Calibration equipment, calibration system, calibration method and calibration board

Abstract

The present application provides a calibration device, a calibration system, a calibration method and a calibration board. The calibration device includes a calibration board and a calibration module. The calibration board includes a first side and a second side opposite to each other, the first side is a white board, and the second side is provided with a plurality of transmissive lamps. The calibration module includes a homography matrix unit, and the homography matrix unit is used to obtain the conversion relationship between the pixel coordinates of the transmissive lamp in the infrared module pixel coordinate system and the pixel coordinates of the ideal lamp in the infrared module pixel coordinate system, wherein the ideal lamp is arranged on an ideal reference plane at a predetermined position. The structured light pattern captured by the infrared module and projected onto the calibration board is corrected according to the conversion relationship to obtain an ideal structured light reference pattern.

Description

Technical Field

[0001] The present application relates to the technical field of optical calibration, and more specifically, to a calibration device, a calibration system, a calibration method, and a calibration plate used in the calibration device, the calibration system, and the calibration method. Background Art

[0002] The calibration of structured light equipment (such as structured light cameras) is of great significance in determining the parameters of structured light equipment, and its calibration results directly affect the measurement accuracy of structured light equipment. Conventional structured light equipment usually uses a white standard plate at a fixed distance as a calibration plate when calibrating depth parameters, and uses a laser rangefinder to calibrate the physical distance and position relationship between the structured light equipment and the calibration plate. Obviously, this calibration method has high requirements on the accuracy of the calibration equipment and the laser rangefinder.

[0003] In fact, structured light equipment will produce deviations when it is disassembled, moved or rotated and then reset, and it is difficult for the structured light equipment itself to have high mechanical precision. If the structured light equipment needs to be recalibrated every time it is disassembled, moved or rotated, it will waste a lot of time and be detrimental to the mass production capacity and measurement accuracy of the structured light equipment. Summary of the invention

[0004] On one hand, the present application provides such a calibration device. The calibration device includes: a calibration plate, including a first side and a second side opposite to each other, the first side is a white board, and the second side is provided with a plurality of transmissive lamps; and a calibration module, including a homography matrix unit, the homography matrix unit is used to obtain the conversion relationship between the pixel coordinates of the transmissive lamp in the infrared module pixel coordinate system and the pixel coordinates of the ideal lamp in the infrared module pixel coordinate system, wherein the ideal lamp is set on an ideal reference plane at a predetermined position; wherein the calibration module corrects the structured light pattern captured by the infrared module and projected onto the calibration plate according to the conversion relationship to obtain an ideal structured light reference pattern.

[0005] In an exemplary embodiment, the calibration plate also includes a light switch. When the light switch is turned on, the infrared module is used to photograph the first side of the calibration plate to obtain the pixel coordinates of the transmissive light; when the light switch is turned off, the projection module is used to project the structured light pattern onto the calibration plate, and the infrared module is used to photograph the first side of the calibration plate to obtain the structured light pattern.

[0006] In an exemplary embodiment, the calibration module includes: an external parameter calculation unit, which calculates the posture relationship of the calibration plate relative to the infrared module based on the pixel coordinates of the transmissive lamp and the world coordinates of the transmissive lamp, wherein the world coordinates of the transmissive lamp are the coordinates of the transmissive lamp in the calibration plate coordinate system; and a pixel calculation unit, which determines the position of the ideal lamp on the ideal reference plane based on the posture relationship and the world coordinates of the transmissive lamp.

[0007] In an exemplary embodiment, the pixel calculation unit calculates the camera coordinates of the transmissive lamp based on the posture relationship and the world coordinates of the transmissive lamp to determine the position of the ideal lamp on the ideal reference plane, wherein the camera coordinates of the transmissive lamp are the coordinates of the transmissive lamp in the infrared module coordinate system; the ideal lamp is arranged at the intersection of the infrared module extension line and the ideal reference plane, wherein the infrared module extension line is the extension line of the line connecting the camera coordinate point of the transmissive lamp and the center of the imaging surface of the infrared module, and the ideal reference plane is parallel to the imaging surface of the infrared module and is at a certain distance away.

[0008] In an exemplary embodiment, the pixel calculation unit calculates the pixel coordinates of the ideal lamp according to the camera coordinates of the ideal lamp, wherein the camera coordinates of the ideal lamp are the coordinates of the ideal lamp in the infrared module coordinate system.

[0009] In an exemplary embodiment, the ideal reference plane is located at a predetermined position 300 mm or 600 mm away from an imaging plane of the infrared module.

