A front and rear emergency collision control method and system

Abstract

The present invention discloses a forward and backward emergency collision control method, and the steps are as follows: S1, determine whether there is a target with dangerous collision, if there is no collision danger, continue to detect; if there is a collision risk, start the rear perception module; S2, determine whether there is a rear-end collision risk, if there is no rear-end collision risk, perform braking and pressure holding operations according to the forward collision risk level; S3, when it is determined that the emergency braking system is in the braking process, suppress the pressure holding state, and adaptively adjust the deceleration value; S4, when the braking pressure holding judgment module determines that the vehicle has stopped and is in the pressure holding state, request the ESC execution control module to release the pressure holding instruction, and request the EMS execution control module to release the torque, so as to reduce the rear-end collision risk. The present invention also discloses a forward and backward emergency collision control system. The present invention can reduce the rear-end collision that may be caused after emergency braking, avoid secondary injuries, and can be widely used in L2-level intelligent driving assistance systems for automobiles.

Description

Technical Field

[0001] The present invention relates to an intelligent automobile driving assistance system, and in particular to a forward and backward emergency collision control method and system. Background Art

[0002] The existing emergency braking system is based on the information about dangerous targets detected by the perception sensor. When it is determined that the vehicle has a risk of collision with the dangerous target in front, the vehicle will automatically brake and hold pressure to avoid or mitigate the forward collision. Due to the complex road conditions, after the vehicle brakes and holds pressure, there is a risk of being rear-ended by the vehicle behind. Since the vehicle is still in the braking or pressure holding state at this time, it cannot make a judgment on the vehicle coming from behind.

[0003] Based on this, some solutions are based on the vehicle with a forward collision system to set up an anti-rear-end collision device. When the forward collision warning is triggered, the brake lights or anti-rear-end collision flashing lights will be turned on to remind the rear vehicle, thereby playing the role of early warning, such as patent CN104276078A. However, this solution can only passively remind and warn, and does not actively control the relevant actuators of the vehicle to operate to avoid collision.

[0004] In response to the above situation, some solutions use radar to monitor the speed and distance of the rear vehicle. When there is a risk of rear-end collision, the EMS actuator is controlled to accelerate and increase the distance from the rear vehicle, such as patent CN103010210A. However, this solution does not take into account the scenario where there is a dangerous target in front of the vehicle, that is, when there is also a vehicle in front of the vehicle, the acceleration of the vehicle will cause a forward collision.

[0005] Therefore, existing technical solutions often fall into the situation of treating the symptoms rather than the root cause. Due to the lack of consideration of the overall driving environment of the vehicle, they often lead to neglecting one thing while focusing on another, and are unable to improve the safety environment of the vehicle. Summary of the invention

[0006] The purpose of the present invention is to overcome the shortcomings of the above-mentioned background technology and provide a front and rear emergency collision control method and system, so that it can reduce the rear-end collision that may be caused after emergency braking and avoid secondary collision injuries.

[0007] The present invention provides a front and rear emergency collision control method, comprising the following steps: S1, a forward sensing module constantly detects and transmits the detection information to a forward collision risk judgment module, the forward collision risk judgment module determines whether there is a target with which there is a danger of collision, if there is no danger of collision, the forward sensing module continues to detect; if there is a risk of collision, the rear sensing module is started; S2, the rear sensing module detects whether there is a vehicle coming from behind and transmits the result to a rear rear-end collision risk judgment module, the rear rear-end collision risk judgment module determines whether there is a risk of rear-end collision, if there is no risk of rear-end collision, the vehicle normally follows the forward collision risk, etc. The brake and pressure-maintaining operations are performed at the first level; S3. When the rear-end collision risk judgment module determines that there is a rear-end collision risk, the brake pressure-maintaining judgment module determines whether it is currently in the braking process or in the brake stop and pressure-maintaining state. When the emergency braking system is in the braking process, the pressure-maintaining state is suppressed, and the deceleration value is adaptively adjusted to enable the vehicle to brake for a longer distance; S4. When the brake pressure-maintaining judgment module determines that the vehicle has stopped and is in the pressure-maintaining state, it requests the ESC execution control module to release the pressure-maintaining instruction, and requests the EMS execution control module to release the torque, so as to control the vehicle to creep for a short distance, increase the distance to the rear vehicle, and reduce the risk of rear-end collision.

[0008] In the above technical solution, the specific process of step S4 is as follows: S41, rear-end collision risk judgment: when the vehicle is in a braking and pressure-maintaining state, the distance between the vehicle and the dangerous target vehicle in front is d0, the distance between the rear vehicle and the vehicle is d1, and the speed of the rear vehicle is v1, and the average braking deceleration of the rear vehicle is set to a, then the braking distance of the rear vehicle is: Compare the size of d2 and d1. When d2>d1, the vehicle is at risk of being rear-ended by the vehicle coming from behind. The rear-end collision distance is: Δd=d2-d1. S42. Calculation of creeping distance: Assume that the minimum safe distance between the vehicle and the vehicle in front is d min , when d0>Δd+d min When d0<Δd+d min When the brake pressure maintenance judgment module determines that the distance between the vehicle and the front vehicle is close, the vehicle is creeping d0-d min The creeping distance is: S43, creep acceleration calculation: minimum collision time of the rear vehicle Then the car should be at t min Complete creep distance d in time r , so the creep acceleration is: The brake pressure holding judgment module limits the upper limit of creep acceleration, and the limit range is set to [0, a max ], the actual creep acceleration is: When the car creeps forward r After that, the braking distance of the following vehicle increases to d1+d r , slow down or avoid rear-end collision with the vehicle behind.

