Calibration device, calibration system and calibration control method

Abstract

This application relates to the field of calibration technology, and discloses a calibration device, calibration system, and calibration control method for camera calibration. The calibration device includes a base and a calibration unit disposed on the base. The calibration unit includes: a collimating light source configured to emit light carrying an optical axis angle calibration image upwards from the base, the optical axis angle calibration image being aligned with the camera's calibration marks during camera preview; and a diffuse reflection light source configured to emit light carrying an optical axis position calibration image upwards from the base, the optical axis position calibration image being aligned with the camera's calibration marks during camera preview. Implementing the solution of this application enables integrated and rapid calibration of the camera's optical axis angle and position, simplifying the operation process, reducing the technical requirements for on-site debugging personnel, and shortening the time for on-site calibration of the camera's optical axis.

Description

Technical Field

[0001] This application relates to the field of calibration technology, and in particular to a calibration device, calibration system and calibration control method for camera calibration. Background Technology

[0002] Currently, many production or process equipment, such as the AA equipment for AR glasses, require the use of industrial cameras. This involves calibrating and setting the optical axis angle and position of the industrial camera, which is a very critical and delicate task.

[0003] In related technologies, the optical axis angle and position calibration of industrial cameras often employs visual methods. However, visual methods rely on the quality of the calibration board and the algorithm, which may conceal systematic errors. Alternatively, autocollimation methods can be used, but these are costly, complex to operate, and require highly skilled technicians. Furthermore, they can only calibrate the optical axis angle of industrial cameras; calibrating the optical axis position requires other methods, which is time-consuming and labor-intensive.

[0004] The aforementioned shortcomings urgently require improvement or resolution by those skilled in the art. Summary of the Invention

[0005] In view of this, the embodiments of this application aim to provide a calibration device, calibration system and calibration control method that can simultaneously achieve rapid calibration of the camera optical axis angle and optical axis position, reduce the technical requirements for on-site debugging personnel and shorten the time for on-site calibration of the camera optical axis.

[0006] In a first aspect, embodiments of this application provide a calibration device for camera calibration, comprising a base and a calibration unit disposed on the base. The calibration unit includes: a collimating light source configured to emit light carrying an optical axis angle calibration image upwards toward the base, the optical axis angle calibration image being used to align with the camera's calibration marks when previewed by the camera; and a diffuse reflection light source configured to emit light carrying an optical axis position calibration image upwards toward the base, the optical axis position calibration image being used to align with the camera's calibration marks when previewed by the camera.

[0007] Secondly, an embodiment of this application provides a calibration system including a reference platform, a camera, X / Y / Z motor axes, a pitch / yaw motor axis, a control unit, and the aforementioned calibration device, wherein: the base of the calibration device is fixedly installed on the reference platform; the camera is disposed above the calibration device; the X / Y / Z motor axes are used to adjust the position of the camera; the pitch / yaw motor axis is used to adjust the pitch / yaw angle of the camera; the control unit is used to control the collimating light source to emit light carrying an optical axis angle calibration image, control the X / Y / Z motor axes and the pitch / yaw motor axis to align the calibration mark of the camera with the optical axis angle calibration image, and save the motion parameters of the pitch / yaw motor axis during alignment; and to control the diffuse reflection light source to emit light carrying an optical axis position calibration image, control the X / Y / Z motor axes to align the calibration mark of the camera with the optical axis position calibration image, and save the motion parameters of the X / Y / Z motor axes during alignment.

[0008] Thirdly, an embodiment of this application provides a calibration control method for calibrating the optical axis angle and optical axis position of a camera using the aforementioned calibration device. The method includes: controlling a collimating light source to emit light carrying an optical axis angle calibration image; controlling the camera to be in a preview state and adjusting the camera's position motion parameters and attitude motion parameters; saving the camera's attitude motion parameters when the camera's calibration mark is aligned with the optical axis angle calibration image; controlling a diffuse reflection light source to emit light carrying an optical axis position calibration image; controlling the camera to be in a preview state and adjusting the camera's position motion parameters; and saving the camera's position motion parameters when the camera's calibration mark is aligned with the optical axis position calibration image.

