A rear-end collision warning system and method for roadside vehicles avoiding pedestrians

Abstract

This invention belongs to the field of motor vehicle driving safety and discloses a rear-end collision warning system and method for roadside vehicles to avoid pedestrians. The warning system includes a pedestrian detection millimeter-wave radar and a vehicle detection millimeter-wave radar, which are electrically connected to the signal input terminal of a controller, and LED warning lights and a voice device, which are electrically connected to the signal output terminal of the controller. The warning system can determine the collision risk between the vehicle in front and the pedestrian, as well as the rear-end collision risk between the vehicle in front and the vehicle behind, based on the parameter information obtained by the pedestrian detection millimeter-wave radar and the vehicle detection millimeter-wave radar and the information preset in the controller. It then provides graded warnings to pedestrians and drivers of vehicles behind through the roadside LED warning lights and the voice device. The warning method solves the problem of the simultaneous occurrence of pedestrian collision and rear-end collision risks, and has high safety and high reliability.

Description

Technical Field

[0001] This invention relates to the field of motor vehicle driving safety, specifically to a rear-end collision warning system and method for roadside vehicles to avoid pedestrians. Background Technology

[0002] It is very common for pedestrians to suddenly cross the road at crosswalks or where there are no crosswalks. If drivers fail to notice pedestrians in time and take emergency braking measures, they are often rear-ended by the vehicles behind.

[0003] Existing methods for mitigating pedestrian and rear-end collision risks are diverse, primarily focusing on vehicle-mounted risk control research. Pedestrian collision mitigation involves installing pedestrian collision absorbers on vehicles to reduce pedestrian injury, or using various sensors installed in the vehicle to determine the presence of pedestrians ahead and the risk of a pedestrian collision. If a risk is identified, the system provides early warning to the driver or initiates emergency braking via vehicle assistance systems. Rear-end collision mitigation mainly utilizes rear-end collision energy-absorbing seats to reduce passenger injury, or uses sensors installed in the vehicle to obtain parameters such as the speed and distance of surrounding vehicles to determine the risk of a rear-end collision. If a risk is identified, the system provides audible or visual warnings to the driver of the vehicle in question or the driver of the other vehicle.

[0004] Most current research focuses on mitigating one type of collision risk, rarely considering scenarios where both risks occur simultaneously. This is especially true when a vehicle slows down to avoid a pedestrian, potentially causing a rear-end collision. Furthermore, sometimes the risk of a collision between the vehicle ahead and a pedestrian is not severe, but a rear-end collision is imminent, leading to emergency braking by the driver and causing unnecessary property damage. Currently, pedestrian and rear-end collision mitigation primarily relies on vehicle-mounted systems for passive or active prevention, rarely utilizing roadside warning systems. However, vehicle-mounted risk mitigation is costly and difficult to widely implement. Therefore, this invention proposes a roadside warning system and method for preventing rear-end collisions when a vehicle is avoiding a pedestrian, considering both pedestrian and rear-end collisions simultaneously. This system provides drivers with timely and necessary information, reducing the probability of a rear-end collision while avoiding a pedestrian. Summary of the Invention

[0005] To address the problems existing in the prior art, the present invention aims to provide a rear-end collision warning system and method for roadside vehicles to avoid pedestrians. This warning system can determine the collision risk between the vehicle in front and the pedestrian, as well as the rear-end collision risk between the vehicle in front and the vehicle behind, based on parameter information obtained from pedestrian detection millimeter-wave radar and vehicle detection millimeter-wave radar, and information pre-set in the controller. It then provides graded warnings to pedestrians and drivers of vehicles behind via roadside LED warning lights and voice devices. This warning method solves the problem of simultaneous pedestrian collision and rear-end collision risks, and is highly safe and reliable.

[0006] To achieve the above objectives, the present invention employs the following technical solutions.

