Backward collision assisting method and device

Abstract

The invention provides a backward collision assisting method and device, and relates to the technical field of vehicles. The invention provides a backward collision assistance method. When the method is executed, radar setting is firstly carried out on a vehicle, radars comprise two medium-long distance ultrasonic radars, two rear angle millimeter wave radars and four short distance ultrasonic radars, then a braking strategy is formulated according to the setting of the radars, and finally backward collision assistance is carried out on the vehicle according to the braking strategy. By using four short-distance ultrasonic radars and additionally adding detection of two middle-long-distance ultrasonic radars and fusion and updating of a braking strategy, more accurate detection of long-distance and close-distance dynamic and static targets can be realized, and then a backward collision assisting effect is improved.

Description

Technical Field

[0001] The present application relates to the field of vehicle technology, and in particular to a rear collision assistance method and device. Background Art

[0002] The RAEB function (Rear Automatic Emergency Braking) and RCW system (Rear Collision Warning System) in the current rear assist function both need to monitor the driving environment and targets behind the vehicle, so as to avoid objects approaching the vehicle from behind and reduce the risk of possible collision. Among them, RAEB is a function that provides braking assistance to the vehicle when there is a possibility of collision with the rear target when reversing at low speed in R gear, and RCW is a scenario in which it prevents the rear vehicle from approaching the vehicle in D gear and provides collision warning to the vehicle when there is a possibility of collision.

[0003] In the existing technology, if we rely on a single sensor, namely corner millimeter-wave radar, to detect and obtain target information, the corner radar sensor can only recognize dynamic targets in the low-speed domain, such as pedestrians, two-wheeled vehicles and vehicles passing sideways, but cannot recognize stationary targets; while the ultrasonic radar sensor can supplement the detection of stationary targets; if we only use the signal detected by the ultrasonic radar, it may lead to frequent false alarms.

[0004] In summary, how to improve the rear collision assistance effect is a problem that technical personnel in this field need to solve urgently. Summary of the invention

[0005] In view of this, the present application provides a rear-end collision assistance method and device, aiming to improve the rear-end collision assistance effect.

[0006] In a first aspect, the present application provides a rear collision assistance method, comprising:

[0007] Setting up radar for the vehicle; the radar includes two medium- and long-range ultrasonic radars, two rear-angle millimeter-wave radars, and four short-range ultrasonic radars;

[0008] formulating a braking strategy according to the setting of the radar;

[0009] The vehicle is provided with rear collision assistance according to the braking strategy.

[0010] Optionally, the two medium- and long-range ultrasonic radars are respectively a first medium- and long-range ultrasonic radar and a second medium- and long-range ultrasonic radar; the first medium- and long-range ultrasonic radar and the second medium- and long-range ultrasonic radar are respectively arranged at a position of 50 degrees to the left rear and a position of 50 degrees to the right rear of the vehicle;

[0011] The two rear-angle millimeter-wave radars are respectively arranged at a 45-degree position on the left rear and a 45-degree position on the right rear of the vehicle;

[0012] The four short-range ultrasonic radars are respectively a first short-range ultrasonic radar, a second short-range ultrasonic radar, a third short-range ultrasonic radar and a fourth short-range ultrasonic radar; the four short-range ultrasonic radars are arranged according to parking area requirements; at the rear of the vehicle from left to right are respectively the first short-range ultrasonic radar, the second short-range ultrasonic radar, the third short-range ultrasonic radar and the fourth short-range ultrasonic radar.

[0013] Optionally, the braking strategy includes:

[0014] When the vehicle speed is greater than or equal to 8 km / h, if the medium- and long-range ultrasonic radar detects a target object, the rear-angle millimeter-wave radar is used to obtain a first heading angle;

[0015] If the first heading angle satisfies a first preset condition, determining that the target object is a longitudinal target;

[0016] If the pre-collision time is 1 second, the vehicle brakes.

[0017] Optionally, the braking strategy includes:

[0018] When the vehicle speed is less than 8 km / h, the target detection signals of the medium- and long-range ultrasonic radar and the target detection signals of the short-range ultrasonic radar received by the rear-angle millimeter-wave radar are fused and screened to obtain the real target position;

[0019] If the millimeter-wave radar determines that the real target position is located within the vehicle body collision area and meets the pre-collision time requirement, the vehicle brakes.

