A target projection method and device for panoramic parking system calibration

Abstract

The application discloses a target projection method and device for panoramic parking system calibration, and the target projection platform is arranged. When it is determined that a vehicle drives to a target area, the vehicle in the target area is identified based on the target projection platform, the vehicle contour line of the vehicle is determined, and the vehicle center coordinate and the vehicle tilt angle of the vehicle are calculated based on the vehicle contour line. According to the vehicle center coordinate, the target position of the target projection platform is determined, and according to the vehicle tilt angle, the rotation angle of the target projection platform is determined. When it is determined that the target projection platform moves to the target position and the target projection platform keeps the unified tilt angle with the vehicle, the target projection platform is controlled to project the checkerboard. Compared with the prior art, the technical scheme of the application can improve the calibration efficiency.

Description

Technical Field

[0001] This invention relates to the technical field of vehicle calibration, and in particular to a target projection method and apparatus for calibrating a panoramic parking system. Background Technology

[0002] With the popularization of automobiles and the development of the automotive industry, 360-degree panoramic and panoramic parking systems are increasingly being installed on cars. These systems rely on the fusion and stitching of multiple cameras on the vehicle body to generate 3D and 2D views. The reason why stitching can be completed is that a coordinate system mapping is established between the camera images and the real world. This is the work that calibration needs to complete.

[0003] The calibration methods for 360-degree panoramic and panoramic parking systems currently rely on a flat grid of ground. With the relative position of the car and the grid fixed, the coordinates of the car's distance from each marker can be determined. Then, a mapping is established one by one based on the image coordinates of the markers in the car's camera image. This is the calibration process.

[0004] In actual production, a checkerboard pattern is pre-drawn on the ground, and then the car is driven to the designated position on the checkerboard. The accuracy of the car's placement directly affects the calibration result. Many car manufacturers in the industry use alignment devices to align the car body to the predetermined location for calibration. These devices have disadvantages such as high cost and low efficiency. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a target projection method and device for calibration of a panoramic parking system, thereby improving calibration efficiency.

[0006] To address the aforementioned technical problems, this invention provides a target projection method for calibrating a panoramic parking system, comprising:

[0007] A target projection platform is set up. When it is determined that a vehicle has driven into the target area, the vehicle in the target area is identified based on the target projection platform, the vehicle outline is determined, and the vehicle center coordinates and vehicle tilt angle are calculated based on the vehicle outline.

[0008] Based on the vehicle's center coordinates, the target position of the target projection platform is determined, and based on the vehicle's tilt angle, the rotation angle of the target projection platform is determined.

[0009] When it is determined that the target projection platform has moved to the target position and the target projection platform maintains the same tilt angle as the vehicle, the target projection platform is controlled to project a checkerboard pattern.

[0010] In one possible implementation, a target projection platform is set up, specifically including:

[0011] A target projection platform is set directly above the target area. The target projection platform includes a camera and projection devices. The projection devices include a first projection device, a second projection device, a third projection device, and a fourth projection device.

[0012] The target projection platform is a rectangular platform. The first projection device, the second projection device, the third projection device and the fourth projection device are respectively set at the four corners of the target projection platform, and the camera is set at the center of the target projection platform.

[0013] The target projection platform is located directly below the movable base, which is connected to the target projection platform via a pivot.

[0014] In one possible implementation, vehicles in the target area are identified based on the target projection platform, the vehicle outlines are determined, and the vehicle center coordinates and tilt angles are calculated based on the vehicle outlines, specifically including:

[0015] Based on the camera in the target projection platform, vehicle images in the target area are acquired, and the vehicle images are processed into grayscale to obtain grayscale vehicle images;

[0016] Edge detection is performed on the grayscale vehicle image based on image processing algorithms to determine the vehicle outline.

[0017] Based on the vehicle outline, the circumscribed rectangle of the vehicle is obtained;

[0018] Obtain the regional coordinate system of the target area, determine the geometric center coordinates of the bounding rectangle based on the regional coordinate system, and determine the vehicle center coordinates of the vehicle based on the geometric center coordinates.

[0019] Based on the circumscribed rectangle and the vehicle center coordinates, the first vehicle length centerline of the vehicle is determined;

[0020] In the regional coordinate system, a vehicle coordinate system is constructed with the vehicle center coordinate as the origin. The skew angle between the first vehicle length centerline and the y-axis in the vehicle coordinate system is calculated, and the skew angle is used as the vehicle tilt angle.

[0021] In one possible implementation, after controlling the target projection platform to project the chessboard grid, the specific steps include:

[0022] Based on the circumscribed rectangle and the vehicle center coordinates, the first width centerline of the vehicle is determined;

[0023] Obtain the projected image of the chessboard grid, determine the center marker corresponding to each grid in the chessboard grid based on the projected image, and generate multiple chessboard grid lines based on multiple center markers;

[0024] Based on the multiple chessboard lines, determine whether the chessboard is parallel to the center line of the vehicle, wherein the center line of the vehicle includes the first vehicle width center line and the first vehicle length center line.

[0025] When it is determined that the chessboard grid is parallel to the center line of the vehicle, the chessboard grid is confirmed to be successfully projected;

[0026] When it is determined that the checkerboard grid is not parallel to the centerline of the vehicle, a first tilt angle between the checkerboard grid and the centerline of the vehicle is determined, and it is determined whether the first tilt angle is greater than a preset threshold tilt angle. If so, it is indicated that there is a deviation in the projection of the checkerboard grid, and the target position and the rotation angle of the target projection platform are readjusted.