[0009] In the above technical solution, the brake pressure holding judgment module calculates the brake output deceleration, the release timing of the pressure holding signal, the creep displacement and the torque signal.

[0010] In the above technical solution, in step S1, the forward sensing module is composed of a camera and a millimeter-wave radar; in step S2, the backward sensing module is a millimeter-wave radar.

[0011] The present invention also discloses a front and rear emergency collision control system, wherein the control system stores a computer program, and the computer program can execute a front and rear emergency collision control method.

[0012] In the above technical solution, it also includes a vehicle information module, and the vehicle information module is used to determine the current state of the vehicle.

[0013] The front and rear emergency collision control method and system of the present invention have the following beneficial effects:

[0014] The present invention adds anti-rear-end collision creep control logic on the basis of forward emergency braking, reduces the risk of rear-end collision caused by emergency braking, and improves the driving safety of the whole vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the structure of the front and rear emergency collision control system of the present invention;

[0016] Figure 2 The overall process of the front and rear emergency collision control method of the present invention is attempted;

[0017] Figure 3 for Figure 2 The logical algorithm flow chart of scenario ②. DETAILED DESCRIPTION

[0018] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments, but the embodiments should not be construed as limiting the present invention.

[0019] like Figure 1 As shown in FIG, the system consists of a radar camera perception module (respectively a forward perception module and a rearward perception module), a vehicle information module, a forward collision risk judgment module, a rearward rear-end collision risk judgment module, and a brake pressure maintenance judgment module (i.e. Figure 1The system is composed of a rear-end collision judgment module, an EMS (Engine-Management-System, engine management system, commonly known as engine computer) execution control module and an ESC (Electronic Stability Controller, electronic stability control system) execution control module. The perception module collects the movement information of dangerous vehicles in front and behind, the vehicle information module determines the current state of the vehicle, the forward collision risk judgment module calculates the TTC (Time To Collision) between the vehicle and the dangerous target in front, the rear-end collision risk judgment module calculates the risk level of the vehicle being rear-ended by the rear vehicle, and the rear-end collision judgment module determines the current control strategy according to the forward and rearward collision risks, and then sends control information to the EMS execution control module and the ESC execution control module for action.

[0020] Among them, the brake pressure holding judgment module calculates the brake output deceleration, the release timing of the pressure holding signal, the creep displacement and torque and other signals.

[0021] like Figure 2 As shown, the front and rear of the vehicle are equipped with sensing detection systems, which are respectively a forward sensing module and a rear sensing module. The forward sensing module is composed of a camera and a millimeter-wave radar, and the rear sensing module is detected by a millimeter-wave radar. The front and rear emergency collision control method of the present invention includes the following steps:

[0022] 1. The forward perception module constantly detects whether there are any dangerous collision targets. If the forward collision risk judgment module determines that there is no collision risk, the forward perception module continues to detect; if the forward collision risk judgment module determines that there is a collision risk, the rear perception module is activated to detect whether there are oncoming vehicles and rear-end collision risks from behind.

[0023] If the rear-end collision risk judgment module determines that there is no rear-end collision risk, the vehicle will perform braking and pressure-maintaining operations normally according to the forward collision risk level; if the rear-end collision risk judgment module determines that there is a rear-end collision risk, the subsequent rear-end collision prevention control strategy will be executed.

[0024] 2. When the rear-end collision risk judgment module determines that there is a rear-end collision risk, the brake pressure holding judgment module determines whether it is currently in the braking process or in the brake stop pressure holding state. When the emergency brake system is in the braking process, the pressure holding state is suppressed and the deceleration value is adaptively adjusted to make the vehicle brake as far as possible;

[0025] 3. When the brake pressure holding judgment module determines that the vehicle has stopped and is in a pressure holding state, it requests the ESC execution control module to release the pressure holding instruction, and requests torque from the EMS execution control module to control the vehicle to creep a short distance, increase the distance between the vehicle and the rear vehicle, and reduce the risk of rear-end collision.

