Multi-size planar target measurement and positioning method and detection device thereof

Abstract

The present application relates to a kind of multi-size plane target measurement and positioning method and its detection device, method includes the following steps, step one: the center coordinates of multi-size plane target are determined;Step two: according to the principle of binocular range finding, the space coordinates of mark point on multi-size plane target are obtained;Step three: whether the mark point space coordinates obtained by binocular measurement is accurate is judged;Step four: the transformation matrix between image acquisition coordinate system and size target is determined;Step five: the space position and posture of target board relative to image acquisition system at current time are obtained.The present application provides a kind of multi-size plane target measurement and positioning method, is not positioned deviation caused by the limitation of viewing angle range, improves the identification and positioning precision of target, the data collected by image acquisition equipment and laser range finder are coupled analysis, to realize the high-precision positioning process of plane target;Positioning device based on the method, solve the difficult problem of positioning difficulty, large deviation.

Description

Technical Field

[0001] This invention relates to the field of indoor visual positioning, and more specifically to a method and device for measuring and positioning multi-size planar targets. Background Technology

[0002] Indoor visual positioning technology has become an indispensable part of modern industry, widely used in industrial inspection, quality inspection, machine vision, and other fields. Traditional visual positioning technologies, such as light pen measurement, use a fixed binocular vision base station to identify the contact measurement part with attached markers. The binocular system identifies the spatial position of each marker relative to the vision base station, thereby calculating the spatial position of the contact measurement part and completing the three-dimensional measurement of the surface of the workpiece. However, the measurement area is greatly limited due to camera placement and target size issues. The PNP algorithm-based visual positioning scheme first needs to extract markers from the image, then match the markers between consecutive frames to calculate the motion of the vision system in space. However, the accuracy is low and is greatly limited by the environment. For objects with few surface features, the positioning accuracy of the vision system is extremely low.

[0003] The main challenge in indoor visual positioning lies in achieving accurate target or feature point localization. Existing optical pen-based spatial positioning methods limit the positioning range due to the limited camera field of view and the size of the markers on the pen. This invention provides a multi-sized planar target, improving target recognition and positioning accuracy. By combining vision with a laser rangefinder, both the positioning range and accuracy are enhanced. Summary of the Invention

[0004] To overcome the shortcomings of existing technologies, and addressing the limitation on positioning range caused by the camera's field of view in current light pen-based spatial positioning processes, this invention provides a method and detection device for measuring and positioning multi-size planar targets. It employs a method that couples and analyzes data collected by an image acquisition device and a laser rangefinder, and utilizes a visual positioning platform to improve the accuracy of target identification and positioning. By combining vision and a laser rangefinder, it enhances both the positioning range and accuracy.

[0005] To achieve the above objectives, the solution adopted by the present invention is as follows:

[0006] A method for measuring and locating multi-size planar targets, comprising the following steps:

[0007] Step 1: Determine the center coordinates of the multi-size planar target;

[0008] The measuring equipment is activated, causing bright spots emitted by multi-sized positioning targets to appear in the image windows of both image acquisition devices; wherein, the center pixel coordinates of the bright spot in the image captured by the first image acquisition device are... The center pixel coordinates of the bright spot in the image captured by the second image acquisition device out of the two image acquisition devices are: Then, the average value of the bright spot coordinates captured by the two image acquisition devices is calculated respectively.

[0009] Move the two image acquisition devices so that their coordinate centers coincide with the average of the coordinate values ​​of all bright spots in the two image acquisition devices, thereby determining the center coordinates of the images captured by the two image acquisition devices;

[0010] Step 2: Obtain the spatial coordinates of the marker points on the multi-sized planar target based on the principle of binocular ranging;

[0011] Based on the principle of binocular ranging, the coordinates of the circular markers on the multi-sized positioning targets in the image window areas captured by the two image acquisition devices are determined as follows: and Then the spatial coordinates of the Jth marker point relative to the first image acquisition device are obtained. The calculation process is as follows:

[0012]

[0013] In the formula: b represents the distance between the baselines of the first image acquisition device and the second image acquisition device; f represents the focal length of the image acquisition device; These represent the x-coordinate, y-coordinate, and vertical coordinate of the J-th marker point of the first image acquisition device, respectively. This represents the x-coordinate of the J-th marker point in the first image acquisition device; This represents the x-coordinate of the J-th marker point in the second image acquisition device; This represents the x-coordinate of the J-th marker point in the first image acquisition device; J is the serial number of the marker point.

[0014] Step 3: Determine whether the spatial coordinates of the marker points obtained by binocular measurement are accurate;

[0015] Step 31: Determine the distance matrix DC of the marker point in the image acquisition device coordinate system;

[0016] Step 32: Determine the standard relative distance matrix DW between each marker point on the size positioning target plate;

[0017] Step 33: Determine the magnitude of the difference between the two matrices;

[0018] Based on the two matrices DW and DC determined in steps 31 and 32, data filtering is performed; the area of ​​the extracted marker points is the filtering target, and the area threshold is set to V. Marker points with an area less than V in the image are removed, and the element corresponding to the index in matrix DW and DC is set to zero.

