Vehicle backward multi-target grading early warning device and method based on 4D millimeter wave radar

Abstract

The invention discloses a vehicle backward multi-target grading early warning device and method based on a 4D millimeter wave radar. The device comprises a 4D millimeter wave radar, a data processing module, a communication module and an early warning module. The 4D millimeter wave radar is integrated into the shark fin shell of the roof, a lightweight hardware architecture is adopted to optimize the manufacturing cost, and the problem that in a traditional scheme, signals are shielded by an approaching vehicle, and consequently early warning cannot be conducted on a rear fast approaching cart is solved through high-position installation of the roof. According to the method, the height and speed fused early warning decision logic is adopted in algorithm, differential early warning is achieved in combination with the height, the relative distance and the collision time, in addition, early warning conflicts are avoided through priority logic, and the problem that it is difficult to carry out differential early warning on a trolley and a cart in a traditional scheme is effectively solved.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle active safety, and particularly relates to a vehicle rear multi-target hierarchical warning device and method based on a 4D millimeter-wave radar. Background Art

[0002] The vehicle rear anti-collision warning system is a key technology to improve driving safety. Its core task is to accurately identify the vehicle approaching rapidly from behind and execute the corresponding rear anti-collision warning logic to reduce the risk of serious rear-end collisions.

[0003] However, in the driving scenario, there is often one or more other vehicles between the vehicle itself and the large truck approaching rapidly from behind. Even if the vehicle is equipped with a traditional rear anti-collision warning device at the rear, it is impossible to detect the rapidly approaching large truck and issue an alarm. In addition, the braking distances of different vehicle types vary greatly. The braking distance of a large truck is long, while that of a small vehicle is short. Therefore, if the effectiveness of the rear anti-collision warning system is to be significantly improved, it is necessary to adopt differentiated warning logics for small vehicles and large vehicles. The prerequisite for realizing this differentiated warning is the accurate judgment of the type of the vehicle behind, such as classification by features such as vehicle body height.

[0004] However, the existing solutions such as millimeter-wave radars, cameras, and lidar commonly used in the prior art all have three major technical bottlenecks: 1. The problem of vehicle type classification failure caused by the lack of perception in the vertical dimension; 2. The warning blind area problem caused by the signal being blocked in the low-mounted solution; 3. The problem that a single warning logic cannot adapt to the differentiated braking characteristics of large / small vehicles.

[0005] For example, an ordinary millimeter-wave radar cannot obtain the height of the target vehicle and it is difficult to judge whether it is a small vehicle or a large vehicle. In addition, because the installation position is low, the signal is easily blocked by the vehicle adjacent behind; the camera solution is significantly affected by environmental light and rain and fog weather, the imaging quality drops sharply and the ranging error is large, and it is difficult to accurately judge the relative distance; although the lidar has high-precision detection ability, its cost is high and it is difficult to be adapted to mid- and low-end vehicles. Therefore, it is necessary to propose a vehicle rear multi-target hierarchical warning device and method based on a 4D millimeter-wave radar to solve the above problems. Summary of the Invention

[0006] The purpose of the present invention is to integrate a 4D millimeter-wave radar with height perception with the roof shark fin, and combine a dynamic TTC compensation algorithm based on vehicle type classification to form an active safety protection system that integrates multi-target tracking, intelligent vehicle type identification, and hierarchical warning decision-making, ensuring seamless integration with the vehicle appearance while more effectively reducing the possibility of being rear-ended.

