Method for estimating vehicle collision time, and vehicle collision warning device

Abstract

The application provides a method for estimating vehicle collision time and a vehicle collision warning device, the method comprising: a first step of estimating the basic collision time of a first current vehicle, comprising: estimating the basic collision time of the first current vehicle according to the driving data of the first current vehicle, the motion state of an obstacle in a target area in front of the first current vehicle, and the positional relationship between the first current vehicle and the obstacle; a second step of estimating the collision time of a second current vehicle, comprising: obtaining the driving data of the second current vehicle and the environmental data in a target area in front of the second current vehicle when the second current vehicle is located in the target area; estimating the basic collision time of the second current vehicle according to the first step; estimating the basic collision time of a preceding vehicle as the collision time of the preceding vehicle according to the first step, or estimating the collision time of the preceding vehicle according to the second step; and estimating the collision time of the second current vehicle according to the collision time of the preceding vehicle and the basic collision time of the second current vehicle.

Description

Technical Field

[0001] This invention relates to the field of traffic safety, and more particularly to a method for estimating vehicle collision time and a vehicle collision warning device. Background Technology

[0002] The Forward Collision Warning (FCW) system uses sensors to constantly monitor vehicles ahead, determine the distance and relative speed between the vehicle and the vehicle in front, and warn the driver when there is a potential collision hazard, thereby reducing the occurrence of vehicle collisions through proactive warnings.

[0003] However, due to limitations in vehicle visibility detection capabilities, onboard sensors cannot measure the driving data of vehicles ahead whose view is blocked by the adjacent vehicle in front. If a vehicle further ahead of the vehicle in front suddenly slows down at this time, it is very likely to cause a rear-end collision, or even lead to a series of chain reactions of collisions for the vehicles behind.

[0004] Therefore, an improved method for forward collision warning of vehicles is needed. Summary of the Invention

[0005] If, while the vehicle is in motion, a vehicle in front of it suddenly slows down or a vehicle to the side suddenly changes lanes, causing the vehicle in front of it to brake suddenly, by the time the vehicle detects the abnormal driving behavior of the vehicle in front of it and begins to brake, it is already too late and a rear-end collision is very likely to occur.

[0006] To address the traffic safety issues arising from this phenomenon, this invention provides a method for estimating vehicle collision time and a vehicle collision warning device, which can greatly improve the accuracy of vehicle collision time estimation and thus reduce the risk of the vehicle being involved in a forward collision.

[0007] The method for estimating vehicle collision time according to embodiments of the present invention includes: a first step of estimating the basic collision time of a first current vehicle, comprising: estimating the basic collision time of the first current vehicle based on the driving data of the first current vehicle, the motion state of an obstacle in a target area in front of the first current vehicle, and the positional relationship between the first current vehicle and the obstacle; a second step of estimating the collision time of a second current vehicle, comprising: acquiring the driving data of the second current vehicle and environmental data in a target area in front of it, wherein when there is a preceding vehicle in the target area in front of the second current vehicle, the environmental data includes the driving data of the preceding vehicle and the environmental data in the target area in front of the preceding vehicle; using the second current vehicle as the first current vehicle, estimating the basic collision time of the second current vehicle according to the first step; using the preceding vehicle as the first current vehicle, estimating the basic collision time of the preceding vehicle according to the first step as the collision time of the preceding vehicle, or using the preceding vehicle as the second current vehicle, estimating the collision time of the preceding vehicle according to the second step; and estimating the collision time of the second current vehicle based on the collision time of the preceding vehicle and the basic collision time of the second current vehicle.

[0008] Optionally, in the second step, estimating the collision time of the second current vehicle based on the collision time of the preceding vehicle and the basic collision time of the second current vehicle includes: when the collision time of the preceding vehicle is less than a preset collision time threshold, reducing the basic collision time of the second current vehicle as the collision time of the second current vehicle; when the collision time of the preceding vehicle is not less than the preset collision time threshold, using the basic collision time of the second current vehicle as the collision time of the second current vehicle.

[0009] Optionally, the second step includes: when the collision time of the preceding vehicle is less than the preset collision time threshold, calculating the difference between the collision time of the preceding vehicle and the preset collision time threshold, and subtracting the absolute value of the difference from the basic collision time of the second current vehicle to obtain the collision time of the second current vehicle.

[0010] Optionally, the second step includes: when there is no vehicle in front in the target area in front of the second current vehicle, taking the second current vehicle as the first current vehicle, and estimating the basic collision time of the second current vehicle based on the first step as the collision time of the second current vehicle.

[0011] Optionally, the second step includes: when there is no vehicle in the target area in front of the preceding vehicle, the preceding vehicle is taken as the first current vehicle, and the basic collision time of the preceding vehicle is estimated as the collision time of the preceding vehicle according to the first step; when there is a vehicle in the target area in front of the preceding vehicle, the preceding vehicle is taken as the second current vehicle, and the collision time of the preceding vehicle is estimated according to the second step.

[0012] Optionally, the second step includes: determining the target area in front of the second current vehicle.

[0013] Determining the target area in front of the second current vehicle includes: determining the range of the target area in front of the second current vehicle based on one or more of the following: the driving data of the second current vehicle, the number of vehicles in front of the second current vehicle, the vehicle spacing, the lane shape, the lane distribution, the position of vehicles exhibiting abnormal driving behavior in front of the second current vehicle, and the communication distance between the second current vehicle and the vehicles in front of it.

[0014] Optionally, when there is a vehicle with abnormal driving behavior in front of the second current vehicle, and the distance between the vehicle with abnormal driving behavior and the second current vehicle is within a preset range, the boundary of the target area in front of the second current vehicle is determined according to the position of the vehicle with abnormal driving behavior.

[0015] Optionally, when the vehicle in front of the second current vehicle is in the same lane as the second current vehicle, the abnormal driving behavior includes: vehicle deceleration or vehicle braking; when the vehicle in front of the second current vehicle is in a different lane from the second current vehicle, the abnormal driving behavior includes: lane change or vehicle steering; wherein, the lane includes straight lanes and / or curved lanes.

[0016] Optionally, obtaining environmental data within the target area in front of the second current vehicle includes: obtaining driving data of vehicles within the target area in front of the second current vehicle based on V2V communication between the second current vehicle and vehicles within the target area in front of it, based on I2V communication between the second current vehicle and roadside units, and / or based on communication between the second current vehicle and base stations.

