Post-protection false target detection method, system and device applied to millimeter wave radar, and storage medium

Abstract

The invention discloses a millimeter wave radar rear bumper false target detection method, system and device and a storage medium thereof, and aims to reduce false target false alarm caused by rear bumper reflection. The method comprises the following steps: firstly, acquiring distance, speed and angle information of a target by using a millimeter-wave radar, and forming a tracking target through an algorithm; then, the Doppler velocity of the target association point is judged, and suspected false targets are counted; once the count reaches a set value, the target is marked as suspected false. And then, secondary confirmation is carried out through the ultrasonic radar, and if the target is confirmed to be false, the alarm is not triggered. According to the method, the Doppler speed threshold value is reasonably set, and the threshold value is dynamically adjusted according to the vehicle acceleration, so that the false target screening precision is improved. The secondary confirmation of the ultrasonic radar further enhances the false target identification capability of the system, and effectively reduces unnecessary alarms, thereby improving the driving experience.

Description

Technical Field

[0001] The present invention belongs to the technical field of vehicle detection, and in particular relates to a method, system, device and storage medium for detecting false targets applied to millimeter wave radar rear-end protection. Background Art

[0002] Millimeter-wave radar is one of the key sensors in ADAS. Many ADAS functions, such as BSD, DOW, and RCTAB, are completed by millimeter-wave radar. These functions are mainly based on the millimeter-wave radar to detect the moving target at the rear, and then make warnings or brakes. Among these targets, there may be false targets. Millimeter-wave radars are installed on both sides of the rear bumper. Generally, after the car owner repaints the rear bumper with metal powder paint, the millimeter-wave radar is highly reflective to metal, so it is easy for the millimeter-wave radar to detect false targets near the rear bumper, resulting in the false triggering of the BSD function warning.

[0003] Due to basic cost considerations, many vehicles are not equipped with rear-view cameras. Therefore, relying solely on millimeter-wave radar without visual fusion, it is generally difficult for millimeter-wave radar to determine whether the target behind is a real target or a false target. Summary of the invention

[0004] The purpose of the present invention is to provide a method for detecting false targets in a millimeter-wave radar rear bumper, which can confirm false targets formed by bumper reflection through secondary confirmation by ultrasonic radar, avoid false alarms caused by false targets, and solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides a method for detecting false targets in millimeter wave radar, the method comprising the following steps:

[0006] S1: Use millimeter wave radar to obtain the distance, speed and angle information of the target; S2: Form a tracking target through an algorithm and perform Doppler speed judgment on the target associated points; S3: Count suspected false targets; S4: When the count of suspected false targets reaches the set value, mark the target as suspected false;

[0007] S5: Perform secondary confirmation of the suspected false target through ultrasonic radar; S6: If the ultrasonic radar confirms that it is a false target, no alarm is issued.

[0008] Preferably, the velocity characteristic of the associated point means that the Doppler velocity of the associated point is less than a preset threshold.

[0009] Preferably, the preset threshold is dynamically adjusted according to the vehicle acceleration, and the calculation formula is Vt=k|az|, wherein k is the adjustment coefficient, and |az| is the absolute value of the Z axis of the accelerometer.

[0010] Preferably, the millimeter-wave radar communicates with the ultrasonic radar via a CAN bus, and the millimeter-wave radar sends the suspected false target information to the CAN bus for the ultrasonic radar to read.

[0011] Preferably, the ultrasonic radar searches for a real target in the target area based on the target information provided by the millimeter wave radar.

[0012] Preferably, if the ultrasonic radar fails to detect the target, the millimeter wave radar identifies the target as a false target, otherwise the false mark is cancelled.

[0013] Preferably, the millimeter wave radar and the ultrasonic radar jointly use a vehicle body coordinate system with the center of the rear axle of the vehicle as the origin.