[0026] like Figure 3 The following example illustrates the judgment logic algorithm flow of the brake pressure holding judgment module in step 3:

[0027] 1. Rear-end collision risk judgment: The vehicle is in a brake-stop pressure-maintaining state, and the pressure-maintaining time is generally 2 seconds. At this time, the distance between the vehicle and the dangerous target vehicle in front is d0, the distance between the rear vehicle and the vehicle is d1, and the speed of the rear vehicle is v1. The average braking deceleration of the rear vehicle is set to a, and the braking distance of the rear vehicle is:

[0028]

[0029] Compare the size of d2 and d1. When d2>d1, the vehicle is at risk of being rear-ended by the vehicle coming from behind. The rear-end collision distance is:

[0030] Δd=d2-d1,

[0031] 2. Calculation of creeping distance: Assume that the minimum safe distance between the vehicle and the vehicle in front is d min , when d0>Δd+d min When d0<Δd+d min When , it means that the distance between the vehicle and the front vehicle is relatively close, and the vehicle can only crawl d0-d min The creeping distance is:

[0032]

[0033] 3. Creep acceleration calculation: minimum collision time of the rear vehicle Then the car should be at t min Complete creep distance d in time r , so the creep acceleration is:

[0034]

[0035] Considering that the creep acceleration is not easy to be too large, the creep acceleration limit range is set to [0, a max ], the actual creep acceleration is:

[0036]

[0037] Among them, a max From experience, a max ∈[0.5,1] m / s 2 ,

[0038] When the car creeps forward r After that, the braking distance of the following vehicle increases to d1+d r , which can slow down or avoid the rear-end collision of the following vehicle to a certain extent.

[0039] It can be seen that the key technical points of the present invention are the following two points:

[0040] 1) Pressure-maintaining and release judgment logic;

[0041] 2) Creep control method and logic.

[0042] The present invention adds anti-rear-end collision creep control logic on the basis of forward emergency braking, reduces the risk of rear-end collision caused by emergency braking, and improves the driving safety of the whole vehicle.

[0043] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

[0044] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

Claims

1. A front-to-back emergency collision control method, characterized in that: The steps include: S1, the forward sensing module detects at all times and transmits the detection information to the forward collision risk judgment module, and the forward collision risk judgment module determines whether there is a target with a dangerous collision. If there is no collision danger, the forward sensing module continues to detect; if there is a collision risk, the backward sensing module is started; S2, the rearward sensing module detects whether there is an oncoming vehicle from behind and transmits the result to the rearward rear-end collision risk judgment module, and the rearward rear-end collision risk judgment module judges whether there is a rear-end collision risk. If there is no rear-end collision risk, the vehicle normally performs braking and pressure-maintaining operations according to the forward collision risk level; S3. When the rear-end collision risk judgment module determines that there is a rear-end collision risk, the brake pressure holding judgment module determines whether the vehicle is currently in the braking process or in the brake stop pressure holding state. When the emergency braking system is in the braking process, the pressure holding state is suppressed and the deceleration value is adaptively adjusted to enable the vehicle to brake for a longer distance. S4: When the brake pressure holding judgment module determines that the vehicle has stopped and is in the pressure holding state, it requests the ESC execution control module to release the pressure holding instruction, and requests the EMS execution control module to make torque, so as to control the vehicle to creep for a short distance, increase the distance with the following vehicle, and reduce the risk of rear-end collision. The specific process is as follows: S41. Rear-end collision risk assessment: When the vehicle is in the braking and pressure-maintaining state, the distance between the vehicle and the dangerous target vehicle in front is d0, the distance between the vehicle and the rear vehicle is d1, and the speed of the rear vehicle is v1. The average braking deceleration of the rear vehicle is set to a, and the braking distance of the rear vehicle is: Compare the size of d2 and d1. When d2>d1, the vehicle is at risk of being rear-ended by the vehicle coming from behind. The rear-end collision distance is: Δd=d2-d1, S42, creeping distance calculation: Assume that the minimum safe distance between the vehicle and the vehicle in front is d min , when d0>Δd+d min When d0<Δd+d min When the brake pressure maintenance judgment module determines that the distance between the vehicle and the front vehicle is close, the vehicle is creeping d0-d min The creeping distance is: S43, creep acceleration calculation: minimum collision time of the rear vehicle Then the car should be at t min Complete creep distance d in time r , so the creep acceleration is: The brake pressure holding judgment module limits the upper limit of creep acceleration, and the limit range is set to 0, a max ], the actual creep acceleration is: Among them, the a max From experience, a max ∈[0.5,1] m / s 2 , When the car creeps forward r After that, the braking distance of the following vehicle increases to d1+d r , slow down or avoid rear-end collision with the vehicle behind.

2. The front and rear emergency collision control method according to claim 1, characterized in that: The brake pressure-maintaining judgment module calculates the brake output deceleration, the release timing of the pressure-maintaining signal, the creep displacement and the torque signal.

3. The front and rear emergency collision control method according to claim 2, characterized in that: In step S1, the forward perception module is composed of a camera and a millimeter wave radar; In step S2, the backward sensing module is a millimeter wave radar.

4. A front and rear emergency collision control system, wherein the control system stores a computer program, and the computer program can execute the front and rear emergency collision control method according to any one of claims 1 to 3.

5. The front and rear emergency collision control system according to claim 4, characterized in that: It also includes a vehicle information module, which is used to determine the current state of the vehicle.

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