A target tracking method, device and computer medium for a cloth control ball

Abstract

The present invention discloses a target tracking method, device and computer medium for a cloth control camera. The method includes: obtaining the coordinate positions of all objects to be tracked, traversing all the position points, and for any position point (r i , θ i , φ i ), calculating the camera limit angles that enable this position point to be within the camera's field of view according to the vertical field of view angle and horizontal field of view angle of the camera; traversing all the position points, and for any position point (r i , θ i , φ i ), when the horizontal rotation angle and vertical rotation angle of the camera are respectively the following 4 limit angle pairs of this point: the maximum horizontal rotation angle β maxi , the maximum vertical rotation angle α maxi , the minimum horizontal rotation angle β mini , the maximum vertical rotation angle α maxi , the maximum horizontal rotation angle β maxi , the minimum vertical rotation angle α mini , the minimum horizontal rotation angle β mini , the minimum vertical rotation angle α mini , determining whether the remaining position points are within the camera's field of view with this limit angle pair as the rotation angle, and obtaining the camera rotation angle that can monitor the largest number of position points.

Description

Technical Field

[0001] The present invention relates to the technical field of security monitoring, and in particular to a target tracking method, device and computer medium for a mobile camera with PTZ function (hereinafter referred to as "ball camera"). Background Art

[0002] At the site of power construction operations, it is necessary to use ball cameras to monitor the operation objects. Currently, the dense areas of operation objects are generally monitored by ball cameras with fixed angles. When the operation objects move, the staff needs to manually control the PTZ to adjust the monitoring angle of the ball camera. It is impossible to automatically adjust the optimal shooting field of view angle according to the position distribution of the operation objects in space, so as to maximize the number of monitored operation objects and improve the monitoring effect and intelligence of the ball camera.

[0003] Currently, the automatic tracking of ball cameras generally uses a single ball to track a single operator, such as locking or randomly selecting a single person for tracking. This monitoring method is not suitable for situations where the operation range is large and the number of deployed ball cameras at the construction site is insufficient. Summary of the Invention

[0004] The purpose of the present invention is to provide a target tracking method, device and computer medium for a ball camera, so as to solve the technical problems that currently it is impossible to automatically adjust the optimal shooting field of view angle according to the distribution position of operation objects and impossible to maximize the number of tracked operation objects.

[0005] On the one hand, the present invention provides a target tracking method for a ball camera, including the following steps:

[0006] Obtain the position point coordinates of all tracked objects. The position point coordinates are in the spherical coordinate system with the center of the camera of the ball camera as the origin. Let the spherical coordinates of the i-th position point be

[0007] Traverse all position points. For any position point According to the vertical field of view angle and horizontal field of view angle of the camera, calculate the camera limit angles that make this position point in the camera's field of view: the maximum vertical rotation angle α maxi , the minimum vertical rotation angle α mini , the maximum horizontal rotation angle β maxi , the minimum horizontal rotation angle β mini , and establish the mapping relationship between any position point and the limit angles that make this point in the camera's field of view;

[0008] Traverse all position points. For any position point When the horizontal rotation angle and vertical rotation angle of the camera are respectively the following 4 limit angle pairs of this point: the maximum horizontal rotation angle β maxi , the maximum vertical rotation angle α maxi, the minimum horizontal rotation angle β mini , the maximum vertical rotation angle α maxi , the maximum horizontal rotation angle β maxi , the minimum vertical rotation angle α mini , the minimum horizontal rotation angle β mini , the minimum vertical rotation angle α mini , determine whether the remaining position points are within the field of view of the camera with this pair of limit angles as the rotation angles, obtain the number of position points within the field of view of the camera with this pair of limit angles, and select the pair of limit angles with the largest number of position points within the camera's field of view as the optimal horizontal rotation angle β OPT , and the optimal vertical rotation angle α OPT ;

[0009] Adjust the horizontal rotation angle of the camera to β OPT , and the vertical rotation angle to α OPT , and the position points within the current camera's field of view are the target position points.

