Camera calibration for radar and camera combined systems, methods of use, and apparatuses

Abstract

The application discloses a camera calibration method, use method and equipment for a radar and camera combined system. The method comprises the following steps: controlling zero position adjustment of a PTZ camera, the zero position optical axis of the PTZ camera is parallel or not parallel to the ground where the PTZ camera is located; determining the projection position coordinate of the PTZ camera on the ground, and constructing a reference calibration coordinate system with the projection position coordinate as the origin, the corresponding position point of the PTZ camera is located on the vertical axis of the reference calibration coordinate system; determining the reference calibration position coordinate adopted in the reference calibration coordinate system, and determining the omnibearing control parameter adopted when the PTZ camera is directed to the reference calibration position, the reference calibration position coordinate is a self-defined selected ground position coordinate; and performing preset calibration on the PTZ camera according to the projection position coordinate, the reference calibration position coordinate and the omnibearing control parameter adopted when the PTZ camera is directed to the reference calibration position. The method reduces the complexity of PTZ camera parameter calibration, and improves the universality of preset calibration on the PTZ camera.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of camera calibration, and in particular to a camera calibration for a radar and camera combined system, a use method and equipment. BACKGROUND

[0002] PTZ cameras are widely used in the field of traffic detection, especially the joint application of radar and PTZ cameras, which can mobilize the PTZ camera to focus on the target to shoot high-definition video or capture pictures with the help of high-precision target positioning of radar.

[0003] In related solutions, the key calibration parameters can be solved by means of the trigonometric function relationship between the ground coordinates and the PTZ coordinates of the PTZ camera, so as to construct the conversion relationship between the target coordinates (such as GPS coordinates) detected by the radar and the PTZ coordinates of the PTZ camera, and then the linkage of the radar and the PTZ camera can be realized according to the conversion relationship.

[0004] However, when calibrating the PTZ camera, the PTZ camera needs to meet many objective conditions, such as requiring the zero optical axis of the PTZ camera to be parallel to the ground, and solving the tilt angle (T value parameter) when aiming at the target of the PTZ camera; and requiring the PTZ camera to be positioned at the horizontal position angle position, and selecting the ground coordinates in the direction of the zero optical axis for calibration, but in the traffic scene or other application scenes, such as the fast lane of the highway or the corresponding position in the water scene, it is not easy to collect coordinates, resulting in high complexity of the calibration of the PTZ camera. SUMMARY

[0005] The present application provides a camera calibration for a radar and camera combined system, a use method, a device, an electronic equipment and a storage medium, to solve the problem of high complexity of the preset calibration of the PTZ camera.

[0006] According to an aspect of the present application, a camera calibration method for a radar and camera combined system is provided, which comprises:

[0007] controlling the zero position adjustment of the PTZ camera, and the zero optical axis of the PTZ camera is parallel or not parallel to the ground where the PTZ camera is located;

[0008] determining the projection position coordinates of the PTZ camera on the ground, and constructing a reference calibration coordinate system with the projection position coordinates as the origin, and the corresponding position point of the PTZ camera is located on the vertical axis of the reference calibration coordinate system;

[0009] determining the reference calibration position coordinates used in the reference calibration coordinate system, and determining the full-orientation control parameters used when the PTZ camera is directed to the reference calibration position, the full-orientation control parameters including the vertical azimuth angle and the horizontal azimuth angle where the PTZ camera is located, and the reference calibration position coordinates are the self-defined ground position coordinates;

[0010] Pre-setting calibration of the PTZ camera according to the projection position coordinates, the reference calibration position coordinates and the all-direction control parameters used when aiming at the reference calibration position, wherein the calibration of the PTZ camera comprises calibration of the conversion relationship between the all-direction control parameters when aiming at the target and the ground position when aiming at the target.

[0011] According to another aspect of the present application, a camera use method for a radar and camera combined system is provided, characterized in that the calibration conversion result of the PTZ camera obtained by using the camera calibration method for a radar and camera combined system in any of the above embodiments is used, and the method comprises:

[0012] determining the horizontal and vertical axis positions of the target on the ground by using the radar;

[0013] determining the all-direction control parameters of the PTZ camera required for photographing the target on the ground according to the calibration conversion result of the PTZ camera, wherein the calibration conversion result of the PTZ camera comprises the all-direction control parameters used when the PTZ camera aims at the target on the ground at the horizontal and vertical axis positions, and the all-direction control parameters comprise the vertical azimuth angle and the horizontal azimuth angle of the PTZ camera;

[0014] controlling the PTZ camera to rotate in linkage according to the all-direction control parameters of the PTZ camera required for photographing the target on the ground.

[0015] According to another aspect of the present application, a camera calibration device for a radar and camera combined system is provided, and the device comprises:

[0016] a position adjustment module for controlling zero position adjustment of the PTZ camera, wherein the zero position optical axis of the PTZ camera is parallel or not parallel to the ground where the PTZ camera is located;

[0017] a reference coordinate system determination module for determining the projection position coordinates of the PTZ camera on the ground, and constructing a reference calibration coordinate system with the projection position coordinates as the origin, wherein the corresponding position point of the PTZ camera is located on the vertical axis of the reference calibration coordinate system;

[0018] a calibration coordinate determination module for determining the reference calibration position coordinates used in the reference calibration coordinate system, and determining the all-direction control parameters used when the PTZ camera aims at the reference calibration position, wherein the all-direction control parameters comprise the vertical azimuth angle and the horizontal azimuth angle of the PTZ camera, and the reference calibration position coordinates are self-defined ground position coordinates;

[0019] The preset calibration determining module is configured to calibrate the PTZ camera according to the projection position coordinates, the reference calibration position coordinates, and the omnibearing control parameters used when the PTZ camera is directed to the reference calibration position coordinates, wherein the calibration of the PTZ camera includes calibration of a conversion relationship between the omnibearing control parameters used when the PTZ camera is directed to the target and the ground position when the PTZ camera is directed to the target.

[0020] According to another aspect of the present application, there is provided a camera using device for a radar and camera combined system, wherein the device comprises the calibration conversion result of the PTZ camera obtained by using the camera calibration method for the radar and camera combined system according to any one of the above embodiments, and the device comprises:

[0021] The position determining module is configured to determine the horizontal and vertical axis positions of the target on the ground by using the radar.

