Radar Chart-Based Water Target Detection Method, Device, Equipment and Medium

Abstract

An embodiment of the present application discloses a method, device, equipment and medium for detecting water targets based on a radar chart. Among them, the method includes: determining a radar chart based on the echo signal obtained by detecting with a radar on a stationary watercraft, and determining the track data of the target to be measured according to the radar chart; if it is determined according to the track data of the target to be measured that the distance between the target to be measured and the stationary watercraft is greater than a first preset distance and less than a second preset distance, then determine whether the heading of the target to be measured is towards the stationary watercraft according to the track data; if the heading of the target to be measured is towards the stationary watercraft, then determine the heading line information of the target to be measured according to the track data of the target to be measured, and predict the relative position relationship between the target to be measured and the stationary watercraft according to the heading line information. This technical solution realizes the accurate detection of water targets and improves the safety of the working watercraft.

Description

Technical Field

[0001] The present invention relates to the technical field of data processing, and particularly to a method, device, equipment and medium for detecting water targets based on a radar chart. Background Art

[0002] A ship operating statically in water may stay at a certain place for a long time for operation. At this time, other ships sailing around the operating ship may collide with the operating ship. It is necessary to always pay attention to the passing trends of the surrounding ships and give early warnings for situations that may pose safety risks.

[0003] In the existing solutions, usually, people observe the situations of the surrounding ships manually and give early warnings under appropriate circumstances. However, in foggy weather, the observation range of the manual observation method is greatly limited, and there may be situations where early warnings are not timely, collisions are likely to occur, and the manual observation method has the problem of low efficiency. Summary of the Invention

[0004] The present invention provides a method, device, equipment and medium for detecting water targets based on a radar chart to achieve accurate detection of water targets and improve the safety of operating ships.

[0005] According to one aspect of the present invention, a method for detecting water targets based on a radar chart is provided. The method includes:

[0006] Determine a radar chart according to the echo signal detected by a radar on a static ship in water, and determine the track data of a target to be detected according to the radar chart;

[0007] If it is determined according to the track data of the target to be detected that the distance between the target to be detected and the static ship in water is greater than a first preset distance and less than a second preset distance, then determine whether the course of the target to be detected is towards the static ship in water according to the track data;

[0008] If the course of the target to be detected is towards the static ship in water, then determine the course line information of the target to be detected according to the track data of the target to be detected, and predict the relative position relationship between the target to be detected and the static ship in water according to the course line information.

[0009] According to another aspect of the present invention, a device for detecting water targets based on a radar chart is provided, including:

[0010] A track data determination module, configured to determine a radar chart according to the echo signal detected by a radar on a static ship in water, and determine the track data of a target to be detected according to the radar chart;

[0011] A distance determination module, configured to determine whether the heading of the target to be measured is towards the stationary watercraft according to the track data of the target to be measured if it is determined that the distance between the target to be measured and the stationary watercraft is greater than a first preset distance and less than a second preset distance according to the track data of the target to be measured;

[0012] A position relationship prediction module, configured to determine the heading line information of the target to be measured according to the track data of the target to be measured and predict the relative position relationship between the target to be measured and the stationary watercraft according to the heading line information if the heading of the target to be measured is towards the stationary watercraft.

[0013] According to another aspect of the present invention, there is provided an electronic device, which includes:

[0014] At least one processor; and

[0015] A memory communicatively connected to the at least one processor; wherein,

[0016] The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the radar chart-based water target detection method according to any embodiment of the present invention.

[0017] According to another aspect of the present invention, there is provided a computer-readable storage medium storing computer instructions for causing a processor to implement the radar chart-based water target detection method according to any embodiment of the present invention when executed.

[0018] The technical solution of the embodiments of the present application determines a radar chart through an echo signal detected by a radar on a stationary watercraft, and determines the track data of the target to be measured according to the radar chart; if it is determined that the distance between the target to be measured and the stationary watercraft is greater than a first preset distance and less than a second preset distance according to the track data of the target to be measured, then determine whether the heading of the target to be measured is towards the stationary watercraft according to the track data; if the heading of the target to be measured is towards the stationary watercraft, then determine the heading line information of the target to be measured according to the track data of the target to be measured and predict the relative position relationship between the target to be measured and the stationary watercraft according to the heading line information. This technical solution detects the target to be measured through a radar, so that the detection range is not limited by weather, and the detection efficiency is higher than that of manual observation, realizing accurate detection of water targets and improving the safety of working watercraft.

[0019] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present application, nor is it used to limit the scope of the present invention. Other features of the present invention will become readily understandable through the following description of the specification. Description of the Drawings

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for the description of the embodiments. 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.

[0021] Figure 1 is a flowchart of a method for detecting water targets based on a radar chart according to Embodiment 1 of the present application;

[0022] Figure 2 is a schematic diagram of a first preset distance and a second preset distance of a method for detecting water targets based on a radar chart according to an embodiment of the present application;

[0023] Figure 3 is a schematic diagram of a first direction and a second direction of a method for detecting water targets based on a radar chart according to an embodiment of the present application;

[0024] Figure 4 is a flowchart of a method for detecting water targets based on a radar chart according to Embodiment 2 of the present application;

[0025] Figure 5 is a schematic diagram of a safe course line of a method for detecting water targets based on a radar chart according to an embodiment of the present application;

[0026] Figure 6 is a schematic diagram of a first tangent and a second tangent of a method for detecting water targets based on a radar chart according to an embodiment of the present application;

[0027] Figure 7 is a flowchart of a method for detecting water targets based on a radar chart according to Embodiment 3 of the present application;

[0028] Figure 8 is a radar scan schematic diagram of a method for detecting water targets based on a radar chart according to an embodiment of the present application;

[0029] Figure 9 is a schematic diagram of adjacent position points of a method for detecting water targets based on a radar chart according to an embodiment of the present application;

[0030] Figure 10It is an interpolation schematic diagram of a water target detection method based on a radar chart provided by an embodiment of the present application;

[0031] Figure 11 It is a flowchart of a water target detection method based on a radar chart provided by Embodiment 4 of the present application;

[0032] Figure 12 It is a schematic structural diagram of a water target detection device based on a radar chart provided by Embodiment 3 of the present application;

[0033] Figure 13 It is a schematic structural diagram of an electronic device for implementing a water target detection method based on a radar chart according to an embodiment of the present application. Detailed implementation manners

[0034] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0035] It should be noted that the terms "first", "second", "target", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and do not have to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units does not have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0036] Embodiment 1

[0037] Figure 1 This is a flowchart of a water target detection method based on a radar chart provided by Embodiment 1 of the present application. The embodiments of the present application are applicable to predicting the relative position relationship between a target to be measured and a stationary ship on the water. This method can be executed by a water target detection device based on a radar chart. The water target detection device based on a radar chart can be implemented in the form of hardware and / or software, and the water target detection device based on a radar chart can be configured in an electronic device with data processing capabilities. As Figure 1 shown, the method includes:

[0038] S110. Determine a radar map based on the echo signal detected by a radar on a stationary watercraft, and determine the track data of a target to be measured based on the radar map.

[0039] Among them, the radar can be installed at any position on the stationary watercraft. The embodiments of the present application do not limit the installation position. The radar can be a millimeter-wave radar, such as a 94 GHz millimeter-wave radar. The radar map is an image used to reflect the reflected echo intensity data at each position within the radar detection area. In the embodiments of the present application, the radar map actually reflects the position information of the target to be measured within a circular area centered on the stationary watercraft and with a radius equal to the radar detection distance. The target to be measured can be various targets such as fishing boats, yachts, and water motorcycles. The track data can reflect the position, navigation speed, and navigation direction of the target to be measured.