[0027] In one possible implementation, after determining the target position of the target projection platform based on the vehicle center coordinates, the method further includes:

[0028] The current coordinate position of the target projection platform is obtained. Based on the current coordinate position and the target position, the first moving direction and the first moving distance of the target projection platform on the x-axis are determined, and the second moving direction and the second moving distance of the target projection platform on the y-axis are determined.

[0029] The mobile base is controlled to move according to the first moving direction, the first moving distance, the second moving direction, and the second moving distance, so that the target projection platform is moved to the target position based on the mobile chassis.

[0030] In one possible implementation, before determining that the vehicle has driven to the target area, the following is also included:

[0031] Determine whether the target projection platform is being used for the first time. If so, control the first projection device, the second projection device, the third projection device, and the fourth projection device in the target projection platform to project the x-axis scale line and the y-axis scale line, respectively.

[0032] Based on all x-axis scale lines, determine whether any two adjacent x-axis scale lines are on the same straight line; and based on all y-axis scale lines, determine whether any two adjacent y-axis scale lines are on the same straight line.

[0033] When it is determined that two adjacent x-axis scale lines are on the same straight line and two adjacent y-axis scale lines are on the same straight line, based on the physical scale, it is determined whether the node scales on the x-axis scale lines and the y-axis scale lines coincide with the node scales on the physical scale. If so, it is determined that the target projection platform is parallel to the ground of the target area; otherwise, it is determined that the target projection platform is not parallel to the ground of the target area, and the target projection platform is adjusted until it is determined that the target projection platform is parallel to the ground of the target area.

[0034] In one possible implementation, before determining that the vehicle has driven to the target area, the following is also included:

[0035] The target area is detected based on the target projection platform. When no vehicle is detected in the target area, it is determined that the vehicle has not yet been driven into the target area.

[0036] When a vehicle is detected in the target area, it is determined whether the vehicle has entered the target area. If so, the status of the vehicle is obtained. If the vehicle is stationary, it is determined that the vehicle has driven into the target area; otherwise, it is determined that the vehicle has not yet driven into the target area.

[0037] The present invention also provides a target projection device for calibration of a panoramic parking system, comprising: a target projection platform setting module, a vehicle recognition module, a target projection platform movement parameter acquisition module, and a checkerboard projection module;

[0038] The target projection platform setting module is used to set the target projection platform.

[0039] The vehicle recognition module is used to identify vehicles in the target area based on the target projection platform when it is determined that a vehicle has driven into the target area, determine the vehicle outline of the vehicle, and calculate the vehicle center coordinates and vehicle tilt angle based on the vehicle outline.

[0040] The target projection platform movement parameter acquisition module is used to determine the target position of the target projection platform based on the vehicle center coordinates, and to determine the rotation angle of the target projection platform based on the vehicle tilt angle.

[0041] The checkerboard projection module is used to control the target projection platform to project a checkerboard pattern when it is determined that the target projection platform has moved to the target position and the target projection platform maintains a uniform tilt angle with the vehicle.

[0042] In one possible implementation, the target projection platform setting module is used to set the target projection platform, specifically including:

[0043] A target projection platform is set directly above the target area. The target projection platform includes a camera and projection devices. The projection devices include a first projection device, a second projection device, a third projection device, and a fourth projection device.

[0044] The target projection platform is a rectangular platform. The first projection device, the second projection device, the third projection device and the fourth projection device are respectively set at the four corners of the target projection platform, and the camera is set at the center of the target projection platform.

[0045] The target projection platform is located directly below the movable base, which is connected to the target projection platform via a pivot.

[0046] In one possible implementation, the vehicle recognition module is used to identify vehicles in the target area based on the target projection platform, determine the vehicle outline, and calculate the vehicle center coordinates and vehicle tilt angle based on the vehicle outline, specifically including:

[0047] Based on the camera in the target projection platform, vehicle images in the target area are acquired, and the vehicle images are processed into grayscale to obtain grayscale vehicle images;

[0048] Edge detection is performed on the grayscale vehicle image based on image processing algorithms to determine the vehicle outline.

[0049] Based on the vehicle outline, the circumscribed rectangle of the vehicle is obtained;

[0050] Obtain the regional coordinate system of the target area, determine the geometric center coordinates of the bounding rectangle based on the regional coordinate system, and determine the vehicle center coordinates of the vehicle based on the geometric center coordinates.

[0051] Based on the circumscribed rectangle and the vehicle center coordinates, the first vehicle length centerline of the vehicle is determined;

[0052] In the regional coordinate system, a vehicle coordinate system is constructed with the vehicle center coordinate as the origin. The skew angle between the first vehicle length centerline and the y-axis in the vehicle coordinate system is calculated, and the skew angle is used as the vehicle tilt angle.

[0053] In one possible implementation, the checkerboard projection module, used to control the target projection platform to project the checkerboard pattern, specifically includes:

[0054] Based on the circumscribed rectangle and the vehicle center coordinates, the first width centerline of the vehicle is determined;

[0055] Obtain the projected image of the chessboard grid, determine the center marker corresponding to each grid in the chessboard grid based on the projected image, and generate multiple chessboard grid lines based on multiple center markers;

[0056] Based on the multiple chessboard lines, determine whether the chessboard is parallel to the center line of the vehicle, wherein the center line of the vehicle includes the first vehicle width center line and the first vehicle length center line.