[0022] The control parameter determining module is configured to determine the omnibearing control parameters of the PTZ camera required for photographing the target on the ground according to the calibration conversion result of the PTZ camera, wherein the calibration conversion result of the PTZ camera includes the omnibearing control parameters used when the PTZ camera is directed to the target at the horizontal and vertical axis positions on the ground, and the omnibearing control parameters include the vertical and horizontal azimuth angles of the PTZ camera.

[0023] The radar and camera linkage module is configured to control the PTZ camera to rotate in linkage according to the omnibearing control parameters of the PTZ camera required for photographing the target on the ground.

[0024] According to another aspect of the present application, there is provided an electronic device, which comprises:

[0025] at least one processor; and

[0026] a memory connected to the at least one processor in communication; wherein

[0027] The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor to enable the at least one processor to execute the camera calibration method for the radar and camera combined system or the camera using method for the radar and camera combined system according to any one of the embodiments of the present application.

[0028] According to another aspect of the present application, there is provided a computer readable storage medium storing computer instructions for enabling a processor to implement the camera calibration method for the radar and camera combined system or the camera using method for the radar and camera combined system according to any one of the embodiments of the present application when executed by the processor.

[0029] The technical scheme of the embodiment of the present application is that the orientation of the PTZ camera is returned to zero, the orthographic projection position coordinates of the PTZ camera on the ground are determined, a reference calibration coordinate system is established with the orthographic projection position coordinates as the origin, the PTZ camera is located on a vertical axis which is perpendicular to the ground where the PTZ camera is located, the reference calibration position coordinates in the reference calibration coordinate system are selected, the all-direction control parameters of the PTZ camera when the PTZ camera is oriented to the reference calibration position are determined according to the reference calibration position coordinates, the PTZ camera is preset calibrated according to the known projection position coordinates, the reference calibration position coordinates and the all-direction control parameters when the PTZ camera is oriented to the reference calibration position, and the preset conversion relationship. The technical scheme is that the reference calibration coordinate system is established, the orthographic projection position coordinates and the reference calibration position coordinates are determined, the PTZ camera is preset calibrated according to the all-direction control parameters when the PTZ camera is oriented to the reference calibration position, the preset calibration can be completed by adjusting the zero optical axis of the PTZ camera to obtain the intermediate parameters, and the preset calibration of the PTZ camera is not limited to the zero optical axis of the PTZ camera being parallel to the ground, and the complexity of the parameter calibration of the PTZ camera is reduced, and the universality of the preset calibration of the PTZ camera is improved.

[0030] It should be understood that the content described in this part is not intended to identify key or important features of the embodiments of the present application, nor is it used to limit the scope of the present application. Other features of the present application will become apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creating laborious work.

[0032] Figure 1 is a flow chart of a camera calibration method for a radar and camera combined system according to an embodiment of the present application;

[0033] Figure 2a is a schematic diagram of a reference calibration coordinate system for PTZ camera calibration according to an embodiment of the present application;

[0034] Figure 2b is a schematic diagram of camera and radar calibration for a radar and camera combined system according to an embodiment of the present application;

[0035] Figure 3 is a flow chart of a camera use method for a radar and camera combined system according to an embodiment of the present application;

[0036] Figure 4is a structural schematic diagram of a PTZ camera calibration device according to an embodiment three of the present application;

[0037] Figure 5 is a structural schematic diagram of a camera using device for a radar and camera combined system according to an embodiment four of the present application;

[0038] Figure 6 is a structural schematic diagram of an electronic device for implementing a camera calibration method for a radar and camera combined system or a camera using method for a radar and camera combined system. DETAILED DESCRIPTION

[0039] In order to make the personnel in the technical field better understand the present application scheme, the technical scheme in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should belong to the scope of protection of the present application.

[0040] It should be noted that the terms "first", "second" and the like in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or a chronological sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0041] Embodiment one

[0042] Figure 1 A flowchart of a camera calibration method for a radar and camera combined system is provided for the embodiment one of the present application. The present embodiment can be applicable to the simple calibration of a PTZ camera. The method can be performed by a camera calibration device for a radar and camera combined system, which can be realized in the form of hardware and / or software. The camera calibration device for a radar and camera combined system can be configured in any electronic device with network communication function. As shown in the figure, the method comprises: Figure 1

[0043] ​S110, control the PTZ camera to be zeroed, and the zeroed optical axis of the PTZ camera is parallel or not parallel to the ground surface at the location of the PTZ camera.

[0044] The zeroed position can be a position where the PTZ camera lens focuses when not shooting a target object. The zeroed optical axis can be a center line through which a light beam passes the center point of the camera lens when the camera is not shooting a target object.

[0045] Specifically, the lens of the PTZ camera is controlled to point to an initial position by an infrared sensor or an Internet technology. The zeroed optical axis of the PTZ camera can be parallel or not parallel to the ground surface of a region including the target object.

[0046] For example, a remote controller based on an infrared sensor technology or a remote setting based on an Internet technology is used to point the lens of the PTZ camera to an initial zeroed position. A light beam emitted from the camera of the PTZ camera can be parallel or not parallel to the horizontal ground surface.

[0047] S120, determine the projection position coordinates of the PTZ camera on the ground surface, and construct a reference calibration coordinate system with the projection position coordinates as the origin, and a corresponding position point of the PTZ camera is located on a vertical axis of the reference calibration coordinate system.

[0048] As an optional but not limited implementation, the determination of the projection position coordinates of the PTZ camera on the ground surface specifically includes the following steps A1-A2:

[0049] Step A1, measure the corresponding projection position coordinates of the PTZ camera on the ground surface by a real-time dynamic measurement device, and the real-time dynamic measurement device uses a carrier phase difference technology to measure the position.

[0050] The orthographic projection can be a projection generated by a parallel light beam emitted from the lens of the PTZ camera perpendicular to the projection surface. The projection position coordinates can be a coordinate position on the ground surface directly opposite the center point of the lens of the PTZ camera. The carrier phase difference technology can be a method in which a carrier observation value and a base station coordinate are transmitted to a user station by a wired transmission or a wireless transmission by an observation device, and the user station calculates a positioning result of the target object according to the received data.