[0010] In some embodiments, it further includes:

[0011] According to the mapping relationship between the position points and the limit angles, obtain the position point coordinates corresponding to the limit angles α OPT , β OPT

[0012] When the rotation angles of the camera are α OPT , β OPT , obtain the position point coordinates with the largest horizontal rotation angle difference from the point among the target position points within the camera's field of view and the position point coordinates with the largest vertical rotation angle difference from the point

[0013] According to the position of the position point coordinates within the camera's field of view, adjust the horizontal rotation angle of the camera from β OPT to increase or decrease and the vertical rotation angle from α OPT to increase or decrease (h - ∣θ i - θ m ∣) / 2, where w and h are the horizontal and vertical field of view angles of the camera respectively.

[0014] In some embodiments, it further includes:

[0015] ​Calculate the horizontal field of view angle scaling ratio 1 / K1 and the vertical field of view angle scaling ratio 1 / K2 of the PTZ camera so that all target position points are out of the PTZ camera's field of view. Select the smaller median of 1 / K1 and 1 / K2 as the field of view angle scaling ratio 1 / K of the PTZ camera. The K1 is obtained through calculation, and the K2 is obtained through h / |θi - θn| calculation;

[0016] Simultaneously reduce the horizontal field of view angle and the vertical field of view angle of the PTZ camera to 1 / K of the original.

[0017] In some embodiments, the position according to the position point coordinates OPT in the camera's field of view, adjust the horizontal rotation angle of the camera from β increase or decrease OPT the vertical rotation angle from α i increase or decrease (h - |θ m - θ |) / 2. Specifically, if the position point coordinates OPT are on the upper left edge of the PTZ camera's field of view, then adjust the horizontal rotation angle of the PTZ camera from β increase OPT the vertical rotation angle from α i decrease (h - |θ m - θ |) / 2; if the position point coordinates OPT are on the upper right edge of the PTZ camera's field of view, then adjust the horizontal rotation angle of the PTZ camera from β decrease OPT the vertical rotation angle from α i decrease (h - |θ m - θ |) / 2; if the position point coordinates OPT are on the lower left edge of the PTZ camera's field of view, then adjust the horizontal rotation angle of the PTZ camera from β increase OPT the vertical rotation angle from α i increase (h - |θ m - θ |) / 2; if the position point coordinates OPT are on the lower right edge of the PTZ camera's field of view, then adjust the horizontal rotation angle of the PTZ camera from β decrease OPT the vertical rotation angle from α i increase (h - |θ m - θ

[0018] In some embodiments, let the vertical rotation angle range of the camera be [0, π / 2]. When the orientation of the camera is parallel to the XOY plane, the vertical rotation angle is π / 2. When the projection of the camera's orientation on the XOY plane coincides with the positive X-axis, the horizontal rotation angle is 0, and the horizontal rotation angle range is [0, 2π]. The α maxi and α mini and β maxi and β mini are obtained through the following formula. The horizontal field of view angle of the camera is w. The α maxi and α mini and β maxi and β mini are obtained through the following formula. The horizontal field of view angle of the camera is w, and the vertical field of view angle is h:

[0019] α maxi = θ i + h / 2,

[0020] α mini = θ i - h / 2,

[0021]

[0022] In some embodiments, the specific method for determining whether a certain position point is within the camera's field of view is as follows:

[0023] Let the vertical rotation angle of the camera be α, and the horizontal rotation angle be β;

[0024] Let the coordinates of the p-th position point in space be

[0025] If the vertical rotation angle θ p of the position point satisfies |θ p - α| ≤ h / 2, and the horizontal rotation angle satisfies then it is determined that the point is within the field of view of the control ball camera.

[0026] In some embodiments, before obtaining the position points of all tracked objects, it further includes: receiving a request to start the mode with the largest number of tracked objects, and the request is triggered periodically or by other electronic devices communicating with the control ball camera.

[0027] In some embodiments, the obtaining of the position points of all tracked objects includes:

[0028] Receiving the position points of all tracked objects sent by the UWB base station. The UWB base station includes three antennas provided on the control ball camera and located in the same plane. The plane where the three antennas are located is parallel to the horizontal plane, and a positioning terminal with a UWB positioning tag is worn on the tracked object;

[0029] The positioning terminal sends UWB radio signals to the UWB base station, and the UWB base station determines the position point coordinates of the object to be tracked through the TDOA algorithm. The position point coordinates are three-dimensional world coordinates, and the three-dimensional world coordinates of the position point are converted into spherical coordinates and then sent to the panoramic camera ball.