[0020] Optionally, the braking strategy includes:

[0021] Utilizing the rear-angle millimeter-wave radar to detect lateral dynamic targets;

[0022] If the pre-collision time is 1.1 seconds, an alarm is issued for a crossing target that collides with the vehicle within 1.1 seconds and the vehicle is braked; the crossing target is a target whose heading angle meets the second preset condition.

[0023] Optionally, the braking strategy includes:

[0024] Detecting short-range static targets or longitudinally moving targets using the second short-range ultrasonic radar or the third short-range ultrasonic radar;

[0025] If the pre-collision time is 0.9 seconds, an alarm is issued for a crossing target that collides with the vehicle within 0.9 seconds and the vehicle is braked.

[0026] Optionally, the braking strategy includes:

[0027] The braking condition of the vehicle includes that the speed of the vehicle is greater than 3 km / h or less than 7 km / h;

[0028] The braking condition of the vehicle includes that the second short-range ultrasonic radar or the third short-range ultrasonic radar detects a target object that is less than 100 cm away from the vehicle.

[0029] In a second aspect, the present application provides a rear collision assistance device, comprising:

[0030] A setting module, used to set the radar of the vehicle; the radar includes two medium- and long-range ultrasonic radars, two rear-angle millimeter-wave radars, and four short-range ultrasonic radars;

[0031] A strategy formulation module, used for formulating a braking strategy according to the setting of the radar;

[0032] A rear collision assistance module is used to perform rear collision assistance on the vehicle according to the braking strategy.

[0033] In a third aspect, an embodiment of the present application provides a computer device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, a rear collision assistance method as described in any one of the implementation methods in the first aspect of the embodiment of the present application is implemented.

[0034] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, in which instructions are stored. When the instructions are executed on a terminal device, the terminal device executes a rear collision assistance method as described in any one of the implementation methods in the first aspect of the embodiment of the present application.

[0035] The present application provides a rear collision assistance method. When executing the method, the vehicle is firstly set up with radar, wherein the radar includes: two medium and long-range ultrasonic radars, two rear-angle millimeter-wave radars, and four short-range ultrasonic radars. Then, a braking strategy is formulated according to the setting of the radar, and finally the vehicle is assisted in rear collision according to the braking strategy. By utilizing four short-range ultrasonic radars, and adding two additional medium- and long-range ultrasonic radars for detection, as well as the fusion and update of the braking strategy, more accurate detection of long-range and short-range dynamic and static targets can be achieved, thereby improving the rear collision assistance effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in this embodiment or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0037] Figure 1 A flowchart of a rear collision assistance method provided in an embodiment of the present application;

[0038] Figure 2 The radar layout diagram of the whole vehicle provided in the embodiment of the present application;

[0039] Figure 3 A schematic diagram of fusion screening based on long-range ultrasonic radar and short-range ultrasonic radar provided in this embodiment;

[0040] Figure 4 A schematic diagram of a vehicle body collision area provided in an embodiment of the present application;

[0041] Figure 5 A schematic structural diagram of a rear-collision assistance device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. The present application provides a rear collision assistance method and device for use in the field of vehicle technology. The above is only an example and does not limit the application field of the method and device provided by the present application.

[0043] The RAEB function (Rear Automatic Emergency Braking) and RCW system (Rear Collision Warning System) in the current rear assist function both need to monitor the driving environment and targets behind the vehicle, so as to avoid objects approaching the vehicle from behind and reduce the risk of possible collision. Among them, RAEB is a function that provides braking assistance to the vehicle when there is a possibility of collision with the rear target when reversing at low speed in R gear, and RCW is a scenario in which it prevents the rear vehicle from approaching the vehicle in D gear and provides collision warning to the vehicle when there is a possibility of collision.

[0044] In the existing technology, if we rely on a single sensor, namely corner millimeter-wave radar, to detect and obtain target information, the corner radar sensor can only recognize dynamic targets in the low-speed domain, such as pedestrians, two-wheeled vehicles and vehicles passing sideways, but cannot recognize stationary targets; while the ultrasonic radar sensor can supplement the detection of stationary targets; if we only use the signal detected by the ultrasonic radar, it may lead to frequent false alarms.