[0051] Specifically, when the camera of the PTZ camera orthographically projects the ground surface, the measurement device measures the corresponding projection position coordinates of the center point of the camera on the ground surface in real time. The real-time dynamic measurement device needs to re-measure the projection position coordinates of the camera orthographically projected on the ground surface every time the shooting angle is updated or the shooting target is updated. The real-time dynamic measurement device is based on the carrier phase difference technology to measure the position.

[0052] S120, determining a reference calibration position coordinate adopted under a reference calibration coordinate system, including: moving the real-time dynamic measurement device to a self-defined selected reference calibration position point, and measuring a reference calibration position coordinate corresponding to the reference calibration position point by the real-time dynamic measurement device.

[0053] The reference calibration coordinate system can be a three-dimensional coordinate system of a ground area including the reference calibration position, which is established with the projection position coordinate as the origin and a vertical axis for installing the PTZ camera as the longitudinal axis.

[0054] Specifically, the PTZ camera needs to solve intermediate parameters to obtain calibration information of the reference calibration position, and the intermediate parameters can be solved by establishing an equation group, so the number of unknown intermediate parameters needs to be preset according to the reference calibration position, and the reference calibration position coordinates of the reference calibration position measured by the real-time dynamic measurement device.

[0055] Specifically, the PTZ camera needs to determine the specific position of the target object according to P calibration, T calibration and Z calibration, solve unknown intermediate parameters by determining P, T and Z calibration of the PTZ camera, and the unknown intermediate parameters include: the angle between the extension line of the camera center point of the PTZ camera and the vertical axis for installing the PTZ camera, the distance between the installation position of the PTZ camera on the vertical rod and the ground, etc., and the number of unknown parameters is determined according to the number of preset reference calibration positions.

[0056] S130, determining a reference calibration position coordinate adopted under a reference calibration coordinate system, and determining a full-direction control parameter adopted when the PTZ camera is directed to the reference calibration position, the full-direction control parameter including a vertical azimuth angle and a horizontal azimuth angle of the PTZ camera, and the reference calibration position coordinate being a self-defined selected ground position coordinate.

[0057] As an optional but not limited implementation manner, the full-direction control parameter includes the horizontal azimuth angle and the vertical azimuth angle of the PTZ camera, and specifically includes the following determination steps B1-B2:

[0058] Step B1, the horizontal azimuth angle is determined by adding a first to-be-calibrated angle and a first reference angle.

[0059] Optionally, the first to-be-calibrated angle is an included angle between a zero-position optical axis of the PTZ camera and a corresponding horizontal axis of the reference calibration coordinate system on a first reference plane, the first reference angle is an included angle between a first reference line and the corresponding horizontal axis of the reference calibration coordinate system on the first reference plane, the first reference line is a line connecting the reference calibration position and the projection position, and the first reference plane is a horizontal-longitudinal axis plane of the reference calibration coordinate system.

[0060] The horizontal angle of the water level can be an angle of a zero position optical axis projection direction of the PTZ camera and a horizontal angle of the reference calibration position and the orthogonal projection position coordinate line OT.

[0061] Specifically, the horizontal angle of the zero position direction of the PTZ camera and the reference calibration position is a sum of the first to-be-calibrated angle and the first reference angle.

[0062] As shown in FIG. 1, the horizontal angle of the zero position direction of the PTZ camera and the reference calibration position is a sum of the first to-be-calibrated angle and the first reference angle. Figure 2a As shown in FIG. 1, the horizontal angle of the zero position direction of the PTZ camera and the reference calibration position is a sum of the first to-be-calibrated angle and the first reference angle.

[0063] The vertical orientation angle is determined by subtracting the second to-be-calibrated angle from the second reference angle in step B2.

[0064] The vertical orientation angle can be an angle of a lens projection direction of the PTZ camera and the horizontal angle of the reference calibration position.

[0065] Optionally, the second to-be-calibrated angle is an angle of the zero position optical axis of the PTZ camera and a corresponding vertical axis of the reference calibration coordinate system on a second reference plane, the second reference angle is an angle of a second reference line and the corresponding vertical axis of the reference calibration coordinate system on the second reference plane, the second reference line is a line connecting the reference calibration position and the PTZ camera, the second reference plane is a plane in the reference calibration coordinate system that is perpendicular to the horizontal and vertical axis plane and passes through the vertical axis, and the PTZ camera to the projection position corresponds to a to-be-calibrated height of the PTZ camera height.

[0066] Specifically, the angle of the lens zero position optical axis projection direction and the angle of the line connecting the reference calibration position and the PTZ camera position is equal to the second to-be-calibrated angle minus the second reference angle.

[0067] As shown in FIG. 1, the horizontal angle of the zero position direction of the PTZ camera and the reference calibration position is a sum of the first to-be-calibrated angle and the first reference angle. Figure 2a As shown in FIG. 1, the horizontal angle of the zero position direction of the PTZ camera and the reference calibration position is a sum of the first to-be-calibrated angle and the first reference angle.

[0068] S140, presetting calibration of the PTZ camera according to the projection position coordinate, the reference calibration position coordinate and the all-azimuth control parameter used when aiming at the reference calibration position, wherein the calibration of the PTZ camera comprises calibration of the conversion relationship between the all-azimuth control parameter used when aiming at the target and the ground position when aiming at the target.

[0069] As an optional but not limited implementation, the all-azimuth control parameter used when the PTZ camera aims at the reference calibration position specifically comprises steps C1-C2:

[0070] Step C1, controlling the PTZ camera to rotate so that the center of the image of the PTZ camera is aligned with the reference calibration position and the image clarity is greater than a preset clarity.

[0071] The preset clarity can be a pre-set parameter to make the clarity of each detail image and its boundary on the image reach a certain clarity standard.

[0072] Specifically, the PTZ camera lens is rotated to focus on the reference calibration position, so that the object on the reference calibration position is placed in the center of the shooting image, and it is required to ensure that the image clarity containing the reference calibration position is greater than the preset clarity.

[0073] Step C2, after the rotation of the PTZ camera is controlled, the all-azimuth control parameter used when the PTZ camera aims at the reference calibration position is obtained.