[0010] In an exemplary embodiment, the calibration device includes a storage module for storing information of the ideal structured light reference pattern and the predetermined position.

[0011] In an exemplary embodiment, a plurality of the transmissive lamps are arranged in an array at predetermined intervals.

[0012] In an exemplary embodiment, grayscale weighted calculation is performed on the plurality of transmissive lamps to obtain pixel coordinates of the plurality of transmissive lamps.

[0013] In an exemplary embodiment, the calibration plate coordinate system is established with any one of the transmissive lamps as the origin to determine the world coordinates of the multiple transmissive lamps, wherein the external parameter calculation unit calculates the posture relationship of the calibration plate relative to the infrared module based on the pixel coordinates of the multiple transmissive lamps and the world coordinates of the multiple transmissive lamps using PNP operation.

[0014] In an exemplary embodiment, the calibration plate is a black and white checkerboard.

[0015] In an exemplary embodiment, the calibration plate is a circular spot pattern plate.

[0016] On the other hand, the present application provides a calibration system, characterized in that the calibration system includes: the above-mentioned calibration device; and a structured light device, the structured light device includes: an infrared module for photographing a calibration plate; and a projection module for projecting a structured light pattern onto the calibration plate.

[0017] On the other hand, the present application provides a calibration method. The calibration method includes: setting the first side of the calibration plate as a whiteboard, and setting a plurality of transmissive lamps on the second side opposite to the first side; using the homography matrix unit of the calibration module to obtain the conversion relationship between the pixel coordinates of the transmissive lamps in the infrared module pixel coordinate system and the pixel coordinates of the ideal lamps in the infrared module pixel coordinate system, wherein the ideal lamps are set on an ideal reference plane at a predetermined position; and correcting the structured light pattern captured by the infrared module and projected onto the calibration plate according to the conversion relationship to obtain an ideal structured light reference pattern.

[0018] In an exemplary embodiment, the method includes: turning on the light switch on the calibration plate, and photographing the first side of the calibration plate using the infrared module to obtain pixel coordinates of the transmissive light; turning off the light switch on the calibration plate, projecting a structured light pattern onto the calibration plate using a projection module, and photographing the first side of the calibration plate using the infrared module to obtain the structured light pattern.

[0019] In an exemplary embodiment, the method includes: the external parameter calculation unit of the calibration module calculates the posture relationship of the calibration plate relative to the infrared module based on the pixel coordinates of the transmissive lamp and the world coordinates of the transmissive lamp, wherein the world coordinates of the transmissive lamp are the coordinates of the transmissive lamp in the calibration plate coordinate system; and the pixel calculation unit of the calibration module determines the position of the ideal lamp on the ideal reference plane based on the posture relationship and the world coordinates of the transmissive lamp.

[0020] In an exemplary embodiment, the method includes: the pixel calculation unit calculates the camera coordinates of the transmissive lamp according to the posture relationship and the world coordinates of the transmissive lamp to determine the position of the ideal lamp on the ideal reference plane, wherein the camera coordinates of the transmissive lamp are the coordinates of the transmissive lamp in the infrared module coordinate system; the ideal lamp is arranged at the intersection of the infrared module extension line and the ideal reference plane, wherein the infrared module extension line is the extension line of the line connecting the camera coordinate point of the transmissive lamp and the center of the imaging surface of the infrared module, and the ideal reference plane is parallel to the imaging surface of the infrared module and is at a certain distance away.

[0021] In an exemplary embodiment, the method includes: the pixel calculation unit calculates the pixel coordinates of the ideal lamp according to the camera coordinates of the ideal lamp, wherein the camera coordinates of the ideal lamp are the coordinates of the ideal lamp in the infrared module coordinate system.

[0022] In an exemplary embodiment, the method includes: setting the ideal reference plane at a predetermined position 300 mm or 600 mm away from an imaging surface of the infrared module.

[0023] In an exemplary embodiment, the method includes: storing the ideal structured light reference pattern and information of the predetermined position using a storage module.

[0024] In an exemplary embodiment, a plurality of the transmissive lamps are arranged in an array at predetermined intervals.

[0025] In an exemplary embodiment, grayscale weighted calculation is performed on the plurality of transmissive lamps to obtain pixel coordinates of the plurality of transmissive lamps.

[0026] In an exemplary embodiment, the calibration plate coordinate system is established with any one of the transmissive lamps as the origin to determine the world coordinates of the multiple transmissive lamps, wherein the external parameter calculation unit calculates the posture relationship of the calibration plate relative to the infrared module based on the pixel coordinates of the multiple transmissive lamps and the world coordinates of the multiple transmissive lamps using PNP operation.