[0040] Specifically, if there is a target to be measured in the radar detection area, the radar reflection wave intensity data at the position of the target to be measured is different from that at other positions, which is then reflected as the pixel point values at the corresponding position of the target to be measured on the radar map being different from those at other positions. Based on this, the position of the target to be measured can be determined according to the radar map. Further, obtain at least two radar maps to determine multiple positions passed by the target to be measured, and determine the navigation speed and navigation direction of the target to be measured based on the multiple positions passed by the target to be measured. Exemplarily, the track data can be expressed as (id n , x n , y n , vx n , vy n ), where id n represents the nth target to be measured, x n represents the abscissa of the target to be measured, y n represents the ordinate of the target to be measured, vx n represents the navigation speed of the target to be measured in the x direction, and vy n represents the navigation speed of the target to be measured in the y direction. Obviously, the higher the acquisition frequency of the radar map, the more accurate the track data, which is beneficial to determining the heading of the target to be measured in subsequent steps.

[0041] S120. If it is determined based on the track data of the target to be measured that the distance between the target to be measured and the stationary watercraft is greater than a first preset distance and less than a second preset distance, then determine whether the heading of the target to be measured is towards the stationary watercraft according to the track data.

[0042] Among them, the first preset distance is less than the second preset distance. The specific values of the first preset distance and the second preset distance can be determined according to the actual situation, and the embodiments of the present application do not limit this. The heading can be the navigation direction of the target to be measured, and its heading can be determined according to the track data of the target to be measured.

[0043] Exemplarily, as Figure 2 shown, the first preset distance can be r, which can be adaptively determined according to the length of the stationary watercraft. The second preset distance can be R. If the distance between the target to be measured and the stationary watercraft is greater than the first preset distance and less than the second preset distance, there may be a collision risk, and it is necessary to determine whether the heading of the target to be measured is towards the stationary watercraft. Exemplarily, the distance L between the target to be measured and the stationary watercraft can be obtained from the track data, and the formula is:

[0044] In the embodiments of the present application, optionally, determining whether the heading of the target to be measured is towards the stationary watercraft according to the track data includes steps A1 - A3:

[0045] Step A1, according to the track data, determine the track points of the target to be measured, and determine the reference vector of the track points of the target to be measured pointing to the stationary watercraft.

[0046] Step A2, determine the component of the reference vector along the first direction and the component along the second direction, and determine the component of the heading of the target to be measured along the first direction and the component along the second direction; wherein, the first direction and the second direction are perpendicular.

[0047] Step A3, if the component of the reference vector along the first direction is in the same direction as the component of the heading of the target to be measured along the first direction, and the component of the reference vector along the second direction is in the same direction as the component of the heading of the target to be measured along the second direction, then determine that the heading of the target to be measured is towards the stationary watercraft.

[0048] Among them, the track point can be the latest position point of the target to be measured. The direction of the reference vector can be the direction from the track point of the target to be measured to the stationary watercraft. Exemplarily, as Figure 3As shown in the figure, the first direction may be the x-axis direction in the Cartesian coordinate system, and the second direction may be the y-axis direction in the Cartesian coordinate system. If the track point of the target to be measured is in the first quadrant, the component of the reference vector along the first direction is less than 0, and the component of the reference vector along the second direction is less than 0. At this time, if the component of the heading of the target to be measured along the first direction is less than 0 and the component along the second direction is less than 0, it is determined that the heading of the target to be measured is towards the stationary watercraft. Similarly, the judgment methods for the remaining quadrants are the same as those for the first quadrant, and will not be elaborated in the embodiments of the present application. It should be noted that if the track point is on the x-axis or y-axis, if the heading of the target to be measured is in the same direction as the reference vector, it is determined that the heading of the target to be measured is towards the stationary watercraft.

[0049] S130. If the heading of the target to be measured is towards the stationary watercraft, determine the heading line information of the target to be measured according to the track data of the target to be measured, and predict the relative position relationship between the target to be measured and the stationary watercraft according to the heading line information.

[0050] Among them, the heading line information can reflect the future sailing track of the target to be measured, and its heading line information can be estimated according to the track data of the target to be measured. The relative position relationship can reflect whether the target to be measured will affect the safety of the stationary water target in the future. For example, if the heading line information reflects that the target to be measured will collide with the stationary water target, the relative position relationship may be a collision relationship; if the heading line information reflects that the target to be measured will move away from the stationary water target, the relative position relationship may be a non-collision relationship.

[0051] Specifically, since the heading of the target to be measured is towards the stationary water target, it may cause safety accidents such as ship collisions. It is necessary to estimate its heading line information according to the track data of the target to be measured, and then predict the relative position relationship between the target to be measured and the stationary water target to avoid the occurrence of safety accidents.

[0052] In the embodiments of the present application, optionally, determining the heading line information of the target to be measured according to the track data of the target to be measured, and predicting the relative position relationship between the target to be measured and the stationary watercraft includes: determining whether the heading line passes through the range of a circle with the stationary watercraft as the center and a first preset distance as the radius according to the heading line information of the target to be measured; if so, determining that the target to be measured is heading towards the stationary watercraft.

[0053] In this solution, a safety area is demarcated with a stationary watercraft as the center and a first preset distance as the radius. If the course line of the target to be measured passes through the circular range with the first preset distance as the radius, it indicates that the target to be measured is very likely to collide with the stationary watercraft, and it can be determined that the target to be measured is approaching the stationary watercraft. In this solution, through the circular range with the first preset distance as the radius, it is ensured that the course line of the target to be measured approaching the stationary watercraft from any direction can be recognized, improving the safety of the stationary watercraft.

[0054] In the technical solution of the embodiment of the present application, an echo signal obtained by detecting with a radar on a stationary watercraft is used to determine a radar map, and track data of the target to be measured is determined according to the radar map; if it is determined according to the track data of the target to be measured that the distance between the target to be measured and the stationary watercraft is greater than a first preset distance and less than a second preset distance, then according to the track data, it is determined whether the course of the target to be measured is towards the stationary watercraft; if the course of the target to be measured is towards the stationary watercraft, then according to the track data of the target to be measured, the course line information of the target to be measured is determined, and the relative position relationship between the target to be measured and the stationary watercraft is predicted according to the course line information. This technical solution detects the target to be measured through radar, making the detection range not limited by weather, and the detection efficiency is higher than that of manual observation, achieving accurate detection of water targets and improving the safety of operating watercraft.

[0055] Embodiment 2

[0056] Figure 4 It is a flowchart of a method for detecting water targets based on a radar map provided in Embodiment 2 of the present application, and the embodiment of the present application is optimized based on the above embodiment.

[0057] As Figure 4 shown, the method of the embodiment of the present application specifically includes the following steps:

[0058] S210, according to an echo signal obtained by detecting with a radar on a stationary watercraft, determine a radar map, and determine track data of the target to be measured according to the radar map.

[0059] S220, if it is determined according to the track data of the target to be measured that the distance between the target to be measured and the stationary watercraft is greater than a first preset distance and less than a second preset distance, then according to the track data, determine whether the course of the target to be measured is towards the stationary watercraft.

[0060] S230, determine the slope of the course line of the target to be measured according to the track data of the target to be measured.

[0061] Specifically, according to the track data of the target to be measured, the sailing direction of the target to be measured at the track point is determined. This sailing direction is close to the sailing direction of the target ship in the next period of time, so this sailing direction is used as the slope of the course line of the target to be measured.

[0062] S240. According to the slope of the course line and the slope of the safe course line, determine whether the course line passes through the range of the circle with the stationary ship on the water as the center and the first preset distance as the radius.

[0063] Among them, as Figure 5 shown, the slope of the safe course line is the tangent slope of the circle with the stationary ship on the water as the center and the first preset distance as the radius passing through the track point. Specifically, as Figure 5 shown, there are two slopes of the safe course line, that is, there are two safe course lines. If the course line is between the two safe course lines, it means that the course line will pass through the range of the circle with the first preset distance as the radius.