[0030] On the other hand, the present invention also provides a target tracking device for a panoramic camera ball, including an object to be tracked position acquisition module, a panoramic camera ball optimal rotation angle calculation module, and a panoramic camera ball rotation angle adjustment module;

[0031] The object to be tracked position acquisition module is used to acquire the position point coordinates of all objects to be tracked. The position point coordinates are in the spherical coordinate system with the center of the camera of the panoramic camera ball as the origin. Let the spherical coordinates of the i-th position point be

[0032] The panoramic camera ball optimal rotation angle calculation module is used to traverse all position points. For any position point According to the vertical field of view angle and horizontal field of view angle of the camera, calculate the camera limit angles that make this position point within the camera's field of view: the maximum vertical rotation angle α maxi 、the minimum vertical rotation angle α mini 、the maximum horizontal rotation angle β maxi 、the minimum horizontal rotation angle β mini ,and establish a mapping relationship between any position point and the camera limit angles α maxi 、α mini 、β maxi and β mini that make this point within the camera's field of view;

[0033] Traverse all position points. For any position point When the horizontal rotation angle and vertical rotation angle of the camera are respectively the following 4 limit angle pairs of this point: the maximum horizontal rotation angle β maxi 、the maximum vertical rotation angle α maxi ,the minimum horizontal rotation angle β mini 、the maximum vertical rotation angle α maxi ,the maximum horizontal rotation angle β maxi 、the minimum vertical rotation angle α mini ,the minimum horizontal rotation angle β mini 、the minimum vertical rotation angle α mini ,judge whether the remaining position points are within the camera's field of view with this limit angle pair as the rotation angle, obtain the number of position points within the camera's field of view with this limit angle pair, and select the limit angle pair with the most position points within the camera's field of view as the optimal horizontal rotation angle β OPT 、optimal vertical rotation angle α OPT ;

[0034] The pan-tilt control ball rotation angle adjustment module is used to adjust the horizontal rotation angle of the camera to β OPT and the vertical rotation angle to α OPT , and the position point within the current camera's field of view is the target position point.

[0035] On the other hand, the present invention also provides a computer storage medium, in which instructions are stored. When the instructions are executed on a computer, the computer is made to execute the above-mentioned method.

[0036] The beneficial effects of the present invention are as follows: By using the method of the present invention, the rotation angle of the camera that can include the most tracked objects within the camera's perspective range can be automatically obtained by positioning the position information of the terminal (tracking object) and the parameter information of the camera itself (such as the vertical field of view angle and the horizontal field of view angle), maximizing the number of operating objects tracked by the pan-tilt control ball, facilitating the supervisor to grasp most of the on-site situation through a small number of pictures, and maximizing the surveillance effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0038] Figure 1 It is a schematic diagram of the position of the positioning terminal provided by the embodiment of the present invention;

[0039] Figure 2 It is a schematic diagram of a three-dimensional coordinate system with the camera of the pan-tilt control ball as the origin provided by the embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0040] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0041] The present invention provides a target tracking method for a pan-tilt control ball, including:

[0042] S1. Obtain the position point coordinates of all tracked objects. The position point coordinates are in the spherical coordinate system with the center of the camera of the ball control camera as the origin. Let the spherical coordinates of the i-th position point be The meaning of the spherical coordinate parameters of the position point, the vertical rotation angle of the camera is α, and the horizontal rotation angle is β, as Figure 2 shown, the range of the vertical rotation angle θ of the position point is [0, π / 2], and the horizontal rotation angle range is [0, 2π];

[0043] In some embodiments of the present invention, obtaining the position point coordinates of all tracked objects in step S1 specifically includes: receiving the position points of all tracked objects sent by the UWB base station. The UWB base station includes three antennas provided on the ball control camera and located in the same plane. The three antennas are located in the same plane on the ball control camera, and the plane where the three antennas are located is parallel to the horizontal plane. The positioning terminal with a UWB positioning tag is worn on the tracked object;

[0044] The positioning terminal sends UWB radio signals to the UWB base station. The UWB base station determines the position point coordinates of the tracked object through the TDOA algorithm. The position point coordinates are three-dimensional world coordinates, and the three-dimensional world coordinates of the position point are converted into spherical coordinates and then sent to the ball control camera.