[0009] By adopting the solution of this application embodiment, rapid calibration of both the optical axis angle and optical axis position of the camera can be achieved simultaneously. Specifically, a collimating light source and a diffuse reflection light source are integrated into the calibration unit of a single calibration device. The collimating light source is configured to emit light carrying an optical axis angle calibration image upwards towards the base. This optical axis angle calibration image is used to align with the camera's calibration marks when previewed by the camera. The diffuse reflection light source is configured to emit light carrying an optical axis position calibration image upwards towards the base. This optical axis position calibration image is used to align with the camera's calibration marks when previewed by the camera. In other words, integrated and rapid calibration of the camera's optical axis angle and position can be achieved, simplifying the operation process, reducing the technical requirements for on-site debugging personnel, and shortening the time for on-site calibration of the camera's optical axis.

[0010] For further technical effects of the various implementation methods of this application, please refer to the relevant descriptions in the specific embodiments. Attached Figure Description

[0011] Figure 1This is a schematic diagram of the front view structure of a calibration device provided in an embodiment of this application; Figure 2 for Figure 1 A top view of the calibration device shown. Figure 3 for Figure 1 A schematic diagram of the isometric structure of the calibration device shown. Figure 4 A front view schematic diagram of a calibration system provided in this application embodiment shows the relative positional relationship between an industrial camera and a calibration device; Figure 5 for Figure 4 A schematic diagram of the isometric structure of the calibration system shown. Figure 6 This is a schematic diagram illustrating a situation where the optical axis angle calibration image and the camera calibration mark (crosshair) are not aligned during the calibration process, as provided in this application embodiment. Figure 7 A schematic diagram provided for an embodiment of this application showing the alignment of the optical axis angle calibration image with the camera calibration (crosshair) mark during the calibration process; Figure 8 This is a schematic diagram illustrating a situation where the optical axis position calibration image and the camera calibration mark (crosshair) are not aligned during the calibration process, as provided in this application embodiment. Figure 9 A schematic diagram illustrating the alignment of the optical axis position calibration image with the camera calibration mark (crosshair) during the calibration process, provided for an embodiment of this application; Figure 10 This is a block diagram illustrating the components of a calibration system provided in an embodiment of this application.

[0012] Figure label: 100 Calibration Device 200 Industrial Cameras 300 benchmark platform 400 X / Y / Z electric shaft 500 pitch / yaw motor shaft 600 control unit 1 base 10 base plate 11 First bolt hole 12 Second bolt hole 13 Third bolt hole 14 Fourth bolt hole 15 First pin hole 16 Second pin hole 17 First support 18 Second support 2 Calibration Unit 20 Top Plate 21 Installation Department 22. Optical mechanism exit pupil 23 micropores 24 Fifth bolt hole 25 Sixth Bolt Hole 26 Seventh bolt hole 27 Eighth bolt hole 28 Third pin hole 29 Fourth pin hole 3 Collimated light source 30 Optical Engine 31. Optical Exit Pupil 4. Diffuse light source 40 surface light sources Detailed Implementation To make the objectives, solutions, and advantages of this application clearer, the technical solutions of the embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be understood that the embodiments described below are only some embodiments of this application, and not all of them; other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are all within the scope of protection of this application. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be arbitrarily combined with each other.

[0013] Industrial cameras are widely used in precision manufacturing and automated inspection, and their optical axis accuracy directly determines the image quality and the reliability of measurement results. Many production equipment and processes, such as active alignment (AA) equipment for AR glasses, image measuring instruments, machine vision inspection systems, and automotive camera module assembly lines, rely on industrial cameras for high-precision visual positioning, image acquisition, and optical parameter detection. In these applications, the optical axis angle and position of the industrial camera are core parameters that need to be precisely calibrated. Deviations in the optical axis angle can lead to image distortion, accumulated measurement errors, and misalignment of reference points in subsequent assembly processes. Deviations in the optical axis position will affect the correspondence between the camera's field of view center and the actual measurement target, thereby reducing the overall accuracy of the equipment and product consistency. Therefore, precise calibration of the optical axis angle and position of industrial cameras is a crucial and meticulous task.

[0014] In related technologies, the calibration of the optical axis angle and position of industrial cameras mainly adopts two technical approaches. One is the vision method, which uses a calibration board (such as a checkerboard, dot matrix, or calibration plate) in conjunction with corresponding image processing algorithms to complete the optical axis calibration. Specifically, this method uses an industrial camera to acquire images and extract features from feature points (such as Mark points) on the calibration board, and then calculates the relative pose relationship between the optical axis and the plane of the calibration board based on the camera imaging model. The advantage of the vision method is that the equipment cost is relatively low and the operation process is relatively intuitive. However, the calibration accuracy of this method is highly dependent on the manufacturing quality of the calibration board itself and the accuracy of the image processing algorithm used. Processing errors of the calibration board, surface flatness defects, and positioning deviations of feature points will all be introduced into the calibration results, forming systematic errors that are difficult to effectively identify and compensate for. In addition, the vision method usually requires taking multiple images of the calibration board at different angles or positions and solving the camera parameters through iterative optimization. This process places high demands on the robustness and computational efficiency of the algorithm. More importantly, when there is a large angular deviation between the calibration plate plane and the camera optical axis, the accuracy of feature extraction will decrease significantly, thus affecting the final calibration result.