[0027] On the other hand, the present application provides a calibration plate, which includes: a body for reflecting and transmitting light; a plurality of transmissive lamps arranged on one side of the body; and a fixing device having a plurality of accommodating spaces corresponding to the plurality of transmissive lamps, wherein the plurality of accommodating spaces respectively accommodate the plurality of transmissive lamps.

[0028] In an exemplary embodiment, the calibration plate includes: a light switch, and when the light switch is turned on, the light emitted by the plurality of transmissive lamps is transmitted through one side of the body to another side opposite to the one side.

[0029] In an exemplary embodiment, the plurality of transmissive lamps are LED lamps.

[0030] The calibration device, calibration system, calibration method and calibration board provided by the present application have at least one of the following advantages:

[0031] 1) Improved calibration accuracy and efficiency. Since there is no need to use a high-precision rangefinder to calibrate the world coordinates of the depth module, the requirements for instrument accuracy are reduced; and

[0032] 2) Reduced the position accuracy requirements for the depth module and calibration plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Other features, purposes and advantages of the present application will become more apparent through the following detailed description of non-limiting embodiments in conjunction with the accompanying drawings. In the accompanying drawings:

[0034] Figure 1 is a schematic block diagram of a calibration device according to an embodiment of the present application;

[0035] Figure 2 is a schematic structural diagram of a calibration plate according to an embodiment of the present application;

[0036] Figure 3 is a flow chart of a calibration method according to an embodiment of the present application; and

[0037] Figure 4 It is a schematic diagram of the structure of a calibration plate according to an implementation manner of the present application. DETAILED DESCRIPTION

[0038] In order to better understand the present application, a more detailed description will be made of various aspects of the present application with reference to the accompanying drawings. It should be understood that these detailed descriptions are only descriptions of exemplary embodiments of the present application, and are not intended to limit the scope of the present application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0039] In the drawings, the thickness, size and shape of the components have been slightly adjusted for ease of illustration. The drawings are for illustration only and are not drawn strictly to scale. As used herein, the terms "substantially," "approximately," and similar terms are used as terms of approximation, not as terms of degree, and are intended to account for the inherent deviations in measurements or calculations that would be recognized by one of ordinary skill in the art.

[0040] It should also be understood that expressions such as "include", "including", "have", "contain" and / or "comprising" are open rather than closed expressions in this specification, which indicate the presence of the stated features, elements and / or components, but do not exclude the presence of one or more other features, elements, components and / or combinations thereof. In addition, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire list of features rather than just the individual elements in the list. In addition, when describing embodiments of the present application, "may" is used to mean "one or more embodiments of the present application". And, the term "exemplary" is intended to refer to an example or illustration.

[0041] Unless otherwise specified, all words (including engineering terms and scientific and technological terms) used in this article have the same meaning as those commonly understood by ordinary technicians in the field to which this application belongs. It should also be understood that, unless clearly stated in this application, words defined in common dictionaries should be interpreted as having the same meaning as their meaning in the context of the relevant technology, and should not be interpreted in an idealized or overly formal sense.

[0042] 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.

[0043] The features, principles and other aspects of the present application are described in detail below.

[0044] Figure 1 is a schematic block diagram of a calibration device 1000 according to an embodiment of the present application. Figure 1 As shown, the calibration device 1000 includes a calibration board 1100 and a calibration module 1200 .

[0045] The first side 1110 of the calibration plate 1100 may be a white plate. Figure 2 As shown, the second side 1120 of the calibration plate 1100 may be provided with a plurality of transmissive lamps 1121, wherein the first side 1110 is arranged opposite to the second side 1120. The plurality of transmissive lamps 1121 may be arranged in an array with a predetermined distance between them. When the plurality of transmissive lamps 1121 are turned on, a plurality of light images may be presented on the whiteboard. When the plurality of transmissive lamps 1121 are turned off, the first side 1110 of the calibration plate 1100 may be a whiteboard.

[0046] The calibration module 1200 may include an external parameter calculation unit 1210. The external parameter calculation unit 1210 may calculate the position and posture relationship of the calibration plate 1100 relative to the infrared module according to the pixel coordinates of the lamp 1121 and the world coordinates of the lamp 1121. Exemplarily, the pixel coordinates of the lamp 1121 may be the coordinates of the lamp 1121 in the infrared module pixel coordinate system obtained by photographing the first side 1110 of the calibration plate 1100 using the infrared module. Specifically, grayscale weighted calculation is performed on multiple lamps 1121 to obtain the pixel coordinates of the multiple lamps. Exemplarily, the world coordinates of the lamp 1121 may be the coordinates of the lamp 1121 in the calibration plate coordinate system. The position and posture relationship of the calibration plate 1100 relative to the infrared module may include the translation distance and rotation angle of the calibration plate 1100 relative to the infrared module. It should be understood that the coordinate system introduced in this application, such as the infrared module pixel coordinate system and the calibration plate coordinate system, can specifically define the origin position in the coordinate system according to actual conditions.