[0045] A more detailed method for obtaining the coordinates of the positioning terminal is as Figure 1 shown. The UWB base station uses three antennas to determine the position of the moving target according to the time difference of the UWB radio signals received by each antenna. Assume that the times when the three antennas receive the UWB signals sent by the UWB tag are t1, t2, and t3 respectively, and the distances from the UWB tag to the three antennas are s1, s2, and s3. The coordinates of the three antennas are known as (x1, y1, z0), (x2, y2, z0), and (x3, y3, z0) respectively. The three antennas are located in the same plane parallel to the horizontal plane, and v is the signal propagation speed. Through the following equations, the coordinates (x, y, z) of the positioning terminal are obtained. First, two z values are obtained through three ternary quadratic equations. And according to the application scenario of the ball control camera in power security, the ball control camera will be installed at a height lower than the monitoring area during actual installation. Therefore, the present invention selects the z value greater than z0;

[0046]

[0047] Through the coordinate transformation formula, the three-dimensional coordinates (x, y, z) of the positioning terminal are converted into spherical coordinates The coordinate transformation formula for this part is known and common, and will not be elaborated here.

[0048] The UWB base station can convert the three-dimensional world coordinates of the positioning terminal into spherical coordinates, and then perform coordinate translation to obtain the coordinate information in the spherical coordinate system with the camera of the cloth control ball as the origin. It can also directly obtain the three-dimensional coordinates with the camera of the cloth control ball as the origin during the calculation of the three-dimensional world coordinates. That is to say, the known coordinates of the three antennas are in the three-dimensional coordinates with the camera of the cloth control ball as the origin, and then only the calculated three-dimensional world coordinates of the positioning terminal need to be converted into spherical coordinates.

[0049] In order to simplify the position calculation of the positioning terminal, the three antennas can be arranged on a plane parallel to the horizontal plane and passing through the center of the camera, and at this time z0 is 0.

[0050] In some embodiments of the present invention, before obtaining the position points of all tracked objects, it further includes: receiving a request to start the mode with the largest number of tracked objects, and the request is triggered periodically or by other electronic devices communicating with the cloth control ball.

[0051] When the cloth control ball is in use, there are multiple modes to choose from, including but not limited to the mode of receiving the largest number of tracked objects. After the cloth control ball receives the request to start the mode with the largest number of tracked objects, it starts step S1. The start request can be initiated periodically through a timing device to adjust the rotation angle of the camera according to the distribution position of the tracked objects at regular intervals, so as to achieve the purpose of maximizing the number of tracked objects. It can also be initiated irregularly according to the supervision needs of the staff to achieve the purpose that the staff can master most of the situation on the site through a small number of pictures.

[0052] S2. Traverse all position points, for any position point According to the vertical field of view angle and horizontal field of view angle of the camera, calculate the camera limit angles that make this position point within the camera's field of view: the maximum vertical rotation angle α maxi 、the minimum vertical rotation angle α mini 、the maximum horizontal rotation angle β maxi 、the minimum horizontal rotation angle β mini , and establish a mapping relationship between any position point and the camera limit angles α maxi 、α mini 、β maxi and β mini ;

[0053] In some embodiments of the present invention, assume that the vertical rotation angle range of the camera is [0, π / 2]. When the camera's orientation is parallel to the XOY plane, the vertical rotation angle is π / 2. When the projection of the camera's orientation on the XOY plane coincides with the positive X-axis, the horizontal rotation angle is 0, and the horizontal rotation angle range is [0, 2π]. The α maxi 、α mini, β maxi , β mini is obtained through the following formula, where the horizontal field of view angle of the camera is w and the vertical field of view angle is h:

[0054] α maxi = θ i + h / 2,

[0055] α mini = θ i - h / 2,

[0056]

[0057] The limit angle is the maximum horizontal rotation angle and vertical rotation angle that the camera can achieve when rotating the camera to ensure that a certain point is within the field of view, and the point must not leave the field of view. This is actually to place the point at the four corners of the rectangular view angle, so as to cover as large a range as possible while keeping the point within the field of view.