[0019] set up The magnitude of the difference between DC and DW is calculated using the following formula:

[0020]

[0021] In the formula: The DC and DW matrices represent the modulus between the two matrices; DC represents the distance matrix of the marker points in the coordinate system of the image acquisition device; DW represents the standard relative distance matrix between the marker points of the size positioning target plate. These represent the column vectors of the 13 marker points in the standard relative distance matrix between each marker point on the size positioning target board; These represent the column vectors of the 13 marker points in the distance matrix of the marker points in the coordinate system of the image acquisition device;

[0022] for Data filtering is performed, and the maximum error threshold of each marker point relative to other marker points is set to D. Marker points with errors less than D and greater than zero are selected to be retained for the next step of calculation, while marker points with errors greater than D are not included in the subsequent calculation.

[0023] Step 4: Determine the transformation matrix between the image acquisition coordinate system and the size target;

[0024] Determine the coordinates of the laser rangefinders relative to the image acquisition device; the coordinates of the four points measured by the four laser rangefinders fall on a multi-sized target board, so a transformation matrix is ​​used... That is, to determine the x-coordinate, y-coordinate, and vertical coordinates of the image acquisition device coordinate system:

[0025] = = =

[0026] In the formula: These represent the horizontal, vertical, and axial coordinates of the first laser rangefinder in the coordinate system of the image acquisition device, respectively. These represent the horizontal, vertical, and axial coordinates of the second laser rangefinder in the coordinate system of the image acquisition device, respectively. These represent the horizontal, vertical, and axial coordinates of the third laser rangefinder in the coordinate system of the image acquisition device, respectively. These represent the horizontal, vertical, and axial coordinates of the fourth laser rangefinder in the coordinate system of the image acquisition device, respectively. These represent the horizontal, vertical, and axial coordinates of the first laser rangefinder in the plane target plate coordinate system, respectively. These represent the horizontal, vertical, and abscissa coordinates of the second laser rangefinder in the plane target plate coordinate system, respectively. These represent the horizontal, vertical, and abscissa coordinates of the third laser rangefinder in the plane target plate coordinate system, respectively. These represent the horizontal, vertical, and abscissa coordinates of the fourth laser rangefinder in the plane target plate coordinate system, respectively. This represents the transformation matrix between the image acquisition coordinate system and the size target.

[0027] Step 5: Obtain the spatial position and orientation of the target board relative to the image acquisition system at the current moment;

[0028] Determine the transformation matrix according to step 4. Finally, the spatial position and attitude of the planar target plate at the current moment are obtained.

[0029] Preferably, in step 1, the average value of the bright spot coordinates in the two image acquisition devices is calculated, and the calculation process is as follows;

[0030] The average value of all bright spot coordinates in the image captured by the first image acquisition device is The result is obtained by calculation according to the following formula;

[0031]

[0032] In the formula: This represents the average x-coordinate of the center pixel of the bright spot in the image captured by the first image acquisition device; v 1c This represents the average ordinate of the center pixels of bright spots in the image captured by the first image acquisition device; This represents the x-coordinate of the center pixel of the i-th bright spot in the image captured by the first image acquisition device; This represents the ordinate of the center pixel of the i-th bright spot in the image captured by the first image acquisition device; i represents the number of the bright spot; n represents the total number of bright spots in the image;

[0033] The average coordinate values ​​of all bright spots in the image captured by the second image acquisition device are: The result is obtained by calculation according to the following formula;

[0034]

[0035] In the formula: This represents the average x-coordinate of the center pixel of the bright spot in the image captured by the first image acquisition device; v2c This represents the average ordinate of the center pixels of bright spots in the image captured by the first image acquisition device; This represents the x-coordinate of the center pixel of the i-th bright spot in the image captured by the first image acquisition device; This represents the ordinate of the center pixel of the i-th bright spot in the image captured by the first image acquisition device.

[0036] Preferably, in step 2, the circular marker points on the multi-size positioning targets in the window areas of the two image acquisition devices are determined as follows:

[0037] Obtain the x-coordinate of the bright spot in the first image acquisition device. The minimum and maximum values ​​are denoted as . and Similarly, the ordinate of the bright spot The minimum and maximum values ​​are denoted as . and Similarly, the coordinates in the second image acquisition device are... , , and Then set the coordinates of the four corners of the window area of ​​the first image acquisition device to . , , , Set the coordinates of the four corners of the window area of ​​the second image acquisition device to... , , , The multi-size positioning target identifies 13 intersecting black and white circular markers within the window area. The pixel coordinates of the center of the markers identified by the first image acquisition device are... The pixel coordinates of the center of the marker point identified in the second image acquisition device are: .

[0038] Preferably, in step 31, determining the distance matrix of the marker point in the coordinate system of the image acquisition device specifically involves:

[0039] The relative distances between each marker point in the coordinate system of the image acquisition device are: , where I and J both represent the marker point number, and c represents the coordinate system of the image acquisition device;

[0040]

[0041] In the formula: This represents the distance between the I-th and J-th marker points in the coordinate system of the image acquisition device. These represent the x-coordinate, y-coordinate, and vertical coordinate of the I-th marker point of the first image acquisition device, respectively; These represent the x-coordinate, y-coordinate, and vertical coordinate of the J-th marker point of the first image acquisition device, respectively.

[0042] A matrix of relative distances between marker points on a multi-size positioning target plate;

[0043]

[0044] In the formula: DC represents the distance matrix of the marker points in the coordinate system of the image acquisition device; Represents the elements in the DC matrix. .