[0015] Another method is autocollimation. This method is based on the optical principle of an autocollimator, using a collimator to emit a collimated beam, which is reflected by optical elements and received by the camera. The optical axis angle is calibrated by judging the degree of overlap between the reflected image and the crosshairs of the reticle. Autocollimation has the advantage of high calibration accuracy. However, this method has several insurmountable limitations. First, the autocollimator and its associated optical elements are extremely expensive, making them unaffordable for some production lines or small and medium-sized manufacturing enterprises with limited budgets. Second, the operation process of autocollimation is very complex. It requires not only pre-calibrating the level of the reference plane with a level, but also precise spatial pose adjustments to multiple optical elements such as the collimator, reflector, and autocollimator, demanding a high level of professional skills and experience from the debugging personnel. Third, autocollimation can usually only calibrate the optical axis angle of industrial cameras. The specific position of the optical axis in space (i.e., the relative positional relationship between the optical axis and the equipment's reference platform) cannot be directly obtained using this method and still requires other independent measurement methods or calibration equipment. This means that when both the optical axis angle and position need to be calibrated simultaneously, the debugging personnel often need to use multiple different calibration methods and equipment in succession, which not only increases the complexity of the process and the debugging time, but also introduces reference transfer errors between multiple sets of equipment.

[0016] In view of this, after research, analysis, in-depth exploration and comprehensive verification, the inventors of this application propose a new calibration scheme that can take into account calibration accuracy, ease of operation and cost-effectiveness, so as to achieve efficient and accurate calibration of the optical axis angle and optical axis position of industrial cameras at the same time.

[0017] Specifically, embodiments of this application provide a calibration apparatus, calibration system, and calibration control method for cameras, including industrial cameras. For ease of understanding and explanation, the calibration apparatus and calibration system are described in detail below with reference to the accompanying drawings; other aspects are extended and supplemented based on this.

[0018] Please see Figures 1 to 3 As shown, the calibration device 100 of this application embodiment may include a base 1 and a calibration unit 2, with the calibration unit 2 fixedly disposed on the base 1.

[0019] Specifically, the base 1 may include a base plate 10, a first support 17 and a second support 18. The first support 17 and the second support 18 are spaced apart on the base plate 10. In one embodiment, the first support 17 and the second support 18 may be respectively located on the base plate 10 near both ends.

[0020] The calibration unit 2 may include a top plate 20, a collimating light source 3, and a diffuse reflection light source 4. The two ends of the top plate 20 are respectively disposed on the first support 17 and the second support 18 of the base 1. The vertical space between the top plate 20 and the base plate 10 and the horizontal space between the first support 17 and the second support 18 form the setting area for the collimating light source 3 and the diffuse reflection light source 4. That is, the collimating light source 3 and the diffuse reflection light source 4 can be set at the corresponding positions in the setting area as needed.

[0021] As an optional implementation, the collimating light source 3 can be an optomechanism 30, i.e., the optical engine used in the optical waveguide. In a specific implementation, an optomechanism exit pupil 22 can be opened at the first position of the top plate 20, and a mounting part 21 can be provided below the first position of the top plate 20. The optomechanism 30 is fixedly installed in the mounting part 21, and the exit pupil of the optomechanism can emit collimated light through the upward direction of the optomechanism exit pupil 22 (for example, in an upward direction generally perpendicular to the top plate 20).

[0022] As an optional implementation, the diffuse reflection light source 4 may include a surface light source 40 and multiple micro-holes 23. In a specific implementation, the multiple micro-holes 23 may be located at a second position on the top plate 20, and the surface light source 40 may be located below the multiple micro-holes 23. For example, as shown in the figure, the surface light source 40 may be located on the base 1, i.e., the base plate 10, below the multiple micro-holes 23. In this way, the diffuse reflection light source 4 is formed by the surface light source 40 and the front perforated plate. When in use, after the surface light source 40 emits light, it can emit light 4 upwards towards the calibration device 100 through the multiple micro-holes 23.