[0058] S3. Traverse all position points. For any position point When the horizontal rotation angle and vertical rotation angle of the camera are the following 4 pairs of limit angles for this point: the maximum horizontal rotation angle β maxi , the maximum vertical rotation angle α maxi , the minimum horizontal rotation angle β mini , the maximum vertical rotation angle α maxi , the maximum horizontal rotation angle β maxi , the minimum vertical rotation angle α mini , the minimum horizontal rotation angle β mini , the minimum vertical rotation angle α mini , determine whether the remaining position points are within the field of view of the camera with this pair of limit angles as the rotation angles, obtain the number of position points within the field of view of the camera with this pair of limit angles, and select the pair of limit angles with the largest number of position points within the camera's field of view as the optimal horizontal rotation angle β OPT and the optimal vertical rotation angle α OPT ;

[0059] In some embodiments of the present invention, the specific method for determining whether a certain position point is within the field of view of the camera is as follows:

[0060] Let the vertical rotation angle of the camera be α and the horizontal rotation angle be β;

[0061] Let the coordinates of the p-th position point in space be

[0062] If the vertical rotation angle θ of the position point p satisfies |θ p - α| ≤ h / 2, and the horizontal rotation angle Meet

[0063] Then it is determined that the point is within the field of view of the ball-mounted camera.

[0064] Through the above judgment method, the part of "judging whether the remaining position points are within the field of view of the camera with this extreme angle as the rotation angle" in step S3 can be realized.

[0065] Steps S2 and S3 are used to calculate the rotation angle of the camera when the number of tracking objects within the field of view is the largest. Since the function of the camera rotation angle and the number of included position points is not an elementary function, it is impossible to obtain the maximum value by methods such as taking derivatives. Therefore, the greedy algorithm is used for calculation. Several extreme angles of the camera are obtained through step S2, and then the extreme angle pair of the ball-mounted camera with the largest number of tracking objects within the field of view is obtained through step S3.

[0066] S4. Adjust the horizontal rotation angle of the camera to β OPT , and the vertical rotation angle to α OPT . The position points within the current camera field of view are the target position points.

[0067] The present invention can pre-bind the positioning terminals to be supervised with the ball-mounted cameras, obtain the position information of the positioning terminals to be supervised, and finally obtain the optimal horizontal rotation angle β of the camera by combining the position of the positioning terminal and the parameter information of the camera itself (such as the vertical field of view angle, horizontal field of view angle) with the operation methods of steps S2 and S3. OPT , the optimal vertical rotation angle α OPT . By adjusting and controlling the horizontal rotation motor and the vertical rotation motor, the horizontal and vertical rotation angles of the camera are adjusted to β OPT , α OPT respectively, realizing the maximization of the number of operation objects tracked by the ball-mounted camera, facilitating the supervisors to master most of the on-site situations through a small number of pictures, and realizing the maximization of the ball-mounted effect.

[0068] In some embodiments of the present invention, it further includes:

[0069] S5. Obtain the position point coordinates corresponding to the extreme angles α OPT , β OPT according to the mapping relationship between the position points and the extreme angles.

[0070] S6. When the rotation angles of the camera are α OPT , β OPT , obtain the position point coordinates with the largest horizontal rotation angle difference from the point among the target position points within the camera field of view. with the point The coordinates of the position point with the largest difference in vertical rotation angle

[0071] S7. According to the coordinates of the position point At the position in the camera's field of view, adjust the horizontal rotation angle of the camera from β OPT Increase or decrease The vertical rotation angle from α OPT Increase or decrease (h - |θ i -θ m |) / 2, where w and h are the horizontal and vertical field of view angles of the camera respectively.

[0072] In some embodiments of the present invention, the adjusting the horizontal rotation angle of the camera from β At the position in the camera's field of view, and the vertical rotation angle from α OPT Increase or decrease Specifically includes: If the coordinates of the position point OPT Increase or decrease (h - |θ i -θ m |) / 2. If the coordinates of the position point Are at the upper left edge of the view field of the PTZ camera, then adjust the horizontal rotation angle of the PTZ camera from β OPT Increase The vertical rotation angle from α OPT Decrease (h - |θ i -θ m |) / 2; if the coordinates of the position point Are at the upper right edge of the view field of the PTZ camera, then adjust the horizontal rotation angle of the PTZ camera from β OPT Decrease The vertical rotation angle from α OPT Decrease (h - |θ i -θ m |) / 2; if the coordinates of the position point Are at the lower left edge of the view field of the PTZ camera, then adjust the horizontal rotation angle of the PTZ camera from β OPT Increase The vertical rotation angle from α OPT Increase (h - |θ i -θ m |) / 2; if the coordinates of the position point Are at the lower right edge of the view field of the PTZ camera, then adjust the horizontal rotation angle of the PTZ camera from β OPT Decrease The vertical rotation angle from α OPT Increase (h - |θ i -θ m |) / 2.