[0045] Preferably, in step 32, the standard relative distance matrix between each marker point on the size positioning target plate is determined as follows:

[0046] Each marker point corresponds to a fixed three-dimensional coordinate in a coordinate system where the calibration plate is a plane. w represents the coordinate system of the multi-size target plate, J represents the marker point number, the x and y axes of the calibration plate coordinate system coincide with the plane of the multi-size positioning target plate, and the Z axis is perpendicular to the plane of the calibration plate, because the size and relative position of the marker points on the multi-size positioning target are fixed; the transformation relationship between these marker points and the three-dimensional coordinates detected by the image acquisition device is as follows:

[0047]

[0048] In the formula: The spatial transformation matrix distance between the multi-size target plate and the first image acquisition device; Let x, y, and y represent the x, y, and y coordinates of the J-th marker on the calibration plate, respectively. ;

[0049] The relative distance between each marker point and the dimensional positioning target plate is The calculation formula is shown below:

[0050]

[0051] In the formula: This represents the distance between the I-th and J-th marker points in the multi-calibration plate coordinate system; These represent the x-coordinate and y-coordinate of the I-th marker on the calibration plate, respectively.

[0052] The matrix of relative distances between the 13 marker points that make up the multi-size positioning target plate is shown below:

[0053]

[0054] In the formula: DW represents the standard relative distance matrix between each marker point on the size positioning target plate; Represents the elements in the DW matrix. .

[0055] Preferably, in step 4, determining the coordinates of the laser rangefinder relative to the image acquisition device specifically involves:

[0056] The change matrices of the first laser rangefinder, the second laser rangefinder, the third laser rangefinder, and the fourth laser rangefinder relative to the first image acquisition device are as follows: , , The coordinates of the measurement points on the multi-size target plate relative to the coordinate systems of each laser rangefinder are: , , , By transforming the matrix , , The coordinates of the four points measured by the four laser rangefinders in the coordinate system of the image acquisition device are as follows:

[0057]

[0058] In the formula: These represent the horizontal, vertical, and axial coordinates of the first laser rangefinder in the coordinate system of the image acquisition device, respectively. These represent the horizontal, vertical, and axial coordinates of the second laser rangefinder in the coordinate system of the image acquisition device, respectively. These represent the horizontal, vertical, and axial coordinates of the third laser rangefinder in the coordinate system of the image acquisition device, respectively. These represent the horizontal, vertical, and axial coordinates of the fourth laser rangefinder in the coordinate system of the image acquisition device, respectively. These represent the abscissa, ordinate, and vertical coordinates of the measurement points of the multi-size target plate relative to the coordinate system of the first laser rangefinder, respectively. These represent the abscissa, ordinate, and vertical coordinates of the measurement point of the multi-size target plate relative to the coordinate system of the second laser rangefinder, respectively. These represent the abscissa, ordinate, and vertical coordinates of the measurement points of the multi-size target plate relative to the coordinate system of the third laser rangefinder, respectively. These represent the abscissa, ordinate, and vertical coordinates of the measurement point of the multi-size target plate relative to the coordinate system of the fourth laser rangefinder, respectively. , , These represent the change matrices of the first laser rangefinder, the second laser rangefinder, the third laser rangefinder, and the fourth laser rangefinder relative to the first image acquisition device, respectively.

[0059] A second aspect of the present invention provides a detection device capable of implementing the above-described multi-size planar target measurement and positioning method, the method being implemented based on the multi-size planar target measurement and positioning device, the detection device comprising a positioning target plate, a high-precision gimbal, two image acquisition devices, and four laser rangefinders;

[0060] The positioning target plate includes an infrared emitting diode and a multi-size positioning target. The positions of the infrared emitting diode and the multi-size positioning target are fixed to each other. The multi-size positioning target is printed with three layers of markers of different sizes and coded information. The outermost markers are the same size but have different coded information. The four markers in the middle layer are the same size but have different coded information. The markers in the innermost layer are all the same size and are located at the very center.

[0061] The high-precision gimbal includes a first motor, a base, a second motor, a rotating main beam, and a rotating bracket; the main shaft of the first motor is fixedly connected to the base, and the rotation of the base is controlled by the motor main shaft; the base and the rotating main beam are fixedly connected; the second motor is fixedly mounted on the rotating main beam, and the main shaft of the second motor is fixedly mounted to the rotating bracket, controlling the rotation of the rotating bracket;

[0062] The two image acquisition devices and four laser rangefinders are fixedly mounted on a rotating bracket. The two image acquisition devices are placed in parallel, and the four laser rangefinders are stacked between the two image acquisition devices. The laser rangefinders are oriented in the same direction as the image acquisition devices.

[0063] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0064] (1) This invention provides a method for measuring and locating multi-size planar targets, which is not limited by the viewing angle range and causes positioning deviation, thus improving the accuracy of target identification and positioning. The data collected by the image acquisition device and the laser rangefinder are coupled and analyzed to achieve a high-precision positioning process for planar targets.

[0065] (2) This invention provides a multi-size planar target measurement and positioning device, which combines an image acquisition device with a newly designed multi-size planar target to construct a new planar positioning device. Based on the positioning method, it solves the problems of difficult planar positioning and large deviation. Attached Figure Description

[0066] Figure 1 This is a simplified diagram of the multi-size planar target measurement and positioning method according to an embodiment of the present invention;

[0067] Figure 2 This is an overall structural diagram of the visual positioning system according to an embodiment of the present invention;

[0068] Figure 3 This is a schematic diagram of the structure of a multi-size target according to an embodiment of the present invention;

[0069] Figure 4a and Figure 4b This is a schematic diagram of the positioning target plate according to an embodiment of the present invention, wherein, Figure 4a This is a schematic diagram of an infrared emitting diode. Figure 4b This is a schematic diagram of a multi-size positioning target.