[0007] (i) A rear-end collision warning system for roadside vehicles when avoiding pedestrians, comprising: a pedestrian detection millimeter-wave radar, a vehicle detection millimeter-wave radar, a controller, an LED warning light, and a voice device; wherein the signal output terminals of the pedestrian detection millimeter-wave radar and the vehicle detection millimeter-wave radar are electrically connected to the signal input terminal of the controller, and the signal output terminal of the controller is electrically connected to the signal input terminal of the LED warning light and the voice device.

[0008] Preferably, the pedestrian detection millimeter-wave radar is installed on the side of the pedestrian crossing to detect the pedestrian's position, direction of travel, lateral speed, distance of the pedestrian entering the boundary of the danger zone, and distance of the pedestrian leaving the boundary of the danger zone.

[0009] The vehicle detection millimeter-wave radar is installed at a first preset distance in front of the pedestrian crossing to detect the speed of the vehicle in front, the speed of the vehicle behind, the longitudinal distance between the two vehicles, the length and width of the vehicle in front, and the position of the two vehicles.

[0010] The controller is installed on the side of the pedestrian walkway and is used to pre-set the lateral and longitudinal safety distances for pedestrians, as well as to process the information detected by the pedestrian detection millimeter-wave radar and the vehicle detection millimeter-wave radar and the pre-set information to determine the corresponding collision risk information; wherein, the collision risk information includes pedestrian collision risk and rear-end collision risk;

[0011] The LED warning light is installed at the center of the road at a second preset distance behind the pedestrian crossing, at a third preset distance above the ground, and is used to provide a light warning to the driver of the vehicle in front based on the collision risk information determined by the controller.

[0012] The voice device is installed on the side of the pedestrian crossing and is used to provide voice reminders to pedestrians based on the collision risk information determined by the controller.

[0013] Preferably, the first preset distance is 30-80 meters.

[0014] Preferably, the second preset distance is 30-80 meters.

[0015] Preferably, the third preset distance is 3-6 meters.

[0016] (II) A method for preventing rear-end collisions when a roadside vehicle avoids a pedestrian, comprising the following steps:

[0017] Step 1: Pedestrian detection millimeter-wave radar detects pedestrian position, direction of travel, and lateral speed v. p Vehicle detection millimeter-wave radar detects the speeds of the vehicle in front (v) and the vehicle behind (v). b Following distance L between vehicles b The length L and width D of the vehicle in front, and the specific positions of the vehicles in front and behind; and the longitudinal distance L between the vehicle in front and the pedestrian calculated based on the position information of the pedestrian and the vehicle. f ;

[0018] If the pedestrian detection millimeter-wave radar detects that a pedestrian is about to enter the danger zone, it detects the distance s from the pedestrian entering the danger zone boundary; if the pedestrian is already in the danger zone, it detects the distance j from the pedestrian leaving the danger zone boundary.

[0019] Step 2: The parameter information acquired by the pedestrian detection millimeter-wave radar and the vehicle detection millimeter-wave radar is transmitted to the controller. At the same time, the controller presets the pedestrian lateral safety distance e and the longitudinal safety distance b. The controller assesses the pedestrian collision risk and the rear-end collision risk based on the acquired parameter information and the preset parameter information.

[0020] Step 3: The controller determines the corresponding warning information for the LED warning lights and voice device based on the assessed pedestrian collision risk and rear-end collision risk.

[0021] Preferably, in step 2, the method for assessing pedestrian collision risk is as follows:

[0022] (a) If a pedestrian is detected about to enter the danger zone, calculate the time it will take for the pedestrian to enter the danger zone. And the time it takes for a pedestrian to leave danger zone B after entering it.

[0023] If the vehicle in front can pass through the danger zone before the pedestrian enters it, i.e., v*t A1 >L+L f +2b, or when the pedestrian leaves the danger zone, the vehicle in front enters the danger zone, i.e., v*t a2 <L f If so, there is no risk of collision for the pedestrian;

[0024] If v*t A1 ≤L+Lf +2b and v*t A2 ≤L f Then pedestrians will be at risk of collision;

[0025] (b) If a pedestrian is detected to be already in the danger zone, calculate the time it takes for the pedestrian to leave the danger zone. Calculate risk value If R≥0, there is a risk of collision for pedestrians; if R<0, there is no risk of collision.