[0074] For example, as shown in Figure 2a The all-azimuth control parameter comprises: the projection of the PTZ camera zero direction on the xoy plane, the angle P of the horizontal angle between the line OT connecting the reference calibration position and the orthographic position coordinate, the angle T of the projection direction of the camera optical axis and the angle between the line connecting the reference calibration position and the PTZ camera position, and the coordinate (x, y) of the reference calibration position.

[0075] As an optional but not limited implementation, the calibration of the PTZ camera according to the projection position coordinate, the reference calibration position coordinate and the all-azimuth control parameter used when aiming at the reference calibration position specifically comprises steps D1-D3:

[0076] Step D1, determining a first conversion formula associated with the PTZ camera, wherein the first conversion formula is constructed according to the trigonometric function relationship between the first reference angle in the horizontal azimuth angle, the projection position coordinate and the reference calibration position coordinate, and the first conversion formula describes the conversion relationship between the reference calibration position coordinate and the horizontal azimuth angle in the all-azimuth control parameter based on the first to-be-calibrated angle in the horizontal azimuth angle.

[0077] Among them, trigonometric functions can be basic elementary functions with angle as the independent variable and the coordinates of the intersection point of the terminal side of any angle with the unit circle or their ratio as the dependent variable.

[0078] For example, such as Figure 2a As shown, the first transformation formula is determined by the tangent trigonometric function relationship of the first reference angle α, which is the horizontal angle P. A right triangle is formed by drawing a perpendicular line from the reference calibration position coordinates (x, y) to the x-axis as one leg of the right triangle, the line OT connecting the reference calibration position coordinates (x, y) and the projected position coordinates as the hypotenuse, and the x-axis of the reference calibration coordinate system. This right triangle lies on the first reference plane xoy, and the angle directly opposite the reference calibration position coordinates is the first reference angle α. The tangent trigonometric function expression for the first reference angle α is as follows:

[0079]

[0080] The first reference angle α can be expressed as:

[0081]

[0082] Step D2: Determine the second conversion formula associated with the PTZ camera. The second conversion formula is constructed according to the trigonometric function relationship between the second reference angle in the vertical azimuth angle, the projection position coordinates, the reference calibration position coordinates, and the height to be calibrated. The second conversion formula describes the conversion relationship between the reference calibration position coordinates and the vertical azimuth angle in the omnidirectional control parameters based on the second angle to be calibrated and the height to be calibrated in the vertical azimuth angle.

[0083] For example, such as Figure 2a As shown, a right triangle is established. The line connecting the origin of the reference coordinate system (i.e., the orthographic projection position coordinate of the PTZ camera) and the PTZ camera position coordinate is perpendicular to the first reference plane xoy. This line serves as one short leg h of the right triangle. The line connecting the reference calibration position coordinate and the origin of the reference coordinate system OT serves as the other leg of the right triangle. The line connecting the PTZ camera position coordinate and the reference calibration position coordinate serves as the hypotenuse L of the triangle. The angle between the short leg h and the hypotenuse L is β. The second transformation formula is determined by the tangent trigonometric function of the second reference angle β, as shown in the following formula:

[0084]

[0085] Step D3: Substitute the values ​​of the projected position coordinates, the reference calibration position coordinates, and the values ​​of the omnidirectional control parameters used when facing the reference calibration position coordinates into the first conversion formula and the second conversion formula in sequence to obtain the values ​​of the first angle to be calibrated, the second angle to be calibrated, and the height to be calibrated.

[0086] As shown in the example, Figure 2a The projection position coordinate is (x0, y0), the reference calibration position coordinate is (x, y), the projection direction of the PTZ camera zero direction on the xoy plane is OT, the horizontal angle between the line OT and the projection position coordinate is angle P, the projection direction of the spherical camera optical axis is OT, the angle between the line OT and the PTZ camera position is angle T, the reference calibration position coordinates are set as two groups (x1, y1) and (x2, y2), and the equation group is as follows:

[0087]

[0088] According to the above formula, the following is obtained:

[0089]

[0090] The reference calibration position coordinate (x, y), the projection position coordinate (x0, y0), and the angle P corresponding to the horizontal angle of the reference calibration position coordinate are substituted into the above formula to obtain the value of the first to-be-calibrated angle a0:

[0091]

[0092] The two groups of reference calibration position coordinates (x1, y1) and (x2, y2), the angles T1 and T2 corresponding to the vertical angles of the reference calibration position coordinates, and the projection position coordinate (x0, y0) are substituted into the following formula:

[0093]

[0094] The equation group is solved as follows:

[0095] The value of the second to-be-calibrated angle b0 and the value of the to-be-calibrated height h are obtained.

[0096] As an optional but not limited implementation manner, the omnibearing control parameter includes a zoom parameter of the PTZ camera, and the PTZ camera is calibrated according to the projection position coordinate, the reference calibration position coordinate, and the omnibearing control parameter used when the PTZ camera is directed to the reference calibration position coordinate.

[0097] The zoom parameter of the PTZ camera can be understood as rotating the PTZ camera to place the target reference position in the center of the shooting picture, and adjusting the focal length and other parameters to make the target reference position clearly visible in the center of the picture.

[0098] Optionally, the zoom parameter of the PTZ camera indicated in the omnibearing control parameter used when the PTZ camera is directed to the reference calibration position coordinate is self-defined according to different reference calibration positions.

[0099] Specifically, by setting different reference calibration position coordinates, rotating the PTZ camera will adjust parameters such as focal length according to the reference calibration position, resulting in different zoom parameters for the PTZ camera at the current reference calibration position.

[0100] Optionally, determining the parameters to be calibrated also includes the following steps E1-E2:

[0101] Step E1: Determine the third conversion formula associated with the PTZ camera. The third conversion formula is constructed according to the linear relationship between the zoom parameters and the distance from the PTZ camera to the reference calibration position. The zoom parameters form a linear relationship with the distance from the PTZ camera to the reference calibration position through the first parameter to be calibrated and the second parameter to be calibrated. The distance from the PTZ camera to the reference calibration position is determined based on the PTZ camera height corresponding to the projection position, forming the calibration height, projection position coordinates, and reference calibration position coordinates.