[0007] In a first aspect, the present invention provides a vehicle rear multi-target hierarchical warning device based on a 4D millimeter-wave radar, comprising: a 4D millimeter-wave radar, a data processing module, a communication module, and a warning module; the 4D millimeter-wave radar is connected to the data processing module, the data processing module is connected to the communication module, the communication module is connected to the warning module and the CAN bus interface of the vehicle, and the 4D millimeter-wave radar is integrated inside the shark fin structure housing on the top of the vehicle;

[0008] The 4D millimeter-wave radar is used to measure the relative distance S between the rear target vehicle and the vehicle, the relative speed ΔV with the vehicle, and the height H of the rear target vehicle;

[0009] The data processing module is used to obtain the vehicle speed V1 through the CAN bus, calculate the time to collision TTC according to the relative distance S between the rear target vehicle and the vehicle and the relative speed ΔV with the vehicle, and perform warning judgment according to the values of V 1、 S, ΔV, TTC, and H;

[0010] The communication module is used to obtain the vehicle speed V1 and the gear signal, activate the warning judgment of the vehicle rear collision warning device when the vehicle speed V1 and the gear signal meet the preset conditions, and transmit the control instruction of the data processing module to the warning module;

[0011] The warning module is used to trigger the vehicle rear collision warning according to the control instruction of the data processing module.

[0012] Further, the shark fin structure housing includes a three-layer gradient composite structure:

[0013] The outer layer is a carbon fiber reinforced PEEK layer with a thickness of 0.8 mm ± 0.05 mm and a surface roughness Ra ≤ 0.8 μm; the windward surface curvature radius R1 = 120 mm ± 5 mm, and the leeward surface curvature radius R2 = 80 mm ± 3 mm;

[0014] The middle layer is a nano-aerogel heat insulation layer with a porosity of 92% ± 1% and a thickness of 2.5 mm ± 0.1 mm;

[0015] The inner layer is a 6061-T6 aluminum alloy substrate with an anodic oxidation film thickness of 25 μm ± 2 μm.

[0016] Further, a thermal conductive silicone layer is provided on the aluminum alloy substrate. The thermal conductive silicone layer has a thickness of 3 mm ± 0.2 mm, contains aluminum nitride particles with a volume fraction of 30%, a particle size D50 = 8 μm ± 1 μm, and forms a concentration gradient along the heat dissipation direction, 35% ± 2% on the laser side and 25% ± 2% on the housing side.

[0017] Further, the three-layer composite structure is manufactured by a gradient sintering process, and the sintering temperature curve adopts a three-stage heating with 300°C, 420°C, and 580°C; the thickness of the interlayer transition layer is 50 ± 5 μm; the cooling rate is 8°C / min ± 0.5°C.

[0018] Further, the operating frequency band of the 4D millimeter-wave radar is 76 - 81 GHz, and the measurement distance is 80 m.

[0019] Second invention, the present invention provides a vehicle rear multi-target hierarchical warning method based on a 4D millimeter-wave radar, which is used for the vehicle rear multi-target hierarchical warning device based on the 4D millimeter-wave radar described above. The method includes:

[0020] Step 1: Activate the vehicle rear multi-target hierarchical warning method based on the 4D millimeter-wave radar when the vehicle is in the D gear and meets any of the following speed conditions: 0 km / h ≤ V1 < 120 km / h;

[0021] Step 2: Obtain the vehicle speed V1 of the vehicle, the relative distance S between the rear target vehicle and the vehicle, the relative speed ΔV with the vehicle, and the height H of the target vehicle, and calculate the time to collision TTC;

[0022] Step 3: Perform warning judgments for the warning modes of preventing being rear-ended by a car and preventing being rear-ended by a large vehicle according to the values of V 1、 ΔV, S, TTC, and H.

[0023] Further, in step 2, calculate the time to collision TTC according to TTC = S / ΔV.

[0024] Further, in step 3, when the body height H of the nearest vehicle behind the vehicle < H', it is the warning mode of preventing being rear-ended by a car; in this warning mode, select the nearest vehicle behind as the target vehicle, and calculate TTC according to the relative distance S between the target vehicle and the vehicle and the relative speed ΔV with the vehicle;

[0025] ΔV > V b , when TTC < T1, trigger the vehicle rear anti-collision warning;

[0026] V a ≤ΔV≤V b , when TTC < (T1 × ΔV) / V b , trigger the vehicle rear anti-collision warning;

[0027] ΔV < V a , do not trigger the vehicle rear anti-collision warning;

[0028] Among them, H' is the preset vehicle height threshold, V a 、V bΔV is the preset ΔV threshold, and T1 is the preset TTC threshold.