[0073] According to the camera angle adjustment calculation method from S2 - S3, when the camera adjusts the rotation angle to θ OPT , the point is located at the edge of the field of view. Once zooming in is performed, the field of view that the camera can illuminate will shrink, and the target position point will move out of the field of view. Therefore, to avoid this situation, the target position point needs to be placed in the middle of the field of view first, and then the field of view is zoomed in to improve the clarity of the target position point.

[0074] Steps S5 - S7 are for calculating the rotation angle that the camera needs to adjust, and how to adjust the rotation angle to move the target position point to the middle of the field of view.

[0075] In some embodiments of the present invention, it further includes:

[0076] S8. Calculate the horizontal field of view angle scaling ratio 1 / K1 and the vertical field of view angle scaling ratio 1 / K2 of the camera so that all target position points are within the camera's field of view. Select the smaller value of 1 / K1 and 1 / K2 as the field of view angle scaling ratio 1 / K of the camera. The K1 is obtained through calculation, and the K2 is obtained through h / ∣θi - θn∣;

[0077] S9. Simultaneously reduce the horizontal field of view angle and the vertical field of view angle of the camera to 1 / K of the original.

[0078] Through steps S8 - S9, calculate the field of view angle scaling ratio that can increase the proportion of the target position point in the field of view, and obtain a high - definition tracking object image.

[0079] On the other hand, the present invention provides a target tracking device for a ball - mounted camera, including a tracked object position acquisition module, an optimal rotation angle calculation module for the ball - mounted camera, and a rotation angle adjustment module for the ball - mounted camera.

[0080] The tracked object position acquisition module is used to acquire the position point coordinates of all tracked objects. The position point coordinates are in a spherical coordinate system with the center of the camera of the ball - mounted camera as the origin. Let the spherical coordinates of the i - th position point be

[0081] The optimal rotation angle calculation module for the ball - mounted camera is used to traverse all position points. For any position point According to the vertical field of view angle and the horizontal field of view angle of the camera, calculate the camera limit angles that make this position point within the camera's field of view: the maximum vertical rotation angle α maxi , the minimum vertical rotation angle α mini , the maximum horizontal rotation angle β maxi , the minimum horizontal rotation angle β mini, and establish a mapping relationship between any position point and the camera's extreme angles α maxi α mini β maxi and β mini ;

[0082] Traverse all position points. For any position point When the horizontal rotation angle and vertical rotation angle of the camera are the following 4 pairs of extreme angles of this point: the maximum horizontal rotation angle β maxi , the maximum vertical rotation angle α maxi , the minimum horizontal rotation angle β mini , the maximum vertical rotation angle α maxi , the maximum horizontal rotation angle β maxi , the minimum vertical rotation angle α mini , the minimum horizontal rotation angle β mini , the minimum vertical rotation angle α mini , determine whether the remaining position points are within the camera's field of view with this pair of extreme angles as the rotation angles, obtain the number of position points within the camera's field of view with this pair of extreme angles, and select the pair of extreme angles with the largest number of position points within the camera's field of view as the optimal horizontal rotation angle β OPT and the optimal vertical rotation angle α OPT ;

[0083] The pan-tilt control ball rotation angle adjustment module is used to adjust the horizontal rotation angle of the camera to β OPT , and the vertical rotation angle to α OPT , and the position points within the current camera's field of view are target position points.

[0084] The device of the embodiment of the present invention corresponds to the above method embodiment. For the specific method that can be implemented by the functional modules of the present invention, refer to the above method technical solution and will not be elaborated here.

[0085] Another aspect of the present invention also provides a computer storage medium. Instructions are stored in the computer storage medium. When the instructions are executed on a computer, the computer is made to execute the above method.

[0086] The above has introduced in detail a target tracking method, device, and storage medium of a pan-tilt control ball provided by the present invention. Specific examples are used in this article to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

[0087] The various embodiments in this application are all described in a progressive manner. For the same or similar parts among the various embodiments, reference can be made to each other. Each embodiment focuses on the differences from other embodiments. In particular, for the apparatus embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and for the relevant parts, reference can be made to the partial description of the method embodiments.