[0014] On the other hand, the present invention provides a false target detection system applied to millimeter wave radar, comprising:

[0015] Data acquisition module: responsible for using millimeter-wave radar to obtain the distance, speed, and angle information of the target, and provide basic data for subsequent processing;

[0016] Target tracking module: The tracking target is formed through an algorithm, and the Doppler velocity of the target associated points is judged, and the authenticity of the target is determined based on the velocity characteristics.

[0017] False target counting module: counts suspected false targets and calculates the frequency of occurrence of suspected false targets;

[0018] False target marking module: When the suspected false target count reaches the set value, the target is marked as a suspected false target to prepare for the next step of ultrasonic radar secondary confirmation;

[0019] Ultrasonic radar confirmation module: Use ultrasonic radar to conduct secondary confirmation of suspected false targets and detect whether the target actually exists through ultrasonic radar;

[0020] Alarm control module: If the ultrasonic radar confirms that the target is a false target, no alarm processing will be performed.

[0021] On the other hand, the present invention proposes a false target detection device, which includes a processor, a memory, and a false target detection program stored in the memory and executable by the processor, wherein when the false target detection program is executed by the processor, the steps of the false target detection method as described above are implemented.

[0022] On the other hand, the present invention provides a computer-readable storage medium, on which a false target detection program is stored, wherein when the false target detection program is executed by a processor, the steps of the false target detection method as described above are implemented.

[0023] Technical effects and advantages of the present invention: Compared with the prior art, the present invention provides a false target detection method for millimeter wave radar, which has the following advantages:

[0024] The present invention effectively reduces the false target false alarm phenomenon caused by rear bumper reflection through the combined use of millimeter wave radar and ultrasonic radar; improves the accuracy of false target screening by setting a reasonable Doppler speed threshold and introducing vehicle acceleration as a dynamic adjustment parameter; enhances the system's ability to identify false targets through the secondary confirmation mechanism of ultrasonic radar, thereby improving the reliability of the overall system; reduces unnecessary alarms, thereby improving the user's driving experience and reducing the trouble caused by frequent error prompts. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a flow chart of a false target detection method applied to millimeter wave radar after protection according to the present invention;

[0026] Figure 2 A block diagram of a false target detection system applied to millimeter wave radar after protection according to the present invention;

[0027] Figure 3 The present invention is a structural schematic diagram of a false target detection device applied to millimeter wave radar after protection. DETAILED DESCRIPTION

[0028] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0029] The present invention provides a method for detecting false targets in a millimeter-wave radar rear bumper. The method uses a millimeter-wave radar to obtain information such as the distance, speed, angle, etc. of a detection point relative to the radar through a signal processing algorithm, and then forms a tracking target through algorithms such as clustering and tracking. A tracking target may contain multiple detection points, and the detection points contained in this tracking target are collectively referred to as associated points. The characteristics of these associated points are judged, and false targets are marked according to the characteristics of the associated points. For the marked targets, it is impossible to accurately confirm whether it is a stable rear-following vehicle or a false point formed by a bumper. Therefore, a secondary confirmation by an ultrasonic radar is performed. If the secondary confirmation is indeed a false target, no alarm processing is performed.

[0030] like Figure 1 As shown, the method comprises the following steps:

[0031] S1: Use millimeter wave radar to obtain the distance, speed and angle information of the target; S2: Form a tracking target through an algorithm and perform Doppler speed judgment on the target associated points; S3: Count suspected false targets; S4: When the count of suspected false targets reaches the set value, mark the target as suspected false;

[0032] S5: Use ultrasonic radar to reconfirm the suspected false target; S6: If the ultrasonic radar confirms that it is a false target, no alarm will be issued. The details are as follows:

[0033] The biggest feature of the false detection point of the rear bumper formed by multiple reflections of the rear bumper material is that the relative speed between the detection point and the radar is basically constant. This is because the electromagnetic waves sent by the millimeter-wave radar will be reflected back by the metal surface, and the bumper is a static object relative to the radar, and its relative motion is zero, so the radial speed detected by the radar is zero, or close to zero.