[0029] Further, in step three, when there is a vehicle with a body height H≥H’ within the rear distance S’ of the host vehicle, it is the large vehicle rear-end collision prevention warning mode; in this warning mode, among the vehicles with a rear body height H≥H’, the vehicle closest to the host vehicle is selected as the target vehicle, and the TTC is calculated based on the relative distance S and the relative speed ΔV between the target vehicle and the host vehicle.

[0030] When 0 km / h ≤ V1 < V’:

[0031] ΔV > V d , a vehicle rearward collision prevention warning is triggered when TTC < T2;

[0032] V c ≤ΔV≤V d , a vehicle rearward collision prevention warning is triggered when TTC < (T2×ΔV) / V d ;

[0033] ΔV < V c , no vehicle rearward collision prevention warning is triggered;

[0034] When V’ ≤ V1 < 120 km / h:

[0035] ΔV > V f , a vehicle rearward collision prevention warning is triggered when S < S1 and TTC < T3;

[0036] V e ≤ΔV≤V f , a vehicle rearward collision prevention warning is triggered when S < S2 and TTC < T3;

[0037] ΔV < V e , no vehicle rearward collision prevention warning is triggered;

[0038] Among them, S’, S1, and S2 are preset distance thresholds, H’ is a preset vehicle height threshold, V’ is a preset speed threshold, and V c 、V d 、V e 、V f are preset ΔV thresholds, and T2 and T3 are preset TTC thresholds.

[0039] Further, when ΔV < 1 km / h, let TTC be infinite to avoid TTC calculation failure; when both the small vehicle rear-end collision prevention warning mode and the large vehicle rear-end collision prevention warning mode are triggered, the warning mode with a smaller TTC is preferentially responded to; when both the small vehicle rear-end collision prevention warning mode and the large vehicle rear-end collision prevention warning mode are triggered, if the TTCs of the two warning modes are equal, the large vehicle rear-end collision prevention warning mode is preferentially responded to.

[0040] The present invention has the following beneficial effects: The vehicle rear multi-target hierarchical warning device and method based on a 4D millimeter-wave radar according to the present invention integrates the 4D millimeter-wave radar into the shark fin housing on the roof, adopts a lightweight hardware architecture to optimize the manufacturing cost, and solves the problem in the traditional solution that the signal is blocked by adjacent vehicles, resulting in the inability to warn of large vehicles approaching rapidly from the rear by installing it at a high position on the roof. In terms of the algorithm, a warning decision logic that fuses height and speed is adopted, and differential warnings are realized by combining height, relative distance, and time to collision. In addition, warning conflicts are avoided through the priority logic, effectively solving the problem that it is difficult to distinguish between small vehicles and large vehicles in the traditional solution. Strong scalability: It supports adjusting the warning threshold through software upgrade to adapt to the road safety standards of different countries / regions. The present invention is applicable to a variety of small and medium-sized vehicles, especially SUVs, MPVs, small and medium-sized trucks, etc. with a vehicle body height higher than 1.6 meters. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions of the present invention, the accompanying drawings required for use in the embodiments will be briefly introduced below. Obviously, for those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0042] Figure 1 It is a module connection diagram of the vehicle rear multi-target hierarchical warning device based on a 4D millimeter-wave radar according to the present invention;

[0043] Figure 2 It is a schematic diagram of the field of view angle of the vehicle rear multi-target hierarchical warning device based on a 4D millimeter-wave radar according to the present invention;

[0044] Figure 3 It is a flowchart of the vehicle rear multi-target hierarchical warning method based on a 4D millimeter-wave radar according to the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0045] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the specific embodiments and corresponding accompanying drawings of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention. The technical solutions provided by each embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

[0046] Please refer to Figure 1 and Figure 2, an embodiment of the present invention provides a vehicle rear multi-target hierarchical warning device based on a 4D millimeter-wave radar, including: a 4D millimeter-wave radar, a data processing module, a communication module, and a warning module; the 4D millimeter-wave radar refers to a four-dimensional radar that can simultaneously measure the distance, speed, horizontal angle, and height of a target. The 4D millimeter-wave radar is connected to the data processing module, the data processing module is connected to the communication module, the communication module is connected to the warning module and the CAN bus interface of the vehicle, and the 4D millimeter-wave radar is integrated inside the shark fin structure housing on the top of the vehicle.