[0045] After research, the inventor proposed the technical solution of this application. First, the vehicle is equipped with radar, including two medium- and long-range ultrasonic radars, two rear-angle millimeter-wave radars, and four short-range ultrasonic radars. Then, a braking strategy is formulated according to the radar settings, and finally the vehicle is assisted in rear-end collision according to the braking strategy. By utilizing four short-range ultrasonic radars, adding two additional medium- and long-range ultrasonic radars for detection, and integrating and updating the braking strategy, more accurate detection of long-range and short-range dynamic and static targets can be achieved, thereby improving the rear-end collision assistance effect.

[0046] In order to enable those skilled in the art to better understand the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application. It should be noted that, for ease of description, only the parts related to the relevant invention are shown in the accompanying drawings. In the absence of conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

[0047] See also Figure 1 , Figure 1 A flowchart of a rear collision assistance method provided in an embodiment of the present application includes:

[0048] S101: Perform radar settings on the vehicle.

[0049] First, set up the vehicle's radar. Figure 2 As shown, Figure 2 The whole vehicle radar layout diagram provided for the embodiment of the present application specifically includes: a first rear-angle millimeter-wave radar c and a second rear-angle millimeter-wave radar d, the first rear-angle millimeter-wave radar c and the second rear-angle millimeter-wave radar d are arranged at 45°. A first medium-long range ultrasonic radar a and a second medium-long range ultrasonic radar b, the first medium-long range ultrasonic radar a and the second medium-long range ultrasonic radar b are arranged at 50° to avoid mutual interference with the millimeter-wave radar. A first short-range ultrasonic radar e, a second short-range ultrasonic radar f, a third short-range ultrasonic radar g and a fourth short-range ultrasonic radar h, wherein the first short-range ultrasonic radar e, the second short-range ultrasonic radar f, the third short-range ultrasonic radar h and the fourth short-range ultrasonic radar g are arranged from left to right at the rear of the vehicle.

[0050] Next, for the newly added ultrasonic radar, each ultrasonic radar needs to add four CAN signals: fault status signal, target detection signal, feedback signal and distance signal. As shown in Table 1 below, Table 1 is a schematic diagram of the newly added signal message:

[0051] Table 1: Schematic Table of Newly Added Signal Messages

[0052]

[0053]

[0054] Among them, 0x1:Zone1 represents a 30-cm area; 0x2:Zone2 represents a 60-cm area; 0x3:Zone3 represents a 90-cm area; 0x4:Zone4 represents an area of 1.2 - 1.5 m.

[0055] S102: Develop a braking strategy according to the settings of the radar.

[0056] Next, set the braking strategy according to the settings of the radar, as follows:

[0057] Braking Strategy One: Use the corner millimeter-wave radar to detect lateral dynamic targets. Specifically, if the alarm threshold TTC = 1.1 s, an alarm and braking are issued for a crossing target that will collide with the rear of the vehicle within 1.1 s. Among them, TTC is the time to pre-collision, and TTC is used to judge the time required for the vehicle to collide from the current moment. Among them, the determination method of the crossing target is as follows: Obtain the heading angle θ. If the heading angle meets the second preset condition, that is, ±tanθ = Vx / Vy < tan30° ≈ 0.577, then the target object is determined as a crossing target. Among them, RAEB is only triggered when the vehicle speed is within 3 km / h - 10 km / h.

[0058] Braking Strategy Two: Use the short-distance ultrasonic radar (the second short-distance ultrasonic radar f or the third short-distance ultrasonic radar g) to detect short-distance static and longitudinal moving targets. Specifically, if the alarm threshold TTC = 0.9 s, an alarm and braking are issued for a crossing target that will collide with the rear of the vehicle within 0.9 s. Among them, RAEB is only triggered when the vehicle speed is within 3 km / h - 7 km / h, and only the targets directly behind the vehicle are detected. The vehicle braking condition also includes: There is a target with distance < 100 cm in the second short-distance ultrasonic radar f or the third short-distance ultrasonic radar g.

[0059] Braking Strategy Three: Use the medium-long-distance ultrasonic radar (the first medium-long-distance ultrasonic radar a or the second medium-long-distance ultrasonic radar b) and the short-distance ultrasonic radar (the first short-distance ultrasonic radar e or the fourth short-distance ultrasonic radar h) for supplementary compensation for medium-long-distance static targets, longitudinal moving targets, and low-speed targets, as follows:

[0060] 1. Detect targets on the side and rear sides of the vehicle, adjacent lanes or parking spaces;

[0061] 2. When the vehicle speed is 8 km / h or above, if the mid- and long-range ultrasonic radar detects a target, the millimeter-wave radar determines whether the heading angle θ satisfies the second preset condition, that is, ±cotθ = Vx / Vy < cot30° ≈ 0.577. If it is satisfied, the target is determined to be a longitudinal target. If TTC = 1.0 s is satisfied, braking measures are taken.