[0017] Optionally, the method is used to estimate the collision time of the vehicle, wherein there are multiple vehicles in the target area in front of the vehicle, and the method includes taking each of the multiple vehicles in the target area in front of the vehicle as the second current vehicle and repeatedly executing the second step; the preset collision time threshold in each execution of the second step is a collision alarm time threshold preset by the forward collision warning system of the vehicle, or the preset collision time threshold in each execution of the second step is a collision alarm time threshold preset by the forward collision warning system of the second current vehicle at the time of executing the second step.

[0018] Optionally, the preceding vehicle in the second step is the vehicle directly adjacent to the second current vehicle within the target area in front of the second current vehicle.

[0019] This invention also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the method for estimating vehicle collision time according to this invention.

[0020] This invention also provides a vehicle collision warning device, including a processor, a memory, and a computer program stored in the memory. When the computer program is executed by the processor, it performs the following steps: estimating the collision time of the vehicle according to the method for estimating vehicle collision time according to the present invention; and issuing an alarm message to the current vehicle when the estimated collision time of the vehicle is less than or equal to a preset collision time threshold.

[0021] Compared with the prior art, the technical solution of the embodiments of the present invention has the following technical effects:

[0022] The method for estimating vehicle collision time in this embodiment of the invention includes: a first step of estimating the basic collision time of a first current vehicle and a second step of estimating the collision time of a second current vehicle. In the second step, when there is a preceding vehicle in the target area in front of the second current vehicle, the basic collision time of the second current vehicle is estimated according to the first step, and the basic collision time of the preceding vehicle is estimated as the collision time of the preceding vehicle according to the first step, or the collision time of the preceding vehicle is estimated according to the second step. Since the basic collision time of the first current vehicle is calculated based on obstacle information in the target area in front of the first current vehicle and the driving data of the first current vehicle in the first step, the method used in the second step to estimate the collision time of the preceding vehicle takes into account the influence of obstacles in the target area in front of the preceding vehicle on the collision time of the preceding vehicle. Taking the preceding vehicle as the second current vehicle and estimating the collision time of the preceding vehicle according to the second step is equivalent to establishing a recursive algorithm. By repeatedly executing the second step, the collision time of the preceding vehicle of the second current vehicle is estimated, and the collision time of the second current vehicle is estimated based on the returned collision time of the preceding vehicle. Therefore, in the second step of estimating the collision time of the second current vehicle, whether the collision time of the preceding vehicle is estimated retrospectively based on the first step or the second step, the influence of the environment of the target area in front of the preceding vehicle on the collision time of the preceding vehicle is considered. The method also includes estimating the collision time of the second current vehicle based on the estimated collision time of the preceding vehicle and the basic collision time of the second current vehicle. Compared with only estimating the basic collision time of the second current vehicle, the method for estimating vehicle collision time in this embodiment of the invention not only considers the influence of the driving behavior of the preceding vehicle on the collision time of the second current vehicle, but also considers the influence of the environment in the target area in front of the preceding vehicle on the collision time of the second current vehicle. This significantly improves the accuracy of vehicle collision time estimation, greatly reduces the risk of collision between the current vehicle and the vehicle in front, and in particular effectively reduces or even avoids the occurrence of chain collision accidents.

[0023] Furthermore, in the second step, based on the relative magnitude of the collision time of the preceding vehicle and the preset collision time threshold, it is determined whether to modify the basic collision time of the second current vehicle. If the collision time of the preceding vehicle is less than the preset collision time threshold, the basic collision time of the second current vehicle is reduced. Thus, if the real-time collision time reserved for the preceding vehicle is insufficient and a collision may occur, a shorter real-time collision time is set for the second current vehicle to provide an earlier collision warning, thereby reducing the occurrence of chain collision accidents.

[0024] Furthermore, in the second step, driving data of vehicles in the target area in front of the second current vehicle is obtained based on V2V communication between the second current vehicle and vehicles in the target area ahead of it, I2V communication between the second current vehicle and roadside units, and / or communication between the second current vehicle and base station. Compared with obtaining driving data of vehicles in the target area ahead using vehicle sensors, this method is not limited by the line-of-sight range of vehicle sensors, has a larger communication range, and can obtain environmental data of a larger area. On the other hand, unlike vehicle sensors such as radar, the accuracy of environmental data collection is easily affected by weather and relative movement between vehicles. The environmental data obtained by using vehicle communication in the vehicle network is more accurate, has stronger anti-interference ability, and more stable data collection. Attached Figure Description

[0025] Figure 1 This is a flowchart illustrating a method for estimating vehicle collision time according to an embodiment of the present invention;

[0026] Figure 2 This is a flowchart illustrating a method for estimating vehicle collision time according to another embodiment of the present invention;

[0027] Figure 3 This is a schematic diagram illustrating an application scenario of a method for estimating vehicle collision time according to an embodiment of the present invention;

[0028] Figure 4 This is a schematic diagram illustrating another application scenario of the method for estimating vehicle collision time according to an embodiment of the present invention;

[0029] Figure 5 This is a schematic diagram illustrating another application scenario of the method for estimating vehicle collision time according to an embodiment of the present invention. Detailed Implementation

[0030] To make the above-mentioned objectives, features and beneficial effects of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0031] refer to Figure 1 , Figure 1 This is a flowchart illustrating a method for estimating vehicle collision time according to an embodiment of the present invention.

[0032] In some embodiments, the method for estimating vehicle collision time includes steps S11 and S13.

[0033] In S11, estimating the basic collision time TTC of the first current vehicle includes: estimating the basic collision time TTC of the first current vehicle based on the driving data of the first current vehicle, the motion state of the obstacle in the target area in front of the first current vehicle, and the positional relationship between the first current vehicle and the obstacle.

[0034] In S13, estimating the collision time TTC' of the second current vehicle includes: acquiring the driving data of the second current vehicle and environmental data within the target area in front of it; when there is a preceding vehicle in the target area in front of the second current vehicle, the environmental data includes the driving data of the preceding vehicle and the environmental data within the target area in front of the preceding vehicle; using the second current vehicle as the first current vehicle, estimating the basic collision time of the second current vehicle according to the first step S11; using the preceding vehicle as the first current vehicle, estimating the basic collision time of the preceding vehicle according to the first step S11 as the collision time of the preceding vehicle, or using the preceding vehicle as the second current vehicle, estimating the collision time of the preceding vehicle according to the second step S13; and estimating the collision time TTC' of the second current vehicle based on the collision time of the preceding vehicle and the basic collision time of the second current vehicle.