[0026] (c) If a pedestrian is detected to be outside the danger zone and is walking in the direction away from the danger zone, then there is no risk of collision with the pedestrian.

[0027] Preferably, in step 2, the method for assessing the rear-end collision risk is as follows:

[0028] A rear-end collision risk model is established using the PATH algorithm. The risk value ω is determined based on the rear-end collision risk model. If ω>1, it means there is no risk of rear-end collision; if ω≤1, there is risk of rear-end collision.

[0029] More preferably, in the rear-end collision risk model, the safe distance formula is:

[0030]

[0031] Where d0 is the distance compensation, v rel τ is the relative speed between the vehicle in front and the vehicle behind, a is the maximum deceleration of the two vehicles, and τ is the sum of the system delay time and the driver's reaction time.

[0032] Risk Value Where, d br The critical braking distance, i.e.

[0033] Preferably, step 3 specifically includes:

[0034] If there is a risk of pedestrian collision, the LED warning light will turn red to remind the driver to slow down and stop, and at the same time the voice device will emit an audible reminder to pedestrians to pay attention to the vehicle;

[0035] If there is no risk of a pedestrian collision, and also no risk of a rear-end collision, the LED warning light will illuminate yellow to remind the driver to slow down; if there is a risk of a rear-end collision, the LED warning light will illuminate green to remind the driver of the vehicle in front to proceed directly, and at the same time, the voice device will emit an audible warning to pedestrians to be aware of the vehicle.

[0036] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0037] (1) In the roadside vehicle avoidance of pedestrian rear-end collision warning system of the present invention, the pedestrian detection millimeter-wave radar and the vehicle detection millimeter-wave radar are used to obtain parameter information. The controller processes the obtained information and the information preset in the controller to determine the pedestrian collision risk and rear-end collision risk information. Finally, the system provides graded warnings to pedestrians and drivers of vehicles behind through LED warning lights and voice devices. The warning system has a simple structure and comprehensive warning methods, which improves the driving safety of roadside vehicles when avoiding pedestrians.

[0038] (2) The method for preventing rear-end collisions when roadside vehicles avoid pedestrians in this invention solves the problem of simultaneous pedestrian collision and rear-end collision risks, and is highly safe and reliable; in addition, it determines the assessment methods for pedestrian collision risks and rear-end collision risks, taking into account all aspects. Attached Figure Description

[0039] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0040] Figure 1 A schematic diagram of a rear-end collision warning system for roadside vehicles when avoiding pedestrians;

[0041] Figure 2 A schematic diagram of the connection of a rear-end collision warning system for roadside vehicles when avoiding pedestrians;

[0042] Figure 3 A diagram illustrating the warning mode of a roadside vehicle rear-end collision warning system when avoiding pedestrians.

[0043] Figure 1 In the middle, 1. Rear vehicle; 2. Front vehicle; 3. Vehicle detection millimeter-wave radar; 4. Voice device; 5. Pedestrian detection millimeter-wave radar; 6. Controller; 7. LED warning lights. Detailed Implementation

[0044] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are only for illustrating the present invention and should not be regarded as limiting the scope of the present invention.

[0045] (I) Reference Figure 1-2 A rear-end collision avoidance warning system for roadside vehicles when avoiding pedestrians includes: a pedestrian detection millimeter-wave radar 5, a vehicle detection millimeter-wave radar 3, a controller 6, an LED warning light 7, and a voice device 4; wherein the signal output terminals of the pedestrian detection millimeter-wave radar 5 and the vehicle detection millimeter-wave radar 3 are electrically connected to the signal input terminals of the controller 6, and the signal output terminals of the controller 6 are electrically connected to the signal input terminals of the LED warning light 7 and the voice device 4.

