A trailer detection method and system based on radar, a vehicle

Abstract

The present invention provides a trailer detection method based on radar, comprising: presetting a detection area, dividing a number of detection units in the detection area; obtaining a point cloud in the detection unit, clustering the point cloud, and obtaining the outline of the target; when the distance between the outline and the vehicle does not change with the speed of the vehicle, identifying the target as a trailer. After adopting the above technical solution, it is possible to automatically detect whether a trailer is attached; the FOV of the radar operation is automatically adjusted according to the size of the trailer, so that the radar can still work when the trailer is attached.

Description

Technical Field

[0001] The present invention relates to the field of vehicles, and in particular to a trailer detection method and system based on radar and a vehicle. Background Art

[0002] In intelligent driving systems, millimeter-wave corner radars are widely used to sense the environment around the vehicle. For safety reasons, the corresponding fault detection system requires the radar to suppress its function when it is blocked, issue an alarm and notify the upper-level controller. However, when mounting a trailer, if the vehicle is not designed with a corresponding signal to inform the radar whether there is a trailer, the corner radar cannot determine the true status behind the vehicle, which will affect performance and even cause false alarms, seriously affecting the driver's experience. At the same time, the trailer body, which is usually made of metal materials, will cause serious mirror reflections and produce false targets. It will also block the radar's FOV (Field of View), thereby affecting the radar's detection range.

[0003] In order to solve the problem that the corner radar cannot determine whether there is a trailer by itself, the general method is to send the signal of the trailer hook (retracted / popped out) to the corner radar, or the driver manually sets the status of the external trailer on the terminal device such as the central control screen to suppress the function of the corner radar and shield the fault signal emitted by the corner radar after being blocked. However, some models did not plan to design the status signal of the trailer hook (popped out / retracted) at the beginning of the design, and it is too cumbersome for the driver to set the trailer status on the terminal device, which affects the driving experience. On the other hand, if the corner radar simply relies on the signal from the whole vehicle to determine whether there is an external trailer, it may also cause the corner radar to not work properly because the driver forgets to retract the trailer hook or forgets to change the status on the terminal device, thereby causing the driver to misjudge the actual status behind the vehicle, affecting driving safety.

[0004] In addition, the existing method for dealing with the problem of false targets caused by trailer body reflection and obstruction of the FOV of the angular radar is generally to directly turn off the detection function of the radar, but at this time, a part of the FOV of the radar is still not blocked and has the ability to work normally. If the size of the front body of the trailer can be accurately obtained, it can be processed at the software level to make full use of this part of the FOV and improve the safety performance of the vehicle when the trailer is mounted.

[0005] In summary, it is necessary to design a method for the corner radar to determine whether the vehicle is attached to a trailer and detect the size of the front part of the trailer box. This can improve the driver's experience while ensuring the driving safety of the vehicle. Through technical means, the radar can continue to work and detect the environment after the trailer is attached, thereby improving the safety of the vehicle. Summary of the invention

[0006] In order to overcome the above technical defects, the present invention provides a radar-based trailer detection method, comprising: presetting a detection area, dividing a number of detection units within the detection area; acquiring a point cloud within the detection unit, clustering the point cloud, and obtaining the contour of the target object; when the distance between the contour and the vehicle does not change with the speed of the vehicle, identifying the target object as a trailer.

[0007] Preferably, the point cloud in the detection unit is obtained, the centroid points obtained by clustering the point cloud are connected, and a filtering operation is performed to obtain the contour of the target object.

[0008] Preferably, the point cloud includes position information, angle information and signal strength information.

[0009] Preferably, the target object is identified as a trailer, and the maximum obstruction angle of the trailer is calculated based on the outline; when the maximum obstruction angle is greater than the deflectable angle of the radar field of view, the detection signal within a first angle is suppressed, and the first angle is the difference between the maximum obstruction angle and the deflectable angle.

[0010] Preferably, when the maximum blocking angle is smaller than the deflectable angle of the radar field of view, the radar is adjusted to be deflected outside the maximum blocking angle.

[0011] Another aspect of the present invention provides a radar-based trailer detection system, comprising a detection module and a control module, wherein the detection module is used to preset a detection area, divide a plurality of detection units within the detection area, and obtain a point cloud within the detection unit;

[0012] The control module is used to cluster the point cloud to obtain the outline of the target object; when the distance between the outline and the vehicle does not change with the speed of the vehicle, the target object is identified as a trailer.

[0013] Preferably, the control module is used to obtain the point cloud in the detection unit, connect the centroid points obtained by clustering the point cloud, and obtain the contour of the target object after performing a filtering operation.

[0014] Preferably, the point cloud includes position information, angle information and signal strength information.

[0015] Preferably, the control module is used to identify the target object as a trailer, and calculate the maximum obstruction angle of the trailer based on the contour; when the maximum obstruction angle is greater than the deflectable angle of the radar field of view, the control module suppresses the detection signal within a first angle, and the first angle is the difference between the maximum obstruction angle and the deflectable angle.

[0016] Preferably, when the maximum blocking angle is smaller than the deflectable angle of the radar field of view, the control module adjusts the radar to be deflected outside the maximum blocking angle.