[0047] In an exemplary embodiment, the calibration module 1200 may further include a pixel calculation unit 1220. The pixel calculation unit 1220 may calculate the camera coordinates of the lamp 1121 based on the above-mentioned posture relationship (such as the translation distance and rotation angle of the calibration plate 1100 relative to the infrared module) and the world coordinates of the lamp 1121. The camera coordinates of the lamp 1121 may be the coordinates of the lamp 1121 in the infrared module coordinate system. It should be understood that in the present application, the infrared module coordinate system may specifically define the origin position in the coordinate system according to actual conditions.

[0048] In an exemplary embodiment, when the calibration device 1000 is calibrated, it is necessary to set the calibration plate 1100 at a predetermined position, such as setting the calibration plate 1100 at a predetermined position 300mm or 600mm away from the imaging surface of the infrared module. However, in actual operation, the setting positions of the infrared module and the calibration plate 1100 are not accurate, and even the infrared module and the calibration plate 1100 are inevitably moved or rotated. If the calibration calculation is still performed with the infrared module and the calibration plate 1100 at a predetermined distance (such as 300mm or 600mm, etc.), the calibration will be inaccurate. The calibration device 1000 provided in the present application can determine the position of the ideal reference plane 100 at a predetermined distance from the infrared module according to the actual position of the infrared module. The ideal reference plane 100 can be a plane parallel to the imaging surface of the infrared module and at a predetermined position 300mm or 600mm away from the imaging surface of the infrared module.

[0049] In an exemplary embodiment, the position of the ideal lamp 110 on the ideal reference plane 100 can be determined by the extended line of the coordinate position of the lamp 1121 in the infrared module coordinate system and the center of the imaging surface of the infrared module. For example, the ideal lamp 110 may be located at the intersection of the coordinate position of the lamp 1121 in the infrared module coordinate system and the extended line of the center of the imaging surface of the infrared module and the ideal reference plane 100. Exemplarily, the pixel calculation unit 1220 may calculate the pixel coordinates of the ideal lamp 110 based on the camera coordinates of the ideal lamp 110 and the internal parameters of the infrared module, wherein the internal parameters of the infrared module are the internal device parameters of the infrared module. The camera coordinates of the ideal lamp 110 may be the coordinates of the ideal lamp 110 in the infrared module coordinate system. The pixel coordinates of the ideal lamp 110 may be the coordinates of the ideal lamp 110 in the infrared module pixel coordinate system.

[0050] In an exemplary embodiment, the calibration module 1200 may further include a homography matrix unit 1230. The homography matrix unit 1230 may be used to obtain a conversion relationship between the pixel coordinates of the light 1121 and the pixel coordinates of the ideal light 110. The conversion relationship may be used for subsequent calibration of depth information.

[0051] In an exemplary embodiment, the calibration plate 1100 may further include a light switch 1130. When the light switch 1130 is turned on, the first side 1110 of the calibration plate 1100 may be photographed by an infrared module to obtain the pixel coordinates of the light 1121. When the light switch 1130 is turned off, the structured light pattern may be projected onto the calibration plate 1100 by a projection module and the first side 1110 of the calibration plate 1100 may be photographed by an infrared module to obtain the structured light pattern. For example, the depth information of the structured light pattern may be obtained based on information such as deformation or light intensity of the structured light pattern. The projection module may be a structured light projector, and the structured light pattern may be a speckle pattern. The structured light projector may project the speckle pattern onto the calibration plate 1100. The infrared module may be an IR camera, and the IR camera may photograph the speckle pattern on the calibration plate 1100. Exemplarily, the depth information of the structured light pattern may be corrected based on the conversion relationship obtained by the homography matrix unit 1230 to obtain an ideal structured light reference pattern. The speckle pattern projected by the structured light projector may have noise or deformation. The present application corrects the speckle pattern by using the homography matrix unit 1230 to generate an ideal structured light reference pattern. The ideal structured light reference pattern can be saved as a reference pattern, and the reference pattern can be used for comparison during actual shooting.