[0064] In the embodiment of the present application, optionally, the tangents of the circle with the stationary ship on the water as the center and the first preset distance as the radius passing through the track point include a first tangent and a second tangent; the coordinate system where the track point is located is a rectangular coordinate system with the stationary ship on the water as the origin; according to the slope of the course line and the slope of the safe course line, determining whether the course line passes through the range of the circle with the stationary ship on the water as the center and the first preset distance as the radius includes Case 1 and Case 2:

[0065] Case 1. In the case where the first tangent does not exist, if the ordinate of the track point is not zero, when any of the following conditions is met, it is determined that the course line passes through the range of the circle with the stationary ship on the water as the center and the first preset distance as the radius: the slope of the second tangent is greater than or equal to zero, and the slope of the course line is greater than or equal to the slope of the second tangent; the slope of the second tangent is less than zero, and the slope of the course line is less than or equal to the slope of the second tangent.

[0066] In this solution, as Figure 6 shown, the first tangent of the target to be measured A does not exist. Exemplarily, let the slope of the course line be k, then

[0067]

[0068] Among them, vy n is the sailing speed of the target to be measured in the y direction at the track point, and vx n is the sailing speed of the target to be measured in the x direction at the track point.

[0069] Let the slope of the second tangent be k3, then

[0070]

[0071] Among them, sign() is the sign function, and sign(x n ) represents taking the positive or negative sign of x, r is the first preset distance, and x n represents the abscissa of the track point, and y n represents the ordinate of the track point.

[0072] If the following conditions are met, it is determined that the course line passes through the range of the circle with the stationary watercraft as the center and the first preset distance as the radius:

[0073]

[0074] Case 2, in the case where both the first tangent line and the second tangent line exist, when any of the following conditions is met, it is determined that the course line passes through the range of the circle with the stationary watercraft as the center and the first preset distance as the radius: If the product of the slopes of the first tangent line and the second tangent line is greater than zero, the slope of the course line is greater than or equal to the minimum value of the slopes of the first tangent line and the second tangent line and less than or equal to the maximum value of the slopes of the first tangent line and the second tangent line; if the product of the slopes of the first tangent line and the second tangent line is less than zero, the slope of the course line is less than or equal to the minimum value of the slopes of the first tangent line and the second tangent line, or greater than or equal to the maximum value of the slopes of the first tangent line and the second tangent line.

[0075] Exemplarily, the target to be measured B is as shown in Figure 6 . Denote the minimum value of the slopes of the first tangent line and the second tangent line as k1, and the maximum value of the slopes of the first tangent line and the second tangent line as k2, then:

[0076]

[0077]

[0078] If the following conditions are met, it is determined that the course line passes through the range of the circle with the stationary watercraft as the center and the first preset distance as the radius:

[0079]

[0080] S250, if it is determined that the course line passes through the range of the circle with the stationary watercraft as the center and the first preset distance as the radius, it is determined that the target to be measured is heading towards the stationary watercraft.

[0081] The technical solution of the embodiment of the present application determines a radar map based on the echo signal obtained by detecting with a radar on a stationary watercraft, and determines the track data of a target to be measured according to the radar map; if it is determined according to the track data of the target to be measured that the distance between the target to be measured and the stationary watercraft is greater than a first preset distance and less than a second preset distance, then according to the track data, it is determined whether the course of the target to be measured is towards the stationary watercraft; according to the track data of the target to be measured, the slope of the course line of the target to be measured is determined; according to the slope of the course line and the slope of the safe course line, it is determined whether the course line passes through the range of a circle with the stationary watercraft as the center and a first preset distance as the radius. If so, it is determined that the target to be measured is heading towards the stationary watercraft. By comparing the slope of the course line and the slope of the safe course line, this technical solution accurately determines whether the course line passes through the range of a circle with the stationary watercraft as the center and a first preset distance as the radius, and obtains the relative position relationship between the target to be measured and the stationary watercraft.

[0082] Embodiment III

[0083] Figure 7 The flowchart of a method for detecting a water target based on a radar map provided by Embodiment III of the present application is optimized based on the above embodiment.

[0084] As Figure 7 shown, the method of the embodiment of the present application specifically includes the following steps:

[0085] S310, according to the intensity data of the echo signals at adjacent position points with equal distances from the radar in adjacent detection directions of the radar, perform intensity interpolation between the adjacent position points to determine the intensity data at the interpolation position points with equal distances from the radar.

[0086] The technical solution of the embodiment of the present application detects a target with a radar. The position of the radar is as Figure 8 shown, and it can be a single-transmitter and single-receiver mechanical scanning millimeter-wave radar. The radar rotates around the center and continuously transmits and receives frequency-modulated radio waves. Among them, the diverging dotted lines emitted from the radar are the detection signals of the radar. The directions corresponding to two adjacent detection signals are adjacent detection directions, and the adjacent position points are the points with equal distances from the radar in adjacent detection directions, as Figure 9Points A and B in it. The reflected echo is the echo that returns after the detection signal emitted by the radar is reflected and is received by the radar. The intensity data of the reflected echo can be detected by the radar. The intensity data of the reflected echo corresponding to a certain position in the environment can reflect whether there is a target at that position, and information such as the position, size, and shape of the target can be determined according to the intensity data of the reflected echo. The detection direction of the radar each time it emits a detection signal can be characterized by the azimuth angle. The azimuth angle of a detection direction can be the horizontal angle from the north-pointing line of the radar in the clockwise direction to the detection direction. When the radar detects each azimuth angle, at each position point with a different distance from the radar at that azimuth angle, an intensity data of a reflected echo is correspondingly obtained. Each azimuth angle corresponds to multiple intensity data, obtaining one-dimensional intensity data. When the radar rotates and sweeps a full circle, two-dimensional intensity data corresponding to each position point represented in polar coordinates can be formed.

[0087] In the embodiment of the present application, different weights can be selected according to the intensity data of adjacent position points to determine the intensity data at the interpolation position point. For example, the intensities of adjacent position points are S A and S B , and their weights are ω1 and ω2 respectively. The intensity data at the interpolation position point is S C , then S C =S A ×ω1 + S B ×ω2.

[0088] In the embodiment of the present application, S310 is optimized. According to the intensity data of the reflected echo at adjacent position points with the same distance from the radar in adjacent detection directions of the radar, intensity interpolation is performed between the adjacent position points to determine the intensity data at the interpolation position points with the same distance from the radar, including: performing intensity interpolation on the concentric circular arc with the adjacent position points as endpoints to obtain the interpolation position point; the concentric circular arc is a circular arc with the radar as the center and the distance from the radar to the adjacent position point as the radius; taking the ratio of the length of the concentric circular arc from the first position point to the interpolation position point among the adjacent position points to the length of the concentric circular arc between the adjacent position points as the first weight value of the intensity data of the second position point among the adjacent position points; taking the ratio of the length of the concentric circular arc from the second position point to the interpolation position point among the adjacent position points to the length of the concentric circular arc between the adjacent position points as the second weight value of the intensity data of the first position point among the adjacent position points; and performing weighted summation on the intensity data of the adjacent position points according to the first weight value and the second weight value as the intensity data of the interpolation position point.

[0089] Specifically, an interpolation method in the embodiment of the present application: Performing intensity interpolation between adjacent position points can be to perform interpolation on the circular arc with the radar as the center and the adjacent position points as endpoints to obtain the interpolation position point. For example Figure 10As shown. The interpolation position points C and D are obtained by interpolation on the The intervals between the interpolation position points can be equal or unequal. As Figure 10 shown, points A and B are adjacent position points, and points C and D are interpolation position points and are located between points A and B. The distances from A, B, C, and D to the radar are the same. Then the intensity data of point C the intensity data of point D

[0090] Exemplarily, the intensity data of the reflected echoes at different distance position points from the radar in the same detection direction of the radar are used as the row elements of the matrix, and the intensity data of the reflected echoes at the same distance position points from the radar in different detection directions of the radar are used as the column elements of the matrix to construct the initial matrix.