[0047] In this embodiment, the shark fin structure integrated with the 4D millimeter-wave radar is installed behind the midline of the vehicle roof, and the height H = 1.6m ± 0.05m. The 4D millimeter-wave radar is used to measure the relative distance S between the rear target vehicle and the vehicle, the relative speed ΔV with the vehicle, and the height H of the rear target vehicle.

[0048] The data processing module is used to obtain the vehicle speed V1 through the CAN bus, calculate the time to collision TTC according to the relative distance S between the rear target vehicle and the vehicle and the relative speed ΔV with the vehicle, and perform warning judgment according to the values of V 1、 S, ΔV, TTC, and H.

[0049] The communication module is used to obtain the vehicle speed V1 and the gear signal, activate the warning judgment of the vehicle rear collision warning device when the vehicle speed V1 and the gear signal meet the preset conditions, and transmit the control instruction of the data processing module to the warning module.

[0050] The warning module is used to trigger the vehicle rear collision warning according to the control instruction of the data processing module. The warning module has the following functions: visual warning, which can flash the taillights of the vehicle to remind the driver of the rear vehicle to reduce the speed; sound warning, which emits a sound alarm through the buzzer to remind the driver of the vehicle to be careful of the rear.

[0051] Specifically, the shark fin structure housing includes a three-layer gradient composite structure: the outer layer is a carbon fiber reinforced polyetheretherketone (PEEK) layer with a thickness of 0.8 mm ± 0.05 mm and a surface roughness Ra ≤ 0.8 μm; the curvature radius R1 of the windward surface A is 120 mm ± 5 mm, and the curvature radius R2 of the leeward surface B is 80 mm ± 3 mm; the middle layer is a nano-aerogel thermal insulation layer with a porosity of 92% ± 1% and a thickness of 2.5 mm ± 0.1 mm; the inner layer is a 6061-T6 aluminum alloy substrate with an anodic oxidation film thickness of 25 μm ± 2 μm. The three-layer composite structure is manufactured by a gradient sintering process, and the sintering temperature curve uses three-stage heating at 300 °C, 420 °C, and 580 °C; the thickness of the interlayer transition layer is 50 ± 5 μm; the cooling rate is 8 °C / min ± 0.5 °C. A thermal conductive silicone layer is provided on the aluminum alloy substrate, with a thickness of 3 mm ± 0.2 mm, containing aluminum nitride particles with a volume fraction of 30%, a particle size D50 = 8 μm ± 1 μm, and a concentration gradient is formed along the heat dissipation direction, 35% ± 2% on the laser side and 25% ± 2% on the housing side. The thermal conductive silicone layer and the three-layer gradient composite structure work together to improve the heat dissipation performance and ensure the stable operation of the device in a high-temperature environment.

[0052] The operating frequency band of the 4D millimeter-wave radar is 76 - 81 GHz, corresponding to a wavelength of approximately 3.7 - 3.95 mm, a horizontal field of view of 120°, a vertical field of view of 45°, and a measurement distance of 80 m. The present invention creatively hides the 4D millimeter-wave radar inside the shark fin housing, achieving a high degree of integration of the two. The volume is significantly reduced compared to traditional millimeter-wave radars and solid-state lidars, without the need to modify the vehicle body structure, and it has visual concealment, maintaining the integrity of the vehicle appearance. The hardware cost of the present invention is significantly lower than that of the lidar solution.