[0046] Specifically, the pedestrian detection millimeter-wave radar 5 is installed on the side of the pedestrian crossing to detect the pedestrian's position, direction of travel, lateral speed, distance of the pedestrian entering the danger zone boundary, and distance of the pedestrian leaving the danger zone boundary.

[0047] The vehicle detection millimeter-wave radar 3 is installed 50 meters in front of the pedestrian crossing and is used to detect the speed of the vehicle in front 2, the speed of the vehicle behind 1, the longitudinal distance between the vehicle in front 2 and the vehicle behind 1, the length and width of the vehicle in front 2, and the position of the vehicle in front 2 and the vehicle behind 1.

[0048] The controller 6 is installed on the side of the pedestrian walkway. One end is electrically connected to the pedestrian detection and vehicle detection millimeter-wave radar 3 via a data interface, and the other end is electrically connected to the LED warning light 7 and the voice device 4 via an output data interface. The controller 6 is used to preset the lateral and longitudinal safety distances for pedestrians, and to process the information detected by the pedestrian detection millimeter-wave radar 5 and the vehicle detection millimeter-wave radar 3, as well as the preset information, to determine the corresponding collision risk information; wherein, the collision risk information includes pedestrian collision risk and rear-end collision risk.

[0049] The LED warning light 7 is installed 50 meters behind the pedestrian crossing in the center of the road, 4 meters above the ground, and is used to provide a light warning to the driver of the vehicle in front 2 based on the collision risk information determined by the controller 6.

[0050] The voice device 4 is installed on the side of the pedestrian crossing and is used to provide voice reminders to pedestrians based on the collision risk information determined by the controller 6.

[0051] (II) A method for preventing rear-end collisions when a roadside vehicle avoids a pedestrian, comprising the following steps:

[0052] Step 1: Pedestrian detection millimeter-wave radar 5 detects pedestrian position, direction of travel, and lateral speed v. p Vehicle detection millimeter-wave radar 3 detects the speed v of the vehicle in front 2 and the speed v of the vehicle behind 1. b The longitudinal distance between the front vehicle 2 and the rear vehicle 1 (i.e., the following distance between the front and rear vehicles) L b The length L and width D of the first vehicle 2, and the specific positions of the first and second vehicles. Calculate the longitudinal distance L between the first vehicle 2 and the pedestrian based on the position information of the pedestrian and vehicles. f .

[0053] A pedestrian collision hazard zone B is defined. Based on the direction of travel, the pedestrian's location is determined, including zone A, hazard zone B, and zone C. Zone A is the area where the pedestrian is about to enter hazard zone B; zone C is the area where the pedestrian is outside hazard zone B and is leaving hazard zone B. If a pedestrian is detected about to enter hazard zone B, the distance s from the pedestrian's entry into hazard zone B is calculated. If the pedestrian is already in hazard zone B, the distance j from the pedestrian's exit from hazard zone B is detected.

[0054] Step 2: The parameter information acquired by the pedestrian detection millimeter-wave radar 5 and the vehicle detection millimeter-wave radar 3 is transmitted to the controller 6. At the same time, the controller 6 pre-sets the pedestrian lateral safety distance e and longitudinal safety distance b. The controller 6 evaluates the pedestrian collision risk X and the rear-end collision risk Y based on the acquired parameter information and the pre-set parameter information, as follows:

[0055] (a) Pedestrian collision risk assessment

[0056] refer to Figure 1 If a pedestrian is detected about to enter danger zone B from area A, calculate the time it will take for the pedestrian to enter danger zone B. And the time it takes for a pedestrian to leave danger zone B after entering it. If vehicle 2 can pass through danger zone B before the pedestrian enters it, i.e., v*t A1 >L+L f +2b, or when the pedestrian leaves danger zone B, the vehicle in front 2 enters danger zone B, i.e., v*t A2 <L f If v*t A1 ≤L+L f +2b and v*t A2 ≤L f If this occurs, pedestrians will be at risk of collision.

[0057] If a pedestrian is detected to be already in danger zone B, calculate the time it takes for the pedestrian to leave danger zone B. Calculate risk value If R ≥ 0, there is a risk of collision for pedestrians; if R < 0, there is no risk of collision.