[0091] In the embodiments of the present application, since the intensity data of the interpolation position points are calculated from the intensity data of the adjacent position points, the intensity data of the reflected echoes at different distance position points from the radar in the same detection direction of the radar are used as the row elements of the matrix. According to the change order of the radar detection directions, the second row, the third row, the fourth row, etc. of the initial matrix are formed in sequence. The intensity data of each detection direction is denoted as the sequence {a n′ |n′∈[1,N]}, a n′ represents the intensity data at a distance of n′×δ meters from the radar, where N is the number of samples and δ is the range resolution of the radar. Each row represents the intensity data of the position points with increasing distances from the radar in the same detection direction of the radar, each column represents the intensity data of the position points with the same distance from the radar in different detection directions, the detection directions corresponding to the adjacent elements in each column are adjacent detection directions, and the detection directions corresponding to the first column element and the last column element are adjacent detection directions. Among them, the initial matrix A is as follows:

[0092]

[0093] Among them, M represents the number of radar detection directions, and N represents the number of samples, that is, the number of intensity data obtained in the same detection direction of the radar. a 11 represents the intensity data of the position point closest to the radar in the initial detection direction of the radar, a 12 represents the intensity data of the second position point whose distance from the radar is greater than a 11 in the initial detection direction of the radar, a 21 represents the intensity data of the position point closest to the radar in the second detection direction of the radar, a 31 represents the intensity data of the position point closest to the radar in the third detection direction of the radar, and so on.

[0094] Further, intensity interpolation is performed according to the column elements in the same column of the initial matrix to obtain an interpolation matrix, and intensity data at an interpolation position point equal to the radar distance is determined according to the interpolation matrix.

[0095] Exemplarily, the size of the initial matrix is M×N. If one interpolation position point is inserted between adjacent position points, the size of the interpolation matrix is 2M×N. If two interpolation position points are inserted between adjacent position points, the size of the interpolation matrix is 3M×N. The embodiments of the present application do not limit the number of interpolations. In the embodiments of the present application, the intensity data of the interpolation position points is calculated according to the intensity data of adjacent position points. In the initial matrix, every two adjacent matrix elements in each column are the intensity data of adjacent position points. For example, a 31 and a 41 are adjacent matrix points. It should be noted that in the same column of the initial matrix, the first element and the last element are adjacent position points.

[0096] In the embodiments of the present application, the position points equal to the radar distance are equally spaced; intensity interpolation is performed according to the column elements in the same column of the initial matrix to obtain an interpolation matrix, including:

[0097] Based on the following formula, equal-interval intensity interpolation is performed according to the column elements in the same column of the initial matrix, and the value of each element in the interpolation matrix can be determined:

[0098]

[0099] where b ij represents the value of the element in the i-th row and j-th column of the interpolation matrix, represents the initial matrix, represents rounding down, % represents the modulo operation, T represents the number of interpolation position points between adjacent position points plus one, and M represents the number of detection directions when the radar scans one week. It should be noted that b ij determined by the above formula may not be an integer. Therefore, in order to make each element in the interpolation matrix an integer, b ij can be rounded to an integer, or rounded up or down. The specific rounding method is not limited. In addition, if the intensity data has not been normalized in the previous execution process, this data can also be normalized to [0, 255] and then rounded.

[0100] In this solution, to facilitate the calculation of the intensity data of the interpolation position points, the position points equal to the radar distance are set to be equally spaced, that is, as Figure 10 shown, A and B are adjacent position points, C and D are interpolation position points, and the distances from A, B, C, and D to the radar are equal. Then the length of is equal to the length of is equal to Length.

[0101] Specifically, if interpolation is performed as Figure 10 shown, the interpolation matrix can be determined as:

[0102]

[0103] S320, determine the position points corresponding to each pixel point in the radar map.

[0104] Among them, the position points include the position points corresponding to each intensity data after intensity interpolation.

[0105] In the embodiments of the present application, determining the position points corresponding to each pixel point in the radar map includes: setting the radar as the image center of the radar map, and converting the pixel coordinates of each pixel point in the radar map into Cartesian coordinates according to the corresponding positions of the actual area scanned by the radar and the pixels of the radar map; determining the polar coordinates corresponding to each pixel point according to the conversion relationship between Cartesian coordinates and polar coordinates; and determining the position points corresponding to each pixel point in the radar map according to the position points corresponding to the polar coordinates.

[0106] Exemplarily, it is set that the radar map F includes P rows and Q columns of pixel points, then

[0107]

[0108] where f pq represents the pixel gray value at the position (p, q), F can be mapped to a rectangular area of PΔ×QΔ, where each pixel corresponds to a square area with a side length of Δ meters in the actual space. For example, if F includes 3000 rows and 2000 columns of pixel points, and if F is mapped to a radar detection area of 600×400 meters, then each pixel corresponds to a square area with a side length of 0.2 meters. In the embodiments of the present application, P and Q can be taken as odd numbers to set the radar position at the center of the radar map.

[0109] Specifically, if the radar position is set at the center of the radar map, the pixel point (p, q) is converted to the Cartesian coordinate system as:

[0110]

[0111] According to the above formula, the Cartesian coordinates corresponding to each pixel point can be obtained. According to the conversion relationship between Cartesian coordinates and polar coordinates, the polar coordinates corresponding to each pixel point can be determined. The conversion relationship is as follows:

[0112]

[0113]

[0114] (γ,θ) is the polar coordinate, and || represents the relationship of "or". By operating on each pixel point through the above formula, the corresponding polar coordinate of each pixel point can be obtained. According to the position points corresponding to the polar coordinates, the position points corresponding to each pixel point in the radar map can be determined. For example, if the polar coordinate is (10, 0°), the position point corresponding to this polar coordinate is: the position 10 meters away from the radar in the initial detection direction of the radar.

[0115] S330. Determine the gray value of the radar image pixel point corresponding to each position point according to the intensity data of each position point, and generate a radar map according to the gray value.

[0116] In the embodiment of the present application, the position points include adjacent position points before interpolation and interpolation position points after interpolation. Correspondingly, the intensity data includes the intensity data of adjacent position points before interpolation and the intensity data of interpolation position points after interpolation. After determining the position points corresponding to each pixel point in the radar map, the gray value of each pixel point can be determined according to the intensity data of the position points, and then the radar map can be drawn according to the gray value. The target can be various objects in the radar detection area, including but not limited to fishing boats, yachts, water signs, etc.

[0117] Based on the following formula, determine the gray value of the radar image pixel point:

[0118]

[0119] where f pq represents the gray value of the pixel point with pixel coordinates (p, q) in the radar map, round represents rounding to the nearest integer, θ represents the azimuth angle of the current detection direction, θ1 represents the azimuth angle of the initial detection direction, σ represents the deflection angle between two adjacent position points with the same distance from the radar after intensity interpolation, γ represents the distance between the position point and the radar, and δ represents the minimum detection distance of the radar. Exemplarily, if no interpolation is performed, if the number of interpolation position points between adjacent position points is 2, then It should be noted that before determining the gray value of the radar image pixel point according to the above formula, b ij needs to be normalized to between [0, 255] to represent the gray value.

[0120] S340. Determine the track data of the target to be measured according to the radar map.

[0121] S350. If it is determined according to the track data of the target to be measured that the distance between the target to be measured and the stationary ship on the water is greater than the first preset distance and less than the second preset distance, then determine whether the heading of the target to be measured is towards the stationary ship on the water according to the track data.

[0122] S360. If the heading of the target to be measured faces the stationary watercraft, determine the heading line information of the target to be measured according to the track data of the target to be measured, and predict the relative position relationship between the target to be measured and the stationary watercraft according to the heading line information.