[0053] An embodiment of the present invention also provides a vehicle rear multi-target hierarchical warning method based on a 4D millimeter-wave radar, which is used for the vehicle rear multi-target hierarchical warning device based on the 4D millimeter-wave radar described above, and is characterized in that the method includes:

[0054] Step 1: Activate the vehicle rear multi-target hierarchical warning method based on the 4D millimeter-wave radar when the vehicle is in the D gear and satisfies any of the following speed conditions: 0 km / h ≤ V1 < 120 km / h.

[0055] Step 2: Obtain the vehicle speed V1 of the host vehicle, the relative distance S between the rear target vehicle and the host vehicle, the relative speed ΔV with the host vehicle, and the height H of the target vehicle, and calculate the time to collision TTC.

[0056] Specifically, in Step 2, the time to collision TTC is calculated according to TTC = S / ΔV.

[0057] Step 3: According to V 1、Perform early warning judgments on the values of ΔV, S, TTC, and H for the early warning modes of preventing being rear-ended by a car and preventing being rear-ended by a large vehicle.

[0058] Specifically, in step three, when the body height H of the nearest vehicle behind the host vehicle is < H’, it is the early warning mode for preventing being rear-ended by a car; in this early warning mode, select the nearest vehicle behind as the target vehicle, and calculate TTC based on the relative distance S between the target vehicle and the host vehicle and the relative speed ΔV between the target vehicle and the host vehicle.

[0059] ΔV > V b , when TTC < T1, trigger the vehicle's rearward collision prevention early warning.

[0060] V a ≤ΔV≤V b , when TTC < (T1×ΔV) / V b , trigger the vehicle's rearward collision prevention early warning.

[0061] ΔV < V a , do not trigger the vehicle's rearward collision prevention early warning.

[0062] Among them, H’ is the preset vehicle height threshold, V a 、V b is the preset ΔV threshold, and T1 is the preset TTC threshold.

[0063] When there is a vehicle with a body height H ≥ H’ within the distance S’ behind the host vehicle, it is the early warning mode for preventing being rear-ended by a large vehicle; in this early warning mode, among the vehicles with a body height H ≥ H’ behind, select the vehicle closest to the host vehicle as the target vehicle, and calculate TTC based on the relative distance S between the target vehicle and the host vehicle and the relative speed ΔV between the target vehicle and the host vehicle.

[0064] When 0 km / h ≤ V1 < V’:

[0065] ΔV > V d , trigger the vehicle's rearward collision prevention early warning when TTC < T2;

[0066] V c ≤ΔV≤V d , trigger the vehicle's rearward collision prevention early warning when TTC < (T2×ΔV) / V d ;

[0067] ΔV < V c , do not trigger the vehicle's rearward collision prevention early warning.

[0068] When V’ ≤ V1 < 120 km / h:

[0069] ΔV > V f , trigger the vehicle's rearward collision prevention early warning when S < S1 and TTC < T3;

[0070] V e ≤ΔV≤V f When S < S2 and TTC < T3, trigger the vehicle's rearward collision avoidance warning;

[0071] ΔV < V e , do not trigger the vehicle's rearward collision avoidance warning;

[0072] Wherein, S’, S1, and S2 are preset distance thresholds, H’ is a preset vehicle height threshold, V’ is a preset speed threshold, and V c 、V d 、V e 、V f are preset ΔV thresholds, and T2 and T3 are preset TTC thresholds.

[0073] The present invention also sets a ΔV approaching zero protection: when ΔV < 1 km / h, set TTC to infinity to avoid TTC calculation failure. Warning priority judgment: when both the warning mode for preventing a car from rear-ending and the warning mode for preventing a large vehicle from rear-ending are triggered, preferentially respond to the warning mode with a smaller TTC; when both the warning mode for preventing a car from rear-ending and the warning mode for preventing a large vehicle from rear-ending are triggered, if the TTCs of the two warning modes are equal, preferentially respond to the warning mode for preventing a large vehicle from rear-ending.