[0017] Another aspect of the present invention provides a vehicle comprising any radar-based trailer detection system as described above.

[0018] Compared with the prior art, the above technical solution has the following beneficial effects:

[0019] 1. Automatic detection of whether a trailer is attached: Using the method mentioned above, the radar can automatically identify whether a trailer is attached at the rear.

[0020] 2. Automatically adjust the radar FOV according to the trailer size: Using the method mentioned above, after the corner radar recognizes the outline of the front of the trailer, it can automatically adjust the available radar FOV deflection angle according to the size of the towed car. When the blocking angle exceeds the maximum deflection capacity, part of the FOV can be shielded from the software level, so that the radar can still work when the trailer is mounted. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic diagram of a trailer detection method based on radar in accordance with an embodiment of the present invention;

[0022] Figure 2 is a schematic diagram of another trailer detection method based on radar in accordance with an embodiment of the present invention;

[0023] Figure 3 is a schematic diagram of a radar-based trailer detection system according to an embodiment of the present invention;

[0024] Figure 4 for Figure 3 A schematic diagram of a radar-based trailer detection system in an embodiment;

[0025] Figure 5 for Figure 3 Another schematic diagram of a radar-based trailer detection system in accordance with an embodiment.

[0026] Reference numerals:

[0027] θ - maximum occlusion angle, θ max - Deflectable angle, Δθ - first angle. DETAILED DESCRIPTION

[0028] The advantages of the present invention are further described below in conjunction with the accompanying drawings and specific embodiments.

[0029] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. Instead, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.

[0030] The terms used in this disclosure are for the purpose of describing specific embodiments only and are not intended to limit the disclosure. The singular forms of "a", "said" and "the" used in this disclosure and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0031] In the description of the present invention, unless otherwise specified and limited, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the internal connection between two components. It can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances.

[0032] In the following description, the suffixes such as "module", "component" or "unit" used to represent elements are only used to facilitate the description of the present invention, and have no specific meanings. Therefore, "module" and "component" can be used interchangeably.

[0033] like Figure 1 As shown in FIG. 1 , a preferred embodiment of the present invention provides a trailer detection method based on radar, comprising:

[0034] S1: presetting a detection area, dividing a number of detection units within the detection area;

[0035] S2: Acquire the point cloud in the detection unit, cluster the point cloud, and obtain the contour of the target object;

[0036] S3: When the distance between the contour and the vehicle does not change with the speed of the vehicle, the target object is identified as a trailer.

[0037] The size of the detection area is the maximum trailer size that can be covered by the vehicle, and the area is divided into a number of detection units according to a certain size. The detection area should not be too large, otherwise it is easy to obtain too much useless information and occupy too many computing resources. In this embodiment, the detection area is a 3*5 meter area behind the vehicle. In other embodiments, it can also be other suitable areas, and the present invention is not limited here.

[0038] The detection unit can be regarded as the smallest detection unit. The detection area can be equally divided into a number of detection units. The data in the detection unit can be statistically analyzed to provide data for the clustering process.

[0039] In another embodiment, the clustering process is specifically as follows: obtaining the point cloud in the detection unit, connecting the centroid points obtained by clustering the point cloud, and performing a filtering operation to obtain the contour of the target object. The point cloud includes information such as the position information, angle information, and signal strength of the detection point.

[0040] Clustering refers to the process of dividing a collection of physical or abstract objects into multiple classes consisting of similar objects. The cluster generated by clustering is a collection of data objects that are similar to objects in the same cluster and different from objects in other clusters. The filtering operation is actually a process of deburring the graph after the centroid points are connected, and the filtering method commonly used in the art can be used.

[0041] After repeatedly calculating clusters and obtaining the precise outline of the target object, we further calculate whether the distance between the outline and the vehicle changes with the speed of the vehicle. If it remains unchanged, it can be considered that the target object remains relatively stationary with the vehicle, and the target object is identified as a trailer.

[0042] In another embodiment, if Figure 2 As shown, the target object is identified as a trailer, and the maximum blocking angle of the trailer is calculated based on the outline; when the maximum blocking angle is greater than the deflectable angle of the radar field of view, the detection signal within a first angle is suppressed, and the first angle is the difference between the maximum blocking angle and the deflectable angle; when the maximum blocking angle is less than the deflectable angle of the radar field of view, the radar is adjusted to be deflected outside the maximum blocking angle.

[0043] In the prior art, after detecting a trailer, the detection function of the radar is generally turned off directly, but at this time, a portion of the radar is still not blocked and has the ability to work normally. Therefore, in this embodiment, based on the contour obtained by previously judging the trailer, the maximum blocking angle θ of the contour to the radar can be calculated, and the maximum blocking angle θ and the deflectable angle θ of the radar field of view can be calculated. max For comparison, if the maximum blocking angle θ is greater than the deflection angle θ maxWhen , it is considered that the radar cannot avoid the maximum blocking angle θ by deflection, so the suppression of the echo of the part with the incident angle from the first angle Δθ can be achieved at the software level (Δθ = θ-θ max ), thereby avoiding the occlusion of the radar working FOV area, so that the radar can still use the remaining unobstructed FOV to work normally. If the maximum obstruction angle θ is less than the deflection angle θ of the radar field of view max When , the radar is deflected to outside the maximum blocking angle θ.