[0123] In the technical solution of the embodiment of the present application, according to the intensity data of the reflected echoes at adjacent position points with equal distances from the radar in adjacent detection directions of the radar, intensity interpolation is performed between the adjacent position points to determine the intensity data at the interpolation position points with equal distances from the radar; determine the position points corresponding to each pixel point in the radar map, and according to the intensity data of each position point, determine the gray value of the radar image pixel point corresponding to each position point, and generate a radar map according to the gray value. This technical solution obtains the intensity data of the interpolation position points through interpolation between adjacent position points, expands the number of position points detected by the radar and the number of intensity data, determines the gray value of the corresponding radar image pixel point according to the intensity data of each position point, quickly draws a radar map for target detection, realizes target detection in areas not detected by the radar, and improves the accuracy of target detection.

[0124] Embodiment 4

[0125] Figure 11 It is a flowchart of a method for detecting water targets based on a radar map provided by Embodiment 4 of the present application. The embodiment of the present application is optimized based on the above embodiment.

[0126] As Figure 11 shown, the method of the embodiment of the present application specifically includes the following steps:

[0127] S410. Determine a radar map according to the echo signal detected by the radar on the stationary watercraft.

[0128] S420. For the pixel point to be recognized in the radar map, determine the target detection position point corresponding to the pixel point to be recognized in the radar detection area and the preset signal intensity probability distribution model corresponding to the radar when scanning at the target detection position point.

[0129] Among them, the pixel point to be recognized can be the pixel point that needs to be detected in the radar map. The target detection position point can be the detection position in the radar detection area corresponding to the pixel point to be recognized in the radar map, and there is a one-to-one correspondence between each pixel point in the radar map and each target detection position point in the radar detection area.

[0130] Specifically, the radar detection area is scanned by radar, and a radar map of the radar detection area is obtained. Then, the target detection position points corresponding to each pixel point to be recognized in the radar map in the radar detection area are determined to ensure the accuracy of the pixel points in the radar map and the corresponding target detection point positions. Furthermore, it is ensured that the subsequent analysis and processing of the pixel points to be recognized can be accurately corresponding to the positions of the target detection position points, facilitating the processing of the target detection position points. At the same time, the preset signal intensity probability distribution model corresponding to the target detection position points needs to be determined to facilitate the subsequent determination of the probability distribution type corresponding to the pixel points to be recognized.

[0131] S430, detecting the matching result between the value of the pixel point to be recognized and the preset signal intensity probability distribution model corresponding to the target detection position point, where the preset signal probability distribution model is used to describe the signal intensity probability distribution of the radar echo signal when scanning the target detection position point in the case that the foreground is not included in the radar detection area.

[0132] Specifically, after obtaining the radar map, the value of the pixel point to be recognized in the radar map is brought into each normal distribution model in the preset signal intensity probability distribution model to determine whether the value of the pixel point to be recognized is adapted to the preset signal intensity probability distribution model. As long as it conforms to one of the normal distribution models in the preset signal intensity probability distribution model, the value of the pixel point to be recognized is adapted to the preset signal intensity probability distribution model.

[0133] In a feasible embodiment, detecting the matching result between the value of the pixel point to be recognized and the preset signal intensity probability distribution model corresponding to the target detection position point may include the following steps B1 - B3:

[0134] Step B1, detecting whether the value of the pixel point to be recognized and at least one normal distribution model in the preset signal intensity probability distribution model corresponding to the target detection position point satisfy the preset matching condition; where the preset matching condition includes that the value of the pixel point to be recognized and the mean value of the normal distribution model satisfy the preset Pauta criterion.

[0135] Step B2, if there is at least one normal distribution model that satisfies the preset matching condition, it is determined that the pixel point to be recognized in the radar map belongs to the background pixel.

[0136] Step B3, if there is no normal distribution model that satisfies the preset matching condition, it is determined that the pixel point to be recognized in the radar map belongs to the foreground pixel.

[0137] Among them, the preset matching condition can be used to determine whether the value of the pixel point to be recognized satisfies at least one normal distribution model in the preset signal intensity probability distribution model corresponding to the target detection position point. The preset Pauta criterion can be expressed by the following formula:

[0138]

[0139] In the formula, x ij is the value of the pixel point to be recognized, is the mean in the preset signal intensity probability distribution model corresponding to the target detection position point, is the variance in the preset signal intensity probability distribution model corresponding to the target detection position point.

[0140] Specifically, a radar map is obtained by scanning the radar detection area with a radar, and the value of the pixel point to be recognized in the radar map is input into the preset signal intensity probability distribution model corresponding to the target detection position point, and it is determined whether at least one normal distribution model in the preset signal intensity probability distribution model corresponding to the target detection position point meets the preset matching condition. If there is at least one normal distribution model that meets the preset matching condition, it is determined that the pixel point to be recognized belongs to the background pixel in the radar map; if there is no normal distribution model that meets the preset matching condition, it is determined that the pixel point to be recognized belongs to the foreground pixel in the radar map.

[0141] S440. According to the matching result, the foreground and background in the radar map are separated, and based on the separated foreground image, the pixel area of the target to be measured is determined.

[0142] Specifically, the values of each pixel point to be recognized in the radar map are input into the preset signal intensity probability distribution model corresponding to each target detection position point. By determining whether at least one normal distribution model in the preset signal intensity probability distribution model corresponding to the target detection position point meets the preset matching condition, it is determined whether each pixel point to be recognized belongs to the background pixel or the foreground pixel, and thus the separation of the foreground and background in the current radar image can be realized, and the separated foreground image can be obtained.

[0143] Furthermore, in addition to the target to be measured, the foreground image may include other targets, such as floating garbage on the water surface. Its contour can be detected, and based on the contour characteristics of the target to be measured, the pixel area of the target to be measured can be determined.

[0144] In another feasible embodiment of the present application, separating the foreground and background of the radar map includes: performing image difference processing on the radar map and a pre-set average background image to obtain a difference image; performing binarization processing on the difference image, and using the binarized image as the foreground image.

[0145] Among them, the average background image can be an image reflecting the state of the radar detection area without the target to be measured, and can be obtained by averaging multiple background images. The background image can be a radar image obtained when there is no target to be measured in the radar detection area. Image difference processing can be to perform a difference operation on the pixel values of two images. Binarization processing means that each pixel on the image has only two possible values or gray level states, that is, the gray value of any pixel point in the image is either 0 or 255, representing black and white respectively.

[0146] In the embodiment of the present application, the average background image avoids the problem of abnormal individual pixel points that may exist in a single background image, and improves the fault tolerance rate.

[0147] Specifically, at least two background images are obtained by using a radar. Each background image can be denoted as F, which is a grayscale image composed of P rows and Q columns, that is, there are P*Q pixel points, and the matrix representation is as follows:

[0148]

[0149] Furthermore, the gray value of each pixel point of the average background image is obtained by averaging the gray values of the corresponding pixel points of each background image. Taking the f 11 pixel point as an example, the gray value of the f 11 pixel point in the average background image is obtained by averaging the gray values of the f 11 pixel points in each background image. In this process, f 11 is the target pixel point. By traversing all the target pixel points, the average background image can be obtained. Expressed by the formula:

[0150]

[0151] Among them, F i is the grayscale image of each image in each background image. U is the number of background images.

[0152] In the embodiment of the present application, the microwave radar image and the average background image are subjected to image difference processing to obtain a difference image F Δ , which can be expressed as:

[0153]

[0154] Among them, F is the grayscale image of the microwave radar image.

[0155] Specifically, the binarization processing can be performed through the following formula:

[0156]

[0157] Among them, f ij' is the gray value of the corresponding pixel point after the binarization process of the radar image. is the gray value of the corresponding pixel point in the difference image, S is a preset gray value. The preset gray value can be the critical value when the gray value of the corresponding pixel point in the radar image is converted to 0 or 255. When the gray value of the corresponding pixel point in the radar image is greater than or equal to the preset gray value, the gray value of the corresponding pixel point is converted to 255, otherwise it is converted to 0. The preset gray value can be determined according to the actual situation, and the embodiments of the present application do not limit this.