[0074] Please refer to Figure 3 , in this embodiment, by optimizing the above threshold parameters, the vehicle rearward multi-target hierarchical warning method based on a 4D millimeter-wave radar is specifically as follows:

[0075] When the body height H of the nearest vehicle behind the host vehicle is < 2.6 m, it is the warning mode for preventing a car from rear-ending; in this warning mode, select the nearest vehicle behind as the target vehicle, and calculate TTC according to the relative distance S between the target vehicle and the host vehicle and the relative speed ΔV between the target vehicle and the host vehicle. H’ = 2.6 m is determined based on the average height of large trucks in the relevant standards of the vehicle outline size limit for road vehicles in this field.

[0076] ΔV > 30 km / h, TTC < 1.5, trigger the vehicle's rearward collision avoidance warning;

[0077] 10 km / h ≤ ΔV ≤ 30 km / h, TTC < 1.5 / 30 × ΔV, trigger the vehicle's rearward collision avoidance warning;

[0078] ΔV < 10 km / h, do not trigger the vehicle's rearward collision avoidance warning.

[0079] When there is a vehicle with a body height ≥ 2.6m within 70m behind the host vehicle, it is the early warning mode to prevent large vehicle rear-end collisions; in this early warning mode, among the vehicles with a rear body height H ≥ 2.6m, the vehicle closest to the host vehicle is selected as the target vehicle, and the TTC is calculated based on the host vehicle speed V1, the relative distance S between the target vehicle and the host vehicle, and the relative speed ΔV with the host vehicle.

[0080] When 0km / h ≤ V1 < 60km / h:

[0081] When ΔV > 40km / h and TTC < 3s, the vehicle rearward collision avoidance warning is triggered;

[0082] When 10km / h ≤ ΔV ≤ 40km / h and TTC < 3 / 40 × ΔV, the vehicle rearward collision avoidance warning is triggered;

[0083] When ΔV < 10km / h, the vehicle rearward collision avoidance warning is not triggered.

[0084] When 60km / h ≤ V1 < 120km / h:

[0085] When ΔV > 30km / h, S < 70m, and TTC < 6s, the vehicle rearward collision avoidance warning is triggered;

[0086] When 10km / h ≤ ΔV ≤ 30km / h, S < 60m and TTC < 6s, the vehicle rearward collision avoidance warning is triggered;

[0087] When ΔV < 10km / h, the vehicle rearward collision avoidance warning is not triggered.

[0088] The following is an example of the typical application scenarios of the present invention:

[0089] Scenario 1: When waiting for a red light, the vehicle speed is 0km / h.

[0090] A 2.9-meter-high muck truck approaches from behind at 60km / h. When the distance from the host vehicle is 50 meters, the system triggers an early warning.

[0091] Scenario 2: In a scenario of slow driving during heavy traffic congestion on the highway, the vehicle speed is 10km / h.

[0092] There is a regular sedan 5 meters behind the host vehicle, and a 3-meter-high large truck approaches at a speed of 60km / h behind it. When the distance between the large truck and the host vehicle is about 50 meters, the system triggers an early warning.

[0093] Scenario 3: In a scenario of high-speed driving, the vehicle speed is 70km / h.

[0094] There is a 3-meter-high large truck approaching from behind the host vehicle at a speed of 95km / h. When the distance between the large truck and the host vehicle is about 42 meters, the system triggers an early warning.

[0095] As can be seen from the above embodiments, the vehicle rear multi-target hierarchical early warning device and method based on a 4D millimeter-wave radar according to the present invention integrate the 4D millimeter-wave radar into the shark fin housing on the roof, adopt a lightweight hardware architecture to optimize the manufacturing cost, and solve the problem that the signal is blocked by adjacent vehicles in the traditional solution, resulting in the inability to give an early warning to a large vehicle approaching rapidly from the rear. In terms of the algorithm, an early warning decision logic that fuses height and speed is adopted, and differential early warning is realized by combining height, relative distance, and time to collision. In addition, the early warning conflict is avoided through the priority logic, effectively solving the problem that it is difficult to distinguish between small vehicles and large vehicles in the traditional solution. It has strong scalability: it supports adjusting the early warning threshold through software upgrade to adapt to the road safety standards of different countries / regions. The present invention is applicable to a variety of small and medium-sized vehicles, especially SUVs, MPVs, small and medium-sized trucks, etc. with a vehicle body height higher than 1.6 meters.