[0070] Figure label:

[0071] 1. First camera; 2. Laser rangefinder; 3. Laser rangefinder; 4. Rotating support; 5. Second camera; 6. Rotating main beam; 7. Encoder (not mentioned in sections 7, 14, and 15 below); 8. Second motor; 9. First motor; 10. Base; 11. Laser rangefinder; 12. Laser rangefinder; 13. Infrared diode; 14. Base plate; 15. Fixing frame; 16. Multi-size positioning target; 17. Outer layer coded marker; 18. Middle layer coded marker; 19. Inner layer non-coded marker; 20. Center marker; 21. High-precision gimbal; 22. Positioning target plate. Detailed Implementation

[0072] The embodiments of the present invention will now be described with reference to the accompanying drawings. To overcome the shortcomings of the prior art, and addressing the limitation on the positioning range caused by the camera's field of view in existing light-pen spatial positioning processes, the present invention provides a method and detection device for measuring and positioning multi-size planar targets. This method couples and analyzes data collected by an image acquisition device and a laser rangefinder, utilizing a visual positioning platform to improve the accuracy of target identification and positioning. By combining vision and a laser rangefinder, the positioning range and accuracy are improved. The embodiments of the present invention provide a method for measuring and positioning multi-size planar targets, as shown in the accompanying drawings. Figure 1 The diagram shown is a simplified representation of the multi-size planar target measurement and positioning method of an embodiment. To demonstrate the applicability of the invention, it is applied to an example, specifically including the following steps:

[0073] S1: Determine the center coordinates of the camera;

[0074] The measuring equipment is activated, causing bright spots emitted by multi-sized positioning targets to appear in the images captured by the camera window; the center pixel coordinates of the bright spots in the first camera are... The center pixel coordinates of the bright spot in the second camera are: Then, calculate the average of the bright spot coordinates in the two cameras respectively;

[0075] The average value of all bright spot coordinates in the first camera is The result is obtained by calculation according to the following formula;

[0076]

[0077] In the formula: This represents the average x-coordinate of the center pixel of the bright spot in the first camera; v 1c This represents the average ordinate of the center pixel of the bright spot in the first camera; This represents the x-coordinate of the center pixel of the i-th bright spot in the first camera; The ordinate of the center pixel of the i-th bright spot in the first camera is represented; i represents the number of the bright spot; n represents the total number of bright spots in the image.

[0078] The average coordinate values ​​of all bright spots in the second camera are The result is obtained by calculation according to the following formula;

[0079]

[0080] In the formula: This represents the average x-coordinate of the center pixel of the bright spot in the first camera; v 2c This represents the average ordinate of the center pixel of the bright spot in the first camera; This represents the x-coordinate of the center pixel of the i-th bright spot in the first camera; This represents the ordinate of the center pixel of the i-th bright spot in the first camera;

[0081] Rotate the gimbal until its center of coordinates coincides with the average of the coordinates of all bright spots in the two cameras, and you can determine the center coordinates of the two cameras.

[0082] S2: Obtain the spatial coordinates of the marker point based on the principle of binocular ranging;

[0083] Obtain the x-coordinate of the bright spot in the first camera. The minimum and maximum values ​​are denoted as . and Similarly, the ordinate of the bright spot The minimum and maximum values ​​are denoted as . and Similarly, the coordinates in the second camera are... , , and Then set the coordinates of the four corners of the first camera's window area as follows: , , , Set the coordinates of the four corners of the second camera's window area to... , , , The multi-size positioning target identifies 13 intersecting black and white circular markers within the window area. The pixel coordinates of the center of the markers identified by the first camera are... The pixel coordinates of the center of the marker point identified by the second camera are: .

[0084] Based on the principle of binocular ranging, the coordinates of the circular markers on the multi-sized positioning targets in the two camera window areas are determined as follows: and Then the spatial coordinates of the Jth marker point relative to the first camera can be obtained. The calculation process is shown below; Table 1 shows the main internal parameters of the camera;

[0085]

[0086] In the formula: b represents the distance between the baselines of the first camera and the second camera; f represents the focal length of the camera; These represent the x-coordinate, y-coordinate, and vertical coordinates of the first camera, respectively. This represents the x-coordinate of the J-th marker point in the first camera; Let J represent the x-coordinate of the J-th marker point in the second camera. This represents the x-coordinate of the J-th marker point in the first camera; J is the index of the marker point.

[0087] Table 1. Main Internal Parameters of the Camera

[0088]

[0089] S3: Determine whether the spatial coordinates of the marker points obtained by binocular measurement are accurate;

[0090] S31: Determine the distance matrix DC of the marker point in the camera coordinate system;

[0091] The relative distances of each marker point in the camera coordinate system are , where I and J both represent the marker point number, and c represents the camera coordinate system;

[0092]

[0093] In the formula: This represents the distance between the I-th and J-th marker points in the multi-calibration plate coordinate system; These represent the x-coordinate and y-coordinate of the I-th marker on the calibration plate, respectively.