[0034] Based on the above characteristics, the millimeter wave radar forms a tracking target for the detected original point data through the data processing algorithm, and at the same time, it judges the Doppler velocity of the original detection point associated with the target.

[0035] A tracking point is usually associated with multiple original points, and the Doppler velocity of all original points in the tracking point cluster group is judged. The suspected false points of the target are counted. When there is an original point with a Doppler velocity greater than a certain threshold [0.01-0.05m / s] among the associated original points, the suspected false point count of the current target is increased by 1.

[0036] The threshold is selected because the electromagnetic waves sent by the millimeter-wave radar will be reflected back by the metal surface. The bumper is a static object relative to the radar, and its relative motion is zero. Therefore, the radial velocity detected by the radar is zero, or close to zero.

[0037] In the actual metal paint spraying test, for the real target that stably follows the vehicle, it is difficult to ensure that the target is relatively still, and it is easy to change slightly. The Doppler velocity of the original point detected by the corresponding radar will also change slightly. Therefore, it is extremely difficult to stably maintain the Doppler velocity of the real target below a certain threshold. Therefore, a certain threshold range is selected to screen the false targets and stably follow the targets, and the suspected false point counts. When the Doppler velocity of the target-related original point is less than 0.01m / s and the radial distance difference between the front and rear frames is less than 0.1m, the target suspected false point count is increased by 1.

[0038] The selection of the radial velocity threshold should be combined with the current vehicle vibration level. When the vehicle is driving on a bumpy road, the radial velocity of the reflected echo will be slightly affected due to the slight vibration of the bumper.

[0039] There is a relationship between the target Doppler velocity Vr, the relative motion angle θ of the bumper and the actual motion velocity V of the vehicle: vr = v·cos(θ).

[0040] The greater the vibration of the bumper, the greater the Doppler velocity of the reflected target. Therefore, the radar dynamically sets the Doppler velocity threshold by acquiring the data of the acceleration sensor of the whole vehicle. The greater the fluctuation of the whole vehicle in the longitudinal direction, the greater the Doppler velocity threshold. The threshold is dynamically adjusted according to the degree of vibration. The threshold can be set to: Vt = k|az|, where k is the adjustment coefficient, which is used to determine the degree of influence of acceleration on the threshold. |az| is the absolute value of the Z axis of the accelerometer, indicating the degree of vibration in the up and down directions of the vehicle. k is generally set to 0.01. At the same time, the Doppler threshold of the target is controlled between [0.01-0.05m / s].

[0041] When the target associated original point is less than the speed threshold, the suspected false point count of the currently tracked target is increased by 1; when the associated original point is greater than the threshold and the suspected false point count is greater than 0, the suspected false point count is reduced by 1.

[0042] When the cumulative count reaches 50, the target is considered a suspected false target. However, in actual situations, since there is a certain probability that the target is being stably followed by the vehicle behind, the ultrasonic radar is required to perform a secondary confirmation of the target.

[0043] The millimeter-wave radar and ultrasonic radar communicate with each other, establish a body coordinate system with the center of the vehicle's rear axle as the origin, and uniformly convert the detected targets into the body coordinate system.

[0044] The millimeter wave radar sends the detection target information with false labels to the CAN bus through the CAN message, and the ultrasonic radar obtains the target information from the CAN bus. The target information contains the distance, speed, angle and other information of the target relative to the origin.

[0045] The ultrasonic radar confirms whether there is a real target near the millimeter-wave radar false target position. If there is no real target, the millimeter-wave radar marks it as a confirmed false target and does not perform any alarm processing on this target. If there is a real target, it is considered to be a real target of stable following, and the millimeter-wave radar cancels its false mark. Regardless of whether it is a false target, the above steps will be repeated.

[0046] On the other hand, the present invention proposes a false target detection system applied to millimeter wave radar, such as Figure 2 As shown, it includes: a data acquisition module, a target tracking module, a false target counting module, a false target marking module, an ultrasonic radar confirmation module and an alarm control module.