[0158] S450, track the target to be measured according to the pixel area of the target to be measured, and determine the track data of the target to be measured.

[0159] In the embodiments of the present application, optionally, tracking the target to be measured according to the pixel area of the target to be measured and determining the track data of the target to be measured may include steps C1 - C9:

[0160] Step C1, perform morphological dilation operation on the foreground image according to the separated foreground image to obtain image A.

[0161] In the radar image, it includes the background and the target to be measured in the radar detection area. After removing the background, the foreground image can be obtained. The area in the foreground image may be misclassified into multiple small areas. Therefore, perform morphological dilation operation on the foreground image to obtain image A, which can eliminate the internal holes in the small areas or the gaps in the neighboring areas.

[0162] Step C2, perform morphological erosion operation on image A to obtain image B.

[0163] Because the area will become larger after dilation, it is necessary to perform morphological erosion operation on image A to obtain image B to restore the area to the size before dilation.

[0164] Step C3, perform Gaussian smoothing on image B to obtain image C.

[0165] There may be noise points in image B. Perform Gaussian smoothing on image B to obtain image C to eliminate some small noise points. Among them, the methods of removing noise include but are not limited to: mean filtering, Gaussian filtering, median filtering, etc.

[0166] Step C4, perform Canny edge detection on image C to obtain image D.

[0167] In this step, the outer contours of each area are obtained through edge detection.

[0168] Step C5, extract the pixel coordinates of the inflection points of the outer boundaries of each area in image D to obtain a set of pixel coordinates of the inflection points of the outer boundaries.

[0169] Let D represent the set of all pixel coordinates of the inflection points of the outer boundaries, as shown below:

[0170]

[0171] Among them, Di represents the set of pixel coordinates of the inflection points on the outer boundary of the i-th region. represents the row and column pixel subscripts of the m-th inflection point on the outer boundary of the i-th region.

[0172] In the above steps, each image processing algorithm used is an existing technology, and the specific content will not be elaborated in the embodiments of the present application.

[0173] Step C6, calculate the pixel coordinates of the geometric center of each region:

[0174]

[0175] Among them, (r i , c i ) is the pixel coordinate of the geometric center of the i-th region.

[0176] Step C7, convert the pixel coordinates of the geometric center of each region into coordinates in the Cartesian coordinate system:

[0177]

[0178] Among them, P and Q are the number of rows and columns of the radar image, and their values can be odd numbers to place the radar at the coordinate center. Δ is the width of the actual detection area corresponding to one pixel point in the radar image. Traverse each region to obtain the set X of the center coordinates of each region,

[0179] X = {(x 1 , y 1 ), (x 2 , y 2 ), …, (x n , y n )}.

[0180] Step C8, cluster the set of center coordinates of each region to obtain the clustered coordinate set X'.

[0181] Step C9, according to at least two radar images, determine the position of the target to be measured at each moment, determine the sailing speed and direction of the target to be measured, and according to the latest obtained radar image, determine the latest position of the target to be measured. Furthermore, represent the track data of one target to be measured as: (id n , x n , y n , vx n , vy n ).

[0182] S460. If it is determined, based on the track data of the target to be measured, that the distance between the target to be measured and the stationary watercraft is greater than a first preset distance and less than a second preset distance, then determine, based on the track data, whether the course of the target to be measured is towards the stationary watercraft.

[0183] S470. If the course of the target to be measured is towards the stationary watercraft, then determine the course line information of the target to be measured based on the track data of the target to be measured, and predict the relative position relationship between the target to be measured and the stationary watercraft according to the course line information.

[0184] In the technical solution of the embodiment of the present application, by detecting whether the value of the pixel point to be recognized matches the preset signal intensity probability distribution model corresponding to the target detection position point, it is determined whether the pixel point to be recognized belongs to the foreground or the background. According to the matching results of each pixel point to be recognized, the background and the foreground in the current radar image are separated to obtain a foreground image, the pixel area of the target to be measured is determined, and the target to be measured is tracked to determine the track data of the target to be measured. This technical solution quickly and accurately determines the target to be measured from the radar image, and determines the track data of the target to be measured based on at least two radar images.

[0185] Embodiment Five

[0186] Figure 12 FIG. is a schematic structural diagram of a water target detection device based on a radar image provided in Embodiment Five of the present application. This device can execute the water target detection method based on a radar image provided in any embodiment of the present invention, and has corresponding functional modules and beneficial effects for executing the method. As Figure 12 shown, the device includes:

[0187] A track data determination module 510, configured to determine a radar image according to an echo signal detected by a radar on a stationary watercraft, and determine the track data of the target to be measured according to the radar image;

[0188] A distance determination module 520, configured to, if it is determined, based on the track data of the target to be measured, that the distance between the target to be measured and the stationary watercraft is greater than a first preset distance and less than a second preset distance, then determine, based on the track data, whether the course of the target to be measured is towards the stationary watercraft;

[0189] A position relationship prediction module 530, configured to, if the course of the target to be measured is towards the stationary watercraft, then determine the course line information of the target to be measured based on the track data of the target to be measured, and predict the relative position relationship between the target to be measured and the stationary watercraft according to the course line information.

[0190] Optionally, the distance determination module 520 includes:

[0191] A track point determination unit, configured to determine track points of the target to be measured according to the track data, and determine a reference vector of the track points of the target to be measured pointing to the stationary watercraft;

[0192] A component determination unit, configured to determine a component of the reference vector along a first direction and a component along a second direction, and determine a component of the heading of the target to be measured along the first direction and a component along the second direction; wherein the first direction and the second direction are perpendicular;

[0193] A heading determination unit, configured to determine that the heading of the target to be measured is towards the stationary watercraft if the component of the reference vector along the first direction is in the same direction as the component of the heading of the target to be measured along the first direction, and the component of the reference vector along the second direction is in the same direction as the component of the heading of the target to be measured along the second direction.

[0194] Optionally, the position relationship prediction module 530 includes:

[0195] A range determination unit, configured to determine whether a heading line passes through a range within a circle centered at the stationary watercraft with a first preset distance as the radius according to the heading line information of the target to be measured;

[0196] A traveling direction determination unit, configured to determine that the target to be measured is traveling towards the stationary watercraft if so.

[0197] Optionally, the range determination unit includes:

[0198] A heading line slope determination subunit, configured to determine the slope of the heading line of the target to be measured according to the track data of the target to be measured;

[0199] A range determination subunit, configured to determine whether the heading line passes through a range within a circle centered at the stationary watercraft with a first preset distance as the radius according to the slope of the heading line and the slope of a safe heading line; wherein the slope of the safe heading line is the slope of the tangent line of the circle centered at the stationary watercraft with a first preset distance as the radius passing through the track point.

[0200] Optionally, the tangent lines of the circle centered at the stationary watercraft with a first preset distance as the radius passing through the track point include a first tangent line and a second tangent line; the coordinate system where the track point is located is a rectangular coordinate system with the stationary watercraft as the origin;

[0201] Further, the range determination subunit is specifically configured to:

[0202] In the case where the first tangent line does not exist, if the ordinate of the track point is not zero, when any of the following conditions is satisfied, it is determined that the heading line passes through a range within a circle centered at the stationary watercraft with a first preset distance as the radius:

[0203] The slope of the second tangent is greater than or equal to zero, and the slope of the course line is greater than or equal to the slope of the second tangent;

[0204] The slope of the second tangent is less than zero, and the slope of the course line is less than or equal to the slope of the second tangent;

[0205] When both the first tangent and the second tangent exist, when any of the following conditions is satisfied, it is determined that the course line passes through the range of the circle with the waterborne stationary ship as the center and the first preset distance as the radius:

[0206] If the product of the slope of the first tangent and the slope of the second tangent is greater than zero, the slope of the course line is greater than or equal to the minimum value of the slope of the first tangent and the slope of the second tangent, and less than or equal to the maximum value of the slope of the first tangent and the slope of the second tangent;

[0207] If the product of the slope of the first tangent and the slope of the second tangent is less than zero, the slope of the course line is less than or equal to the minimum value of the slope of the first tangent and the slope of the second tangent, or greater than or equal to the maximum value of the slope of the first tangent and the slope of the second tangent.