[0094] A matrix of relative distances between marker points on a multi-size positioning target plate;

[0095]

[0096] In the formula: DC represents the distance matrix of the marker point in the camera coordinate system; Represents the elements in the DC matrix. ;

[0097] S32: Determine the standard relative distance matrix DW between each marker point on the size positioning target plate;

[0098] Each marker point corresponds to a fixed three-dimensional coordinate in a coordinate system where the calibration plate is a plane. w represents the coordinate system of the multi-size target plate, J represents the marker point number, the x and y axes of the calibration plate coordinate system coincide with the plane of the multi-size positioning target plate, and the Z axis is perpendicular to the plane of the calibration plate, because the size and relative position of the marker points on the multi-size positioning target are fixed; the transformation relationship between these marker points and the three-dimensional coordinates detected by the camera is as follows:

[0099]

[0100] In the formula: The spatial transformation matrix of the multi-size target plate relative to the first camera; Let x, y, and y represent the x, y, and y coordinates of the J-th marker on the calibration plate, respectively. ;

[0101] The relative distance between each marker point and the dimensional positioning target plate is The calculation formula is shown below:

[0102]

[0103] In the formula: This represents the distance between the I-th and J-th marker points in the multi-calibration plate coordinate system; These represent the x-coordinate and y-coordinate of the I-th marker on the calibration plate, respectively.

[0104] The matrix of relative distances between the 13 marker points that make up the multi-size positioning target plate is shown below:

[0105]

[0106] In the formula: DW represents the standard relative distance matrix between each marker point on the size positioning target plate; Represents the elements in the DW matrix. .

[0107] S33: Determine the magnitude of the difference between the two matrices mentioned above;

[0108] Based on the two relative distance matrices DW and DC determined by S31 and S32, data filtering is performed; the area of ​​the extracted marker points is the filtering target, and the area threshold is set to V. Marker points with an area less than V in the image are removed, and the element of the corresponding index in the relative distance matrix DW and DC is set to zero.

[0109] set up The magnitude of the difference between DC and DW is calculated using the following formula:

[0110]

[0111] In the formula: This represents the modulus between the two matrices DC and DW; These represent the column vectors of the 13 marker points in the standard relative distance matrix between each marker point on the size positioning target board; These represent the column vectors of the 13 marker points in the distance matrix of the marker points in the camera coordinate system;

[0112] for Data filtering is performed, and the maximum error threshold of each marker point relative to other marker points is set to D. Marker points with errors less than D and greater than zero are selected to be retained for the next step of calculation, while marker points with errors greater than D are not included in the subsequent calculation.

[0113] S4: Determine the transformation matrix between the image acquisition coordinate system and the size target;

[0114] The coordinates of the laser rangefinders relative to the camera are determined, and the transformation matrices of the first, second, third, and fourth laser rangefinders relative to the first camera are as follows: , , The coordinates of the measurement points on the multi-size target plate relative to the coordinate systems of each laser rangefinder are: , , , By transforming the matrix , , The coordinates of the four points measured by the four laser rangefinders in the camera coordinate system are as follows:

[0115]

[0116] In the formula: These represent the horizontal, vertical, and axial coordinates of the first laser rangefinder in the coordinate system of the image acquisition device, respectively. These represent the horizontal, vertical, and axial coordinates of the second laser rangefinder in the coordinate system of the image acquisition device, respectively. These represent the horizontal, vertical, and axial coordinates of the third laser rangefinder in the coordinate system of the image acquisition device, respectively. These represent the horizontal, vertical, and axial coordinates of the fourth laser rangefinder in the coordinate system of the image acquisition device, respectively. These represent the abscissa, ordinate, and vertical coordinates of the measurement points of the multi-size target plate relative to the coordinate system of the first laser rangefinder, respectively. These represent the abscissa, ordinate, and vertical coordinates of the measurement point of the multi-size target plate relative to the coordinate system of the second laser rangefinder, respectively. These represent the abscissa, ordinate, and vertical coordinates of the measurement points of the multi-size target plate relative to the coordinate system of the third laser rangefinder, respectively. These represent the abscissa, ordinate, and vertical coordinates of the measurement point of the multi-size target plate relative to the coordinate system of the fourth laser rangefinder, respectively. , , These represent the change matrices of the first laser rangefinder, the second laser rangefinder, the third laser rangefinder, and the fourth laser rangefinder relative to the first image acquisition device, respectively.

[0117] The coordinates of the four points measured by the four laser rangefinders fall on a multi-sized target plate, so after transformation matrix... This allows us to determine the x-coordinate, y-coordinate, and vertical coordinates of the camera coordinate system:

[0118] = = =

[0119] In the formula: These represent the horizontal, vertical, and axial coordinates of the first laser rangefinder in the coordinate system of the image acquisition device, respectively. These represent the horizontal, vertical, and axial coordinates of the second laser rangefinder in the coordinate system of the image acquisition device, respectively. These represent the horizontal, vertical, and axial coordinates of the third laser rangefinder in the coordinate system of the image acquisition device, respectively. These represent the horizontal, vertical, and axial coordinates of the fourth laser rangefinder in the coordinate system of the image acquisition device, respectively. These represent the horizontal, vertical, and axial coordinates of the first laser rangefinder in the plane target plate coordinate system, respectively. These represent the horizontal, vertical, and abscissa coordinates of the second laser rangefinder in the plane target plate coordinate system, respectively. These represent the horizontal, vertical, and abscissa coordinates of the third laser rangefinder in the plane target plate coordinate system, respectively. These represent the horizontal, vertical, and abscissa coordinates of the fourth laser rangefinder in the plane target plate coordinate system, respectively. This represents the transformation matrix between the image acquisition coordinate system and the size target.