Claims

1. A target tracking method for a cloth control ball, characterized in that It includes the following steps: Obtain the position point coordinates of all tracked objects. The position point coordinates are in the spherical coordinate system with the center of the camera of the mobile control station as the origin. Let the spherical coordinates of the i-th position point be Traverse all position points. For any position point According to the vertical field of view angle and horizontal field of view angle of the camera, calculate the camera limit angles that enable this position point to be within the camera's field of view: the maximum vertical rotation angle α maxi , the minimum vertical rotation angle α mini , the maximum horizontal rotation angle β maxi , the minimum horizontal rotation angle β mini , and establish a mapping relationship between any position point and the camera limit angles α maxi , α mini , β maxi and β mini ; Traverse all position points. For any position point When the horizontal rotation angle and vertical rotation angle of the camera are the following 4 pairs of limit angles of this point: the maximum horizontal rotation angle β maxi , the maximum vertical rotation angle α maxi , the minimum horizontal rotation angle β mini , the maximum vertical rotation angle α maxi , the maximum horizontal rotation angle β maxi , the minimum vertical rotation angle α mini , the minimum horizontal rotation angle β mini , the minimum vertical rotation angle α mini , determine whether the remaining position points are within the field of view of the camera with this pair of limit angles as the rotation angles, obtain the number of position points within the field of view of the camera with this pair of limit angles, and select the pair of limit angles with the largest number of position points within the camera's field of view as the optimal horizontal rotation angle β OPT and the optimal vertical rotation angle α OPT ; Adjust the horizontal rotation angle of the camera to β OPT , and the vertical rotation angle to α OPT . All position points within the current camera's field of view are target position points.

2. The target tracking method of the panoramic control camera according to claim 1, wherein It also includes: According to the mapping relationship between the position points and the limit angles, obtain the position point coordinates corresponding to the limit angles α OPT , β OPT ​ When the rotation angles of the camera are α OPT and β OPT , obtain the coordinates of the position point within the camera's field of view that has the largest horizontal rotation angle difference from the point , and the coordinates of the position point that has the largest vertical rotation angle difference from the point and the point ​ According to the position point coordinates At the position in the camera's field of view, adjust the horizontal rotation angle of the camera from β OPT Increase or decrease The vertical rotation angle from α OPT Increase or decrease (h - ∣θ i -θ m ∣) / 2, where w and h are the horizontal field of view angle and the vertical field of view angle of the camera respectively.

3. The target tracking method of the cloth control ball according to claim 2, characterized in that, It also includes: Calculate the horizontal field of view angle scaling ratio 1 / K1 and the vertical field of view angle scaling ratio 1 / K2 of the PTZ camera so that all target position points are out of the PTZ camera's field of view. Select the smaller of 1 / K1 and 1 / K2 as the field of view angle scaling ratio 1 / K of the PTZ camera. K1 is obtained through calculation, and K2 is obtained through h / ∣θ i -θn∣ calculation; Simultaneously reduce the horizontal field of view angle and the vertical field of view angle of the mobile video surveillance device to 1 / K of the original.

4. The target tracking method of the panoramic camera according to claim 2, characterized in that According to the position point coordinates at the position in the camera's field of view, adjust the horizontal rotation angle of the camera from β OPT to increase or decrease the vertical rotation angle from α OPT by increasing or decreasing (h - ∣θ i - θ m ∣) / 2. Specifically, it includes: If the position point coordinates are at the upper left edge of the field of view of the mobile video surveillance device, then adjust the horizontal rotation angle of the mobile video surveillance device from β OPT to increase the vertical rotation angle from α OPT by decreasing (h - ∣θ i - θ m ∣) / 2; if the position point coordinates are at the upper right edge of the field of view of the mobile video surveillance device, then adjust the horizontal rotation angle of the mobile video surveillance device from β OPT to decrease the vertical rotation angle from α OPT by decreasing (h - ∣θ i - θ m ∣) / 2; if the position point coordinates are at the lower left edge of the field of view of the mobile video surveillance device, then adjust the horizontal rotation angle of the mobile video surveillance device from β OPT to increase the vertical rotation angle from α OPT by increasing (h - ∣θ i - θ m ∣) / 2; if the position point coordinates are at the lower right edge of the field of view of the mobile video surveillance device, then adjust the horizontal rotation angle of the mobile video surveillance device from β OPT to decrease the vertical rotation angle from α OPT by increasing (h - ∣θ i - θ m ∣) / 2.