[0035] In some embodiments, the preceding vehicle is the vehicle directly adjacent to the second current vehicle.

[0036] The method for estimating vehicle collision time in this embodiment of the invention is used to estimate the collision time of the vehicle itself. There may be multiple vehicles in front of the vehicle, including not only the vehicle directly adjacent to the vehicle but also the vehicle located in front of the vehicle directly in front. When estimating the collision time of the vehicle itself, the second step S13 is executed first, that is, the vehicle itself is taken as the second current vehicle, and the collision time of the vehicle itself is estimated according to S13. During the execution of the second step S13, it is necessary to estimate the collision time of the vehicle directly adjacent to the vehicle itself. At this time, the collision time of the vehicle directly in front is calculated by calling the first step S11 or repeating the execution of step S13. If the first step S11 is called and the collision time of the vehicle directly in front is obtained, the collision time of the vehicle itself can be obtained by returning to the second step S13. If the second step S13 is repeated, the vehicle directly in front is taken as the second current vehicle, and the collision time of the vehicle directly in front is estimated using the same method as estimating the collision time of the vehicle itself, thus forming a recursive algorithm.

[0037] In some embodiments of the present invention, the collision time of the vehicle estimated by the method for estimating vehicle collision time is used in the vehicle's forward collision warning system.

[0038] refer to Figure 2 and Figure 3 , Figure 2This is a flowchart illustrating a method for estimating vehicle collision time according to an embodiment of the present invention. Figure 3 This is a schematic diagram illustrating an application scenario of the method for estimating vehicle collision time according to an embodiment of the present invention.

[0039] like Figure 3 As shown, in some embodiments, the vehicle 21, the first preceding vehicle 23, and the second preceding vehicle 25 travel along the longitudinal direction of the lane 20, i.e., the direction indicated by the X-axis, wherein the first preceding vehicle 23 is the preceding vehicle directly adjacent to the vehicle 21, and the second preceding vehicle 25 is the preceding vehicle directly adjacent to the first preceding vehicle 23.

[0040] Combination Figure 2 The method for estimating the collision time of vehicle 21 includes the following steps: S20, S22, S24, S26, S28, S30, S32.

[0041] Execute S20 to obtain the driving data of the second current vehicle and the environmental data of the target area in front of it. When there is a preceding vehicle in the target area in front of the second current vehicle, the environmental data includes the driving data of the preceding vehicle and the environmental data of the target area in front of the preceding vehicle.

[0042] When the second current vehicle is the vehicle 21, the environmental data includes the driving data of the first preceding vehicle 23 and the environmental data of the target area in front of the first preceding vehicle 23. The environmental data of the target area in front of the first preceding vehicle 23 may include the driving data of vehicles located in that area, such as the driving data of the second preceding vehicle 25.

[0043] In some embodiments, before acquiring environmental data within the target area in front of the second current vehicle, S20 further includes: determining the range of the target area in front of the second current vehicle. Specifically, the range of the target area in front of the second current vehicle can be determined based on one or more of the following factors: the driving data of the second current vehicle, the number of vehicles in front of the second current vehicle, the vehicle spacing, the lane shape, the lane distribution, the position of vehicles exhibiting abnormal driving behavior in front of the second current vehicle, and the communication distance between the second current vehicle and the vehicles in front of it.

[0044] In some embodiments, the range of the target area in front of the second current vehicle can be determined solely based on the number of vehicles in front of the second current vehicle. For example, the target area may encompass the area where one or two vehicles are located in front of the second current vehicle. In other embodiments, when the vehicles in the lane are densely distributed and the distance between adjacent vehicles is small, the target area in front of the second current vehicle may encompass the area where a larger number of vehicles are located in front of the second current vehicle, for example, the area where three to five vehicles are located in front of it.

[0045] In other embodiments, when there is a vehicle exhibiting abnormal driving behavior in front of the second current vehicle, and the distance between the vehicle exhibiting abnormal driving behavior and the second current vehicle is within a preset distance range (to prevent the detected distance between the vehicle exhibiting abnormal driving behavior and the second current vehicle from being too far, thus affecting the collision time of the second current vehicle), the boundary of the target area in front of the second current vehicle is determined based on the position of the vehicle exhibiting abnormal driving behavior. For example... Figure 3 As shown, when the second current vehicle is the vehicle 21, if the vehicle detects abnormal driving behavior of the second preceding vehicle 25, then the target area in front of the vehicle 21 includes the area where the first preceding vehicle 23 and the second preceding vehicle 25 are located.

[0046] In some embodiments, when there are multiple vehicles with abnormal driving behavior in front of the second current vehicle, the boundary of the target area in front of the second current vehicle is determined based on the distance from the second current vehicle within the preset distance range and the vehicle with the largest distance from the second current vehicle that has abnormal driving behavior.

[0047] In some embodiments, when a vehicle in front of the second current vehicle is in the same lane as the second current vehicle, the abnormal driving behavior includes: vehicle deceleration or vehicle braking; when a vehicle in front of the second current vehicle is in a different lane from the second current vehicle, the abnormal driving behavior includes: lane change or vehicle steering; wherein, the lane includes straight lanes and / or curved lanes.

[0048] In some embodiments, the second current vehicle can determine whether there is abnormal driving behavior from the vehicle ahead based on the driving data of the vehicle ahead received by the second current vehicle via V2X communication. Specifically, the second current vehicle can determine whether there is abnormal driving behavior from the vehicle ahead based on the braking signal or steering signal it receives from the vehicle ahead. Alternatively, it can predict whether the vehicle ahead will exhibit abnormal driving behavior by combining the driving trajectory of the vehicle ahead predicted by the second current vehicle with parameters such as steering wheel angle, heading angle, position, and / or speed. The boundary of the target area in front of the second current vehicle is then determined based on the predicted position of the vehicle ahead that will exhibit abnormal driving behavior.