[0208] Optionally, the track data determination module 510 includes:

[0209] An interpolation unit, configured to perform intensity interpolation between adjacent position points according to the intensity data of the echo signals at adjacent position points with equal distances from the radar in adjacent detection directions of the radar, and determine the intensity data at the interpolation position points with equal distances from the radar;

[0210] A position point determination unit, configured to determine the position points corresponding to each pixel point in the radar map; wherein, the position points include the position points corresponding to each intensity data after intensity interpolation;

[0211] A radar map generation unit, configured to determine the gray values of the radar image pixels corresponding to each position point according to the intensity data of each position point, and generate a radar map according to the gray values.

[0212] Optionally, the interpolation unit includes:

[0213] An interpolation subunit, configured to perform intensity interpolation on the concentric arc with the adjacent position points as endpoints to obtain interpolation position points; the concentric arc is an arc with the radar as the center and the distance from the radar to the adjacent position points as the radius;

[0214] A first weight value determination subunit, configured to use the ratio of the length of the concentric arc from the first position point to the interpolation position point among the adjacent position points to the length of the concentric arc between the adjacent position points as the first weight value of the intensity data of the second position point among the adjacent position points;

[0215] A second weight value determining subunit, configured to use the ratio of the concentric arc length from the second position point to the interpolation position point among adjacent position points to the concentric arc length between adjacent position points as the second weight value of the intensity data of the first position point among adjacent position points;

[0216] An intensity data determining subunit, configured to perform weighted summation on the intensity data of adjacent position points according to the first weight value and the second weight value, and use the result as the intensity data of the interpolation position point.

[0217] Optionally, the track data determining module 510 includes:

[0218] A model determining unit, configured to, for a pixel point to be recognized in a radar map, determine a target detection position point corresponding to the pixel point to be recognized in the radar detection area and a preset signal intensity probability distribution model corresponding to the radar scan at the target detection position point;

[0219] A matching result detecting unit, configured to detect a matching result between the value of the pixel point to be recognized and the preset signal intensity probability distribution model corresponding to the target detection position point, where the preset signal probability distribution model is used to describe the signal intensity probability distribution of the radar echo signal when scanning the target detection position point in the case that the foreground is not included in the radar detection area;

[0220] A separating unit, configured to separate the foreground and the background in the radar map according to the matching result, and determine a pixel area of the target to be measured according to the separated foreground image;

[0221] A track data determining unit, configured to track the target to be measured according to the pixel area of the target to be measured, and determine the track data of the target to be measured.

[0222] The water target detection device based on a radar map provided by an embodiment of the present application can execute the water target detection method based on a radar map provided by any embodiment of the present invention, and has corresponding functional modules and beneficial effects for executing the method.

[0223] Embodiment Six

[0224] Figure 13FIG. shows a schematic structural diagram of an electronic device 10 that can be used to implement an embodiment of the present invention. The electronic device is intended to represent various forms of digital computers, such as, for example, laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as, for example, personal digital processors, cellular phones, smart phones, wearable devices (such as helmets, glasses, watches, etc.) and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the present invention described and / or claimed herein.

[0225] As Figure 13 shown, the electronic device 10 includes at least one processor 11, and a memory communicatively connected to the at least one processor 11, such as a read-only memory (ROM) 12, a random access memory (RAM) 13, etc., wherein the memory stores a computer program executable by the at least one processor. The processor 11 can perform various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 12 or the computer program loaded from the storage unit 18 into the random access memory (RAM) 13. In the RAM 13, various programs and data required for the operation of the electronic device 10 can also be stored. The processor 11, the ROM 12, and the RAM 13 are connected to each other via a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0226] A plurality of components in the electronic device 10 are connected to the I / O interface 15, including: an input unit 16, such as a keyboard, a mouse, etc.; an output unit 17, such as various types of displays, speakers, etc.; a storage unit 18, such as a magnetic disk, an optical disk, etc.; and a communication unit 19, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 19 allows the electronic device 10 to exchange information / data with other devices via a computer network such as the Internet and / or various telecommunication networks.

[0227] The processor 11 can be various general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of the processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. The processor 11 executes the various methods and processes described above, such as the method for detecting water targets based on a radar chart.

[0228] In some embodiments, the method for detecting water targets based on a radar chart can be implemented as a computer program tangibly embodied in a computer-readable storage medium, such as storage unit 18. In some embodiments, part or all of the computer program can be loaded and / or installed onto the electronic device 10 via the ROM 12 and / or the communication unit 19. When the computer program is loaded into the RAM 13 and executed by the processor 11, one or more steps of the method for detecting water targets based on a radar chart described above can be executed. Alternatively, in other embodiments, the processor 11 can be configured to execute the method for detecting water targets based on a radar chart by any other suitable means (e.g., by means of firmware).

[0229] The various embodiments of the systems and techniques described above in this document can be implemented in digital electronic circuitry, integrated circuit systems, field programmable gate arrays (FPGA), application specific integrated circuits (ASIC), application specific standard products (ASSP), systems on a chip (SOC), complex programmable logic devices (CPLD), computer hardware, firmware, software, and / or combinations thereof. These various embodiments can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special-purpose or general-purpose programmable processor that receives data and instructions from a storage system, at least one input device, and at least one output device, and transmits the data and instructions to the storage system, the at least one input device, and the at least one output device.

[0230] The computer programs for implementing the methods of the present invention can be written in any combination of one or more programming languages. These computer programs can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when the computer programs are executed by the processor, the functions / operations specified in the flowcharts and / or block diagrams are implemented. The computer programs can be executed entirely on the machine, partially on the machine, as a stand-alone software package partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0231] In the context of the present invention, a computer-readable storage medium can be a tangible medium that can contain or store a computer program for use by or in connection with an instruction execution system, apparatus, or device. The computer-readable storage medium can include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. Alternatively, the computer-readable storage medium can be a machine-readable signal medium. More specific examples of the machine-readable storage medium would include an electrical connection based on one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0232] To provide for interaction with a user, the systems and techniques described herein can be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and a pointing device (e.g., a mouse or a trackball) by which the user can provide input to the electronic device. Other kinds of devices can also be used to provide for interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including acoustic input, voice input, or tactile input).

[0233] The systems and techniques described herein can be implemented in a computing system that includes back-end components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes front-end components (e.g., a user computer having a graphical user interface or a web browser through which the user can interact with an implementation of the systems and techniques described herein), or a computing system that includes any combination of such back-end components, middleware components, or front-end components. The components of the system can be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: local area network (LAN), wide area network (WAN), blockchain network, and the Internet.

[0234] A computing system may include a client and a server. The client and the server are generally far from each other and usually interact via a communication network. The client-server relationship is created by computer programs running on respective computers and having a client-server relationship with each other. The server may be a cloud server, also known as a cloud computing server or a cloud host, which is a host product in the cloud computing service system, solving the defects of difficult management and weak business scalability existing in traditional physical hosts and VPS services.

[0235] It should be understood that various forms of the processes shown above can be used, with steps reordered, added, or deleted. For example, the steps recited in the present invention can be executed in parallel, sequentially, or in a different order, as long as the desired results of the technical solution of the present invention can be achieved, and no limitation is imposed herein.