[0044] Therefore, by properly adjusting the radar, it is possible to continue working within a limited angle range and improve work efficiency.

[0045] In another embodiment of the present invention, a trailer detection system based on radar is provided, including a detection module and a control module, such as Figure 3 As shown, the detection module in this embodiment is a rear corner radar of the vehicle, including a left rear corner radar and a right rear corner radar, and the control module can be an MCU of the vehicle. The detection module is used to preset a detection area, divide a number of detection units in the detection area, and obtain a point cloud in the detection unit.

[0046] The control module is used to cluster the point cloud to obtain the outline of the target object; when the distance between the outline and the vehicle does not change with the speed of the vehicle, the target object is identified as a trailer. Figure 4 It can be seen that after the rear-angle radar divides the detection unit in the detection area and obtains the point cloud information in each detection unit, the control module then connects the centroid points obtained by clustering the point cloud and obtains the outline of the target object after filtering operation.

[0047] After obtaining the accurate outline of the target object, if the distance between the outline and the vehicle does not change with the vehicle speed, the target object is determined to be a trailer. The control module calculates the maximum blocking angle of the trailer according to the outline; when the maximum blocking angle is greater than the deflectable angle of the radar field of view, the control module suppresses the detection signal within a first angle, where the first angle is the difference between the maximum blocking angle and the deflectable angle.

[0048] Preferably, when the maximum blocking angle is smaller than the deflectable angle of the radar field of view, the control module adjusts the radar to be deflected outside the maximum blocking angle.

[0049] The technical features of the radar-based trailer detection system in other embodiments of the present invention are the same as those of the radar-based trailer detection method, and the present invention will not be elaborated herein.

[0050] In addition, embodiments of the present invention include vehicles that use the above-mentioned radar-based trailer detection system to more flexibly identify whether a trailer is mounted behind the vehicle; and the radar can still work when the trailer is mounted.

[0051] It can be understood that the deflection, rotation or suppression of the radar FOV within a certain angle described in the present invention is achieved by adjusting the antenna phase and processing digital signals, which belongs to the work at the signal processing level and does not specifically refer to the physical rotation of the radar antenna.

[0052] It should be noted that the embodiments of the present invention have better practicability and do not impose any form of limitation on the present invention. Any technician familiar with the field may use the technical content disclosed above to change or modify it into an equivalent effective embodiment. However, any modification or equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A trailer detection method based on radar, characterized in that: include: A detection area is preset, and a number of detection units are divided within the detection area; Acquire a point cloud in the detection unit, cluster the point cloud, and obtain a contour of the target object; When the distance between the contour and the vehicle does not change with the speed of the vehicle, identifying the target object as a trailer; Identify the target object as a trailer, and calculate the maximum blocking angle of the trailer according to the outline; When the maximum blocking angle is greater than the deflectable angle of the radar field of view, suppressing the detection signal within a first angle, where the first angle is the difference between the maximum blocking angle and the deflectable angle; When the maximum blocking angle is smaller than the deflectable angle of the radar field of view, adjusting the radar to be deflected beyond the maximum blocking angle; The deflection, rotation or suppression of the radar FOV within a certain angle is achieved by adjusting the antenna phase and processing digital signals.

2. The radar-based trailer detection method according to claim 1, characterized in that: The point cloud in the detection unit is obtained, the centroid points obtained by clustering the point cloud are connected, and the contour of the target object is obtained after filtering operation.

3. The radar-based trailer detection method of claim 2, wherein: The point cloud includes location information, angle information and signal strength information.

4. A radar-based trailer detection system, characterized in that: Including detection module and control module, The detection module is used to preset a detection area, divide a number of detection units within the detection area, and obtain a point cloud within the detection unit; The control module is used to cluster the point cloud to obtain the outline of the target object; when the distance between the outline and the vehicle does not change with the speed of the vehicle, the target object is identified as a trailer; The control module is used to identify the target object as a trailer and calculate the maximum blocking angle of the trailer according to the outline; When the maximum blocking angle is greater than the deflectable angle of the radar field of view, the control module suppresses the detection signal within a first angle, where the first angle is the difference between the maximum blocking angle and the deflectable angle; When the maximum blocking angle is smaller than the deflectable angle of the radar field of view, the control module adjusts the radar to deflect beyond the maximum blocking angle; The deflection, rotation or suppression of the radar FOV within a certain angle is achieved by adjusting the antenna phase and processing digital signals.

5. The radar-based trailer detection system of claim 4, wherein: The control module is used to connect the centroid points obtained by clustering the point cloud and obtain the outline of the target object after performing a filtering operation.

6. The radar-based trailer detection system of claim 5, wherein: The point cloud includes location information, angle information and signal strength information.

7. A vehicle comprising a radar based trailer detection system as claimed in any one of claims 4 to 6.

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