[0049] In some embodiments, the target area in front of the second current vehicle can be determined based on the position of the second current vehicle, its driving direction (e.g., heading angle and / or steering wheel angle), and the communication distance R between the second current vehicle and the vehicle in front. Specifically, the target area in front of the second current vehicle can be a fan-shaped area with the second current vehicle as the center, the communication distance R of the vehicle-to-everything (V2X) network as the radius, and an angle of -30° to 30°, -45° to 45°, -60° to 60°, or -90° to 90° with respect to the heading line of the second current vehicle. The target area in front of the second current vehicle may include not only the lane area where the second current vehicle is located, but also the areas on both sides of the lane where the second current vehicle is located.

[0050] In some embodiments, the second current vehicle communicates with the vehicle in front of it via V2V, specifically DSRC technology or point-to-point direct communication based on 5G V2X PC5, in which case the communication distance R can be 300 meters to 1000 meters.

[0051] In other embodiments, the second current vehicle communicates with the vehicle in front of it via I2V. Specifically, the second current vehicle can communicate with the roadside unit (RSU) via the PC5 interface of 5G NR-V2X, and the communication distance R can be 300 meters to 1000 meters. Alternatively, the 5G base station can communicate with the onboard unit (OBU) of the second current vehicle via the UU interface, and the communication distance R depends on the communication range of the base station. The base station can be a 4G base station or a 5G base station, and the communication distance R can be 2.5 km.

[0052] In other embodiments, the range of the target area in front of the second current vehicle can be determined based on the current position of the second current vehicle, its driving direction (e.g., heading angle and / or steering wheel angle), and the impact distance of a chain-reaction collision. Specifically, the target area can be a fan-shaped area with the second current vehicle as the center and the impact distance of the chain-reaction collision (e.g., an empirical distance of 1 km) as the radius, forming an angle of -30° to 30°, -45° to 45°, -60° to 60°, or -90° to 90° with the heading line of the second current vehicle, covering the semi-circular areas directly in front of, to the left of, to the right of, to the left of, and to the right of the second current vehicle's heading. In some embodiments, the target area may differ depending on the driving direction of the second current vehicle.

[0053] In some embodiments, step S20, acquiring the driving data of the second current vehicle includes acquiring one or more of the following data: position, direction, speed, acceleration, braking signal, gear signal, vehicle size, and headlight signals of the second current vehicle. Specifically, the driving direction of the second current vehicle may include the heading angle and / or steering wheel angle of the second current vehicle. The heading angle is the angle between the vehicle's center of gravity velocity direction and the lane tangent direction. The steering wheel angle is the rotation angle of the steering wheel when the vehicle turns, and the steering wheel angle can be used to predict the vehicle's driving trajectory. The headlight signals may include left-turn or right-turn signals. The driving data of the second current vehicle may be real-time updated data, representing the current driving state of the second current vehicle.

[0054] In some embodiments, the driving data of the second current vehicle may be obtained by the electronic control unit (ECU) of the second current vehicle, which includes V2X communication capabilities, via the vehicle CAN network or the Global Positioning System (GPS).

[0055] In some embodiments, step S20, obtaining environmental data within the target area in front of the second current vehicle includes: using the communication of the second current vehicle in the vehicle network (such as V2X communication mode) to obtain environmental data within the target area in front of the second current vehicle.

[0056] In some other embodiments, step S20, obtaining environmental data within the target area in front of the second current vehicle, further includes: using the onboard sensors of the second current vehicle to obtain environmental data within the target area in front of the second current vehicle.

[0057] In some embodiments, step S20 further includes: fusing the environmental data obtained by the second current vehicle through communication in the vehicle network with the environmental data obtained by the on-board sensors of the second current vehicle. Since the environmental data obtained through the vehicle network includes information on the absolute motion state of vehicles located in the target area, and the environmental data obtained by the on-board sensors includes information on the relative motion state of the vehicle in front of the second current vehicle and the second current vehicle, and the vehicle sensors have a limited line-of-sight range for detecting the surrounding environment, are easily affected by environmental interference, and are related to the relative motion of the second current vehicle and its in front vehicle, fusing the environmental data obtained in the two ways can obtain more comprehensive and accurate environmental data of the second current vehicle.

[0058] In some embodiments, the V2X communication mode may include V2V (Vehicle to Vehicle) or I2V (Infrastructure to Vehicle). In step S20, when there is a preceding vehicle in the target area in front of the second current vehicle, environmental data located in the target area in front of the second current vehicle is obtained based on the V2V communication between the second current vehicle and the preceding vehicle, the I2V communication between the second current vehicle and the Road Side Unit (RSU), and / or the communication between the second current vehicle and the base station.

[0059] When all vehicles within the target area are equipped with an Onboard Unit (OBU), in V2V communication mode, the vehicles within the target area broadcast their respective Basic Safety Messages (BSMs). The Basic Safety Messages contain data packets containing vehicle position, driving direction, speed, and other information related to vehicle status or predicted path. The second current vehicle receives the BSM messages through V2V communication mode.

[0060] However, not every vehicle in the target area may be equipped with an OBU. In this case, in I2V communication mode, the roadside unit (RSU) can detect the driving status of vehicles in the target area through cameras, radar or lasers, and broadcast the information it has detected through I2V communication. For example, the roadside unit (RSU) broadcasts a Sensor Sharing Message (SSM) defined by C-SAE, and the second current vehicle receives the SSM message.

[0061] In some embodiments, step S20, acquiring environmental data within the target area in front of the second current vehicle includes: acquiring one or more of the following data: the position, driving direction (e.g., heading angle or steering wheel angle), vehicle speed, predicted driving trajectory, braking signal, and steering signal of the vehicle located within the target area in front of the second current vehicle; and may also include acquiring information about other obstacles besides vehicles located within the target area in front of the second current vehicle. These other obstacles may be in motion (e.g., pedestrians) or stationary (e.g., signs). The environmental data may be real-time updated data, including the current motion state of the vehicle ahead or the other obstacles, or it may be predictive data, such as the motion state of the vehicle ahead over a future period.

[0062] In some embodiments, step S20 includes: determining the relative position information of the second current vehicle and vehicles located within the target area in front of it based on the acquired driving data of the second current vehicle and environmental data within the target area in front of it. Specifically, this includes: constructing a unified coordinate system, determining the position coordinates of the second current vehicle and vehicles within the target area in front of it in the unified coordinate system; and obtaining the relative position information of the second current vehicle and vehicles within the target area in front of it based on the determined position coordinates of each vehicle.