[0102] Specifically, the optimal zoom parameter Z of the PTZ camera is directly proportional to the distance L from the PTZ camera to the reference calibration position. Therefore, the third transformation equation represents the linear relationship between the optimal zoom parameter Z of the PTZ camera and the distance L from the PTZ camera to the reference calibration position, which can be expressed as a linear function as follows:

[0103] Z = k * L + b

[0104] Specifically, such as Figure 2a As shown, the distance L from the PTZ camera to the reference calibration position is determined by the PTZ camera height forming the calibration height h, the projection position coordinates (x0, y0), and the reference calibration position coordinates (x, y).

[0105] Step E2: Substitute the values ​​of the height to be calibrated, the coordinates of the projected position, the coordinates of the reference calibration position, and the values ​​of the omnidirectional control parameters used when facing the reference calibration position into the third transformation formula to obtain the values ​​of the first parameter to be calibrated and the second parameter to be calibrated.

[0106] For example, to solve for the values ​​of the first calibration parameter k and the second calibration parameter b, substitute the reference calibration position coordinates (x1, y1) and (x2, y2), the PTZ camera orthographic projection position coordinates (x0, y0), and the calibration height h obtained above into the equation L to obtain L1 and L2. Substituting L1 and L2 into the above linear function yields the system of equations:

[0107]

[0108] Solving the above equation set obtains the value of the first to-be-calibrated parameter k and the value of the second to-be-calibrated parameter b.

[0109] Referring to Figure 2b , the radar and the PTZ camera (such as a PTZ dome camera) are usually directly calibrated, and several data need to be actually measured in the process, which is too large in workload and low in efficiency. It is not suitable for mass use. In the existing scheme, the radar and the dome camera are 1:1 calibrated. Since the visual range of the dome camera is larger than that of the radar, in actual application scenarios, one dome camera needs to work with multiple radars, so the dome camera needs to be calibrated with multiple radars. Such calibration is huge in workload. Moreover, the spatial distance between the dome camera and the radar is large, and necessary parameters cannot be accurately measured, so the existing calibration technology cannot effectively complete the calibration. By using GPS as a bridge, multiple radars and dome cameras are calibrated with GPS respectively, and then the calibration of multiple radars and dome cameras is indirectly completed. This method effectively solves the linkage application problem of large-area dome cameras and multiple radars.

[0110] The technical scheme of the embodiment of the application sets the orientation of the PTZ camera to zero, determines the orthographic projection position coordinates of the PTZ camera on the ground, establishes a reference calibration coordinate system with the orthographic projection position coordinates as the origin, the PTZ camera is located on a vertical axis, the vertical axis is perpendicular to the ground on which the PTZ camera is located, selects reference calibration position coordinates in the reference calibration coordinate system, determines the omnidirectional control parameters of the PTZ camera when the orientation is directed to the reference calibration position according to the reference calibration position coordinates, and performs preset calibration on the PTZ camera according to the known projection position coordinates, reference calibration position coordinates, and omnidirectional control parameters used when the orientation is directed to the reference calibration position and through a preset conversion relationship. According to the technical scheme, the reference calibration coordinate system is established, the orthographic projection position coordinates and the reference calibration position coordinates are determined, and the PTZ camera is preset calibrated according to the omnidirectional control parameters used when the orientation is directed to the reference calibration position. The preset calibration can be completed by adjusting the zero optical axis of the PTZ camera to obtain intermediate parameters, without limiting that the zero optical axis of the PTZ camera is parallel to the ground, thereby reducing the complexity of PTZ camera parameter calibration and improving the universality of preset calibration of the PTZ camera.

[0111] Embodiment two

[0112] Figure 3 A flowchart of a camera use method for a radar and camera combined system is provided for the embodiment two of the application. The embodiment can be applied to the linkage of a PTZ camera and a radar. The method can be performed by a camera use device for a radar and camera combined system. The camera use device for a radar and camera combined system can be realized in the form of hardware and / or software. The camera use device for a radar and camera combined system can be configured in any electronic device with network communication function. Figure 3 As shown in the figure, the method comprises:

[0113] S310, determining the horizontal and vertical axis position of the target on the ground by radar.

[0114] S320, determining the required omni-directional control parameters of the PTZ camera for shooting the target on the ground according to the calibration conversion result of the PTZ camera, the calibration conversion result of the PTZ camera including the corresponding omni-directional control parameters used by the PTZ camera when shooting the target on the ground at the horizontal and vertical axis position, the omni-directional control parameters including the vertical and horizontal azimuth angles of the PTZ camera.

[0115] The calibration conversion result of the PTZ camera is obtained by the camera calibration method for the radar and camera combined system in any of the above embodiments, which will not be repeated here.

[0116] S330, controlling the PTZ camera to rotate in linkage according to the required omni-directional control parameters of the PTZ camera, and shooting the target on the ground.

[0117] Embodiment three

[0118] Figure 4 A structure schematic diagram of a PTZ camera calibration device provided for embodiment three of the present application is shown in FIG. 3. As shown in the figure, the device includes: Figure 4 A position adjustment module 210 for controlling the zero position adjustment of the PTZ camera, the zero position optical axis of the PTZ camera being parallel or not parallel to the ground where the PTZ camera is located;

[0119] A reference coordinate system determination module 220 for determining the projection position coordinates of the PTZ camera on the ground, and constructing a reference calibration coordinate system with the projection position coordinates as the origin, the corresponding position point of the PTZ camera being located on the vertical axis of the reference calibration coordinate system;

[0120] A calibration coordinate determination module 230 for determining the reference calibration position coordinates adopted in the reference calibration coordinate system, and determining the omni-directional control parameters adopted by the PTZ camera when aiming at the reference calibration position, the omni-directional control parameters including the vertical and horizontal azimuth angles of the PTZ camera, the reference calibration position coordinates being the self-defined ground position coordinates;

[0121] A preset calibration determination module 240 for performing preset calibration on the PTZ camera according to the projection position coordinates, the reference calibration position coordinates, and the omni-directional control parameters adopted when aiming at the reference calibration position, the calibration on the PTZ camera including the calibration of the conversion relationship between the omni-directional control parameters when aiming at the target and the ground position when aiming at the target.

[0122] The calibration conversion result of the PTZ camera is obtained by the camera calibration method for the radar and camera combined system in any of the above embodiments, which will not be repeated here.