[0096] An embodiment of the present invention also provides a storage medium, in which a computer program is stored. When the computer program is executed by a processor, some or all of the steps in the embodiments of the vehicle rear multi-target hierarchical early warning method based on a 4D millimeter-wave radar provided by the present invention are implemented. The storage medium can be a magnetic disk, an optical disk, a read-only memory (ROM), a random access memory (RAM), or the like.

[0097] Those skilled in the art can clearly understand that the technology in the embodiments of the present invention can be implemented by means of software plus a necessary general hardware platform. Based on such an understanding, the technical solution in the embodiments of the present invention, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in various embodiments or some parts of the embodiments of the present invention.

[0098] The above-described embodiments of the present invention do not constitute a limitation to the protection scope of the present invention.

Claims

1. A vehicle rearward multi-target graded warning device based on 4D millimeter wave radar, characterized in that: Including: A 4D millimeter-wave radar, a data processing module, a communication module, and a warning module; the 4D millimeter-wave radar is connected to the data processing module, the data processing module is connected to the communication module, the communication module is connected to the warning module and the CAN bus interface of the vehicle, and the 4D millimeter-wave radar is integrated inside the shark fin structure housing on the top of the vehicle; The 4D millimeter-wave radar is used to measure the relative distance S between the rear target vehicle and the vehicle itself, the relative speed ΔV with the vehicle itself, and the height H of the rear target vehicle; The data processing module is used to obtain the vehicle speed V1 through the CAN bus, calculate the collision time TTC according to the relative distance S between the rear target vehicle and the vehicle and the relative speed ΔV between the rear target vehicle and the vehicle, and calculate the collision time TTC according to V 1、 The values ​​of S, ΔV, TTC, and H are used to perform early warning judgment; The communication module is used to obtain the vehicle speed V1 and gear signal of the vehicle itself, activate the warning judgment of the vehicle rear collision warning device when the vehicle speed V1 and gear signal meet the preset conditions, and transmit the control instruction of the data processing module to the warning module; The warning module is used to trigger the vehicle rear collision warning according to the control instruction of the data processing module.

2. The vehicle rearward multi-target graded warning device based on 4D millimeter wave radar as claimed in claim 1, characterized in that: The shark fin structure housing includes a three-layer gradient composite structure: The outer layer is a carbon fiber reinforced PEEK layer with a thickness of 0.8mm ± 0.05mm and a surface roughness Ra ≤ 0.8μm; the windward surface curvature radius R1 = 120mm ± 5mm, and the leeward surface curvature radius R2 = 80mm ± 3mm; The middle layer is a nano-aerogel heat insulation layer with a porosity of 92% ± 1% and a thickness of 2.5mm ± 0.1mm; The inner layer is a 6061-T6 aluminum alloy substrate with an anodic oxidation film thickness of 25μm ± 2μm.

3. The vehicle rearward multi-target graded warning device based on 4D millimeter wave radar as claimed in claim 2, characterized in that: A thermal conductive silicone layer is provided on the aluminum alloy substrate, the thickness of the thermal conductive silicone layer is 3mm ± 0.2mm, it contains aluminum nitride particles with a volume fraction of 30%, the particle size D50 = 8μm ± 1μm, and a concentration gradient is formed along the heat dissipation direction, 35% ± 2% on the laser side and 25% ± 2% on the housing side.

4. The vehicle rearward multi-target graded warning device based on 4D millimeter wave radar as claimed in claim 3 is characterized in that: The three-layer composite structure is manufactured by a gradient sintering process, and the sintering temperature curve uses three-stage heating at 300°C, 420°C, and 580°C; the thickness of the interlayer transition layer is 50 ± 5μm; the cooling rate is 8°C / min ± 0.5°C.

5. The vehicle rearward multi-target graded warning device based on 4D millimeter wave radar as claimed in claim 4, characterized in that: The working frequency band of the 4D millimeter-wave radar is 76 - 81GHz, and the measurement distance is 80m.