[0057] When it is determined that the chessboard grid is parallel to the center line of the vehicle, the chessboard grid is confirmed to be successfully projected;

[0058] When it is determined that the checkerboard grid is not parallel to the centerline of the vehicle, a first tilt angle between the checkerboard grid and the centerline of the vehicle is determined, and it is determined whether the first tilt angle is greater than a preset threshold tilt angle. If so, it is indicated that there is a deviation in the projection of the checkerboard grid, and the target position and the rotation angle of the target projection platform are readjusted.

[0059] In one possible implementation, the target projection platform movement parameter acquisition module, after determining the target position of the target projection platform based on the vehicle center coordinates, further includes:

[0060] The current coordinate position of the target projection platform is obtained. Based on the current coordinate position and the target position, the first moving direction and the first moving distance of the target projection platform on the x-axis are determined, and the second moving direction and the second moving distance of the target projection platform on the y-axis are determined.

[0061] The mobile base is controlled to move according to the first moving direction, the first moving distance, the second moving direction, and the second moving distance, so that the target projection platform is moved to the target position based on the mobile chassis.

[0062] The present invention provides a target projection device for calibration of a panoramic parking system, which further includes: a ground calibration module;

[0063] The ground calibration module is used to determine whether the target projection platform is being used for the first time. If so, it controls the first projection device, the second projection device, the third projection device and the fourth projection device in the target projection platform to project the x-axis scale line and the y-axis scale line respectively.

[0064] Based on all x-axis scale lines, determine whether any two adjacent x-axis scale lines are on the same straight line; and based on all y-axis scale lines, determine whether any two adjacent y-axis scale lines are on the same straight line.

[0065] When it is determined that two adjacent x-axis scale lines are on the same straight line and two adjacent y-axis scale lines are on the same straight line, based on the physical scale, it is determined whether the node scales on the x-axis scale lines and the y-axis scale lines coincide with the node scales on the physical scale. If so, it is determined that the target projection platform is parallel to the ground of the target area; otherwise, it is determined that the target projection platform is not parallel to the ground of the target area, and the target projection platform is adjusted until it is determined that the target projection platform is parallel to the ground of the target area.

[0066] In one possible implementation, the vehicle recognition module, before determining that the vehicle has driven into the target area, further includes:

[0067] The target area is detected based on the target projection platform. When no vehicle is detected in the target area, it is determined that the vehicle has not yet been driven into the target area.

[0068] When a vehicle is detected in the target area, it is determined whether the vehicle has entered the target area. If so, the status of the vehicle is obtained. If the vehicle is stationary, it is determined that the vehicle has driven into the target area; otherwise, it is determined that the vehicle has not yet driven into the target area.

[0069] The present invention also provides a terminal device, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor executes the computer program to implement the target projection method for calibration of a panoramic parking system as described in any of the preceding claims.

[0070] The present invention also provides a computer-readable storage medium comprising a stored computer program, wherein, when the computer program is executed, it controls the device on which the computer-readable storage medium is located to perform a target projection method for calibration of a panoramic parking system as described in any of the preceding claims.

[0071] This invention provides a target projection method and apparatus for calibrating a panoramic parking system, which, compared with the prior art, has the following advantages:

[0072] By setting up a target projection platform, when a vehicle is determined to be driving into a target area, the platform identifies the vehicle in the target area, determines the vehicle's outline, and calculates the vehicle's center coordinates and tilt angle based on the outline. The target position of the target projection platform is determined based on the vehicle's center coordinates, and the rotation angle of the platform is determined based on the vehicle's tilt angle. When the platform moves to the target position and maintains a uniform tilt angle with the vehicle, it projects a checkerboard pattern. Compared with existing technologies, this invention uses a combination of camera-based vehicle position recognition and checkerboard projection, allowing the checkerboard pattern to follow the vehicle's position and angle, ensuring a fixed relative position between the vehicle and the checkerboard. Furthermore, each calibration requires only the projection platform, not the heavy vehicle body, and the platform's movement distance changes minimally after the vehicle enters the designated area, improving calibration efficiency. Attached Figure Description

[0073] Figure 1 This is a flowchart illustrating an embodiment of a target projection method for calibrating a panoramic parking system provided by the present invention.

[0074] Figure 2 This is a schematic diagram of an embodiment of a target projection device for calibration of a panoramic parking system provided by the present invention;

[0075] Figure 3 This is a schematic diagram of the target projection platform according to an embodiment of the present invention;

[0076] Figure 4 This is a side view schematic diagram of a target projection platform according to an embodiment of the present invention;

[0077] Figure 5 This is a schematic diagram illustrating the determination of vehicle tilt angle according to an embodiment of the present invention;

[0078] Figure 6 This is a schematic diagram of a chessboard projection according to an embodiment of the present invention. Detailed Implementation

[0079] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0080] Example 1, see Figure 1, Figure 1 This is a schematic flowchart of an embodiment of a target projection method for calibration of a panoramic parking system provided by the present invention, as shown below. Figure 1 As shown, the method includes steps 101-104, as detailed below:

[0081] Step 101: Set up a target projection platform. When the vehicle is determined to be driving into the target area, identify the vehicle in the target area based on the target projection platform, determine the vehicle outline, and calculate the vehicle center coordinates and vehicle tilt angle based on the vehicle outline.

[0082] In one embodiment, a target projection platform is set directly above the target area, wherein the target projection platform includes a camera and projection devices, and the projection devices include a first projection device, a second projection device, a third projection device, and a fourth projection device.

[0083] In one embodiment, the target projection platform is a planar device, and the target projection platform is rectangular in shape, preferably square in shape.

