real coordinate system, and the actual coordinate value corresponding to each image point is calculated based on the affine transformation matrix.

[0013] Preferably, the method for obtaining the affine transformation matrix comprises:

[0014] The coordinates of the calibration block image coordinate points and the corresponding points in the real coordinate system are processed by the cvGetAffineTransform function in the open source OpenCv to obtain the affine transformation matrix.

[0015] Preferably, the method for calculating the relative position relationship of the origins of different planes includes:

[0016] The different planes of the calibration block are moved to the center of the camera field of view respectively to obtain the physical coordinates of the moving axis, and the relative position relationship of the origins of different planes is calculated based on the physical coordinates.

[0017] Preferably, the method for calculating the relative position relationship of the origins of different planes further includes:

[0018] The lower left corner or upper left corner of each plane of the calibration block is used as the coordinate origin of each plane, and the relative position relationship of the coordinate origin of each plane is obtained.

[0019] The present invention also provides a computing system for multi-plane position calibration, comprising:

[0020] An image acquisition module, used for acquiring images with calibration blocks;

[0021] A visual calibration module, used to perform visual calibration on different planes on an image with a calibration block;

[0022] A position relationship calculation module for different plane coordinate origins, used to calculate the relative position relationship of different plane coordinate origins;

[0023] The different plane position calibration module is used to convert different planes to the same plane according to visual calibration and relative position relationship, and perform different plane position correction in the same plane.

[0024] Preferably, the module for calculating the positional relationship of the origins of coordinates of different planes includes a first calculation unit and a second calculation unit;

[0025] The first calculation unit is used to move different planes of the calibration block to the center of the camera field of view respectively, obtain the physical coordinates of the moving axis, and calculate the relative position relationship of the origins of different planes based on the physical coordinates;

[0026] The second calculation unit is used to use the lower left corner or the upper left corner of each plane of the calibration block as the coordinate origin of each plane, and obtain the relative position relationship of the coordinate origin of each plane.

[0027] Compared with the prior art, the present invention has the following advantages and technical effects:

[0028] The present invention discloses a calculation method and system for multi-plane position calibration, including: collecting images with calibration blocks through a 2D camera; calculating calibration data of planes at different heights of the image with calibration blocks; calculating the relative position relationship of the origins of different planes; converting different planes into the same plane based on the calibration data and the relative position relationship of the origins, and performing position correction of different planes in the same plane. The present invention can obtain the calibration data of each plane based on the calibration block images of different planes collected by the 2D camera, and then obtain the relative coordinate relationship of the origins of different planes by calculation, and finally convert different planes into a unified plane to realize multi-plane position correction calculation. The present invention is relatively simple to operate, highly efficient, and highly accurate, and can well meet the needs of different users. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0030] Figure 1 is a flow chart of a method according to an embodiment of the present invention;

[0031] Figure 2 4 is a system structure diagram of an embodiment of the present invention. DETAILED DESCRIPTION

[0032] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0033] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0034] Embodiment 1

[0035] like Figure 1 As shown, this embodiment provides a calculation method for multi-plane position calibration, including the following steps:

[0036] Capture images with calibration blocks through a 2D camera;

[0037] Calculate the calibration data of different height planes of the image with the calibration block;

[0038] Calculate the relative position relationship of the origins of different planes;

[0039] Based on the calibration data and the relative position relationship of the origin, different planes are converted to the same plane, and the position correction of different planes is performed in the same plane.

[0040] The specific steps are as follows:

[0041] S10: Trigger the 2D camera to acquire the image with the calibration block.

[0042] Image information mainly includes two-dimensional data information of different planes (X, Y two-dimensional coordinate information), brightness, etc.

[0043] In this embodiment, the 2D camera is triggered to collect the calibration block image to obtain two-dimensional data information of different planes;

[0044] The specific steps are: triggering a 2D camera to capture images to obtain two-dimensional data information of different planes. The image data captured by the 2D camera is called a grayscale image, and each point has two-dimensional coordinate information (X, Y).

[0045] S20: Calculate calibration data of respective height planes on the acquired images respectively.

[0046] The calibration block contains calibration information of planes at different heights. By acquiring images of the calibration block, the calibration data of each plane can be calculated respectively.

[0047] Record the coordinates of the calibration block image coordinate points and the corresponding points in the real coordinate system during calibration, and obtain the affine transformation matrix through the cvGetAffineTransform function in the open source OpenCv Thus, the actual coordinate value corresponding to each image point can be obtained.

[0048] S30: Calculation of the relative position relationship of the origin after calibration of planes at different heights.

[0049]

[0050] Move the different planes of the calibration block to the center of the camera field of view to obtain the physical coordinates of the moving axis at this moment. The relative position relationship of the origins of different planes can be calculated through these physical coordinates.

[0051] S40: Convert to a single plane to achieve multi-plane position calibration.

[0052] Through the relative position relationship of the origins of different planes and the plane calibration data of each plane itself, multiple planes can be converted into the same plane, and finally the calculation of multiple plane position correction can be realized.

[0053] For example, if a user wants to calculate the needle tip position of a product with a needle after secondary welding, this method can be used to achieve this.