[0063] In some embodiments, constructing a unified coordinate system includes: based on the position coordinates of the second current vehicle and the vehicles in the target area ahead of it obtained in step S20, transforming the position coordinates of the second current vehicle and the vehicles in the target area ahead of it into the same coordinate system. For example, a Gaussian plane coordinate system can be constructed. Specifically, the GPS position data of each vehicle obtained in step S20 can be converted into Gaussian plane coordinates, and then the relative distance and relative motion between the second current vehicle and the vehicles in the target area ahead of it can be calculated. In other embodiments, other types of coordinate systems besides the Gaussian plane coordinate system can also be constructed.

[0064] Continue to refer to Figure 2 and Figure 3 Execute step S22, taking the second current vehicle (at this time, the vehicle 21) as the first current vehicle, and estimate the basic collision time (TTC) of the second current vehicle (at this time, the vehicle 21) according to step S24. 21 In step 24, based on the driving data of the first current vehicle (currently the vehicle 21), the motion state of obstacles in the target area in front of the first current vehicle, and the positional relationship between the first current vehicle and the obstacles, the basic collision time (TTC) of the first current vehicle is estimated. 21 When a vehicle is present in the target area ahead of the second current vehicle, the obstacle includes the vehicle directly adjacent to the first current vehicle, and the basic collision time (TTC) of the first current vehicle is estimated. 21 That is, to estimate the basic collision time between the first current vehicle and its directly adjacent preceding vehicle, specifically... Figure 3In the illustrated embodiment, the basic collision time between the current vehicle 21 and the first preceding vehicle 23 is estimated in step S24. When there is no preceding vehicle in the target area in front of the second current vehicle, the obstacle in the basic collision time of the second current vehicle estimated according to step S24 can be other obstacles in the target area in front of the second current vehicle besides vehicles. The other obstacles can be in motion (e.g., pedestrians) or in a stationary state (e.g., road signs or directional signs).

[0065] Execute step S26 to determine whether there is a preceding vehicle in the target area in front of the first preceding vehicle 23. If not, that is, when there is no preceding vehicle in the target area in front of the first preceding vehicle 23, then execute step S28, taking the first preceding vehicle 23 as the first current vehicle, estimating the basic collision time of the first preceding vehicle 23 according to step S24, and returning the estimated basic collision time of the first preceding vehicle 23 to calculation step S28. In step S28, the basic collision time of the first preceding vehicle 23 returned by step S24 is used as the collision time TTC of the first preceding vehicle 23. 23 If so, that is, when there is a vehicle in front of the first vehicle 23 in the target area, step S30 is executed, taking the first vehicle 23 as the second current vehicle, and performing the step of estimating the collision time of the first vehicle 23 according to steps S20, S22, S24, S26, S28 and S30.

[0066] Specifically Figure 3 In the illustrated embodiment, since a second vehicle 25 exists in the target area in front of the first vehicle 23, step S26 is followed by step S30. Steps S20, S22, S24, S26, S28, and S30 are repeated, using the first vehicle 23 as the second current vehicle, to estimate the time to collision (TTC) of the first vehicle 23. 23 '.

[0067] When the first leading vehicle 23 is the second current vehicle, when step S20 is executed, the driving data of the first leading vehicle 23 and the environmental data of the target area in front of it are obtained. The environmental data includes the driving data of the second leading vehicle 25 and the environmental data of the target area in front of the second leading vehicle 25.

[0068] Execute step S22, taking the first preceding vehicle 23 as the first current vehicle, and estimate the basic collision time (TTC) of the first preceding vehicle 23 according to step S24. 23 Step S26 can be executed simultaneously to determine whether there is a preceding vehicle in the target area in front of the second preceding vehicle 25, because Figure 3In one embodiment, if there is no preceding vehicle in the target area in front of the second preceding vehicle 25, step S28 is executed, and the second preceding vehicle 25 is taken as the first current vehicle. The basic collision time (TTC) of the second preceding vehicle 25 is estimated according to step S24. 25 The time of collision of the second preceding vehicle 25 was determined by the TTC. 25 '.

[0069] In some embodiments, in step S24, the estimated basic collision time of the first current vehicle is the collision time between the first current vehicle and an obstacle in the target area in front of it. If there is no obstacle in the target area in front of the second leading vehicle 25, then the basic collision time TTC of the second leading vehicle 25 is... 25 Approaching infinity, that is, the collision time TTC of the second preceding vehicle 25 obtained in step S28. 25 It also approaches infinity.

[0070] Then proceed to step S32, based on the collision time TTC of the second preceding vehicle 25. 25 The basic collision time (TTC) between the second current vehicle (which is now the first preceding vehicle 23) and the second current vehicle. 23 Estimated time to collision (TTC) of the second current vehicle (currently the first preceding vehicle 23). 23 '.

[0071] In some embodiments, step S32 further includes: when the collision time TTC of the second leading vehicle 25 25 'less than the preset collision time threshold T' h At the same time, reduce the basic collision time (TTC) of the second current vehicle (which is the first preceding vehicle 23 at this time). 23 The second current vehicle collision time TTC 23 '; When the second preceding vehicle 25 collided at time TTC 25 Not less than the preset collision time threshold T h At that time, the basic collision time TTC of the second current vehicle (which is the first preceding vehicle 23 at this time) is used. 23 The collision time TTC of the second current vehicle (at this time, the first preceding vehicle 23) 23 '.

[0072] When the collision time TTC of the second preceding vehicle 25 obtained in step S28 25 When it approaches infinity, the basic collision time TTC of the first preceding vehicle 23 is used. 23 The time of collision of the first preceding vehicle 23 (TTC) 23 ', i.e., TTC 23 =TTC 23 .

[0073] In some embodiments, the basic collision time (TTC) of the first preceding vehicle 23 is estimated according to step S24. 23 This includes: estimating the basic time to collision (TTC) between the first leading vehicle 23 and its directly adjacent second leading vehicle 25 based on the driving data of the first leading vehicle 23, the motion state of the vehicles in the target area in front of the first leading vehicle 23 (i.e., the second leading vehicle 25), and the positional relationship between the first leading vehicle 23 and the second leading vehicle 25. 23 The relative speed and relative acceleration of the first leading vehicle 23 and the second leading vehicle 25 can be obtained based on the driving data of the first leading vehicle 23 and the motion state of the second leading vehicle 25.