[0084] In one embodiment, the first projection device, the second projection device, the third projection device, and the fourth projection device are respectively disposed at the four corners of the target projection platform, and the camera is disposed at the center of the target projection platform; Figure 3 As shown, Figure 3 This is a schematic diagram of the target projection platform.

[0085] Preferably, the first projection device, the second projection device, the third projection device, and the fourth projection device are each a 2x2 projection device; the first projection device, the second projection device, the third projection device, and the fourth projection device can adjust the size of the projected image according to the erection height of the target projection platform, so that the four projected images projected by the four projection devices can be stitched together to form a complete calibration checkerboard.

[0086] In one embodiment, the target projection platform is located directly below the movable base, which is connected to the target projection platform via a pivot; wherein the movable base is used to move the target projection platform, and the pivot is used to rotate the target projection platform, allowing the target projection platform to move and rotate along the x and y axes in the horizontal plane; Figure 4 As shown, Figure 4 This is a side view of the target projection platform.

[0087] Preferably, the rotating shaft can rotate 360 ​​degrees clockwise and counterclockwise, and rotates by a corresponding angle according to the vehicle's tilt angle, so that the vehicle's center line is always parallel to the projected checkerboard.

[0088] In one embodiment, since the ground is pre-planned to be flat and the projection platform is parallel to the ground when the target projection platform is set up, site calibration is required when the target projection platform is used for the first time in order to achieve this state.

[0089] Specifically, it is determined whether the target projection platform is being used for the first time. If so, the first projection device, the second projection device, the third projection device, and the fourth projection device in the target projection platform are controlled to project the x-axis scale line and the y-axis scale line, respectively.

[0090] Specifically, based on all x-axis scale lines, it is determined whether any two adjacent x-axis scale lines are on the same straight line. Similarly, based on all y-axis scale lines, it is determined whether any two adjacent y-axis scale lines are on the same straight line. When both x-axis and y-axis scale lines are confirmed to be on the same straight line, based on the physical scale, it is determined whether the node markings on the x-axis and y-axis scale lines coincide with the node markings on the physical scale. If so, the target projection platform is determined to be parallel to the ground of the target area. Otherwise, the target projection platform is determined to be non-parallel to the ground of the target area, and the target projection platform is adjusted until it is determined to be parallel to the ground of the target area, thus achieving site calibration.

[0091] Specifically, when determining whether the node scales on the x-axis and y-axis scales coincide with the node scales on the physical scale, the physical scale is placed flush against the projected scale lines to check whether the node scales on the physical scale coincide with those on the projected scale lines.

[0092] In one embodiment, before determining that the vehicle has driven to the target area, the method further includes: detecting the target area based on the target projection platform; when no vehicle is detected in the target area, determining that the vehicle has not yet driven to the target area; when a vehicle is detected in the target area, determining whether the vehicle has entered the target area; if so, obtaining the state of the vehicle; if the state of the vehicle is stationary, determining that the vehicle has driven to the target area; otherwise, determining that the vehicle has not yet driven to the target area.

[0093] Specifically, the camera on the target projection platform will detect certain behaviors, such as when the projection platform is started, if the vehicle does not enter the designated area, or if the vehicle body exceeds the target area or the vehicle is not in a stationary state, the target projection platform will send the status back to the host computer connected to it and notify the operator to check.

[0094] In one embodiment, after determining that the vehicle has driven to the target area, the vehicle image in the target area is acquired by the camera in the target projection platform, and the vehicle image is processed into grayscale to obtain a grayscale vehicle image; the grayscale vehicle image is then processed by an image processing algorithm to perform edge detection and determine the vehicle outline.

[0095] In one embodiment, the circumscribed rectangle of the vehicle is obtained based on the vehicle outline; the regional coordinate system of the target area is obtained; the geometric center coordinates of the circumscribed rectangle are determined based on the regional coordinate system; and the vehicle center coordinates of the vehicle are determined based on the geometric center coordinates.

[0096] Specifically, the regional coordinate system of the target area has the center of the target area as the origin.

[0097] Specifically, the geometric center coordinates are used as the vehicle center coordinates of the vehicle.

[0098] In one embodiment, the first vehicle length centerline is determined based on the circumscribed rectangle and the vehicle center coordinates.

[0099] Specifically, based on the vehicle width, two wide sides of the circumscribed rectangle are selected, the midpoints of the two wide sides are determined, and a line is drawn connecting the midpoints of the two wide sides and the coordinate point of the vehicle center coordinates to determine the first vehicle length centerline.

[0100] In one embodiment, in the regional coordinate system, a vehicle coordinate system is constructed with the vehicle center coordinates as the origin. The skew angle between the first vehicle length centerline and the y-axis in the vehicle coordinate system is calculated, and the skew angle is used as the vehicle tilt angle. Figure 5 As shown, Figure 5 This is a diagram illustrating how the vehicle's tilt angle is determined.

[0101] Preferably, when the centerline of a vehicle in the target area is parallel to the target area, the first vehicle length centerline coincides with the y-axis in the vehicle coordinate system, and the skew angle is 0.

[0102] Step 102: Determine the target position of the target projection platform based on the vehicle center coordinates, and determine the rotation angle of the target projection platform based on the vehicle tilt angle.

[0103] In one embodiment, the vehicle's center coordinates are used as the target position of the target projection platform, and the vehicle's tilt angle is used as the rotation angle of the target projection platform.

[0104] In one embodiment, after determining the target position of the target projection platform based on the vehicle center coordinates, the current coordinate position of the target projection platform is also obtained. Based on the current coordinate position and the target position, a first moving direction and a first moving distance of the target projection platform on the x-axis are determined, and a second moving direction and a second moving distance of the target projection platform on the y-axis are also determined.