[0052] In an exemplary embodiment, the calibration device 1000 may further include a storage module 1300. The storage module 1300 may be used to store information of an ideal structured light reference pattern and a predetermined position. It should be understood that the storage module provided in the present application may be any device having a storage function. In addition, the present application does not specifically limit the storage location of the structured light reference pattern and the predetermined position information.

[0053] In such Figure 2 In the schematic diagram of the target provided by the present application, when the light is turned on, the light energy is relatively concentrated and does not diverge, and the actual distance of the light is consistent and the error with the design value does not exceed 1mm. Specifically, the coordinate system projection formula of the light can be:

[0054]

[0055] in, is the internal parameter matrix of the infrared module; u and v are the pixel coordinates of the lamp; fx and fy are the effective focal lengths of the infrared module; cx and cy are the offsets from the origin of the infrared module coordinate system to the origin of the infrared module pixel coordinate system; r(3×3) is the rotation matrix between the infrared module pixel coordinate system and the calibration board coordinate system; t(3×1) is the translation matrix between the infrared module pixel coordinate system and the calibration board coordinate system; XYZ is the world coordinates of the lamp.

[0056] In an exemplary embodiment, a calibration plate coordinate system can be established with any lamp as the origin to determine the world coordinates of the multiple lamps. The external parameter calculation unit can calculate the position relationship of the calibration plate 1100 relative to the infrared module using PNP operation according to the pixel coordinates of the multiple lamps and the world coordinates of the multiple lamps.

[0057] In an exemplary embodiment, the calibration plate 1100 may be a black and white chessboard. The black and white chessboard is a calibration plate 1100 composed of black and white squares. Exemplarily, the black and white chessboard can be used as a calibration object for calibration module 1110, that is, an object mapped from the real world to a digital image. Considering that the plane chessboard pattern is easier to handle than a complex three-dimensional object, but at the same time, a two-dimensional object will lack some information relative to a three-dimensional object, the orientation of the chessboard can be changed multiple times to capture the image in order to obtain richer coordinate information. And by a series of transformation calibration modules 1200 and the position state of the calibration plate 1100, the calibration image obtained on the calibration plate 1100 can be affine transformed and projected from the world coordinate system, and finally discrete image points in the pixel coordinate system are obtained, and each parameter matrix will be gradually introduced in this process. Of course, the calibration plate 1100 can also be a circular spot plate. The specific working principle of using the circular spot plate can refer to the implementation method using the black and white checkerboard. To make this application concise, the introduction of using the circular spot plate as the calibration plate 1100 is omitted here. It should be understood that this application does not specifically limit the specific structure of the calibration plate 1100. This application is only an example. Under the condition of meeting actual needs, any appropriate calibration plate 1100 can be selected for calibration.

[0058] On the other hand, the present application provides a calibration system. The calibration system may include the above-mentioned calibration device and a structured light device. The structured light device may include an infrared module and a projection module. The infrared module may be used to photograph a calibration plate to complete the calibration of depth information. The projection module may be used to project a structured light pattern onto the calibration plate.

[0059] After the infrared module provided in this application completes the depth calibration, the distortion algorithm of the calibration pattern calculated can be:

[0060]

[0061] Since the calibration of the internal optical parameters of the infrared module is relatively simple and does not require the infrared module to be rotated, it is beneficial to reduce the position accuracy of the calibration plate and the structured light camera and reduce the difficulty of operation. Therefore, the structured light device of the present application uses the calibrated infrared module to calibrate the depth parameters. This is beneficial to reduce the position accuracy of the calibration plate and the structured light camera, reduce the difficulty of operation, and improve the operation efficiency.

[0062] In most cases, the structured light device needs to be rotated when calibrating the depth information of the structured light device, and a laser rangefinder needs to be used to measure the physical distance between the structured light device and the calibration plate. It is difficult to use a laser rangefinder to measure the physical distance between the structured light device and the calibration plate during calibration, and the accuracy requirements for the calibration device and the laser rangefinder are high. It is also difficult to ensure the mechanical accuracy of the structured light device. For example, under normal circumstances, there is a deviation when the structured light device is rotated or moved and reset. However, the calibration device provided by the user does not require a laser rangefinder, and the accuracy requirements for the calibration device and the laser rangefinder are low, which can solve at least one problem in actual calibration.

[0063] Figure 3 2 is a flow chart of a calibration method 2000 according to an embodiment of the present application. As shown in the figure, the calibration method 2000 may include the following steps:

[0064] In S2100 , a first side of the calibration plate is set as a white plate, and a second side opposite to the first side is set with a plurality of transmissive lamps.