[0123] In the embodiment of the present application, the reference coordinate system determination module 220 comprises:

[0124] The ground projection position coordinate determination unit is configured to measure the projection position coordinates corresponding to the PTZ camera when the PTZ camera projects onto the ground by using a real-time dynamic measurement device, wherein the real-time dynamic measurement device uses carrier phase difference technology to measure the position.

[0125] Correspondingly, the reference calibration position coordinates used in the reference calibration coordinate system comprise:

[0126] The reference calibration position coordinate determination unit is configured to move the real-time dynamic measurement device to the self-defined reference calibration position point, and measure the reference calibration position coordinates corresponding to the reference calibration position point by using the real-time dynamic measurement device.

[0127] The full-orientation control parameters comprise a horizontal orientation angle and a vertical orientation angle of the PTZ camera, wherein the horizontal orientation angle is determined by adding the first to-be-calibrated angle and the first reference angle, and the vertical orientation angle is determined by subtracting the second to-be-calibrated angle from the second reference angle; wherein the first to-be-calibrated angle is an angle between the zero optical axis of the PTZ camera and the corresponding horizontal axis of the reference calibration coordinate system on the first reference plane, the first reference angle is an angle between the first reference line and the corresponding horizontal axis of the reference calibration coordinate system on the first reference plane, the first reference line is a line connecting the reference calibration position and the projection position, and the first reference plane is a horizontal and vertical axis plane of the reference calibration coordinate system; the second to-be-calibrated angle is an angle between the zero optical axis of the PTZ camera and the corresponding vertical axis of the reference calibration coordinate system on the second reference plane, the second reference angle is an angle between the second reference line and the corresponding vertical axis of the reference calibration coordinate system on the second reference plane, the second reference line is a line connecting the reference calibration position and the PTZ camera, the second reference plane is a plane of the reference calibration coordinate system that is perpendicular to the horizontal and vertical axis plane and passes through the vertical axis, and the PTZ camera height corresponding to the projection position forms a to-be-calibrated height.

[0128] In the embodiment of the present application, the preset calibration determination module 240 comprises:

[0129] The camera alignment position adjustment unit is configured to control the PTZ camera to rotate, so that the center of the image of the PTZ camera is aligned with the reference calibration position and the image clarity is greater than a preset clarity.

[0130] The parameter acquisition unit is configured to acquire the full-orientation control parameters of the PTZ camera when the PTZ camera is directed to the reference calibration position after the control of the PTZ camera to rotate is completed.

[0131] In the embodiment of the present application, the preset calibration determination module 240 comprises:

[0132] The first conversion formula determination unit is configured to determine a first conversion formula associated with the PTZ camera, the first conversion formula being constructed according to a trigonometric function relationship among a first reference angle in the horizontal azimuth angle, the projection position coordinate, and a reference calibration position coordinate, and the first conversion formula describing a conversion relationship between the reference calibration position coordinate and the horizontal azimuth angle in the omnibearing control parameter based on a first to-be-calibrated angle in the horizontal azimuth angle;

[0133] The second conversion formula determination unit is configured to determine a second conversion formula associated with the PTZ camera, the second conversion formula being constructed according to a trigonometric function relationship among a second reference angle in the vertical azimuth angle, the projection position coordinate, the reference calibration position coordinate, and a to-be-calibrated height, and the second conversion formula describing a conversion relationship between the reference calibration position coordinate and the vertical azimuth angle in the omnibearing control parameter based on a second to-be-calibrated angle in the vertical azimuth angle and the to-be-calibrated height.

[0134] The control parameter acquisition unit is configured to sequentially substitute a value of the projection position coordinate, a value of the reference calibration position coordinate, and a value of the omnibearing control parameter used when facing the reference calibration position coordinate into the first conversion formula and the second conversion formula to obtain a value of the first to-be-calibrated angle, a value of the second to-be-calibrated angle, and a value of the to-be-calibrated height.

[0135] In the embodiments of the present application, the control parameter acquisition unit is specifically configured to:

[0136] The PTZ camera is calibrated according to the projection position coordinate, the reference calibration position coordinate, and the omnibearing control parameter used when facing the reference calibration position coordinate, and the method further includes:

[0137] A third conversion formula associated with the PTZ camera is determined, the third conversion formula being constructed according to a linear relationship between the zoom parameter and a distance from the PTZ camera to the reference calibration position, the zoom parameter forming a linear relationship with the distance from the PTZ camera to the reference calibration position through the first to-be-calibrated parameter and the second to-be-calibrated parameter, and the distance from the PTZ camera to the reference calibration position being determined based on a PTZ camera height corresponding to the projection position, the to-be-calibrated height, the projection position coordinate, and the reference calibration position coordinate;

[0138] The value of the to-be-calibrated height, the value of the projection position coordinate, the value of the reference calibration position coordinate, and the value of the omnibearing control parameter used when facing the reference calibration position coordinate are sequentially substituted into the third conversion formula to obtain the value of the first to-be-calibrated parameter and the value of the second to-be-calibrated parameter.

[0139] The zoom parameter of the PTZ camera indicated in the omnibearing control parameter adopted when aiming at the reference calibration position coordinates is customized according to different reference calibration positions.

[0140] The camera calibration device for the radar and camera combined system provided in the embodiments of the present application can execute the camera calibration method for the radar and camera combined system provided in any of the embodiments of the present application, has the corresponding functions and beneficial effects of executing the camera calibration method for the radar and camera combined system, and the detailed processes refer to the related operations of the camera calibration method for the radar and camera combined system in the foregoing embodiments.

[0141] Embodiment four

[0142] Figure 5 A structural diagram of a camera use device for a radar and camera combined system is provided for the fourth embodiment of the present application. The fourth embodiment can be applied to the case that a PTZ camera is linked with a radar. The camera use device for the radar and camera combined system can be realized in the form of hardware and / or software. The camera use device for the radar and camera combined system can be configured in any electronic device with network communication function. As shown in the figure, the device includes: Figure 5

[0143] The position determination module 510 is configured to determine the horizontal and vertical axis positions of the photographed target on the ground by the radar.

[0144] The control parameter determination module 520 is configured to determine the omnibearing control parameters of the PTZ camera required for photographing the photographed target on the ground according to the calibration conversion result of the PTZ camera. The calibration conversion result of the PTZ camera includes the omnibearing control parameters used when the PTZ camera aims at the photographed target on the ground. The omnibearing control parameters include the vertical azimuth angle and the horizontal azimuth angle of the PTZ camera.