[0105] Specifically, the coordinates of the current coordinate position of the target projection platform are the origin coordinates of the target coordinate system. By comparing the X value in the coordinates of the current coordinate position with the X value in the coordinates of the target position, the first moving direction and the first moving distance of the target projection platform on the x-axis are determined. By comparing the Y value in the coordinates of the current coordinate position with the Y value in the coordinates of the target position, the second moving direction and the second moving distance of the target projection platform on the Y-axis are determined.

[0106] In one embodiment, the mobile base is controlled to move according to the first moving direction, the first moving distance, the second moving direction, and the second moving distance, so that the target projection platform is moved to the target position based on the mobile chassis.

[0107] In one embodiment, after determining the rotation angle of the target projection platform based on the vehicle tilt angle, the first vehicle length centerline obtained in step 101 is further used to determine the quadrant regions of the vehicle coordinate system in which the first vehicle length centerline is distributed. When the first vehicle length centerline is distributed in the first and third quadrant regions of the vehicle coordinate system, the vehicle tilt direction is determined to be tilted to the right. When the first vehicle length centerline is distributed in the second and fourth quadrant regions of the vehicle coordinate system, the vehicle tilt direction is determined to be tilted to the left. Based on the tilt direction and the vehicle tilt angle, the target projection platform is rotated based on the pivot axis to ensure that the target projection platform maintains a uniform tilt angle with the vehicle.

[0108] Step 103: When it is determined that the target projection platform has moved to the target position and the target projection platform maintains the same tilt angle as the vehicle, control the target projection platform to project the checkerboard pattern.

[0109] In one embodiment, since mechanical devices such as the pivot or moving base may malfunction in certain situations, causing the target projection platform to fail to move to the target position or fail to rotate to an angle parallel to the vehicle body, the projection effect is also detected based on the camera of the target projection platform after the projection is completed.

[0110] In one embodiment, after controlling the target projection platform to project the checkerboard pattern, the first width centerline of the vehicle is determined based on the circumscribed rectangle and the vehicle center coordinates.

[0111] In one embodiment, a camera on a target projection platform acquires a projected image of the chessboard grid. Based on the projected image, the center marker corresponding to each grid cell in the chessboard grid is determined, and multiple chessboard grid lines are generated based on multiple center markers.

[0112] Specifically, each square in the chessboard corresponds to a projection device, and the center marker of each square is the center of the projection area formed by the projection device.

[0113] In one embodiment, based on the projected image, the center point corresponding to each cell in the chessboard is determined. Specifically, based on the projected image, a first projection area corresponding to a first projection device, a second projection area corresponding to a second projection device, a third projection area corresponding to a third projection device, and a fourth projection area corresponding to a fourth projection device are obtained. The center point of the first projection area is taken as the first center point corresponding to the first cell in the chessboard, the center point of the second projection area is taken as the second center point corresponding to the second cell in the chessboard, the center point of the third projection area is taken as the third center point corresponding to the third cell in the chessboard, and the center point of the fourth projection area is taken as the fourth center point corresponding to the fourth cell in the chessboard.

[0114] In one embodiment, multiple chessboard lines are generated based on multiple center markers; specifically, the multiple center markers include a first center marker, a second center marker, a third center marker, and a fourth center marker; connecting the first center marker and the second center marker yields a first chessboard line, connecting the second projected chessboard line and the third center marker yields a second chessboard line, connecting the third center marker and the fourth center marker yields a third chessboard line, and connecting the fourth center marker and the first center marker yields a fourth chessboard line.

[0115] In one embodiment, it is determined whether the chessboard grid is parallel to the centerline of the vehicle based on the plurality of chessboard grid lines, wherein the centerline of the vehicle includes the first vehicle width centerline and the first vehicle length centerline.

[0116] Specifically, it is determined whether the first checkerboard grid line is parallel to the center line of the first vehicle width, whether the second checkerboard grid line is parallel to the center line of the first vehicle length, whether the third checkerboard grid line is parallel to the center line of the first vehicle width, and whether the fourth checkerboard grid line is parallel to the center line of the first vehicle length. If the first checkerboard grid line is parallel to the center line of the first vehicle width, the second checkerboard grid line is parallel to the center line of the first vehicle length, the third checkerboard grid line is parallel to the center line of the first vehicle width, and the fourth checkerboard grid line is parallel to the center line of the first vehicle length, then the checkerboard grid is determined to be parallel to the center line of the vehicle. Figure 6 As shown, Figure 6 This is a schematic diagram of a chessboard projection, where the control center point is the center marker.

[0117] In one embodiment, when it is determined that the chessboard grid is parallel to the centerline of the vehicle, the chessboard grid is confirmed to have been successfully projected.

[0118] In one embodiment, when it is determined that the chessboard grid is not parallel to the center line of the vehicle, a first tilt angle between the chessboard grid and the center line of the vehicle is determined, and it is determined whether the first tilt angle is greater than a preset threshold tilt angle. If so, it is indicated that there is a deviation in the projection of the chessboard grid, and the target position and the rotation angle of the target projection platform are readjusted.

[0119] Specifically, when the first tilt angle is greater than the preset threshold tilt angle, the status is fed back to the operator, and at the same time, the image of the target projection platform camera is transmitted to the operator's host computer in real time. The operator can also manually control the movement and rotation angle of the target projection platform. In order to ensure the effectiveness of each operation, after the target projection platform completes each projection task, the projection effect can be manually confirmed by the operator. The target projection platform camera captures and records the effect of each projection as production record data.