[0047] Exemplarily, the data acquisition module is responsible for obtaining the distance, speed, and angle information of the target using the millimeter wave radar, and providing basic data for subsequent processing;

[0048] Exemplarily, the target tracking module forms a tracking target through an algorithm, performs Doppler velocity judgment on target associated points, and judges the authenticity of the target based on velocity characteristics.

[0049] Exemplarily, the false target counting module counts the suspected false targets and calculates the frequency of occurrence of the suspected false targets;

[0050] Exemplarily, when the suspected false target count reaches a set value, the false target marking module marks the target as a suspected false target, in preparation for the next step of secondary confirmation by the ultrasonic radar;

[0051] Exemplarily, the ultrasonic radar confirmation module uses the ultrasonic radar to perform secondary confirmation on the suspected false target, and detects whether the target actually exists through the ultrasonic radar;

[0052] Exemplarily, if the ultrasonic radar confirms that the target is a false target, the alarm control module does not perform alarm processing.

[0053] In addition, the above-mentioned data acquisition module, target tracking module, false target counting module, false target marking module, ultrasonic radar confirmation module and alarm control module are also used to implement the other steps of the above-mentioned false target detection method applied to millimeter wave radar after protection when executed, which will not be repeated here one by one.

[0054] The combined use of millimeter-wave radar and ultrasonic radar effectively reduces false target alarms caused by rear bumper reflections. The accuracy of false target screening is improved by setting a reasonable Doppler velocity threshold and introducing vehicle acceleration as a dynamic adjustment parameter. The secondary confirmation mechanism of ultrasonic radar enhances the system's ability to identify false targets, thereby improving the reliability of the overall system. This technology reduces unnecessary alarms, thereby improving the user's driving experience and reducing the trouble caused by frequent false prompts.

[0055] On the other hand, the present invention proposes a false target detection device. The false target detection method applied to millimeter wave radar in this embodiment is mainly applied to the false target detection device, which can be a PC, a portable computer, a mobile terminal and other devices with display and processing functions.

[0056] Specifically, Figure 3 As shown, the false target detection device may include a processor (such as a CPU), a communication bus, a user interface, a network interface, and a memory. The communication bus is used to realize the connection and communication between these components; the user interface may include a display screen (Display), an input unit such as a keyboard (Keyboard); the network interface may optionally include a standard wired interface, a wireless interface (such as a WI-FI interface); the memory may be a high-speed RAM memory, or a stable memory (non-volatile memory), such as a disk memory, and the memory may optionally be a storage device independent of the aforementioned processor.

[0057] Among them, the memory stores a readable storage medium, and the readable storage medium stores a false target detection program. The processor can call the false target detection program stored in the memory and execute the false target detection method applied to millimeter wave radar after-protection provided by an embodiment of the present invention.

[0058] It is understood that a readable storage medium can be a tangible device that can hold and store instructions used by an instruction execution device. Computer-readable storage media can be, for example, but not limited to, an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the above. More specific examples of computer-readable storage media (a non-exhaustive list) include: portable computer disks, hard disks, random access memories (RAM), read-only memories (ROM), erasable programmable read-only memories (EPROM or flash memory), static random access memories (SRAM), portable compact disk read-only memories (CD-ROM), digital versatile disks (DVD), memory sticks, floppy disks, mechanical encoding devices, such as punch cards or raised structures in grooves on which instructions are stored, and any suitable combination of the above. The computer-readable storage medium used here is not to be interpreted as a transient signal itself, such as a radio wave or other freely propagating electromagnetic wave, an electromagnetic wave propagating through a waveguide or other transmission medium (e.g., a light pulse through a fiber optic cable), or an electrical signal transmitted through a wire.

[0059] The computer-readable program instructions described herein can be downloaded from a computer-readable storage medium to each computing / processing device, or downloaded to an external computer or external storage device via a network, such as the Internet, a local area network, a wide area network, and / or a wireless network. The network can include copper transmission cables, optical fiber transmissions, wireless transmissions, routers, firewalls, switches, gateway computers, and / or edge servers. The network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards the computer-readable program instructions for storage in the computer-readable storage medium in each computing / processing device.