[0120] S5: Finally, the spatial position and orientation of the target board relative to the image acquisition system at the current moment are obtained;

[0121] The transformation matrix can be determined based on S4. Finally, the spatial position and attitude of the planar target plate at the current moment are obtained.

[0122] A second aspect of the present invention also provides a detection device capable of realizing the aforementioned multi-size planar target measurement and positioning method, as shown in the attached diagram. Figure 2 The diagram shown is an overall structural diagram of an embodiment of the present invention; the device includes a positioning target plate, a high-precision gimbal 21, two cameras, and four laser rangefinders; (See attached diagram) Figure 3 This is a schematic diagram of the positioning system of the present invention;

[0123] The positioning target plate 22 is as shown in the attached figure. Figure 4a and Figure 4b The diagram shown is a schematic representation of the structure of a multi-size target in an embodiment of the present invention. It consists of 12 infrared emitting diodes 13 and a multi-size positioning target 16. The positions of the infrared emitting diodes 13 and the multi-size positioning target 16 are fixed to each other. The multi-size positioning target 16 is composed of multiple markers of different sizes and encoded information. The outermost markers 17 are all the same size but have different encoded information. The four markers 18 in the middle layer are all the same size but have different encoded information. The four markers 19 in the innermost layer are all the same size. The marker 20 is located at the very center.

[0124] The high-precision gimbal includes a first motor 9, a base 10, a second motor 8, a rotating main beam 6, and a rotating bracket 4; the spindle of the first motor 9 is fixedly connected to the base 10, and the rotation of the base 10 is controlled by the spindle of the first motor; the base 10 is fixedly connected to the rotating main beam 6; the second motor 8 is fixedly installed on the rotating main beam 6, and the spindle of the second motor 8 is fixedly installed to the rotating bracket 4, controlling the rotation of the rotating bracket 4;

[0125] The first camera 1, the second camera 5, and the laser rangefinders 2, 3, 11, and 12 are fixedly mounted on the rotating bracket 4. The first camera 1 and the second camera 5 are placed in parallel, and the laser rangefinders 2, 3, 11, and 12 are stacked between the two cameras, with the same orientation as the cameras.

[0126] Comparison method: The calibration board designed in this paper was acquired using the above scheme, and feature points were extracted from the image. and Based on the principle of binocular measurement, the three-dimensional coordinates of each feature point are calculated. Then, the proposed method was used to perform plane fitting on the selected marker points, and the traditional method was used to perform plane fitting directly on all marker points. The error of the plane fitting was then evaluated. Table 2 lists the calculation results of the proposed method and the traditional method under six different conditions. The calculation results in the table show that the calculation error of the proposed method is smaller than that of the traditional calculation method, and the accuracy is higher, which can meet the needs of practical applications.

[0127] Table 2 Comparison of calculation results between this method and other methods

[0128]

[0129] In summary, the positioning method used in this case demonstrates its excellent application performance based on the calculation results.

[0130] (1) The present invention provides a method and detection device for measuring and locating multi-size planar targets. This method is not limited by the viewing angle range and thus does not cause positioning deviation. It improves the accuracy of target identification and positioning. The data collected by the image acquisition device and the laser rangefinder are coupled and analyzed to achieve a high-precision positioning process for planar targets. This device combines the image acquisition device with a newly designed multi-size planar target to construct a new planar positioning device. Based on the positioning method, it solves the problems of difficult planar positioning and large deviation.

[0131] (2) The present invention provides a method for measuring and locating multi-size planar targets and a detection device thereof. Through multiple calculations and analyses, the present invention proves that the calculation accuracy of this method is higher than that of traditional calculation methods. The application of this method and device can better solve the problems currently encountered and has good application prospects.