[0120] Preferably, when the production workshop construction and calibration scheme are changed, such as when the vehicle model changes and the chessboard grid specifications change, the vehicle calibration can be flexibly achieved simply by changing the projected chessboard grid.

[0121] In summary, the target projection method for calibration of a panoramic parking system provided in this embodiment uses a camera to identify the vehicle position and project a checkerboard pattern. This method is not limited to the vehicle position and allows the checkerboard pattern to be projected according to the vehicle's position angle, thereby ensuring that the relative position of the vehicle and the checkerboard pattern is fixed. Moreover, each calibration does not require moving the heavy vehicle body; only the projection platform needs to be moved. After the vehicle enters the designated area, the movement distance of the projection platform changes little, thus improving calibration efficiency.

[0122] Example 2, see Figure 2 , Figure 2 This is a schematic diagram of an embodiment of a target projection device for calibrating a panoramic parking system provided by the present invention, as shown below. Figure 2 As shown, the device includes a target projection platform setting module 201, a vehicle recognition module 202, a target projection platform movement parameter acquisition module 203, and a checkerboard projection module 204, as detailed below:

[0123] The target projection platform setting module 201 is used to set the target projection platform.

[0124] The vehicle recognition module 202 is used to identify vehicles in the target area based on the target projection platform when it is determined that a vehicle has driven into the target area, determine the vehicle outline of the vehicle, and calculate the vehicle center coordinates and vehicle tilt angle based on the vehicle outline.

[0125] The target projection platform movement parameter acquisition module 203 is used to determine the target position of the target projection platform based on the vehicle center coordinates, and to determine the rotation angle of the target projection platform based on the vehicle tilt angle.

[0126] The checkerboard projection module 204 is used to control the target projection platform to project a checkerboard pattern when it is determined that the target projection platform has moved to the target position and the target projection platform maintains a uniform tilt angle with the vehicle.

[0127] In one embodiment, the target projection platform setting module 201 is used to set the target projection platform, specifically including: setting the target projection platform directly above the target area, wherein the target projection platform includes a camera and projection devices, the projection devices including a first projection device, a second projection device, a third projection device, and a fourth projection device; the target projection platform is a rectangular platform, the first projection device, the second projection device, the third projection device, and the fourth projection device are respectively set at the four corners of the target projection platform, and the camera is set at the center of the target projection platform; the target projection platform is located directly below the movable base, and the movable base is connected to the target projection platform through a pivot.

[0128] In one embodiment, the vehicle recognition module 202 is used to recognize vehicles in the target area based on the target projection platform, determine the vehicle outline, and calculate the vehicle center coordinates and vehicle tilt angle based on the vehicle outline. Specifically, it includes: acquiring vehicle images in the target area based on the camera in the target projection platform; performing grayscale processing on the vehicle images to obtain grayscale vehicle images; performing edge detection on the grayscale vehicle images based on image processing algorithms to determine the vehicle outline; obtaining the circumscribed rectangle of the vehicle based on the vehicle outline; obtaining the regional coordinate system of the target area; determining the geometric center coordinates of the circumscribed rectangle based on the regional coordinate system; determining the vehicle center coordinates based on the geometric center coordinates; determining the first vehicle length centerline of the vehicle based on the circumscribed rectangle and the vehicle center coordinates; and constructing a vehicle coordinate system in the regional coordinate system with the vehicle center coordinates as the origin, calculating the tilt angle between the first vehicle length centerline and the y-axis in the vehicle coordinate system, and using the tilt angle as the vehicle tilt angle.

[0129] In one embodiment, the checkerboard projection module 204, used to control the target projection platform to project a checkerboard pattern, specifically includes: determining the first vehicle width centerline of the vehicle based on the circumscribed rectangle and the vehicle center coordinates; acquiring a projection image of the checkerboard pattern; determining the center marker corresponding to each cell in the checkerboard pattern based on the projection image; and generating multiple checkerboard lines based on the multiple center markers; determining whether the checkerboard pattern is parallel to the vehicle's centerline based on the multiple checkerboard lines, wherein the vehicle's centerline includes the first vehicle width centerline and the first vehicle length centerline; confirming successful checkerboard projection when the checkerboard pattern is parallel to the vehicle's centerline; determining a first tilt angle between the checkerboard pattern and the vehicle's centerline when the checkerboard pattern is not parallel to the vehicle's centerline; determining whether the first tilt angle is greater than a preset threshold tilt angle; if so, indicating a deviation in the checkerboard pattern projection and readjusting the target position and rotation angle of the target projection platform.

[0130] In one embodiment, the target projection platform movement parameter acquisition module 203, after determining the target position of the target projection platform based on the vehicle center coordinates, further includes: acquiring the current coordinate position of the target projection platform; determining a first movement direction and a first movement distance of the target projection platform on the x-axis based on the current coordinate position and the target position; and simultaneously determining a second movement direction and a second movement distance of the target projection platform on the y-axis; and controlling the movement of the mobile base based on the first movement direction, the first movement distance, the second movement direction, and the second movement distance, so as to move the target projection platform to the target position based on the mobile chassis.

[0131] The target projection device for calibrating a panoramic parking system provided in this embodiment also includes a ground calibration module.