[0054] The needle tip of the product is on one height plane, and the needle seat is on another height plane, and there is a height difference between the two. The position of all needle tips relative to the needle seat plane can be calculated.

[0055] like Figure 2 As shown, this embodiment also provides a computing system for multi-plane position calibration, including:

[0056] An image acquisition module, used for acquiring images with calibration blocks;

[0057] A visual calibration module, used to perform visual calibration on different planes on an image with a calibration block;

[0058] A position relationship calculation module for different plane coordinate origins, used to calculate the relative position relationship of different plane coordinate origins;

[0059] The different plane position calibration module is used to convert different planes to the same plane according to visual calibration and relative position relationship, and perform different plane position correction in the same plane.

[0060] The system modules are described in detail as follows:

[0061] The image acquisition module is used to acquire the calibration block image.

[0062] The calibration block image information mainly includes two-dimensional data information (X, Y two-dimensional coordinate information), brightness, etc. of different planes of the calibration block. In this embodiment, the image acquisition module camera acquires the calibration block image to obtain the two-dimensional data information of different planes of the calibration block, specifically by triggering the 2D camera to acquire the calibration block image to obtain the two-dimensional data information of different planes of the calibration block. The data acquired by the 2D camera is called a grayscale image, and each point has two-dimensional coordinate information (X, Y).

[0063] The visual calibration module is used to perform visual calibration on different planes on the acquired calibration block image and establish the relationship between pixel coordinates and actual physical coordinates.

[0064] The position relationship calculation module of different plane coordinate origins is used to calculate the relative position relationship of different plane coordinate origins.

[0065] In this embodiment, the user can move different planes of the calibration block to the center of the camera field of view respectively to obtain the physical coordinates of the moving axis at this moment. The relative position relationship of the origins of different planes can be calculated through these physical coordinates.

[0066] The different plane position calibration modules will eventually convert different planes to the same plane to achieve multi-plane position calibration calculation.

[0067] In this embodiment, the module for calculating the positional relationship of the coordinate origins of different planes may also allow the calibration plane of the calibration block to be at the center of the camera field of view without using a moving axis. At this time, the lower left corner or upper left corner of each plane of the calibration block is uniformly used as the coordinate origin of each plane to obtain the relative positional relationship of the coordinate origin of each plane.

[0068] The above are only preferred specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A calculation method for multi-plane position calibration, characterized in that: The following steps are involved: Capture images with calibration blocks through a 2D camera; Calculating calibration data of different height planes of the image with the calibration block; Calculate the relative position relationship of the origins of different planes; Based on the calibration data and the relative position relationship of the origin, different planes are converted into the same plane, and position correction of different planes is performed in the same plane.

2. The calculation method for multi-plane position calibration according to claim 1, characterized in that: The image with the calibration block is a grayscale image, and the grayscale image includes two-dimensional data information of different planes.

3. The calculation method for multi-plane position calibration according to claim 1, characterized in that: Methods for calculating calibration data include: The coordinates of the calibration block image coordinate points and the corresponding points in the real coordinate system are recorded during calibration, an affine transformation matrix is ​​obtained based on the coordinates of the calibration block image coordinate points and the corresponding points in the real coordinate system, and the actual coordinate value corresponding to each image point is calculated based on the affine transformation matrix.

4. The calculation method for multi-plane position calibration according to claim 3, characterized in that: The method for obtaining the affine transformation matrix comprises: The coordinates of the calibration block image coordinate points and the corresponding points in the real coordinate system are processed by the cvGetAffineTransform function in the open source OpenCv to obtain the affine transformation matrix.

5. The calculation method for multi-plane position calibration according to claim 1, characterized in that: The method for calculating the relative position relationship of the origins of different planes comprises: The different planes of the calibration block are moved to the center of the camera field of view respectively to obtain the physical coordinates of the moving axis, and the relative position relationship of the origins of different planes is calculated based on the physical coordinates.

6. The calculation method for multi-plane position calibration according to claim 1, characterized in that: The method for calculating the relative position relationship of the origins of different planes also includes: The lower left corner or upper left corner of each plane of the calibration block is used as the coordinate origin of each plane, and the relative position relationship of the coordinate origin of each plane is obtained.

7. A computing system for multi-plane position calibration, characterized in that: include: An image acquisition module, used for acquiring images with calibration blocks; A visual calibration module, used to perform visual calibration on different planes on an image with a calibration block; A position relationship calculation module for different plane coordinate origins, used to calculate the relative position relationship of different plane coordinate origins; The different plane position calibration module is used to convert different planes to the same plane according to visual calibration and relative position relationship, and perform different plane position correction in the same plane.

8. The computing system for multi-plane position calibration according to claim 7, characterized in that: The module for calculating the positional relationship of the origins of different plane coordinates includes a first calculation unit and a second calculation unit; The first calculation unit is used to move different planes of the calibration block to the center of the camera field of view respectively, obtain the physical coordinates of the moving axis, and calculate the relative position relationship of the origins of different planes based on the physical coordinates; The second calculation unit is used to use the lower left corner or the upper left corner of each plane of the calibration block as the coordinate origin of each plane, and obtain the relative position relationship of the coordinate origin of each plane.

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