[0062] 3. When the vehicle speed is below 8 km / h, the detection target of the mid- and long-range ultrasonic radar does not give a braking feedback. After the millimeter-wave radar receives the target detection signal of the mid- and long-range ultrasonic radar, it fuses and filters it with the target detection signal of the short-range ultrasonic radar. The specific method is as follows:

[0063] (1) In a conventional scenario, there are no other obstacles around. Since the can signal of the ultrasonic radar is the target distance in millimeters, taking a group of mid- and long-range ultrasonic radar a and short-range ultrasonic radar e on the same side as an example, as Figure 3 shown, Figure 3 is a schematic diagram of fusion and filtering based on the long-range ultrasonic radar and the short-range ultrasonic radar provided by this embodiment. Taking the mid- and long-range ultrasonic radar a and the short-range ultrasonic radar e as the center, draw circles with the target distance as the radius respectively to obtain circle m and circle n. If the two circles have intersections, there are one or two solutions at most. Discard the false points, and the remaining real points are the positions of the actual targets. After obtaining the real target position, if the millimeter-wave radar determines that the target object is within the vehicle body collision area and meets the TTC requirement, braking is taken. As Figure 4 shown, Figure 4 is a schematic diagram of the vehicle body collision area provided by an embodiment of this application. Among them, the area between the dashed line q and the dashed line p is the vehicle body collision area.

[0064] (2) If it is in the blind area of the mid- and long-range ultrasonic radar, the judgment of the short-range ultrasonic radar distance shall prevail.

[0065] (3) If the vehicle is close to the wall, the mid- and long-range ultrasonic radar will continuously detect the target. If the detection exceeds 0.9 s and the detected target distance is constant within a certain range interval, the target signal of the mid- and long-range ultrasonic radar will be suppressed, and only the first short-range ultrasonic radar e or the fourth short-range ultrasonic radar h will give a braking feedback. After the mid- and long-range ultrasonic radar does not detect the target for more than 1 s, the target signal is restored.

[0066] (4) If there is no intersection between circle m and circle n, the judgment of the short-range ultrasonic radar distance shall prevail.

[0067] S103: Perform rearward collision assistance on the vehicle according to the braking strategy.

[0068] In the embodiment of the present application, the vehicle is firstly set up with radar, wherein the radar includes: two medium- and long-range ultrasonic radars, two rear-angle millimeter-wave radars, and four short-range ultrasonic radars. Then, a braking strategy is formulated according to the setting of the radar, and finally the vehicle is assisted in rearward collision according to the braking strategy. By utilizing four short-range ultrasonic radars, and adding two additional medium- and long-range ultrasonic radars for detection, as well as the integration and update of the braking strategy, more accurate detection of long-range and short-range dynamic and static targets can be achieved, thereby improving the rearward collision assistance effect.

[0069] In some cases, false alarms and missed alarms may occur. For example, in parking scenarios, the parking false alarm rate is high because the distance between vehicles in the parking lot is very close and the reversing angle is very extreme; manhole cover false alarms, ultrasonic radar is prone to false detection, resulting in false triggering of the RAEB function; ultrasonic radar is not accurate and responds slowly. This application also provides compensation measures for false alarm and missed alarm scenarios: dynamic targets only judge horizontal targets, and do not judge longitudinal targets; judge the depth of the driver's brake pedal, that is, during the general reversing process, the driver will generally step on the brake pedal. When the foot steps on the brake pedal more than 30%, the system will not brake; the speed limit is between 3km / h-10km / h to avoid false alarms in ultra-low speed scenarios; increase the judgment of the steering wheel angle, and the function will not be triggered when the vehicle is reversing into the warehouse at a large angle.

[0070] In addition, in order to further improve the accuracy and comfort of the rear collision assistance system, the targets provided by the millimeter-wave radar and ultrasonic radar are weighted. After weighting the target information in various typical case environments, the triggering frequency of the function can be controlled. Specifically, based on the data collected from big data and actual vehicle road tests, the frequency of triggering functions in various environments is summarized, and then combined with user needs, the target weight in this environment is increased or decreased to increase or decrease the number of times the function is triggered and optimize the user experience; for those problems that cannot be solved with simple weighting, the functional comfort is optimized through software iteration and scene reproduction.