[0132] In one embodiment, the ground calibration module is used to determine whether the target projection platform is being used for the first time. If so, it controls the first, second, third, and fourth projection devices in the target projection platform to project x-axis and y-axis scale lines respectively. Based on all x-axis scale lines, it determines whether any two adjacent x-axis scale lines are on the same straight line, and based on all y-axis scale lines, it determines whether any two adjacent y-axis scale lines are on the same straight line. When it is determined that both adjacent x-axis scale lines and adjacent y-axis scale lines are on the same straight line, based on the physical scale, it determines whether the node scales on the x-axis and y-axis scale lines coincide with the node scales on the physical scale. If so, it determines that the target projection platform is parallel to the ground of the target area; otherwise, it determines that the target projection platform is not parallel to the ground of the target area, and adjusts the target projection platform until it is determined that the target projection platform is parallel to the ground of the target area.

[0133] In one embodiment, the vehicle identification module 202 is further configured to: before determining that a vehicle has driven to the target area, detect the target area based on the target projection platform; when no vehicle is detected in the target area, determine that the vehicle has not yet driven to the target area; when a vehicle is detected in the target area, determine whether the vehicle has entered the target area; if so, obtain the state of the vehicle; if the state of the vehicle is stationary, determine that the vehicle has driven to the target area; otherwise, determine that the vehicle has not yet driven to the target area.

[0134] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working process of the device described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0135] It should be noted that the above-described embodiment of the target projection device for calibrating a panoramic parking system is merely illustrative. The modules described as separate components may or may not be physically separate, and the components shown as modules may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0136] Based on the above-described embodiments of the target projection method for calibrating a panoramic parking system, another embodiment of the present invention provides a target projection terminal device for calibrating a panoramic parking system. This target projection terminal device includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, it implements the target projection method for calibrating a panoramic parking system according to any embodiment of the present invention.

[0137] For example, in this embodiment, the computer program can be divided into one or more modules, which are stored in the memory and executed by the processor to complete the present invention. The one or more modules can be a series of computer program instruction segments capable of performing specific functions, which describe the execution process of the computer program in the target projection terminal device used for calibrating the panoramic parking system.

[0138] The target projection terminal device used for calibration of the panoramic parking system can be a computing device such as a desktop computer, laptop, handheld computer, or cloud server. The target projection terminal device used for calibration of the panoramic parking system may include, but is not limited to, a processor and a memory.

[0139] The processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor. This processor is the control center of the target projection terminal equipment used for calibrating the panoramic parking system, connecting all parts of the target projection terminal equipment using various interfaces and lines.

[0140] The memory can be used to store the computer programs and / or modules. The processor implements various functions of the target projection terminal device for panoramic parking system calibration by running or executing the computer programs and / or modules stored in the memory and calling the data stored in the memory. The memory may mainly include a program storage area and a data storage area. The program storage area may store the operating system, at least one application program required for a function, etc.; the data storage area may store data created based on the use of the mobile phone, etc. In addition, the memory may include high-speed random access memory, and may also include non-volatile memory, such as hard disk, memory, plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, at least one disk storage device, flash memory device, or other volatile solid-state storage device.

[0141] Based on the above embodiments of the target projection method for calibrating a panoramic parking system, another embodiment of the present invention provides a storage medium comprising a stored computer program, wherein, when the computer program is executed, the device containing the storage medium executes the target projection method for calibrating a panoramic parking system according to any embodiment of the present invention.

[0142] In this embodiment, the storage medium is a computer-readable storage medium, and the computer program includes computer program code, which can be in the form of source code, object code, executable file, or some intermediate form. The computer-readable medium can include any entity or device capable of carrying the computer program code, recording media, USB flash drive, portable hard drive, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc. It should be noted that the content included in the computer-readable medium can be appropriately added or removed according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electrical carrier signals and telecommunication signals.

[0143] In summary, the present invention provides a target projection method and apparatus for calibrating a panoramic parking system. By setting up a target projection platform, when a vehicle is determined to have driven into a target area, the method identifies the vehicle in the target area based on the target projection platform, determines the vehicle outline, and calculates the vehicle center coordinates and vehicle tilt angle based on the vehicle outline. The method then determines the target position of the target projection platform based on the vehicle center coordinates and the rotation angle of the target projection platform based on the vehicle tilt angle. When the target projection platform is determined to have moved to the target position and maintains a uniform tilt angle with the vehicle, the method controls the target projection platform to project a checkerboard pattern. Compared with the prior art, the technical solution of the present invention can improve calibration efficiency.

[0144] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. A target projection method for calibration of a panoramic parking system, characterized in that, The method comprises the following steps: Setting a target projection platform, when determining that a vehicle drives to a target area, identifying the vehicle in the target area based on the target projection platform, determining a vehicle contour line of the vehicle, and calculating a vehicle center coordinate and a vehicle tilt angle of the vehicle based on the vehicle contour line; According to the vehicle center coordinate, determine the target position of the target projection platform, and according to the vehicle tilt angle, determine the rotation angle of the target projection platform; When determining that the target projection platform moves to the target position and the target projection platform maintains a unified tilt angle with the vehicle, control the target projection platform to project a checkerboard.

2. The target projection method for calibration of panoramic parking system according to claim 1, characterized in that, Setting a target projection platform, specifically comprising: A target projection platform is arranged directly above the target area, wherein the target projection platform comprises a camera and a projection device, and the projection device comprises a first projection device, a second projection device, a third projection device and a fourth projection device; The target projection platform is a rectangular platform, and the first projection device, the second projection device, the third projection device and the fourth projection device are arranged at the four corners of the target projection platform respectively, and the camera is arranged at the center position of the platform of the target projection platform; The target projection platform is located directly below a moving base, and the moving base is connected to the target projection platform through a rotating shaft.