[0236] The above specific embodiments do not constitute a limitation on the protection scope of the present invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for detecting water targets based on a radar chart, characterized in that The method includes: Determining a radar map based on an echo signal detected by a radar on a stationary watercraft, and determining track data of a target to be measured according to the radar map; If, according to the track data of the target to be measured, it is determined that the distance between the target to be measured and the stationary watercraft is greater than a first preset distance and less than a second preset distance, then according to the track data, determining whether the course of the target to be measured is towards the stationary watercraft; If the course of the target to be measured is towards the stationary watercraft, then determining course line information of the target to be measured according to the track data of the target to be measured, and predicting a relative position relationship between the target to be measured and the stationary watercraft according to the course line information; Among them, determining whether the course of the target to be measured is towards the stationary watercraft according to the track data includes: Determining a track point of the target to be measured according to the track data, and determining a reference vector of the track point of the target to be measured pointing to the stationary watercraft; Determining a component of the reference vector in a first direction and a component in a second direction, and determining a component of the course of the target to be measured in the first direction and a component in the second direction; wherein, the first direction and the second direction are perpendicular; If the component of the reference vector in the first direction is in the same direction as the component of the course of the target to be measured in the first direction, and the component of the reference vector in the second direction is in the same direction as the component of the course of the target to be measured in the second direction, then determining that the course of the target to be measured is towards the stationary watercraft.

2. The method according to claim 1, wherein Determining course line information of the target to be measured according to the track data of the target to be measured, and predicting a relative position relationship between the target to be measured and the stationary watercraft according to the course line information includes: Determining whether the course line passes through a range within a circle with the stationary watercraft as the center and a first preset distance as the radius according to the course line information of the target to be measured; If so, determining that the target to be measured is approaching the stationary watercraft.

3. The method according to claim 2, wherein Determining whether the course line passes through a range within a circle with the stationary watercraft as the center and a first preset distance as the radius according to the course line information of the target to be measured includes: Determining a slope of the course line of the target to be measured according to the track data of the target to be measured; Determining whether the course line passes through a range within a circle with the stationary watercraft as the center and a first preset distance as the radius according to the slope of the course line and a safe course line slope; wherein, the safe course line slope is the slope of a tangent line to the circle with the stationary watercraft as the center and a first preset distance as the radius passing through the track point.

4. The method according to claim 3, wherein The tangent lines to the circle with the stationary watercraft as the center and a first preset distance as the radius passing through the track point include a first tangent line and a second tangent line; the coordinate system where the track point is located is a rectangular coordinate system with the stationary watercraft as the origin; Determining whether the course line passes through a range within a circle with the stationary watercraft as the center and a first preset distance as the radius according to the slope of the course line and a safe course line slope includes: In the case where the first tangent line does not exist, if the ordinate of the track point is not zero, when any of the following conditions is satisfied, it is determined that the course line passes through the range of the circle with the waterborne stationary ship as the center and the first preset distance as the radius: The slope of the second tangent line is greater than or equal to zero, and the slope of the course line is greater than or equal to the slope of the second tangent line; The slope of the second tangent line is less than zero, and the slope of the course line is less than or equal to the slope of the second tangent line; In the case where both the first tangent line and the second tangent line exist, when any of the following conditions is satisfied, it is determined that the course line passes through the range of the circle with the waterborne stationary ship as the center and the first preset distance as the radius: If the product of the slopes of the first tangent line and the second tangent line is greater than zero, the slope of the course line is greater than or equal to the minimum value of the slopes of the first tangent line and the second tangent line and less than or equal to the maximum value of the slopes of the first tangent line and the second tangent line; If the product of the slopes of the first tangent line and the second tangent line is less than zero, the slope of the course line is less than or equal to the minimum value of the slopes of the first tangent line and the second tangent line, or greater than or equal to the maximum value of the slopes of the first tangent line and the second tangent line.

5. The method according to claim 1, characterized in that, According to the echo signal detected by the radar on the waterborne stationary ship, a radar map is determined, including: According to the intensity data of the echo signals at the adjacent position points with equal distances from the radar in adjacent detection directions of the radar, intensity interpolation is performed between the adjacent position points to determine the intensity data at the interpolation position points with equal distances from the radar; Determine the position points corresponding to each pixel point in the radar map; wherein, the position points include the position points corresponding to each intensity data after intensity interpolation; According to the intensity data of each position point, determine the gray value of the radar image pixel point corresponding to each position point, and generate a radar map according to the gray value.

6. The method according to claim 5, wherein According to the intensity data of the reflected echo signals at the adjacent position points with equal distances from the radar in adjacent detection directions of the radar, intensity interpolation is performed between the adjacent position points to determine the intensity data at the interpolation position points with equal distances from the radar, including: Perform intensity interpolation on the concentric circular arc with the adjacent position points as endpoints to obtain the interpolation position points; the concentric circular arc is an arc with the radar as the center and the distance from the radar to the adjacent position points as the radius; Take the ratio of the length of the concentric circular arc from the first position point to the interpolation position point among the adjacent position points to the length of the concentric circular arc between the adjacent position points as the first weight value of the intensity data of the second position point among the adjacent position points; Take the ratio of the length of the concentric circular arc from the second position point to the interpolation position point among the adjacent position points to the length of the concentric circular arc between the adjacent position points as the second weight value of the intensity data of the first position point among the adjacent position points; According to the first weight value and the second weight value, perform weighted summation on the intensity data of the adjacent position points as the intensity data of the interpolation position point.

7. The method according to claim 1, characterized in that, According to the radar map, determine the track data of the target to be measured, including: For the pixel points to be recognized in the radar map, determine the target detection position point corresponding to the pixel points to be recognized mapped in the radar detection area and the preset signal intensity probability distribution model corresponding to the radar when scanning at the target detection position point; Detect the matching result between the value of the pixel point to be recognized and the preset signal intensity probability distribution model corresponding to the target detection position point, where the preset signal probability distribution model is used to describe the signal intensity probability distribution of the radar echo signal when scanning the target detection position point without including the foreground in the radar detection area; According to the matching result, separate the foreground and background in the radar map, and determine the pixel area of the target to be measured according to the separated foreground image; Track the target to be measured according to the pixel area of the target to be measured, and determine the track data of the target to be measured.

8. An apparatus for detecting water targets based on a radar chart, characterized in that, The device includes: A track data determination module, configured to determine a radar map according to the echo signal detected by a radar on a stationary watercraft, and determine the track data of the target to be measured according to the radar map; A distance determination module, configured to determine whether the heading of the target to be measured is towards the stationary watercraft according to the track data if it is determined according to the track data of the target to be measured that the distance between the target to be measured and the stationary watercraft is greater than a first preset distance and less than a second preset distance; A position relationship prediction module, configured to determine the heading line information of the target to be measured according to the track data of the target to be measured and predict the relative position relationship between the target to be measured and the stationary watercraft according to the heading line information if the heading of the target to be measured is towards the stationary watercraft; Wherein, the distance determination module includes: A track point determination unit, configured to determine the track point of the target to be measured according to the track data, and determine a reference vector of the track point of the target to be measured pointing to the stationary watercraft; A component determination unit, configured to determine the component of the reference vector along a first direction and the component along a second direction, and determine the component of the heading of the target to be measured along the first direction and the component along the second direction; wherein, the first direction and the second direction are perpendicular; A heading determination unit, configured to determine that the heading of the target to be measured is towards the stationary watercraft if the component of the reference vector along the first direction is in the same direction as the component of the heading of the target to be measured along the first direction, and the component of the reference vector along the second direction is in the same direction as the component of the heading of the target to be measured along the second direction.

9. An electronic device, characterized in that, The electronic device includes: At least one processor; and A memory communicatively connected to the at least one processor; wherein, The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the radar map-based water target detection method according to any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions for causing a processor to execute the radar map-based water target detection method according to any one of claims 1-7 when executed.

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