[0065] In S2200, the conversion relationship between the pixel coordinates of the transmissive lamp in the infrared module pixel coordinate system and the pixel coordinates of the ideal lamp in the infrared module pixel coordinate system is obtained using the homography matrix unit of the calibration module, wherein the ideal lamp is set on an ideal reference plane at a predetermined position. It should be understood that the coordinate system introduced in this application, such as the infrared module pixel coordinate system, can specifically define the origin position in the coordinate system according to actual conditions.

[0066] In S2300, the structured light pattern photographed by the infrared module and projected onto the calibration plate is corrected according to the conversion relationship to obtain an ideal structured light reference pattern.

[0067] In an exemplary embodiment, the calibration method further includes: the pixel calculation unit of the calibration module can calculate the camera coordinates of the lamp according to the posture relationship (such as the translation distance and rotation angle of the calibration plate relative to the infrared module) and the world coordinates of the lamp, wherein the camera coordinates of the lamp are the coordinates of the lamp in the infrared module coordinate system. It should be understood that the infrared module coordinate system can specifically define the origin position in the coordinate system according to actual conditions.

[0068] In an exemplary embodiment, the calibration method further includes: determining the position of an ideal reference plane at a predetermined distance from the infrared module according to the actual position of the infrared module. The ideal reference plane may be a plane parallel to the imaging plane of the infrared module and at a predetermined position 300 mm or 600 mm from the imaging plane of the infrared module. Furthermore, the position of the ideal lamp on the ideal reference plane may be determined by a line connecting the coordinate position of the lamp in the infrared module coordinate system and the center of the imaging plane of the infrared module. For example, the ideal lamp may be located at the intersection of the line connecting the coordinate position of the lamp in the infrared module coordinate system and the center of the imaging plane of the infrared module and the ideal reference plane. Exemplarily, the pixel calculation unit may calculate the pixel coordinates of the ideal lamp according to the camera coordinates of the ideal lamp 110 and the internal parameters of the infrared module, wherein the internal parameters of the infrared module are the internal device parameters of the infrared module. The camera coordinates of the ideal lamp may be the coordinates of the ideal lamp in the infrared module coordinate system. The pixel coordinates of the ideal lamp may be the coordinates of the ideal lamp in the infrared module pixel coordinate system.

[0069] In an exemplary embodiment, the calibration method further includes: using a homography matrix unit of the calibration module to obtain a conversion relationship between the pixel coordinates of the light and the pixel coordinates of the ideal light. The obtained conversion relationship can be used for subsequent calibration of depth information.

[0070] In an exemplary embodiment, the calibration method further includes: turning on a light switch on the calibration board, photographing the first side of the calibration board using an infrared module to obtain pixel coordinates of the light. Turning off the light switch on the calibration board, projecting a structured light pattern onto the calibration board using a projection module, and photographing the first side of the calibration board using an infrared module to obtain depth information of the structured light pattern. Correcting the depth information of the structured light pattern according to the conversion relationship obtained by the homography matrix calculation unit to obtain an ideal structured light reference pattern. Multiple lights are arranged in an array at a predetermined distance on the second side of the calibration board. Grayscale weighted calculation is performed on the multiple lights to obtain pixel coordinates of the multiple lights. The ideal structured light reference pattern and information of the predetermined position are stored using a storage module.

[0071] In an exemplary embodiment, a calibration plate coordinate system is established with any one of the lamps as the origin to determine the world coordinates of the multiple lamps, wherein the external parameter calculation unit calculates the position relationship of the calibration plate relative to the infrared module using PNP operation according to the pixel coordinates of the multiple lamps and the world coordinates of the multiple lamps. It should be understood that the calibration plate coordinate system can specifically define the origin position in the coordinate system according to actual conditions.

[0072] Figure 4 It is a schematic diagram of the structure of the calibration board 3000 according to the implementation mode of the present application.

[0073] The calibration plate 3000 may include a main body 3100 , a plurality of transmissive lamps 3200 , and a fixing device 3300 .

[0074] The body 3100 may be used to reflect and transmit light. A plurality of transmissive lamps 3200 may be disposed at one side of the body 3100. The fixture 3300 may have a plurality of accommodating spaces corresponding to the plurality of transmissive lamps 3200. The plurality of accommodating spaces may respectively accommodate the plurality of transmissive lamps 3200. For example, the accommodating space 3311 may accommodate the transmissive lamps 3210 corresponding thereto.