[0023] In order to calibrate the optical axis angle and optical axis position of a camera (in this embodiment, an industrial camera 200 is used as an example), a collimating light source 3 is configured to emit light carrying an optical axis angle calibration image toward the base 1, i.e., the calibration device 100. This optical axis angle calibration image can be used to align with the calibration marks of the industrial camera 200 when previewed by the industrial camera 200. A diffuse reflection light source 4 is configured to emit light carrying an optical axis position calibration image toward the base 1, i.e., the calibration device 100. This optical axis position calibration image is used to align with the calibration marks of the industrial camera 200 when previewed by the industrial camera 200.

[0024] During the use of the calibration device 100, it can be fixed to the reference platform 300, which is also the equipment platform. An industrial camera 200 and its drive control system are also deployed on the reference platform 300. When it is necessary to calibrate the optical axis of the industrial camera 200, the optical axis angle of the industrial camera 200 can be calibrated first. Specifically, in conjunction with... Figure 6 and Figure 7 As shown, the optical engine 30 can output a 9-dot image (as a calibration image for the optical axis angle). The industrial camera 200 is moved above the calibration device 100 and placed in preview mode. The virtual image output by the optical engine 30 is captured, and the calibration marker (e.g., a crosshair) of the industrial camera 200 is then activated. By continuously adjusting the pitch / yaw angle of the industrial camera 200, the crosshair of the industrial camera 200 is aligned with the center dot of the 9-dot image of the optical engine virtual image, and the current pitch and yaw motor axis motion parameters at the time of alignment are saved. Furthermore, after alignment, the state of the crosshair in the preview image can be observed by moving the industrial camera 200 a predetermined distance, such as 1-2 mm. If the state of the crosshair remains unchanged, it indicates that the optical axis of the industrial camera 200 is aligned with the optical axis of the optical engine.

[0025] Then calibrate the optical axis position of the industrial camera 200, specifically, in combination with Figure 8 and Figure 9 As shown, when it is necessary to calibrate the optical axis position of the industrial camera 200, the surface light source 40 below multiple micro-holes 23 is lit. After the light passes through the micro-holes 23, it forms a diffuse reflection light source 4. The industrial camera 200 is moved above the diffuse reflection light source 4 of the calibration unit 2, so that the industrial camera 200 is in preview mode. The calibration mark (e.g., crosshair) on the preview screen is aligned with the center of the micro-hole light spot imaged by the output light of the diffuse reflection light source, so that the optical axis of the industrial camera is at the center of the micro-hole light source, and the displacement motion parameters of the industrial camera 200 are saved.

[0026] In addition, since the specific position and size data of each device inside and outside are known, the calibration position information between devices can be further calculated based on this known data and the data saved in the calibration. For example, the specific position information of the camera optical axis on the reference platform 300 can be obtained by combining the position relationship between the base mounting point and the micro-hole center.

[0027] In summary, the calibration device 100 described in the above embodiments overcomes multiple shortcomings of related technologies, specifically including: First, it avoids the sources of systematic errors in visual methods. Traditional visual calibration relies on the quality of the calibration plate and image processing algorithms. Processing errors, surface flatness defects, and feature point positioning deviations of the calibration plate are all introduced into the calibration results, forming systematic errors that are difficult to identify and compensate for. The above embodiments provide a physical reference through the built-in collimating optical engine and micro-aperture light source, eliminating the dependence on external calibration plates and fundamentally eliminating the uncertainty caused by fluctuations in the quality of the calibration plate. Second, it overcomes the cost and operational barriers of self-collimation methods. Self-collimation methods in related technologies are not only expensive in terms of equipment costs, but also require high-precision flat glass and parallel light emitters, with extremely high requirements for combined accuracy. Moreover, it can only calibrate the optical axis angle, and position correction still requires the assistance of other equipment. The above embodiments adopt an integrated design, which can complete calibration without expensive optical components and professional debugging personnel, significantly reducing equipment procurement and labor costs.

[0028] Furthermore, this method enables simultaneous integrated calibration of optical axis angle and position. In related technologies, angle calibration and position calibration typically involve different methods and equipment, requiring switching between multiple devices and introducing reference transfer errors. The above embodiment integrates a collimating optical engine (for angle calibration) and a diffuse reflection light source + micro-aperture array (for position calibration) on the same calibration unit, achieving integrated calibration using the same machine and reference. During calibration, angle calibration and position calibration are performed sequentially at the same station and under the same clamping condition, eliminating reference conversion errors between multiple devices.