[0058] If a pedestrian is detected to be outside danger zone B and walking in the direction away from danger zone B, meaning the pedestrian is currently in zone C, then there is no risk of collision for the pedestrian.

[0059] (b) Rear-end collision risk assessment

[0060] The rear-end collision risk model primarily considers the collision risk of the following vehicle 1 due to the deceleration of the preceding vehicle 2. This invention uses the PATH algorithm to establish the rear-end collision risk model, and the safe distance formula is:

[0061]

[0062] Where d0 is the distance compensation, v rel τ is the relative speed between the front vehicle 2 and the rear vehicle 1, a is the maximum deceleration of the two vehicles, and τ is the sum of the system delay time and the driver's reaction time.

[0063] Based on the established rear-end collision risk model, calculate the risk value. Where, d br The critical braking distance, i.e. If ω>1, it means there is no risk of rear-end collision; if ω≤1, there is a risk of rear-end collision.

[0064] Step 3: Based on the assessed pedestrian collision risk X and rear-end collision risk Y, controller 6 determines the corresponding warning information for LED warning lights 7 and voice device 4, as follows:

[0065] in accordance with Figure 3 In the warning mode diagram, if there is a risk of pedestrian collision (X), the LED warning light 7 will turn red to remind the driver to slow down and stop, and at the same time the voice device 4 will emit an audible warning to remind the pedestrian to pay attention to the vehicle.

[0066] If there is no risk of a pedestrian collision (X) and no risk of a rear-end collision (Y), the LED warning light 7 will turn yellow to remind the driver to slow down. If there is a risk of a rear-end collision (Y), the LED warning light 7 will turn green to remind the driver of the vehicle in front to pass directly, and at the same time the voice device 4 will emit an audible warning to the pedestrian to pay attention to the vehicle.

[0067] Although the present invention has been described in detail in this specification with general description and specific embodiments, some modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention are within the scope of protection claimed by the present invention.

Claims

1. A method for preventing rear-end collisions when a roadside vehicle avoids a pedestrian, characterized in that, Includes the following steps: Step 1: Pedestrian detection millimeter-wave radar detects pedestrian position, direction of travel, and lateral speed v. p Vehicle detection millimeter-wave radar detects the speeds of the vehicle in front (v) and the vehicle behind (v). b Following distance L between vehicles b The length L and width D of the vehicle in front, and the specific positions of the vehicles in front and behind; and the longitudinal distance L between the vehicle in front and the pedestrian calculated based on the position information of the pedestrian and the vehicle. f ; If the pedestrian detection millimeter-wave radar detects that a pedestrian is about to enter a danger zone, it detects the distance s of the pedestrian entering the danger zone boundary; If the pedestrian is in the danger zone, then detect the distance j of the pedestrian from the boundary of the danger zone; Step 2: The parameter information acquired by the pedestrian detection millimeter-wave radar and the vehicle detection millimeter-wave radar is transmitted to the controller. At the same time, the controller presets the pedestrian lateral safety distance e and the longitudinal safety distance b. The controller assesses the pedestrian collision risk and the rear-end collision risk based on the acquired parameter information and the preset parameter information. The method for assessing pedestrian collision risk is as follows: (a) If a pedestrian is detected about to enter the danger zone, calculate the time it will take for the pedestrian to enter the danger zone. And the time it takes for a pedestrian to leave danger zone B after entering it. If the vehicle in front can pass through the danger zone before the pedestrian enters it, i.e., v*t A1 >L+L f +2b, or when the pedestrian leaves the danger zone, the vehicle in front enters the danger zone, i.e., v*t A2 <L f If so, there is no risk of collision for the pedestrian; If v*t A1 ≤L+L f +2b and v*t A2 ≤L f Then pedestrians will be at risk of collision; (b) If a pedestrian is detected to be already in the danger zone, calculate the time it takes for the pedestrian to leave the danger zone. Calculate risk value If R≥0, there is a risk of collision for pedestrians; if R<0, there is no risk of collision. (c) If a pedestrian is detected to be outside the danger zone and is walking in the direction away from the danger zone, then there is no risk of collision with the pedestrian; The method for assessing the risk of rear-end collisions is as follows: A rear-end collision risk model is established using the PATH algorithm. The risk value ω is determined based on the rear-end collision risk model. If ω > 1, it means there is no risk of rear-end collision; if ω ≤ 1, there is a risk of rear-end collision. In the rear-end collision risk model, the safe distance formula is: Where d0 is the distance compensation, v rel τ is the relative speed between the vehicle in front and the vehicle behind, a is the maximum deceleration of the two vehicles, and τ is the sum of the system delay time and the driver's reaction time. Risk Value Where, d br The critical braking distance, i.e. Step 3: The controller determines the corresponding warning information for the LED warning lights and voice device based on the assessed pedestrian collision risk and rear-end collision risk.