6. A vehicle rearward multi-target graded warning method based on 4D millimeter wave radar, used in the vehicle rearward multi-target graded warning device based on 4D millimeter wave radar according to any one of claims 1 to 5, characterized in that: The method includes: Step 1: Activate the vehicle rear multi-target hierarchical warning method based on the 4D millimeter-wave radar when the vehicle is in the D gear and meets any of the following speed conditions: 0km / h ≤ V1 < 120km / h; Step 2: Obtain the vehicle speed V1 of the vehicle itself, the relative distance S between the rear target vehicle and the vehicle itself, the relative speed ΔV with the vehicle itself, and the height H of the target vehicle, and calculate the time to collision TTC; Step 3: According to V 1、 The values ​​of ΔV, S, TTC, and H execute the warning judgment of the warning mode for preventing the rear-end collision by a small car and the warning mode for preventing the rear-end collision by a large car.

7. The vehicle rearward multi-target graded warning method based on 4D millimeter wave radar as claimed in claim 6, characterized in that: In Step 2, Calculate the time to collision TTC according to TTC = S / ΔV.

8. The vehicle rearward multi-target graded warning method based on 4D millimeter wave radar as claimed in claim 6, characterized in that: In Step 3, When the body height H of the nearest vehicle behind the vehicle is < H', it is the warning mode to prevent small vehicle rear-end collision; in this warning mode, select the nearest vehicle behind as the target vehicle, and calculate TTC according to the relative distance S between the target vehicle and the vehicle itself and the relative speed ΔV with the vehicle itself; ΔV>V b , when TTC < T1, trigger the vehicle's rear collision avoidance warning; V a ≤ΔV≤V b , TTC < (T1 × ΔV) / V b When the vehicle's rear collision warning is triggered; ΔV <V a , the vehicle's rearward collision avoidance warning is not triggered; Where H' is the preset vehicle height threshold, V a 、V b is the preset ΔV threshold, and T1 is the preset TTC threshold.

9. The vehicle rearward multi-target graded warning method based on 4D millimeter wave radar as claimed in claim 6, characterized in that: In Step 3, When there is a vehicle with a height H≥H' within the distance S' behind the vehicle, the warning mode is activated to prevent rear-end collision with a large vehicle. In this warning mode, among the vehicles with a height H≥H' behind the vehicle, the vehicle closest to the vehicle is selected as the target vehicle, and the TTC is calculated based on the relative distance S between the target vehicle and the vehicle and the relative speed ΔV between the target vehicle and the vehicle. When 0km / h≤V1 <V’: ΔV>V d , when TTC < T2, trigger the vehicle's rear collision avoidance warning; V c ≤ΔV≤V d , TTC < (T2 × ΔV) / V d When the vehicle's rear collision warning is triggered; ΔV <V c , the vehicle's rearward collision avoidance warning is not triggered; When V'≤V1<120km / h: ΔV > V f When, f , S < S1 and TTC < T3, trigger the vehicle's rearward collision avoidance warning; V e ≤ΔV≤V f When S < S2 and TTC < T3, trigger the vehicle's rear collision avoidance warning; ΔV <V e , the vehicle's rearward collision avoidance warning is not triggered; Wherein, S', S1, S2 are preset distance thresholds, H' is the preset vehicle height threshold, V' is the preset speed threshold, V c 、V d 、V e 、V f is the preset ΔV threshold, T2 and T3 are the preset TTC thresholds.

10. The vehicle rearward multi-target graded warning method based on 4D millimeter wave radar as claimed in claim 6, characterized in that: When ΔV is less than 1km / h, TTC is set to infinity to avoid TTC calculation failure; when both the small car rear-end collision prevention warning mode and the large car rear-end collision prevention warning mode are triggered, the warning mode with a smaller TTC is prioritized; when both the small car rear-end collision prevention warning mode and the large car rear-end collision prevention warning mode are triggered, if the TTCs of the two warning modes are equal, the large car rear-end collision prevention warning mode is prioritized.

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