[0029] Furthermore, this method can improve the accuracy and reliability of optical axis angle calibration. The above embodiment uses a 9-point diagram emitted by a collimating optical engine as the angle reference. Since the collimating light provides an infinity-based directional reference, when there is an angular deviation between the camera's optical axis and the collimating light, the imaging point will deviate from the center. During calibration, the pitch and yaw motor axes are adjusted to align the crosshair with the center dot of the 9-point diagram. Then, a translation verification (translating 1-2 mm and observing no change in the camera's crosshairs) confirms that the angle calibration is complete. This dual verification mechanism, employing alignment and translation verification, effectively avoids accidental errors that may occur during a single alignment, ensuring the reliability of the angle calibration.

[0030] Furthermore, high-precision spatial positioning of the optical axis can be achieved. The position calibration in the above embodiment uses a precision point light source reference formed by a combination of a surface light source and a micro-hole plate. The surface light source can provide uniform illumination, and the micro-holes constrain the light source into an extremely fine divergent beam. Its physical center is the geometric center of the light source, and it is not affected by the mounting error of the light-emitting chip. During the calibration process, by adjusting the displacement of the industrial camera 200, the crosshair can be aligned with the center of the micro-hole spot, thus ensuring that the camera optical axis accurately passes through the center of the micro-hole. Since the relative positional relationship between the base mounting point and the center of the micro-hole is known, by recording the motion parameters of the displacement motor shaft and combining them with geometric calculations, the spatial coordinates of the camera optical axis on the equipment reference platform can be accurately obtained. This positioning method based on physical micro-holes rather than software algorithms effectively avoids the sub-pixel fitting error that may be introduced by image processing algorithms.

[0031] In addition, the operation process can be simplified and the reliance on personnel can be reduced. Compared with the extremely high requirements for the professional skills of the debugging personnel in the autocollimation method in related technologies, the operation process of the calibration device 100 in the above embodiment is more intuitive. After the calibration device is installed on the equipment platform, the optical engine and diffuse reflection light source are lit in sequence. The calibration can be completed by guiding the electric axis adjustment of the camera through the preview screen. The entire calibration process does not involve complex optical component debugging and spatial attitude calculation. Ordinary production line technicians can be competent after simple training, which effectively reduces the company's reliance on highly skilled debugging personnel and also improves production efficiency and production line compatibility.

[0032] See Figure 4 , Figure 5 and Figure 10 This application also provides a calibration system, which may include a reference platform 300, an industrial camera 200, the calibration device 100 described in the foregoing embodiments, an X / Y / Z electric axis 400, a pitch / yaw electric axis 500, and a control unit 600.

[0033] The reference platform 300 is the equipment platform, and the base of the calibration device 100 is fixedly mounted on the reference platform 300. The industrial camera 200 is deployed above the calibration device 100, meaning that the industrial camera 200 can be positioned above the calibration device 100 by adjusting its position. The X / Y / Z electric axis 400 is part of the drive control system of the industrial camera 200 and is used to adjust the position (i.e., displacement, or positional motion parameters) of the industrial camera 200. The pitch / yaw electric axis 500 is also part of the drive control system of the industrial camera 200 and is used to adjust the pitch / yaw angle (i.e., attitude motion parameters) of the industrial camera 200.

[0034] The control unit 600 can be implemented using a dedicated controller. The control unit 600 is electrically connected and / or signal control connected to the calibration device 100, the industrial camera 200, the X / Y / Z motorized axes 400, and the pitch / yaw motorized axes 500. The control unit 600 is used to control the collimating light source 3 of the calibration device 100 to emit an image carrying the optical axis angle calibration (e.g., during the optical axis angle calibration process of the industrial camera 200). Figure 6 or Figure 7 The control unit 600 controls the X / Y / Z motor axes 400 and the pitch / yaw motor axes 500 to align the calibration marks (such as crosshairs) of the industrial camera 200 with the optical axis angle calibration image, and saves the current motion parameters of the pitch / yaw motor axes during alignment. The control unit 600 is also used to control the diffuse reflection light source 4 to emit light carrying the optical axis position calibration image (such as...) during the optical axis position calibration process of the industrial camera 200. Figure 8 or Figure 9 The light from the micro-aperture spot shown controls the X / Y / Z motor axis 400, aligning the calibration mark of the industrial camera 200 with the calibration image of the optical axis position, and saving the motion parameters of the current X / Y / Z motor axis during alignment.