[0145] The radar and camera linkage module 530 is configured to control the PTZ camera to link and rotate according to the omnibearing control parameters of the PTZ camera required for photographing the photographed target on the ground.

[0146] The camera use device for the radar and camera combined system provided in the embodiments of the present application can execute the camera use method for the radar and camera combined system provided in any of the embodiments of the present application, has the corresponding functions and beneficial effects of executing the camera use method for the radar and camera combined system, and the detailed processes refer to the related operations of the camera use method for the radar and camera combined system in the foregoing embodiments.

[0147] Embodiment five

[0148] Figure 6 ​A schematic diagram of an electronic device 10 that can be used to implement embodiments of the present invention is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices (e.g., helmets, glasses, watches, etc.), and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the invention described and / or claimed herein.

[0149] like Figure 6 As shown, the electronic device 10 includes at least one processor 11 and a memory, such as a read-only memory (ROM) 12 or a random access memory (RAM) 13, communicatively connected to the at least one processor 11. The memory stores computer programs executable by the at least one processor. The processor 11 can perform various appropriate actions and processes based on the computer program stored in the ROM 12 or loaded from storage unit 18 into the RAM 13. The RAM 13 may also store various programs and data required for the operation of the electronic device 10. The processor 11, ROM 12, and RAM 13 are interconnected via a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0150] Multiple components in electronic device 10 are connected to I / O interface 15, including: input unit 16, such as keyboard, mouse, etc.; output unit 17, such as various types of displays, speakers, etc.; storage unit 18, such as disk, optical disk, etc.; and communication unit 19, such as network card, modem, wireless transceiver, etc. Communication unit 19 allows electronic device 10 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0151] Processor 11 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. Processor 11 performs the various methods and processes described above, such as camera calibration methods for radar and camera combined systems or camera usage methods for radar and camera combined systems.

[0152] In some embodiments, the camera calibration method for a radar and camera combined system or the camera usage method for a radar and camera combined system can be implemented as a computer program tangibly embodied in a computer readable storage medium, e.g., storage unit 18. In some embodiments, parts or all of the computer program can be loaded and / or installed onto electronic device 10 via, e.g., ROM 12 and / or communication unit 19. When the computer program is loaded onto RAM 13 and executed by processor 11, one or more steps of the camera calibration method for a radar and camera combined system or the camera usage method for a radar and camera combined system described above can be performed. Alternatively, in other embodiments, processor 11 can be configured to perform the camera calibration method for a radar and camera combined system or the camera usage method for a radar and camera combined system by any other suitable means, e.g., with the aid of firmware.

[0153] The various implementations of the system and techniques described above can be realized in digital electronic circuitry, integrated circuitry, a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), a system on a chip (SOC), a programmable logic device (PLD), a computer hardware, firmware, software, and / or combinations thereof. These various implementations can include implementation in one or more computer programs that are executable and / or interpretable on a programmable system including at least one programmable processor, which can be special or general purpose, coupled to receive data and instructions from, and to transmit data and instructions to, a storage system, at least one input device, and at least one output device.

[0154] Computer programs used to implement the methods of the present application can be written in any combination of one or more programming languages. These computer programs can be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the computer program, when executed by the processor of the machine, implements the functions / acts specified in the flowcharts and / or block diagrams. The computer program can be executed entirely on a machine, partially on a machine, partially on a machine as a stand-alone software package, or entirely on a remote machine or server.

[0155] In the context of the present application, a computer-readable storage medium can be a tangible medium that can contain or store a computer program for use by or in connection with an instruction execution system, apparatus, or device. A computer-readable storage medium can include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium can be a machine-readable signal medium. More specific examples of a machine-readable storage medium will include one or more lines of a program of instructions in a transitory signal, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0156] To provide for interaction with a user, the systems and techniques described here can be implemented on an electronic device having a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user and a keyboard and a pointing device (e.g., a mouse or a trackball) by which the user can provide input to the electronic device. Other kinds of devices can be used to provide for interaction with a user as well; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form, including acoustic, speech, or tactile input.

[0157] The systems and techniques described here can be implemented in a computing system that includes a back end component (e.g., as a data server), or that includes a middleware component (e.g., an application server), or that includes a front end component (e.g., a user computer having a graphical user interface or a Web browser through which a user can interact with an implementation of the systems and techniques described here), or any combination of such back end, middleware, or front end components. The components of the system can be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include a local area network (LAN), a wide area network (WAN), a blockchain network, and the Internet.

[0158] The computing system can include clients and servers. A client and server are generally remote from each other and typically interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other. The server can be a cloud server, also known as a cloud computing server or cloud host, which is a host product in the cloud computing service system, to solve the defects of large management difficulty and weak business scalability in traditional physical host and VPS service.

[0159] It should be understood that the various forms of flow shown above can be used to reorder, add or delete steps. For example, each step described in the present application can be executed in parallel, sequentially or in a different order, as long as the desired results of the technical solutions of the present application can be achieved, which is not limited herein.