[0075] In an exemplary embodiment, the calibration plate may further include a light switch (not shown). When the light switch is turned on, light emitted by the plurality of transmissive lamps 3200 may be transmitted through one side of the body 3100 to the other side opposite to the one side. The plurality of transmissive lamps 3200 may be LED lamps.

[0076] The above description is only an implementation method of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of protection involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the technical concept. For example, the above features are replaced with the technical features with similar functions disclosed in this application (but not limited to) by each other.

Claims

1. A calibration device, characterized in that: The calibration equipment comprises: A calibration plate, comprising a first side and a second side opposite to each other, wherein the first side is a white plate, and the second side is provided with a plurality of transmissive lamps; and A calibration module, comprising a homography matrix unit, the homography matrix unit being used to obtain a conversion relationship between pixel coordinates of the transmissive lamp in the infrared module pixel coordinate system and pixel coordinates of an ideal lamp in the infrared module pixel coordinate system, wherein the ideal lamp is arranged on an ideal reference plane at a predetermined position; The calibration module corrects the structured light pattern photographed by the infrared module and projected onto the calibration plate according to the conversion relationship to obtain an ideal structured light reference pattern. The ideal lamp is arranged at the intersection of the infrared module extension line and the ideal reference plane, wherein the infrared module extension line is the extension line of the line connecting the camera coordinate point of the transmissive lamp and the center of the imaging surface of the infrared module, and the ideal reference plane is parallel to the imaging surface of the infrared module and is at a certain distance, and The pixel coordinates of the ideal lamp are calculated according to the camera coordinates of the ideal lamp and the internal parameters of the infrared module, wherein the camera coordinates of the ideal lamp are the coordinates of the ideal lamp in the infrared module coordinate system, and the internal parameters of the infrared module are the internal device parameters of the infrared module.

2. The calibration device according to claim 1, characterized in that: The calibration board also includes a light switch, When the light switch is turned on, the infrared module is used to photograph the first side of the calibration plate to obtain the pixel coordinates of the transmissive light; When the light switch is turned off, the projection module is used to project the structured light pattern onto the calibration plate, and the infrared module is used to photograph the first side of the calibration plate to obtain the structured light pattern.

3. The calibration device according to claim 1, characterized in that: The calibration module comprises: an external parameter calculation unit, wherein the external parameter calculation unit calculates the posture relationship of the calibration plate relative to the infrared module according to the pixel coordinates of the transmissive lamp and the world coordinates of the transmissive lamp, wherein the world coordinates of the transmissive lamp are the coordinates of the transmissive lamp in the calibration plate coordinate system; and A pixel calculation unit is used to determine the position of the ideal lamp on the ideal reference plane according to the posture relationship and the world coordinates of the transmissive lamp.

4. The calibration device according to claim 3, characterized in that: The pixel calculation unit calculates the camera coordinates of the transmissive lamp according to the posture relationship and the world coordinates of the transmissive lamp to determine the position of the ideal lamp on the ideal reference plane. The camera coordinates of the transmissive lamp are the coordinates of the transmissive lamp in the infrared module coordinate system.

5. The calibration device according to claim 4, characterized in that: The pixel calculation unit calculates the pixel coordinates of the ideal lamp according to the camera coordinates of the ideal lamp and the internal parameters of the infrared module.

6. The calibration device according to claim 1 or 4, characterized in that: The ideal reference plane is located at a predetermined position 300 mm or 600 mm away from the imaging surface of the infrared module.

7. The calibration device according to any one of claims 1 to 6, characterized in that: The calibration device includes a storage module for storing information of the ideal structured light reference pattern and the predetermined position.

8. The calibration device according to claim 3, characterized in that: The plurality of transmissive lamps are arranged in an array at predetermined intervals.

9. The calibration device according to claim 8, characterized in that: Grayscale weighted calculation is performed on the plurality of transmissive lamps to obtain pixel coordinates of the plurality of transmissive lamps.

10. The calibration device according to claim 9, characterized in that: The calibration plate coordinate system is established with any one of the transmissive lamps as the origin to determine the world coordinates of the plurality of transmissive lamps. The external parameter calculation unit calculates the position and posture relationship of the calibration plate relative to the infrared module using PNP calculation according to the pixel coordinates of the plurality of transmissive lamps and the world coordinates of the plurality of transmissive lamps.

11. The calibration device according to claim 1, characterized in that: The calibration plate is a black and white chessboard.