[0035] In addition, the control unit 600 can also be used to: after completing the optical axis position calibration and saving the motion parameters of the X / Y / Z electric axis 400, calculate and output the spatial absolute coordinate value of the current camera optical axis in the reference platform coordinate system based on the pre-stored internal and external position information of each device.

[0036] Furthermore, since the relative positions of the internal and external parts of each device, i.e. the size data between them, are known, the calibration position information between the devices can be further calculated based on this known data and the data saved during calibration. For example, the specific position information of the camera optical axis on the reference platform 300 can be obtained by combining the positional relationship between the base mounting point and the center of the micro-hole.

[0037] By adopting the calibration system of the above embodiments, a higher level of automation in the calibration process can be achieved, significantly improving calibration efficiency and consistency. In this embodiment, the control unit 600 can control the collimating light source 3 to emit an optical axis angle calibration image and control the diffuse reflection light source 4 to emit an optical axis position calibration image, and automatically drive the X / Y / Z electric axes 400 and the pitch / yaw electric axes 500 to complete the alignment operation. After alignment, the motion parameters of the corresponding electric axes are automatically saved. This eliminates subjective errors caused by differences in operating habits and experience among different debugging personnel, making the calibration results of each industrial camera 200 highly consistent in mass production.

[0038] Furthermore, parameter solidification enables the digital storage and rapid reproduction of calibration results. In related technologies, traditional calibration methods heavily rely on the on-site operations of the technicians, resulting in no objective records for traceability after calibration. When equipment requires maintenance or recalibration, the entire calibration process must be repeated. In this embodiment, the control unit automatically saves the motion parameters of the pitch / yaw motor axes and the X / Y / Z motor axes 400 after alignment. These parameters are stored numerically in the control unit or host computer. When recalibrating the same model camera or restarting the equipment after shutdown, the saved motion parameters can be directly called to drive the motor axes to quickly reset to the calibration position, eliminating the need to re-execute the complete alignment process and significantly reducing equipment downtime. In addition, the motor axis parameters from each calibration can be recorded and uploaded to the manufacturing execution system, forming a traceable calibration data chain and providing objective data support for product quality analysis.

[0039] In addition, a joint calibration system for angle and position using the same equipment and calibration benchmark can be established. In this embodiment, the base of the calibration device 100 is fixedly installed on the benchmark platform 300, and the industrial camera 200 is positioned above the calibration device 100. The control unit 600 first controls the optical axis angle calibration (aligning the camera's calibration mark with the center dot of the 9-point diagram of the optical-mechanical virtual image via the pitch / yaw motor axis), and then controls the optical axis position calibration (aligning the camera's calibration mark with the center of the micro-aperture spot via the X / Y / Z motor axis). Throughout the process, the camera's angle calibration and position calibration are completed sequentially at the same workstation, under the same clamping condition, and with the same physical benchmark (calibration device) on the benchmark platform as a reference. This eliminates the benchmark transfer error and secondary clamping error introduced by the traditional technology, which requires angle calibration and position calibration to be completed using different equipment at different workstations.

[0040] Furthermore, decoupled calibration of angle and position can be achieved through control logic, improving calibration accuracy. In the above embodiment, the control unit is configured to: first complete the optical axis angle calibration, confirm and save the pitch / yaw parameters, and then perform optical axis position calibration. This sequential control logic ensures that when position calibration begins, the camera optical axis angle has been adjusted to be parallel to the collimated light, avoiding additional offset of the imaging position of the micro-aperture spot on the camera sensor due to optical axis tilt, thereby preventing angle errors from interfering with position determination. The decoupled calibration of the two degrees of freedom of angle and position significantly improves the mathematical convergence and accuracy of the final spatial pose calibration.

[0041] Furthermore, the absolute coordinates of the camera's optical axis spatial position can be determined. In this embodiment, since the internal and external geometrical relationships of the calibration device 100's base and other components are known fixed values, after the control unit 600 completes the optical axis position calibration and saves the motion parameters of the X / Y / Z motor axes, it can calculate and output the current absolute spatial coordinates of the camera's optical axis in the reference platform coordinate system based on the pre-stored geometrical relationships. This allows the system to not only complete the physical alignment of the camera's optical axis but also quantify the optical axis position into specific spatial coordinate data, providing accurate numerical basis for subsequent equipment debugging, error compensation, and coordinate unification of multi-camera systems.