[0074] Specifically, in step S24, the basic collision time TTC is estimated for the collision between the first preceding vehicle 23 and its directly adjacent second preceding vehicle 25. 23 Formula (1) can be used to estimate the relative distance, relative speed, and relative acceleration of two adjacent vehicles.

[0075]

[0076] In formula (1), s is the relative distance between two adjacent vehicles, d is the safe stopping distance of the rear vehicle in a pair of adjacent vehicles, and a vel It is the relative acceleration between the following vehicle and the vehicle in front, v vel It is the relative speed between the following vehicle and the vehicle in front.

[0077] In some embodiments, the basic collision time TTC of the first forward vehicle 23 is calculated according to formula (1). 23 = 2.4s, thus the collision time TTC of the first preceding vehicle 23 in step S28 is... 23 =TTC 23 = 2.4s, which is equivalent to returning the value in step S28 when the vehicle 21 is the second current vehicle. In some embodiments, when the vehicle 21 is the second current vehicle, the basic collision time TTC of the vehicle 21 obtained in step S22 is... 21 =2.8s, then when executing step S32, according to the collision time TTC of the first preceding vehicle 23. 23 'and the basic collision time TTC of the vehicle 21 21 Estimated collision time of vehicle 21 (TTC) 21 In this embodiment, the preset collision time threshold T h The time is 2.7 seconds, because the collision time of the first preceding vehicle 23 is TTC. 23 'less than the preset collision time threshold T' hTherefore, it is necessary to reduce the basic collision time of the vehicle 21 (TTC). 21 The second current vehicle collision time TTC 21 '.

[0078] In some embodiments, reducing the basic collision time of the second current vehicle includes: when the collision time of the preceding vehicle is less than the preset collision time threshold, calculating the difference between the collision time of the preceding vehicle and the preset collision time threshold, and subtracting the absolute value of the difference from the basic collision time of the second current vehicle to obtain the collision time of the second current vehicle. Specifically, the vehicle 21 is the second current vehicle, and its collision time TTC... 21 =TTC 21 -|TTC 23 '-T h |=2.8s-|2.4s-2.7s|=2.5s.

[0079] Therefore, it can be seen that although the basic collision time TTC between the vehicle 21 and its directly adjacent first preceding vehicle 23 is estimated using formula (1), 21 =2.8s is greater than the preset collision time threshold T h =2.7s, but since formula (1) only considers the relative distance and relative motion between the vehicle 21 and its adjacent first preceding vehicle 23, it does not take into account the possible impact of the real-time collision time of the first preceding vehicle 23 on the real-time collision time of the vehicle 21. Therefore, the basic collision time TTC of the vehicle 21 estimated by this method is 2.7s. 21 =2.8s is inaccurate due to TTC 21 >T h The forward collision warning system of vehicle 21 will not send a warning message to vehicle 21, which greatly increases the likelihood of vehicle 21 colliding with the vehicle in front. However, using the method for estimating vehicle collision time according to this embodiment of the invention, the estimated collision time (TTC) of vehicle 21 is... 21 = 2.5s <T h The method for estimating vehicle collision time based on embodiments of the present invention can be used when there is insufficient real-time collision time (i.e., less than T) with respect to the vehicle ahead. h In the event of a collision, the insufficient time will be reduced from the vehicle's basic collision time (TTC) of 21. 21 The deduction is made so that the forward collision warning system of vehicle 21 can send warning information to vehicle 21 as early as possible based on a shorter and more realistic real-time collision time, which greatly reduces the risk of collision between vehicle 21 and the vehicle in front, especially avoiding the occurrence of a chain rear-end collision caused by the first vehicle 23 colliding with the second vehicle 25.

[0080] In this embodiment of the invention, based on Figure 2The recursive algorithm shown takes into account the impact of the collision time of the second preceding vehicle 25 on the collision time of the first preceding vehicle 23, and the impact of the collision time of the first preceding vehicle 23 on the collision time of the vehicle 21. That is, it takes into account the propagation effect between vehicles that may have a chain collision accident. Therefore, the collision time of the vehicles estimated by the method based on the embodiment of the present invention is more accurate.

[0081] In some embodiments, the method of the present invention is used to estimate the collision time of a vehicle, wherein there are multiple vehicles in a target area in front of the vehicle, and the method includes repeatedly executing the method with each of the multiple vehicles in the target area in front of the vehicle as a second current vehicle. Figure 2 The steps shown are repeated each time. Figure 2 The preset collision time thresholds for the steps shown can all be the collision alarm time thresholds preset by the forward collision warning system of the vehicle, or the preset collision time thresholds in each loop can be the collision alarm time thresholds preset by the forward collision warning system of the second current vehicle when the loop steps are executed, or they can be calculated by the vehicle based on information such as the vehicle model in the target area ahead.

[0082] In some embodiments, the vehicle in front of the target area in front of the second current vehicle is the vehicle directly adjacent to the second current vehicle.

[0083] refer to Figure 4 , Figure 4 This is a schematic diagram illustrating another application scenario of the method for estimating vehicle collision time according to an embodiment of the present invention.

[0084] In this embodiment, the vehicle 31 and the first vehicle 33, the second vehicle 35 and the third vehicle 37 located in front of it travel along the longitudinal direction of the lane 30, i.e., the X-axis. The first vehicle 33 is the vehicle directly adjacent to the vehicle 31, the second vehicle 35 is the vehicle directly adjacent to the first vehicle 33, and the third vehicle 37 is the vehicle directly adjacent to the second vehicle 35.

[0085] In this embodiment, the method for estimating the vehicle 31 can be referred to Figure 2 and Figure 3 The detailed steps of the embodiment shown are not repeated here; only the collision time TTC of the vehicle 31 estimated by the method according to the embodiment of the present invention is briefly described. 31 The result.