[0160] The above detailed description does not constitute a limitation on the protection scope of the present application. Those skilled in the art should understand that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A camera calibration method for a radar and camera combined system, characterized in that, The application relates to a PTZ camera calibration method and device. The application comprises: controlling zero position adjustment of the PTZ camera, and the zero position optical axis of the PTZ camera is parallel or not parallel to the ground surface where the PTZ camera is located; determining the projection position coordinates of the PTZ camera on the ground surface, and constructing a reference calibration coordinate system with the projection position coordinates as the origin, and the corresponding position point of the PTZ camera is located on the vertical axis of the reference calibration coordinate system; determining the reference calibration position coordinates adopted in the reference calibration coordinate system, and determining the omnibearing control parameters adopted when the PTZ camera faces the reference calibration position, wherein the omnibearing control parameters comprise the horizontal azimuth angle and the vertical azimuth angle of the PTZ camera, and the reference calibration position coordinates are self-defined ground position coordinates; pre-setting calibration of the PTZ camera according to the projection position coordinates, the reference calibration position coordinates and the omnibearing control parameters adopted when the PTZ camera faces the reference calibration position, wherein the pre-setting calibration of the PTZ camera comprises calibration of the conversion relationship between the omnibearing control parameters when the PTZ camera faces the target and the ground position when the PTZ camera faces the target; determining the projection position coordinates of the PTZ camera on the ground surface, comprising: measuring the corresponding projection position coordinates of the PTZ camera on the ground surface by using a real-time dynamic measurement device, wherein the real-time dynamic measurement device adopts carrier phase difference technology to measure the position; correspondingly, determining the reference calibration position coordinates adopted in the reference calibration coordinate system, comprising: moving the real-time dynamic measurement device to the self-defined reference calibration position point, and measuring the reference calibration position coordinates corresponding to the reference calibration position point by using the real-time dynamic measurement device; the omnibearing control parameters comprise the horizontal azimuth angle and the vertical azimuth angle of the PTZ camera, the horizontal azimuth angle is determined by adding the first to-be-calibrated angle and the first reference angle, and the vertical azimuth angle is determined by subtracting the second to-be-calibrated angle from the second reference angle; wherein the first to-be-calibrated angle is the included angle between the zero position optical axis of the PTZ camera and the corresponding horizontal axis of the reference calibration coordinate system on the first reference plane, the first reference angle is the included angle between the first reference line and the corresponding horizontal axis of the reference calibration coordinate system on the first reference plane, the first reference line is the line connecting the reference calibration position and the projection position, and the first reference plane is the horizontal and vertical axis plane of the reference calibration coordinate system; the second to-be-calibrated angle is the included angle between the zero position optical axis of the PTZ camera and the corresponding vertical axis of the reference calibration coordinate system on the second reference plane, the second reference angle is the included angle between the second reference line and the corresponding vertical axis of the reference calibration coordinate system on the second reference plane, the second reference line is the line connecting the reference calibration position and the PTZ camera, the second reference plane is the plane perpendicular to the horizontal and vertical axis plane of the reference calibration coordinate system and passing through the vertical axis, and the PTZ camera height corresponding to the projection position forms a to-be-calibrated height; calibrating the PTZ camera according to the projection position coordinates, the reference calibration position coordinates and the omnibearing control parameters adopted when the PTZ camera faces the reference calibration position, comprising: determining a first conversion formula associated with the PTZ camera, the first conversion formula being constructed according to a trigonometric function relationship among a first reference angle in the horizontal azimuth angle, the projection position coordinate, and a reference calibration position coordinate, the first conversion formula describing a conversion relationship between the reference calibration position coordinate and the horizontal azimuth angle in the omnibearing control parameter based on a first to-be-calibrated angle in the horizontal azimuth angle; determining a second conversion formula associated with the PTZ camera, the second conversion formula being constructed according to a trigonometric function relationship among a second reference angle in the vertical azimuth angle, the projection position coordinate, the reference calibration position coordinate, and a to-be-calibrated height, the second conversion formula describing a conversion relationship between the reference calibration position coordinate and the vertical azimuth angle in the omnibearing control parameter based on a second to-be-calibrated angle in the vertical azimuth angle and the to-be-calibrated height; substituting the value of the projection position coordinate, the value of the reference calibration position coordinate, and the value of the omnibearing control parameter used when the PTZ camera is directed to the reference calibration position coordinate into the first conversion formula and the second conversion formula in sequence to obtain the value of the first to-be-calibrated angle, the value of the second to-be-calibrated angle, and the value of the to-be-calibrated height.

2. The method of claim 1, wherein, determining the omnibearing control parameter used when the PTZ camera is directed to the reference calibration position, comprising: controlling the PTZ camera to rotate so that the center of the image of the PTZ camera is aligned with the reference calibration position and the image clarity is greater than a preset clarity; after the control of the PTZ camera to rotate is completed, obtaining the omnibearing control parameter used when the PTZ camera is directed to the reference calibration position.

3. The method of claim 1, wherein, the omnibearing control parameter includes a zoom parameter of the PTZ camera; the calibration of the PTZ camera according to the projection position coordinate, the reference calibration position coordinate, and the omnibearing control parameter used when the PTZ camera is directed to the reference calibration position further comprises: determining a third conversion formula associated with the PTZ camera, the third conversion formula being constructed according to a linear relationship between the zoom parameter and the distance from the PTZ camera to the reference calibration position, the zoom parameter forming a linear relationship with the distance from the PTZ camera to the reference calibration position through the first to-be-calibrated parameter and the second to-be-calibrated parameter, the distance from the PTZ camera to the reference calibration position being determined based on the PTZ camera height corresponding to the projection position, the to-be-calibrated height, the projection position coordinate, and the reference calibration position coordinate; substituting the value of the to-be-calibrated height, the value of the projection position coordinate, the value of the reference calibration position coordinate, and the value of the omnibearing control parameter used when the PTZ camera is directed to the reference calibration position coordinate into the third conversion formula in sequence to obtain the value of the first to-be-calibrated parameter and the value of the second to-be-calibrated parameter.

4. The method of claim 3, wherein, the zoom parameter of the PTZ camera indicated in the omnibearing control parameter used when the PTZ camera is directed to the reference calibration position coordinate is customized according to different reference calibration positions.

5. A camera usage method for a radar and camera combined system, characterized in that, the calibration conversion result of the PTZ camera obtained by the camera calibration method for a radar and camera combined system according to any one of claims 1 to 4, the method comprising: Determine the horizontal and vertical axis positions of the target on the ground by radar; Determine the all-direction control parameters of the PTZ camera required for photographing the target on the ground according to the calibration conversion results of the PTZ camera, the calibration conversion results of the PTZ camera including the all-direction control parameters corresponding to the PTZ camera when aiming at the target on the ground at the horizontal and vertical axis positions, the all-direction control parameters including the vertical azimuth angle and the horizontal azimuth angle of the PTZ camera; Control the PTZ camera to rotate in linkage according to the all-direction control parameters of the PTZ camera required for photographing the target on the ground.

6. An electronic device, comprising: The electronic device comprises: at least one processor; and a memory connected to the at least one processor in communication; wherein, the memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor to enable the at least one processor to execute the camera calibration method for the radar and camera combined system according to any one of claims 1-4 or the camera use method for the radar and camera combined system according to claim 5.

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