[0042] It should be noted that, in the above embodiments, in order to improve the stability of the calibration device 100 and its operation, and to reduce potential errors, the fixing method between the calibration unit 2 and the base 1, and between the base 1 and the reference platform 300, can adopt a combination of bolts and pins. Specifically, as follows: Figure 2 and Figure 3 As shown, the two ends of the base plate 10 can be fixed to two positions of the reference platform 300 by a set of bolts and pins respectively. Specifically, the first end of the base plate 10 has a first bolt hole 11 and a second bolt hole 12 on both sides of the first support 17, and the first end of the base plate 10 has a first pin hole 15 on the first side of the first support 17. The second end of the base plate 10 has a third bolt hole 13 and a fourth bolt hole 14 on both sides of the second support 18, and the second end of the base plate 10 has a second pin hole 16 on the second side of the second support 18. In this way, each end of the base plate 10 is fixed to the reference platform 300 by a set of bolts passing through the corresponding two bolt holes and a pin passing through the corresponding pin hole. Similarly, the top plate 20 is fixed to the first support 17 and the second support 18 by a set of bolts and pins at both ends. Specifically, the first end of the top plate 20 is provided with a fifth bolt hole 24 and a sixth bolt hole 25 spaced apart, and a third pin hole 28 is provided near the fifth bolt hole 24. The second end of the top plate 20 is provided with a seventh bolt hole 26 and an eighth bolt hole 27 spaced apart, and a fourth pin hole 29 is provided near the eighth bolt hole 27. In this way, each end of the top plate 20 is fixed to the first support (or the second support) by a set of bolts passing through two corresponding bolt holes and a pin passing through one corresponding pin hole.

[0043] After adopting the above scheme, each set of bolts and pins can work together to form a reliable connection that is tightly fixed and positioned. The bolt connection provides clamping force (axial preload) to both parties, pressing them together, while the pin connection provides high-precision positioning and shear resistance, ensuring coaxiality and positional accuracy of the holes, preventing slippage, and withstanding lateral forces or vibrations. Furthermore, the pin connection can share some of the shear load of the bolt connection, preventing hole wall deformation. Therefore, this scheme can improve the stability of the calibration device 100 during operation and reduce potential errors.

[0044] In the calibration apparatus, calibration system and implementation methods of the above embodiments, the collimating light source 3 is illustrated by taking the optomechanical system 30 and the diffuse reflection light source 4 as a surface light source 40 with a front perforated plate. However, in other embodiments, it is not limited to this and other forms of collimating light sources and diffuse reflection light sources can also be used.

[0045] In the above embodiments and implementations, the calibration unit 2 adopts a top plate 20 and a collimating light source 3 and a diffuse reflection light source 4 disposed below the top plate 20. However, in other embodiments, it is not limited to this. For example, other forms of structures can be used to replace the top plate 20 to realize the deployment of the collimating light source and the diffuse reflection light source, as long as the corresponding configuration and function of the collimating light source and the diffuse reflection light source can be realized. Correspondingly, in other embodiments, the form of the base 1 is not limited to adopting a base plate 10 and a first support 17 and a second support 18 disposed on the base plate 10, as long as it can realize the support and installation of the calibration unit.

[0046] In the above embodiments and implementations, the camera calibration mark uses a crosshair, the optical axis angle calibration image uses an optomechanical 9-point diagram, and the optical axis position calibration image uses a micro-aperture spot. However, in other embodiments, this is not the case. For example, the standard mark of the camera can also use other types of graphic marks.

[0047] This application embodiment also provides a calibration control method. This calibration control method uses the aforementioned calibration device 100 for calibrating the optical axis angle and position of an industrial camera 200. The method includes: controlling the collimating light source 3 to emit light carrying an optical axis angle calibration image (such as a 9-point optical-mechanical diagram); controlling the industrial camera 200 to be in preview mode and adjusting the position motion parameters (motion parameters of the X / Y / Z electric axes 400) and attitude motion parameters (motion parameters of the pitch / yaw electric axes 500) of the industrial camera 200; saving the attitude motion parameters of the industrial camera 200 when the calibration mark of the industrial camera 200 is aligned with the optical axis angle calibration image; controlling the diffuse reflection light source 4 to emit light carrying an optical axis position calibration image (such as a micro-aperture spot); controlling the industrial camera 200 to be in preview mode and adjusting the position motion parameters of the industrial camera 200; saving the position motion parameters of the industrial camera 200 when the calibration mark of the industrial camera 200 is aligned with the optical axis position calibration image.