[0132] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A multi-size planar target measurement and localization method, characterized by, It comprises the following steps: Step 1: determining the center coordinates of the images captured by the two image acquisition devices; The measuring device is started, so that the bright spots emitted by the multi-size positioning target appear in the image windows of the two image acquisition devices; wherein the center pixel coordinates of the bright spots in the image captured by the first image acquisition device of the two image acquisition devices are ; the center pixel coordinates of the bright spots in the image captured by the second image acquisition device of the two image acquisition devices are ; then, the average values of the bright spot coordinate values in the images captured by the two image acquisition devices are respectively calculated; Step 2: obtaining the spatial coordinates of the mark points on the multi-size positioning target according to the principle of binocular distance measurement; Step 3: judging whether the spatial coordinates of the mark points obtained by the binocular measurement are accurate; According to the binocular distance measuring principle, the coordinates of the circular mark points on the multi-size positioning target in the image window area captured by the two image acquisition devices are respectively determined as and ; and the spatial coordinates of the Jth mark point relative to the first image acquisition device are obtained as The calculation process is as follows: ； wherein: b represents the distance of the base line between the first image acquisition device and the second image acquisition device; f represents the focal length of the image acquisition device; respectively represent the horizontal coordinate, the vertical coordinate and the vertical direction coordinate of the Jth marker point of the first image acquisition device; represents the horizontal coordinate of the Jth marker point in the first image acquisition device; represents the horizontal coordinate of the Jth marker point in the second image acquisition device; represents the horizontal coordinate of the Jth marker point in the first image acquisition device; J is the serial number of the marker point; Step 31: determining the distance matrix DC of the mark points in the image acquisition device coordinate system; Step 32: determining the standard relative distance matrix DW between the mark points on the size positioning target plate; Step 33: determining the modulus of the difference between the two matrices; According to the two matrices DW and DC determined in steps 31 and 32, data screening is performed; the area of the extracted mark points is the screening target, and an area threshold V is set; for the mark points whose area in the image is less than V, they are removed, and the element corresponding to the serial number in the matrix DW and DC is set to zero; Step 4: determining the transformation matrix between the image acquisition coordinate system and the size target; Let DC and DW, the formula is as follows: ； In the formula: represents the modulus of the difference between the two matrices DC and DW; respectively represent the 13 landmark column vectors in the standard relative distance matrix between the landmark points of the size positioning target plate; respectively represent the 13 landmark column vectors in the distance matrix of the landmark points in the image acquisition device coordinate system; For , data screening is performed, a maximum error threshold D of each marker point relative to other marker points is set, and for the marker points with error less than D and greater than zero, selection is retained for calculation in the next step, and the marker points with error greater than D are not involved in the next calculation; Step 5: obtaining the spatial position and attitude of the target plate relative to the image acquisition system at the current time; Determine the coordinates of the laser range finder relative to the image acquisition device; the coordinate values of the four points measured by the four laser range finders are on the multi-size target plate, so the transformation matrix That is, determine the horizontal coordinate, vertical coordinate and vertical direction coordinate of the image acquisition device coordinate system: = = = ； In the formula: respectively represent the horizontal coordinate, the vertical coordinate and the vertical direction coordinate of the first laser range finder in the image acquisition device coordinate system; respectively represent the horizontal coordinate, the vertical coordinate and the vertical direction coordinate of the second laser range finder in the image acquisition device coordinate system; respectively represent the horizontal coordinate, the vertical coordinate and the vertical direction coordinate of the third laser range finder in the image acquisition device coordinate system; respectively represent the horizontal coordinate, the vertical coordinate and the vertical direction coordinate of the fourth laser range finder in the image acquisition device coordinate system; respectively represent the horizontal coordinate, the vertical coordinate and the vertical direction coordinate of the first laser range finder in the plane target plate coordinate system; respectively represent the horizontal coordinate, the vertical coordinate and the vertical direction coordinate of the second laser range finder in the plane target plate coordinate system; respectively represent the horizontal coordinate, the vertical coordinate and the vertical direction coordinate of the third laser range finder in the plane target plate coordinate system; respectively represent the horizontal coordinate, the vertical coordinate and the vertical direction coordinate of the fourth laser range finder in the plane target plate coordinate system; represents the transformation matrix between the image acquisition coordinate system and the dimension target. In step 1, the average value of the bright spot coordinates in the two image acquisition devices is calculated as follows: Determine the transformation matrix according to step 4 Finally, the spatial position and pose of the planar target plate at the current time are obtained.

2. The multi-size planar target measurement and localization method of claim 1, wherein, i represents the number of bright spots; n represents the total number of bright spots in the image; The average of all bright spot coordinate values in the image captured in the first image acquisition device is calculated according to the following formula; ； wherein: denotes the average value of the horizontal pixel coordinate of the center of the bright spot in the image captured in the first image acquisition device; v 1c denotes the average value of the vertical pixel coordinate of the center of the bright spot in the image captured in the first image acquisition device; denotes the horizontal pixel coordinate of the center of the i-th bright spot in the image captured in the first image acquisition device; denotes the vertical pixel coordinate of the center of the i-th bright spot in the image captured in the first image acquisition device; In step 2, the circular mark points on the multi-size positioning target in the window area of the two image acquisition devices are determined, which is specifically: The average value of the coordinate values of all bright spots captured in the image captured by the second image acquisition device is calculated according to the following formula; ； wherein: denotes the average value of the horizontal pixel coordinate of the center of the bright spot in the image captured in the first image acquisition device; v 2c denotes the average value of the vertical pixel coordinate of the center of the bright spot in the image captured in the first image acquisition device; denotes the horizontal pixel coordinate of the center of the i-th bright spot in the image captured in the first image acquisition device; denotes the vertical pixel coordinate of the center of the i-th bright spot in the image captured in the first image acquisition device.

3. The multi-size planar target measurement and localization method of claim 1, wherein, In step 31, the distance matrix of the mark points in the image acquisition device coordinate system is determined, which is specifically: Obtain the x-coordinate of the bright spot in the first image acquisition device. The minimum and maximum values ​​are denoted as . and Similarly, the ordinate of the bright spot The minimum and maximum values ​​are denoted as . and ; Similarly, the coordinates of the second image acquisition device are marked as , , and , the coordinates of the four corners of the window region of the first image acquisition device are set as , , , ; the coordinates of the four corners of the window region of the second image acquisition device are set as , , , ; wherein the multi-size positioning target identifies 13 black and white intersecting circular mark points in the window region, the coordinates of the circular mark points on the multi-size positioning target in the image window region captured by the first image acquisition device are ; and the coordinates of the circular mark points on the multi-size positioning target in the image window region captured by the second image acquisition device are .