[0060] The computer program instructions for performing the operations of the present disclosure may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages, such as Smalltalk, C++, etc., and conventional procedural programming languages, such as "C" language or similar programming languages. The computer-readable program instructions may be executed entirely on the user's computer, partially on the user's computer, as an independent software package, partially on the user's computer, partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer via any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., using an Internet service provider to connect via the Internet). In some embodiments, by utilizing state information of computer-readable program instructions to personalize an electronic circuit, such as a programmable logic circuit, a field programmable gate array (FPGA), or a programmable logic array (PLA), the electronic circuit can execute the computer-readable program instructions to implement various aspects of the present disclosure.

[0061] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A false target detection method applied to millimeter wave radar, characterized in that: The method comprises the following steps: S1: Use millimeter wave radar to obtain the distance, speed and angle information of the target; S2: The tracking target is formed through the algorithm, and the Doppler velocity of the target associated point is judged; S3: Count suspected false targets; S4: When the count of suspected false targets reaches the set value, the target is marked as suspected false; S5: Secondary confirmation of suspected false targets through ultrasonic radar; S6: If the ultrasonic radar confirms that it is a false target, no alarm will be issued.

2. The method for detecting false targets in millimeter wave radar according to claim 1, characterized in that: The velocity characteristic of the associated point refers to that the Doppler velocity of the associated point is less than a preset threshold.

3. The method for detecting false targets in millimeter wave radar according to claim 2, characterized in that: The preset threshold is dynamically adjusted according to the vehicle acceleration, and the calculation formula is Vt=k|az|, where k is the adjustment coefficient and |az| is the absolute value of the Z axis of the accelerometer.

4. The method for detecting false targets in millimeter wave radar according to claim 1, characterized in that: The millimeter-wave radar communicates with the ultrasonic radar via a CAN bus, and the millimeter-wave radar sends suspected false target information to the CAN bus for the ultrasonic radar to read.

5. The method for detecting false targets in millimeter wave radar according to claim 4, characterized in that: The ultrasonic radar searches for a real target in the target area based on the target information provided by the millimeter wave radar.

6. The method for detecting false targets in millimeter wave radar according to claim 5, characterized in that: If the ultrasonic radar fails to detect the target, the millimeter-wave radar confirms the target as a false target, otherwise the false mark is cancelled.

7. The method for detecting false targets in millimeter wave radar according to claim 4, characterized in that: The millimeter wave radar and the ultrasonic radar jointly use a vehicle body coordinate system with the center of the rear axle of the vehicle as the origin.

8. A false target detection system according to the false target detection method according to any one of claims 1 to 7, comprising: Data acquisition module: responsible for using millimeter-wave radar to obtain the distance, speed, and angle information of the target, and provide basic data for subsequent processing; Target tracking module: The tracking target is formed through an algorithm, and the Doppler velocity of the target associated points is judged, and the authenticity of the target is determined based on the velocity characteristics. False target counting module: counts suspected false targets and calculates the frequency of their occurrence; False target marking module: When the suspected false target count reaches the set value, the target is marked as a suspected false target to prepare for the next step of secondary confirmation by ultrasonic radar; Ultrasonic radar confirmation module: Use ultrasonic radar to conduct secondary confirmation of suspected false targets and detect whether the target actually exists through ultrasonic radar; Alarm control module: If the ultrasonic radar confirms that the target is a false target, no alarm processing will be performed.

9. A false target detection device, characterized in that: The false target detection device includes a processor, a memory, and a false target detection program stored in the memory and executable by the processor, wherein when the false target detection program is executed by the processor, the steps of the false target detection method as described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a false target detection program, wherein when the false target detection program is executed by a processor, the steps of the false target detection method according to any one of claims 1 to 7 are implemented.

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