[0086] In some embodiments, the basic collision times estimated according to formula (1) for the vehicle 31, the first vehicle 33, the second vehicle 35, and the third vehicle 37 located in front of it are TTC. 31 =3s,TTC33 =2.9s, TTC 35 =2.6s, TTC 37 =2.8s, therefore, due to the estimated basic collision time TTC of the third vehicle 37. 37 Greater than T h Therefore, there is no need to specify the basic collision time (TTC) for the second vehicle 35. 35 The time of impact for the second vehicle 35 has been corrected to TTC. 35 =TTC 35 = 2.6s, due to the collision time TTC of the second vehicle 35 35 ' <T h Therefore, it is necessary to reduce the basic collision time of the first vehicle 33 (TTC). 33 That is, the basic collision time (TTC) of the first vehicle 33 needs to be determined. 33 To make a correction, specifically, the collision time of the first vehicle 33 is TTC. 33 =TTC 33 -|TTC 35 '-T h |=2.9s-0.1s=2.8s, due to the collision time TTC of the first vehicle 33 33 '>T h Therefore, there is no need to specify the basic collision time (TTC) of the vehicle 31. 31 The time to collision (TTC) of vehicle 31 is corrected. 31 =TTC 31 =2.8s.

[0087] refer to Figure 5 , Figure 5 This is a schematic diagram illustrating another application scenario of estimating vehicle collision time according to an embodiment of the present invention.

[0088] In this embodiment, the vehicle 41 and the first vehicle 43, the second vehicle 45, and the third vehicle 47 located directly in front of it are traveling along the longitudinal direction of the lane 40, i.e., the x-axis. The fourth vehicle 49 is entering the lane 40 in the direction indicated by arrow A. The vehicle 41 receives a turning signal from the fourth vehicle 49 located to its side and front via communication in the vehicle network, and determines that the fourth vehicle is exhibiting abnormal driving behavior. The first vehicle 43 is the vehicle directly in front of the vehicle 41, the second vehicle 45 is the vehicle directly in front of the first vehicle 43, and the third vehicle 47 is the vehicle directly in front of the second vehicle 45. The vehicle 41 also receives a braking signal from the third vehicle 47, and determines that the third vehicle 47 is also exhibiting abnormal driving behavior. At this time, it is necessary to estimate the collision time of the vehicle 41 based on two propagation chains. That is, when there are multiple vehicles with abnormal driving behavior in front of the vehicle 41, the collision time of the vehicle 41 is estimated based on the propagation chain formed by each vehicle with abnormal driving behavior, the vehicle 41, and the vehicles between them. The multiple vehicles with abnormal driving behavior may be located in the same direction or different directions of the vehicle 41.

[0089] Specifically Figure 5 The embodiment shown requires estimating the collision time of the vehicle 41 based on the first propagation chain: the third vehicle 47, the second vehicle 45, the first vehicle 43 and the vehicle 41, and the second propagation chain: the third vehicle 47, the second vehicle 45, the fourth vehicle 49, the first vehicle 43 and the vehicle 41, respectively, and then taking the minimum value of the two collision times of the vehicle 41 estimated based on the two propagation chains.

[0090] In some embodiments, the basic collision time of the vehicle 41, the basic collision time between the first vehicle 43 and the second vehicle 45 located directly in front of it, the basic collision time of the second vehicle 45, and the basic collision time of the third vehicle 47, estimated according to formula (1), are respectively TTC. 41 =3.5s, TTC 43-45 =2.6s, TTC 45 =2.7s, TTC 47 =2.3s, the estimated basic collision time between the fourth vehicle 49 and the second vehicle 45 is TTC. 49-45 = 2.5s, the basic collision time between the first vehicle 43 and the fourth vehicle 49 is TTC. 43-49 =2.4s, then the first collision time TTC of the vehicle 41 estimated according to the first propagation chain is... 41 =TTC 41 -|TTC 43-45 -|TTC 45 -|TTC 47 -T h|-T h |-T h |=3.5s-|2.6s-|2.7s-|2.3s-2.7s|-2.7s|-2.7s|-2.7s|=3s, the second collision time TTC of the vehicle 41 estimated according to the second propagation chain. 41 =TTC 41 -|TTC 43-49 -|TTC 49-45 -|TTC 45 -|TTC 47 -T h |-T h |-T h |-T h |=3.5s-|2.4s-|2.5s-|2.7s-|2.3s-2.7s|-2.7s|-2.7s|-2.7s|-2.7s|=2.6s. Due to the second collision time TTC of the vehicle 41 estimated according to the second propagation chain. 41 "Less than the first collision time (TTC) of the vehicle 41 estimated according to the first propagation chain." 41 Therefore, the collision time of vehicle 41 is TTC. 41 = 2.6s.

[0091] It should be noted that, Figures 3 to 5 The illustrated embodiment uses an example of 2 to 4 vehicles in front of the vehicle for explanation. It is understood that in other embodiments of the present invention, the number of vehicles in the target area in front of the vehicle is not limited to 4. Figures 3 to 5 The embodiments shown illustrate the method for estimating vehicle collision time in this invention using a straight lane as an example. It is understood that the method for estimating vehicle collision time in this invention can also be applied to estimating the collision time of vehicles on curved lanes or lanes that include both straight and curved lanes.

[0092] This invention also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the method for estimating vehicle collision time described in the foregoing embodiments of this invention.

[0093] In some embodiments, when the computer program is executed by the processor, it further implements the following step: if the collision time of the vehicle estimated by the method for estimating vehicle collision time according to the foregoing embodiments of the present invention is less than or equal to a preset collision time threshold T. h If so, an alarm message will be issued.

[0094] This invention also provides a vehicle collision warning device, including a processor, a memory, and a computer program stored in the memory. When the computer program is executed by the processor, it performs the following steps: estimating the collision time of the vehicle according to the method for estimating vehicle collision time according to the foregoing embodiments of the present invention; and issuing an alarm message to the vehicle when the estimated collision time of the vehicle is less than or equal to a preset collision time threshold.

[0095] The steps of the methods or algorithms described in the embodiments of this invention can be embodied in hardware, software modules executed by a processor, or a combination of both. The software modules can be stored in RAM, flash memory, ROM, EPROM, EEPROM, registers, hard disks, removable disks, CD-ROMs, or any other form of storage medium. As an example, the storage medium is coupled to the processor, allowing the processor to read information from and write information to the storage medium. In another embodiment, the storage medium can be integrated into the processor.