4. The multi-size planar target measurement and localization method of claim 1, wherein, The matrix of the relative distances between the mark points on the multi-size positioning target plate is composed; The relative distance of each marker point in the image acquisition device coordinate system is where I and J both represent marker point numbers, and c represents the image acquisition device coordinate system. ， ； wherein: denotes the relative distance of the Ith marker point and the Jth marker point in the image acquisition device coordinate system; denotes the horizontal coordinate, the vertical coordinate and the vertical direction coordinate of the Ith marker point of the first image acquisition device, respectively; denotes the horizontal coordinate, the vertical coordinate and the vertical direction coordinate of the Jth marker point of the first image acquisition device, respectively; In step 32, the standard relative distance matrix between the mark points on the size positioning target plate is determined, which is specifically: ； wherein: DC represents a distance matrix of the landmark points in the image acquisition device coordinate system; denotes an element in the DC matrix, .

5. The multi-size planar target measurement and localization method of claim 1, wherein, The matrix of the relative distances between the 13 mark points on the multi-size positioning target plate is as follows: Each mark point corresponds to a fixed three-dimensional coordinate in the coordinate system of the calibration plate , w represents the coordinate system of the multi-size target plate, J represents the mark point number, the x-axis and y-axis of the calibration plate coordinate system coincide with the multi-size positioning target plate plane, and the Z-axis is perpendicular to the calibration plate plane, because the size and relative position of the mark points on the multi-size positioning target plate are fixed; wherein the transformation relationship between these mark points and the three-dimensional coordinates detected by the image acquisition device is: ； In the formula: is a spatial transformation matrix of the multi-size target plate relative to the first image acquisition device; respectively represent the horizontal coordinate, the vertical coordinate and the vertical direction coordinate of the Jth identification point on the calibration plate, and ; The relative distance of each marker point in the size positioning target plate is The calculation formula is as follows: ； In the formula: represents the distance between the Ith and Jth mark points in the multi-calibration board coordinate system; respectively represent the horizontal coordinate and the vertical coordinate of the Ith mark point on the calibration board. In step 4, the coordinates of the laser range finder relative to the image acquisition device are determined, which is specifically: ； In the formula, DW represents the standard relative distance matrix between the mark points of the size positioning target plate; represents the element in the DW matrix, .

6. The multi-size planar target measurement and localization method of claim 1, wherein, The detection device comprises a positioning target plate, a high-precision gimbal, two image acquisition devices and four laser range finders; The change matrices of the first laser range finder, the second laser range finder, the third laser range finder and the fourth laser range finder relative to the first image acquisition device are respectively , , , ; the coordinates of the measurement points of the multi-size target plate relative to the coordinate systems of the respective laser range finders are , , , , the coordinates of the four points measured by the four laser range finders in the coordinate system of the image acquisition device are obtained through the change matrix , , , . ； In the formula: respectively represent the horizontal coordinate, the vertical coordinate and the vertical direction coordinate of the first laser range finder in the plane target plate coordinate system; respectively represent the horizontal coordinate, the vertical coordinate and the vertical direction coordinate of the second laser range finder in the plane target plate coordinate system; respectively represent the horizontal coordinate, the vertical coordinate and the vertical direction coordinate of the third laser range finder in the plane target plate coordinate system; respectively represent the horizontal coordinate, the vertical coordinate and the vertical direction coordinate of the fourth laser range finder in the plane target plate coordinate system; respectively represent the horizontal coordinate, the vertical coordinate and the vertical direction coordinate of the multi-size target plate measurement point relative to the first laser range finder coordinate system; respectively represent the horizontal coordinate, the vertical coordinate and the vertical direction coordinate of the multi-size target plate measurement point relative to the second laser range finder coordinate system; respectively represent the horizontal coordinate, the vertical coordinate and the vertical direction coordinate of the multi-size target plate measurement point relative to the third laser range finder coordinate system; respectively represent the horizontal coordinate, the vertical coordinate and the vertical direction coordinate of the multi-size target plate measurement point relative to the fourth laser range finder coordinate system; , , , respectively represent the change matrix of the first laser range finder, the second laser range finder, the third laser range finder and the fourth laser range finder relative to the first image acquisition device.

7. A detection device for implementing a multi-size planar target measurement and positioning method according to one of claims 1 to 6, characterized in that, The positioning target plate comprises an infrared emitting diode and a multi-size positioning target, the positions of the infrared emitting diode and the multi-size positioning target are fixed relative to each other, the multi-size positioning target is printed with three layers of mark points with different sizes and coding information, the outermost mark points have the same size but different coding information, the four mark points in the middle layer have the same size but different coding information, and the mark points in the innermost layer have the same size and are in the center; The high-precision gimbal comprises a first motor, a base, a second motor, a rotating main beam and a rotating support; the main shaft of the first motor is fixedly connected with the base and controls the rotation of the base through the motor main shaft; the base and the rotating main beam are fixedly connected; the second motor is fixedly installed on the rotating main beam, and the second motor main shaft and the rotating support are fixedly installed to control the rotation of the rotating support; ​ The two image acquisition devices and four laser range finders are fixedly installed on a rotating support, wherein two image acquisition devices are placed in parallel, four laser range finders are stacked in the middle of the two image acquisition devices, and the orientations of the laser range finders are the same as the orientations of the image acquisition devices.

Images