[0048] The technical effects of the calibration control method in this application are similar to those of the calibration device and calibration system in the signed embodiment. Please refer to the relevant description above, which will not be repeated here.

[0049] It should be noted that in the description of this application and its various embodiments, terms such as "top," "end," "bottom," "side," "upper," "lower," and "height" indicate orientation or positional relationships, which are general expressions based on the orientation or positional relationships shown in the accompanying drawings or under actual field conditions. These are merely for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0050] In this application and its various embodiments, unless otherwise explicitly stated or affecting logical consistency, the terms "set," "install," "connect," "link," "fix," etc., should be interpreted broadly. For example, where there is no conflict, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0051] In this application and its various embodiments, unless otherwise expressly specified and limited, the phrase "above" or "below" a second feature may include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of a second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" a second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0052] The specific embodiments described above have provided a detailed explanation of the purpose, technical solutions, and beneficial effects of this application. It should be understood that the above descriptions are merely specific embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A calibration device for calibrating a camera, characterized in that, The device includes a base and a calibration unit disposed on the base. The calibration unit includes: a collimating light source configured to emit light carrying an optical axis angle calibration image upwards toward the base, the optical axis angle calibration image being used to align with the calibration marks of the camera when previewed by the camera; and a diffuse reflection light source configured to emit light carrying an optical axis position calibration image upwards toward the base, the optical axis position calibration image being used to align with the calibration marks of the camera when previewed by the camera.

2. The calibration device as described in claim 1, characterized in that, The calibration unit also includes a top plate disposed on the base, and an optomechanical exit pupil is disposed at a first position on the top plate; the collimating light source is an optomechanical system, which is disposed below the optomechanical exit pupil.

3. The calibration device as described in claim 2, characterized in that, The top plate has a mounting part on the bottom side of the first position, and the optical engine is disposed in the mounting part.

4. The calibration device as described in claim 1, characterized in that, The calibration unit also includes a top plate disposed on the base, and the diffuse reflection light source includes a plurality of micro-holes disposed at a second position on the top plate and a surface light source disposed below the plurality of micro-holes.

5. The calibration apparatus as described in claim 4, characterized in that, The surface light source is disposed on the base.

6. The calibration apparatus as described in claim 1, characterized in that, The base includes a base plate and a first support and a second support spaced apart from the base plate; the calibration unit also includes a top plate, with its two ends respectively disposed on the first support and the second support; the top plate and the base plate, as well as the first support and the second support, form the setting area for the collimating light source and the diffuse reflection light source.

7. The calibration apparatus as described in claim 6, characterized in that, The top plate is respectively attached to the first support and the second support by a set of bolts and pins at both ends.

8. A calibration system, characterized in that, The system includes a reference platform, a camera, X / Y / Z motorized axes, a pitch / yaw motorized axis, a control unit, and the calibration device according to any one of claims 1 to 7, wherein: the base of the calibration device is fixedly mounted on the reference platform; the camera is disposed above the calibration device; the X / Y / Z motorized axes are used to adjust the position of the camera; the pitch / yaw motorized axes are used to adjust the pitch / yaw angle of the camera; the control unit is used to control the collimating light source to emit light carrying an optical axis angle calibration image, control the X / Y / Z motorized axes and the pitch / yaw motorized axes to align the calibration mark of the camera with the optical axis angle calibration image, and save the motion parameters of the pitch / yaw motorized axes during alignment; and to control the diffuse reflection light source to emit light carrying an optical axis position calibration image, control the X / Y / Z motorized axes to align the calibration mark of the camera with the optical axis position calibration image, and save the motion parameters of the X / Y / Z motorized axes during alignment.

9. The calibration system as described in claim 8, characterized in that, The calibration device is fixed to the reference platform at both ends by a set of bolts and pins.

10. A calibration control method, characterized in that, The calibration control method uses the calibration device described in any one of claims 1 to 7 for calibrating the optical axis angle and optical axis position of a camera, the method comprising: Control the collimated light source to emit light carrying an image of the optical axis angle calibration; Control the camera to preview mode and adjust the camera's position and attitude motion parameters; When the camera's calibration mark is aligned with the optical axis angle calibration image, the camera's attitude motion parameters are saved; Control the diffuse light source to emit light carrying an image of the optical axis position calibration; Control the camera to preview mode and adjust the camera's position and motion parameters; The camera's position and motion parameters are saved when the camera's calibration marks are aligned with the optical axis position calibration image.

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