12. The calibration device according to claim 1, characterized in that: The calibration plate is a circular spot plate.

13. The calibration device according to claim 2, characterized in that: The calibration plate comprises: a body for reflecting and transmitting light, wherein the body comprises the first side and the second side; and The fixing device has a plurality of accommodating spaces corresponding to the plurality of transmissive lamps, wherein the plurality of accommodating spaces respectively accommodate the plurality of transmissive lamps.

14. The calibration device according to claim 13, characterized in that: When the light switch is turned on, the light emitted by the plurality of transmissive lamps is transmitted through the second side of the body to the first side.

15. The calibration device according to claim 14, characterized in that: The plurality of transmissive lamps are LED lamps.

16. A calibration system, characterized in that: The calibration system comprises: The calibration device according to any one of claims 1 to 15; and A structured light device, the structured light device comprising: Infrared module, used to photograph the calibration plate; and The projection module is used to project the structured light pattern onto the calibration plate.

17. A calibration method, characterized in that: The calibration method comprises: The first side of the calibration plate is set as a white plate, and a plurality of transmissive lamps are set on a second side opposite to the first side; Obtaining a conversion relationship between pixel coordinates of the transmissive lamp in the infrared module pixel coordinate system and pixel coordinates of an ideal lamp in the infrared module pixel coordinate system using a homography matrix unit of a calibration module, wherein the ideal lamp is disposed on an ideal reference plane at a predetermined position; and Correcting the structured light pattern captured by the infrared module and projected onto the calibration plate according to the conversion relationship to obtain an ideal structured light reference pattern; The ideal lamp is arranged at the intersection of the infrared module extension line and the ideal reference plane, wherein the infrared module extension line is the extension line of the line connecting the camera coordinate point of the transmissive lamp and the center of the imaging surface of the infrared module, and the ideal reference plane is parallel to the imaging surface of the infrared module and is at a certain distance from the ideal reference plane, and The pixel coordinates of the ideal lamp are calculated according to the camera coordinates of the ideal lamp and the internal parameters of the infrared module, wherein the camera coordinates of the ideal lamp are the coordinates of the ideal lamp in the infrared module coordinate system, and the internal parameters of the infrared module are the internal device parameters of the infrared module.

18. The calibration method according to claim 17, characterized in that: The method comprises: Turning on the light switch on the calibration plate, and photographing the first side of the calibration plate using the infrared module to obtain the pixel coordinates of the transmissive lamp; Turn off the light switch on the calibration plate, use the projection module to project the structured light pattern to the calibration plate, and use the infrared module to photograph the first side of the calibration plate to obtain the structured light pattern.

19. The calibration method according to claim 17, characterized in that: The method comprises: The external parameter calculation unit of the calibration module calculates the posture relationship of the calibration plate relative to the infrared module according to the pixel coordinates of the transmissive lamp and the world coordinates of the transmissive lamp, wherein the world coordinates of the transmissive lamp are the coordinates of the transmissive lamp in the calibration plate coordinate system; and The pixel calculation unit of the calibration module determines the position of the ideal lamp on the ideal reference plane according to the posture relationship and the world coordinates of the transmissive lamp.

20. The calibration method according to claim 19, characterized in that: The method comprises: the pixel calculation unit calculates the camera coordinates of the transmissive lamp according to the posture relationship and the world coordinates of the transmissive lamp to determine the position of the ideal lamp on the ideal reference plane, The camera coordinates of the transmissive lamp are the coordinates of the transmissive lamp in the infrared module coordinate system.

21. The calibration method according to claim 20, characterized in that: The method comprises: the pixel calculation unit calculates the pixel coordinates of the ideal lamp according to the camera coordinates of the ideal lamp and the internal parameters of the infrared module.

22. The calibration method according to claim 21, characterized in that: The method comprises: setting the ideal reference plane at a predetermined position 300 mm or 600 mm away from the imaging surface of the infrared module.

23. The calibration method according to claim 22, characterized in that: The method includes: using a storage module to store information of the ideal structured light reference pattern and the predetermined position.

24. The calibration method according to claim 17, characterized in that: The plurality of transmissive lamps are arranged in an array at predetermined intervals.

25. The calibration method according to claim 23, characterized in that: Grayscale weighted calculation is performed on the plurality of transmissive lamps to obtain pixel coordinates of the plurality of transmissive lamps.

26. The calibration method according to claim 25, characterized in that: The calibration plate coordinate system is established with any one of the transmissive lamps as the origin to determine the world coordinates of the plurality of transmissive lamps. The external parameter calculation unit calculates the position and posture relationship of the calibration plate relative to the infrared module using PNP calculation according to the pixel coordinates of the plurality of transmissive lamps and the world coordinates of the plurality of transmissive lamps.

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