[0071] The above are some specific implementations of the rear collision assistance method provided by the embodiment of the present application. Based on this, the present application also provides a corresponding device. The device provided by the embodiment of the present application will be introduced from the perspective of functional modularization.

[0072] See also Figure 5 , Figure 5 The following is a schematic diagram of a rear collision assistance device provided in an embodiment of the present application. The rear collision assistance device 500 includes:

[0073] A setting module 510 is used to set the radar of the vehicle; the radar includes two medium- and long-range ultrasonic radars, two rear-angle millimeter-wave radars, and four short-range ultrasonic radars;

[0074] A strategy formulation module 520, for formulating a braking strategy according to the settings of the radar;

[0075] The rear collision assistance module 530 is used to perform rear collision assistance on the vehicle according to the braking strategy.

[0076] Optionally, the two medium- and long-range ultrasonic radars are respectively a first medium- and long-range ultrasonic radar and a second medium- and long-range ultrasonic radar; the first medium- and long-range ultrasonic radar and the second medium- and long-range ultrasonic radar are respectively arranged at a position of 50 degrees to the left rear and a position of 50 degrees to the right rear of the vehicle;

[0077] The two rear-angle millimeter-wave radars are respectively arranged at a 45-degree position on the left rear and a 45-degree position on the right rear of the vehicle;

[0078] The four short-range ultrasonic radars are respectively a first short-range ultrasonic radar, a second short-range ultrasonic radar, a third short-range ultrasonic radar and a fourth short-range ultrasonic radar; the four short-range ultrasonic radars are arranged according to parking area requirements; at the rear of the vehicle from left to right are respectively the first short-range ultrasonic radar, the second short-range ultrasonic radar, the third short-range ultrasonic radar and the fourth short-range ultrasonic radar.

[0079] Optionally, the braking strategy includes:

[0080] When the vehicle speed is greater than or equal to 8 km / h, if the medium- and long-range ultrasonic radar detects a target object, the rear-angle millimeter-wave radar is used to obtain a first heading angle;

[0081] If the first heading angle satisfies a first preset condition, determining that the target object is a longitudinal target;

[0082] If the pre-collision time is 1 second, the vehicle brakes.

[0083] Optionally, the braking strategy includes:

[0084] When the vehicle speed is less than 8 km / h, the target detection signals of the medium- and long-range ultrasonic radar and the target detection signals of the short-range ultrasonic radar received by the rear-angle millimeter-wave radar are fused and screened to obtain the real target position;

[0085] If the millimeter-wave radar determines that the real target position is located within the vehicle body collision area and meets the pre-collision time requirement, the vehicle brakes.

[0086] Optionally, the braking strategy includes:

[0087] Utilizing the rear-angle millimeter-wave radar to detect lateral dynamic targets;

[0088] If the pre-collision time is 1.1 seconds, an alarm is issued for a crossing target that collides with the vehicle within 1.1 seconds and the vehicle is braked; the crossing target is a target whose heading angle meets the second preset condition.

[0089] Optionally, the braking strategy includes:

[0090] Detecting short-range static targets or longitudinally moving targets using the second short-range ultrasonic radar or the third short-range ultrasonic radar;

[0091] If the pre-collision time is 0.9 seconds, an alarm is issued for a crossing target that collides with the vehicle within 0.9 seconds and the vehicle is braked.

[0092] Optionally, the braking strategy includes:

[0093] The braking condition of the vehicle includes that the speed of the vehicle is greater than 3 km / h or less than 7 km / h;

[0094] The braking condition of the vehicle includes that the second short-range ultrasonic radar or the third short-range ultrasonic radar detects a target object that is less than 100 cm away from the vehicle.

[0095] The embodiments of the present application also provide corresponding devices and computer storage media for implementing the solutions provided by the embodiments of the present application.

[0096] The device includes a memory and a processor, the memory is used to store instructions or codes, and the processor is used to execute the instructions or codes so that the device executes the method described in any embodiment of the present application.

[0097] The computer storage medium stores codes, and when the codes are executed, a device executing the codes implements the method described in any embodiment of the present application.