5. The target tracking method of the panoramic ball camera according to claim 1, wherein The vertical rotation angle range of the camera is [0, π / 2]. When the orientation of the camera is parallel to the XOY plane, the vertical rotation angle is π / 2. When the projection of the camera's orientation on the XOY plane coincides with the positive X-axis, the horizontal rotation angle is 0, and the horizontal rotation angle range is [0, 2π], and the α maxi and α mini and β maxi and β mini are obtained through the following formula. The horizontal field of view angle of the camera is w, and the vertical field of view angle is h: α maxi = θ i + h / 2, α mini = θ i -h / 2, 6. The target tracking method of the cloth control ball according to claim 1, characterized in that, The specific method for determining whether a certain position point is within the camera's field of view is as follows: Let the vertical rotation angle of the camera be α and the horizontal rotation angle be β; Let the coordinates of the p-th position point in space be If the vertical rotation angle θ of the position point p satisfies ∣θ p -α∣≤h / 2, and the horizontal rotation angle satisfies then it is determined that the point is within the field of view of the PTZ camera.

7. The target tracking method of the mobile video surveillance device according to claim 1, wherein Before obtaining the position points of all tracked objects, it also includes: receiving a request to start the mode with the largest number of tracked objects, and the request is triggered periodically or by other electronic devices communicating with the mobile video surveillance device.

8. The target tracking method of the cloth control ball according to claim 1, characterized in that, The obtaining of the position point coordinates of all tracked objects includes: Receiving the position points of all tracked objects sent by the UWB base station. The UWB base station includes three antennas provided on the mobile video surveillance device and located in the same plane. The plane where the three antennas are located is parallel to the horizontal plane, and a positioning terminal with a UWB positioning tag is worn on the tracked object; The positioning terminal sends UWB radio signals to the UWB base station. The UWB base station determines the position point coordinates of the tracked object through the TDOA algorithm. The position point coordinates are three-dimensional world coordinates, and the three-dimensional world coordinates of the position point are converted into spherical coordinates and then sent to the mobile video surveillance device.

9. A target tracking device for a mobile video surveillance ball, characterized in that, It includes a tracked object position acquisition module, an optimal rotation angle calculation module for the mobile video surveillance device, and a rotation angle adjustment module for the mobile video surveillance device. The tracked object position acquisition module is used to obtain the position point coordinates of all tracked objects. The position point coordinates are in a spherical coordinate system with the center of the camera of the PTZ camera as the origin. Let the spherical coordinates of the i-th position point be The optimal rotation angle calculation module of the cloth control ball is used to traverse all position points. For any position point According to the vertical field of view angle and horizontal field of view angle of the camera, calculate the camera limit angles that enable this position point to be within the camera's field of view: the maximum vertical rotation angle α maxi , the minimum vertical rotation angle α mini , the maximum horizontal rotation angle β maxi , the minimum horizontal rotation angle β mini , and establish the mapping relationship between any position point and the camera limit angles α maxi , α mini , β maxi and β mini that enable this point to be within the camera's field of view; Traverse all position points. For any position point When the horizontal rotation angle and vertical rotation angle of the camera are respectively the following 4 pairs of limit angles of this point: the maximum horizontal rotation angle β maxi , the maximum vertical rotation angle α maxi , the minimum horizontal rotation angle β mini , the maximum vertical rotation angle α maxi , the maximum horizontal rotation angle β maxi , the minimum vertical rotation angle α mini , the minimum horizontal rotation angle β mini , the minimum vertical rotation angle α mini , determine whether the remaining position points are within the field of view of the camera with this pair of limit angles as the rotation angles, obtain the number of position points within the field of view of the camera with this pair of limit angles, and select the pair of limit angles with the largest number of position points within the camera's field of view as the optimal horizontal rotation angle β OPT , the optimal vertical rotation angle α OPT ; The pan-tilt rotation angle adjustment module is used to adjust the horizontal rotation angle of the camera to β OPT , and the vertical rotation angle to α OPT . All position points within the current camera's field of view are target position points.

10. A computer storage medium, characterized in that, The computer storage medium stores instructions that, when executed on a computer, cause the computer to execute the method according to any one of claims 1-8.

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