2. The method for preventing rear-end collisions when roadside vehicles avoid pedestrians according to claim 1, characterized in that, Step 3 specifically involves: If there is a risk of pedestrian collision, the LED warning light will turn red to remind the driver to slow down and stop, and at the same time the voice device will emit an audible reminder to pedestrians to pay attention to the vehicle; If there is no risk of a pedestrian collision, and also no risk of a rear-end collision, the LED warning light will illuminate yellow to remind the driver to slow down; if there is a risk of a rear-end collision, the LED warning light will illuminate green to remind the driver of the vehicle in front to proceed directly, and at the same time, the voice device will emit an audible warning to pedestrians to be aware of the vehicle.

3. A warning system based on the method for preventing rear-end collisions when roadside vehicles avoid pedestrians as described in claim 1 or 2, characterized in that, include: The system includes a pedestrian detection millimeter-wave radar, a vehicle detection millimeter-wave radar, a controller, an LED warning light, and a voice device; wherein the signal output terminals of the pedestrian detection millimeter-wave radar and the vehicle detection millimeter-wave radar are electrically connected to the signal input terminal of the controller, and the signal output terminal of the controller is electrically connected to the signal input terminals of the LED warning light and the voice device. The pedestrian detection millimeter-wave radar is installed on the side of the pedestrian crossing to detect the pedestrian's position, direction of travel, lateral speed, distance of the pedestrian entering the danger zone boundary, and distance of the pedestrian leaving the danger zone boundary. The vehicle detection millimeter-wave radar is installed at a first preset distance in front of the pedestrian crossing to detect the speed of the vehicle in front, the speed of the vehicle behind, the longitudinal distance between the two vehicles, the length and width of the vehicle in front, and the position of the two vehicles. The controller is installed on the side of the pedestrian walkway and is used to pre-set the lateral and longitudinal safety distances for pedestrians, as well as to process the information detected by the pedestrian detection millimeter-wave radar and the vehicle detection millimeter-wave radar and the pre-set information to determine the corresponding collision risk information; wherein, the collision risk information includes pedestrian collision risk and rear-end collision risk; The LED warning light is installed at the center of the road at a second preset distance behind the pedestrian crossing, at a third preset distance from the ground, and is used to provide a light warning to the driver of the vehicle in front based on the collision risk information determined by the controller. If there is a risk of collision with a pedestrian, the LED warning light will turn red to remind the driver to slow down and stop; If there is no risk of collision with pedestrians and no risk of rear-end collision with the vehicle, the LED warning light will turn yellow to remind the driver to slow down. If there is no risk of collision with the pedestrian, but there is a risk of rear-end collision with the vehicle, the LED warning light will turn green to indicate to the driver of the vehicle in front that the vehicle can proceed directly. The voice device is installed on the side of the pedestrian crossing and is used to provide voice reminders to pedestrians based on the collision risk information determined by the controller.

4. The early warning system according to claim 3, characterized in that, The first preset distance is 30-80 meters, the second preset distance is 30-80 meters, and the third preset distance is 3-6 meters.

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