[0098] Through the description of the above implementation methods, it can be known that those skilled in the art can clearly understand that all or part of the steps in the above-mentioned embodiment method can be implemented by means of software plus a general hardware platform. Based on such an understanding, the technical solution of the present application can be embodied in the form of a software product, which can be stored in a storage medium, such as a read-only memory (ROM) / RAM, a magnetic disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network communication device such as a router) to execute the methods described in each embodiment of the present application or some parts of the embodiments.

[0099] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0100] It should also be noted that the various embodiments in this specification are described in a progressive manner, and the same and similar parts between the various embodiments can refer to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the equipment and device embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can refer to the partial description of the method embodiment. The device embodiments described above are merely schematic, in which the units described as separate components may or may not be physically separated, and the components prompted as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0101] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A rear collision assistance method, characterized in that: include: Setting up radar for the vehicle; the radar includes two medium- and long-range ultrasonic radars, two rear-angle millimeter-wave radars, and four short-range ultrasonic radars; formulating a braking strategy according to the setting of the radar; The vehicle is provided with rear collision assistance according to the braking strategy.

2. The method according to claim 1, characterized in that The two medium- and long-range ultrasonic radars are respectively a first medium- and long-range ultrasonic radar and a second medium- and long-range ultrasonic radar; the first medium- and long-range ultrasonic radar and the second medium- and long-range ultrasonic radar are respectively arranged at a position of 50 degrees to the left rear and 50 degrees to the right rear of the vehicle; The two rear-angle millimeter-wave radars are respectively arranged at a 45-degree position on the left rear and a 45-degree position on the right rear of the vehicle; The four short-range ultrasonic radars are respectively a first short-range ultrasonic radar, a second short-range ultrasonic radar, a third short-range ultrasonic radar and a fourth short-range ultrasonic radar; the four short-range ultrasonic radars are arranged according to parking area requirements; at the rear of the vehicle from left to right are respectively the first short-range ultrasonic radar, the second short-range ultrasonic radar, the third short-range ultrasonic radar and the fourth short-range ultrasonic radar.

3. The method according to claim 1, characterized in that The braking strategy includes: When the vehicle speed is greater than or equal to 8 km / h, if the medium- and long-range ultrasonic radar detects a target object, the rear-angle millimeter-wave radar is used to obtain a first heading angle; If the first heading angle satisfies a first preset condition, determining that the target object is a longitudinal target; If the pre-collision time is 1 second, the vehicle brakes.

4. The method according to claim 3, characterized in that The braking strategy includes: When the vehicle speed is less than 8 km / h, the target detection signals of the medium- and long-range ultrasonic radar and the target detection signals of the short-range ultrasonic radar received by the rear-angle millimeter-wave radar are fused and screened to obtain the real target position; If the millimeter-wave radar determines that the real target position is located within the vehicle body collision area and meets the pre-collision time requirement, the vehicle brakes.

5. The method according to claim 1, characterized in that The braking strategy includes: Utilizing the rear-angle millimeter-wave radar to detect lateral dynamic targets; If the pre-collision time is 1.1 seconds, an alarm is issued for a crossing target that collides with the vehicle within 1.1 seconds and the vehicle is braked; the crossing target is a target whose heading angle meets the second preset condition.

6. The method according to claim 1, characterized in that The braking strategy includes: Detecting short-range static targets or longitudinally moving targets using the second short-range ultrasonic radar or the third short-range ultrasonic radar; If the pre-collision time is 0.9 seconds, an alarm is issued for a crossing target that collides with the vehicle within 0.9 seconds and the vehicle is braked.

7. The method according to claim 6, characterized in that The braking strategy includes: The braking condition of the vehicle includes that the speed of the vehicle is greater than 3 km / h or less than 7 km / h; The braking condition of the vehicle includes that the second short-range ultrasonic radar or the third short-range ultrasonic radar detects a target object that is less than 100 cm away from the vehicle.

8. A rear collision assistance device, characterized in that: include: A setting module, used to set the radar of the vehicle; the radar includes two medium- and long-range ultrasonic radars, two rear-angle millimeter-wave radars, and four short-range ultrasonic radars; A strategy formulation module, used for formulating a braking strategy according to the setting of the radar; A rear collision assistance module is used to perform rear collision assistance on the vehicle according to the braking strategy.

9. A computer device, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the rear collision assistance method as described in any one of claims 1 to 7 is implemented.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores instructions, and when the instructions are executed on a terminal device, the terminal device executes the rear collision assistance method as described in any one of claims 1 to 7.

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