[0096] The steps depicted in the flowcharts of the above embodiments of the present invention are illustrative. Although the method typically follows the numbered order of the depicted steps for clarity in describing the method as a sequence of numbered steps, in other exemplary embodiments of the present invention, the order of one or more steps may be rearranged, combined into fewer steps, and / or separated into more steps than shown. It should be understood that some of these steps may be omitted, implemented in parallel, or implemented without requiring a strict sequence.

[0097] The present application has been described in detail above with reference to specific embodiments. Obviously, the above description and the embodiments shown in the accompanying drawings should be understood as exemplary and not as limiting the present application. Those skilled in the art can make various modifications or alterations without departing from the spirit of the present application, and such modifications or alterations do not depart from the scope of the present application.

Claims

1. A method for estimating vehicle collision time, characterized in that, include: The first step of estimating the basic collision time of the first current vehicle includes: estimating the basic collision time of the first current vehicle based on the driving data of the first current vehicle, the motion state of obstacles in the target area in front of the first current vehicle, and the positional relationship between the first current vehicle and the obstacles; The second step in estimating the collision time of the second current vehicle includes: The driving data of the second current vehicle and the environmental data of the target area in front of it are obtained. When there is a vehicle in front of the second current vehicle in the target area in front of it, the environmental data includes the driving data of the vehicle in front and the environmental data of the target area in front of the vehicle in front. Using the second current vehicle as the first current vehicle, estimate the basic collision time of the second current vehicle according to the first step; Using the preceding vehicle as the first current vehicle, the basic collision time of the preceding vehicle is estimated according to the first step as the collision time of the preceding vehicle; or using the preceding vehicle as the second current vehicle, the collision time of the preceding vehicle is estimated according to the second step. The collision time of the second current vehicle is estimated based on the collision time of the preceding vehicle and the basic collision time of the second current vehicle.

2. The method for estimating vehicle collision time according to claim 1, characterized in that, In the second step, estimating the collision time of the second current vehicle based on the collision time of the preceding vehicle and the basic collision time of the second current vehicle includes: When the collision time of the preceding vehicle is less than a preset collision time threshold, the basic collision time of the second current vehicle is reduced, and the reduced basic collision time of the second current vehicle is used as the collision time of the second current vehicle. When the collision time of the preceding vehicle is not less than the preset collision time threshold, the basic collision time of the second current vehicle is used as the collision time of the second current vehicle.

3. The method for estimating vehicle collision time according to claim 2, characterized in that, The second step includes: when the collision time of the preceding vehicle is less than the preset collision time threshold, calculating the difference between the collision time of the preceding vehicle and the preset collision time threshold, and subtracting the absolute value of the difference from the basic collision time of the second current vehicle to obtain the collision time of the second current vehicle.

4. The method for estimating vehicle collision time according to claim 1, characterized in that, The second step includes: When there is no vehicle in front of the target area in front of the second current vehicle, the second current vehicle is used as the first current vehicle, and the basic collision time of the second current vehicle is estimated according to the first step as the collision time of the second current vehicle.

5. The method for estimating vehicle collision time according to claim 1, characterized in that, The second step includes: When there is no vehicle in the target area in front of the vehicle in front, the vehicle in front is taken as the first current vehicle, and the basic collision time of the vehicle in front is estimated according to the first step as the collision time of the vehicle in front. When there is a vehicle in front of the target area, the vehicle in front is taken as the second current vehicle, and the collision time of the vehicle in front is estimated according to the second step.

6. The method for estimating vehicle collision time according to claim 1, characterized in that, The second step includes: determining the target area in front of the second current vehicle. Determining the target area in front of the second current vehicle includes: determining the range of the target area in front of the second current vehicle based on one or more of the following: the driving data of the second current vehicle, the number of vehicles in front of the second current vehicle, the vehicle spacing, the lane shape, the lane distribution, the position of vehicles exhibiting abnormal driving behavior in front of the second current vehicle, and the communication distance between the second current vehicle and the vehicles in front of it.

7. The method for estimating vehicle collision time according to claim 6, characterized in that, When there is a vehicle with abnormal driving behavior in front of the second current vehicle, and the distance between the vehicle with abnormal driving behavior and the second current vehicle is within a preset range, the boundary of the target area in front of the second current vehicle is determined according to the position of the vehicle with abnormal driving behavior.

8. The method for estimating vehicle collision time according to claim 6, characterized in that, When a vehicle located in front of the second current vehicle is in the same lane as the second current vehicle, the abnormal driving behavior includes: vehicle deceleration or vehicle braking; When the vehicle in front of the second current vehicle is in a different lane from the second current vehicle, the abnormal driving behavior includes: lane change or vehicle steering; The lanes include straight lanes and / or curved lanes.

9. The method for estimating vehicle collision time according to claim 1, characterized in that, Obtaining environmental data within the target area in front of the second current vehicle includes: Based on V2V communication between the second current vehicle and vehicles in the target area ahead of it, I2V communication between the second current vehicle and roadside units, and / or communication between the second current vehicle and base stations, driving data of vehicles in the target area ahead of the second current vehicle are obtained.

10. The method for estimating vehicle collision time according to claim 2 or 3, characterized in that, The method is used to estimate the collision time of the vehicle. There are multiple vehicles in the target area in front of the vehicle. The method includes taking each of the multiple vehicles in the target area in front of the vehicle as the second current vehicle and repeating the second step. The preset collision time threshold in each execution of the second step is the collision alarm time threshold preset by the forward collision warning system of the vehicle, or the preset collision time threshold in each execution of the second step is the collision alarm time threshold preset by the forward collision warning system of the second current vehicle at the time of execution of the second step.

11. The method for estimating vehicle collision time according to claim 1, characterized in that, The preceding vehicle in the second step is the vehicle directly adjacent to the second current vehicle within the target area in front of the second current vehicle.

12. A computer program product, comprising a computer program, characterized in that, When executed by a processor, the computer program implements the steps of the method for estimating vehicle collision time according to any one of claims 1 to 11.

13. A vehicle collision warning device, comprising a processor, a memory, and a computer program stored in the memory, characterized in that, When the computer program is executed by the processor, it performs the following steps: The method for estimating vehicle collision time according to any one of claims 1 to 11 estimates the collision time of the current vehicle; When the estimated collision time of the current vehicle is less than or equal to a preset collision time threshold, an alarm message is sent to the current vehicle.

Images