3. The target projection method for calibration of panoramic parking system according to claim 2, characterized in that, Based on the target projection platform, the vehicle in the target area is identified, the vehicle contour line of the vehicle is determined, and the vehicle center coordinate and the vehicle tilt angle of the vehicle are calculated based on the vehicle contour line, specifically comprising: Based on the camera in the target projection platform, the vehicle image in the target area is collected, the vehicle image is subjected to gray scale processing to obtain a gray scale vehicle image; Based on an image processing algorithm, the gray scale vehicle image is subjected to edge detection to determine the vehicle contour line of the vehicle; According to the vehicle contour line, the circumscribed rectangle of the vehicle is obtained; The region coordinate system of the target area is obtained, the geometric center coordinate of the circumscribed rectangle is determined according to the region coordinate system, and the vehicle center coordinate of the vehicle is determined according to the geometric center coordinate; Based on the circumscribed rectangle and the vehicle center coordinate, the first vehicle length center line of the vehicle is determined; And in the region coordinate system, a vehicle coordinate system is constructed based on the vehicle center coordinate as the coordinate origin, the skew angle of the first vehicle length center line and the y-axis in the vehicle coordinate system is calculated, and the skew angle is taken as the vehicle tilt angle of the vehicle.

4. The target projection method for calibration of panoramic parking system according to claim 3, characterized in that, After the target projection platform projects the checkerboard, specifically comprising: Based on the circumscribed rectangle and the vehicle center coordinate, the first vehicle width center line of the vehicle is determined; The projection image of the checkerboard is obtained, the center points corresponding to each grid in the checkerboard are determined based on the projection image, and a plurality of checkerboard lines are generated according to a plurality of center points; According to the plurality of checkerboard lines, it is judged whether the checkerboard is parallel to the center line of the vehicle, wherein the center line of the vehicle comprises the first vehicle width center line and the first vehicle length center line; When it is judged that the checkerboard is parallel to the center line of the vehicle, it is confirmed that the checkerboard projection is successful; When it is judged that the checkerboard is not parallel to the center line of the vehicle, a first inclination angle of the checkerboard to the center line of the vehicle is determined, it is judged whether the first inclination angle is greater than a preset threshold inclination angle, if yes, it is prompted that the checkerboard projection has deviation, and the target position and the rotation angle of the target projection platform are readjusted.

5. The target projection method for calibration of panoramic parking system according to claim 2, wherein, After the target position of the target projection platform is determined according to the vehicle center coordinates, the method further includes: obtaining a current coordinate position of the target projection platform, and determining a first movement direction and a first movement distance of the target projection platform on the x-axis and a second movement direction and a second movement distance of the target projection platform on the y-axis based on the current coordinate position and the target position; controlling the movement base to move according to the first movement direction, the first movement distance, the second movement direction and the second movement distance, so as to move the target projection platform to the target position based on the movement base.

6. The target projection method for calibration of panoramic parking system according to claim 2, wherein, Before determining that the vehicle drives to the target area, the method further includes: if yes, controlling the first projection device, the second projection device, the third projection device and the fourth projection device in the target projection platform to respectively project x-axis scale lines and y-axis scale lines; judging whether two adjacent x-axis scale lines are on the same straight line according to all the x-axis scale lines, and judging whether two adjacent y-axis scale lines are on the same straight line according to all the y-axis scale lines; when it is determined that two adjacent x-axis scale lines are on the same straight line and two adjacent y-axis scale lines are on the same straight line, judging whether the node scales on the x-axis scale lines and the y-axis scale lines coincide with the node scales on the physical scale based on the physical scale, if yes, it is determined that the target projection platform is parallel to the ground of the target area, otherwise, it is determined that the target projection platform is not parallel to the ground of the target area, and the target projection platform is adjusted until it is determined that the target projection platform is parallel to the ground of the target area.

7. The target projection method for calibration of panoramic parking system according to claim 1, wherein, Before determining that the vehicle drives to the target area, the method further includes: based on the target projection platform detecting the target area, when it is detected that there is no vehicle in the target area, it is determined that the vehicle has not driven to the target area; when it is detected that there is a vehicle in the target area, it is judged whether the vehicle has completed entering the target area, if yes, the state of the vehicle is obtained, if the state of the vehicle is a stationary state, it is determined that the vehicle has driven to the target area, otherwise, it is determined that the vehicle has not driven to the target area.

8. A target projection device for calibration of a surround view parking system, characterized in that, including: a target projection platform setting module, a vehicle identification module, a target projection platform movement parameter acquisition module and a checkerboard projection module; wherein the target projection platform setting module is configured to set a target projection platform; The vehicle recognition module is configured to, when determining that a vehicle drives to a target area, recognize the vehicle in the target area based on the target projection platform, determine a vehicle contour line of the vehicle, and calculate a vehicle center coordinate and a vehicle tilt angle of the vehicle based on the vehicle contour line. The target projection platform movement parameter acquisition module is configured to determine a target position of the target projection platform according to the vehicle center coordinate, and determine a rotation angle of the target projection platform according to the vehicle tilt angle. The chessboard grid projection module is configured to, when determining that the target projection platform moves to the target position and the target projection platform and the vehicle maintain a unified tilt angle, control the target projection platform to project a chessboard grid.

9. A terminal device, comprising: A computer program product includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, and the processor implements the target projection method for calibrating a panoramic parking system according to any one of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium, characterized in that, The computer readable storage medium includes a stored computer program, wherein the computer readable storage medium controls a device where the computer readable storage medium is located to execute the target projection method for calibrating a panoramic parking system according to any one of claims 1 to 7 when the computer program runs.

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