Express-highway obstacle detection system

Abstract

To provide an express-highway obstacle detection system that can perform obstacle detection with high accuracy.SOLUTION: A target detection unit 34 detects a position Pt and a time zone Tt of a target Q that is suspected to be an obstacle based on vehicle travel information VI which contains operation for each vehicle (steering, accelerator, brake, turn signal, etc.) and a behavior associated with those operations (acceleration / deceleration, forward / backward / left / right acceleration, yaw acceleration, etc.). An obstacle detection unit 36 determines whether the target Q is an obstacle 26 based on whether speed distributions of a plurality of vehicles 10 and 12 that have traveled through the position Pt and at the time zone Tt exhibit a bimodal distribution to detect the obstacle 26. As a result, the obstacle detection can be performed with high accuracy.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an obstacle detection system for expressways that detects obstacles on expressways based on vehicle travel information of vehicles traveling on the expressways. [Background technology]

[0002] A technology for detecting obstacles on a highway based on vehicle travel information of a vehicle traveling on the highway has been disclosed, for example, in a system described in Patent Document 1. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-87309 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned conventional system, obstacle detection is performed based on information on each vehicle's operation (steering, accelerator, brake, blinker, etc.) and the behavior associated with the operation (acceleration / deceleration, front / rear / left / right acceleration, yaw acceleration, etc.), i.e., vehicle driving information. For example, if vehicle driving information suspected of avoiding an obstacle is seen in the same place and at the same time, it is determined and detected as an obstacle. However, there is a problem in that the vehicle driving information for obstacle avoidance is similar to vehicle driving information for vehicles heading toward an expressway exit or an entrance to a service area, parking area, etc. (hereinafter referred to as an expressway exit), which makes it prone to false detection.

[0005] The present invention has been made in light of the above circumstances, and an object of the present invention is to provide an obstacle detection system for expressways that can detect obstacles with high accuracy. [Means for solving the problem]

[0006] The gist of the present invention is an obstacle detection system for a highway that (a) detects an obstacle on the highway based on vehicle travel information transmitted from a plurality of vehicles traveling on the highway and notifies vehicles traveling within a predetermined range of the obstacle of the obstacle detection information, and includes: (b) an object detection unit that detects the position and time period of an object suspected to be an obstacle based on the vehicle travel information; and (c) an obstacle detection unit that determines whether the object is the obstacle based on whether the speed distribution of the plurality of vehicles traveling at the position and in the time period shows a bimodal distribution, and detects the obstacle. [Effects of the Invention]

[0007] According to the highway obstacle detection system of the present invention, the object detection unit detects the position and time period of an object suspected to be an obstacle from the vehicle travel information, and the obstacle detection unit determines whether the object is an obstacle based on whether the speed distribution of the multiple vehicles that traveled at the position and in the time period shows a bimodal distribution, thereby detecting the obstacle. This allows for accurate obstacle detection.

[0008] Preferably, when the obstacle detection unit determines that the speed distribution shows bimodalities and that the object is not an obstacle, the vehicle is traveling toward the expressway exit, and the exit congestion determination unit determines whether the median value of the low-speed side of the speed distribution is equal to or less than a preset threshold. If the median value is equal to or less than the threshold, the expressway exit is determined to be congested. This allows for accurate detection of congestion at the expressway exit. Furthermore, expressway exit congestion information can be notified to vehicles traveling within a predetermined range of the expressway exit. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic diagram illustrating an obstacle detection system for a highway according to an embodiment of the present invention; [Figure 2]2 is a flowchart illustrating the control operation of the highway obstacle detection system of FIG. 1. [Figure 3] 2A and 2B are diagrams illustrating the difference between the vehicle behavior and speed distribution when avoiding an obstacle and the vehicle behavior and speed distribution when traveling toward an expressway exit on the expressway in FIG. 1. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. [Example]

[0011] FIG. 1 shows lanes in one direction (for example, an uphill direction) of a highway 20 in one embodiment of the present invention, with a vehicle 10 traveling in a driving lane 22 and a vehicle 12 traveling in an overtaking lane 24.

[0012] The vehicles 10, 12 are equipped with sensors that detect the driver's operation of the steering, accelerator, brake, turn signal, etc., a sensor that detects the vehicle speed V (km / h), a sensor (GPS sensor) that detects the vehicle position represented by longitude and latitude, a sensor (G sensor) that detects the acceleration in the forward / backward and left / right directions of the vehicles 10, 12, and a sensor (yaw acceleration sensor) that detects the rotational angular velocity of the vehicles 10, 12 about the vertical axis, and the vehicle driving information VI detected by these sensors is transmitted from the vehicles 10, 12 to the road information management center 30 described below, as shown by the dashed line in Figure 1.

[0013] The road information management center 30 includes a server 32 that can communicate with the vehicles 10, 12 via radio or other means. The server 32 includes an electronic control device known as a computer, which includes, for example, a CPU, RAM, ROM, an input / output interface, and the like. The server 32 accumulates vehicle travel information VI from the vehicles 10, 12, and detects obstacles and notifies the users of the obstacle detection information based on the vehicle travel information VI. The server 32 corresponds to the "expressway obstacle detection system" of the present invention.

[0014] In a conventional obstacle detection system, for example, when vehicle travel information VI suspected of avoiding an obstacle is seen in the same place and at the same time, it is determined to be an obstacle 26 and detected. However, there is a problem in that the vehicle travel information VI for obstacle avoidance and the vehicle travel information VI for a vehicle heading toward an expressway exit 28 are similar, which makes it easy for false detection to occur.

[0015] The server 32 of this embodiment accurately detects the obstacle 26 through a control operation that will be described later with reference to Fig. 2. The server 32 functionally includes an object detection unit 34 that detects the position Pt of an object Q suspected of having an obstacle 26 and the time period Tt of the occurrence based on the vehicle travel information VI, an obstacle detection unit 36 ​​that detects and determines whether or not the object Q is the obstacle 26, and an exit congestion determination unit 38 that, if it is determined that the object Q is not the obstacle 26, determines whether or not the expressway exit 28 is congested, and assumes that the vehicle is traveling toward the expressway exit 28.

[0016] 2 is a flowchart illustrating the control operation of the server 32 for detecting an obstacle 26. First, in step S1 (hereinafter, the term "step" will be omitted) corresponding to the object detection unit 34, vehicle travel information VI transmitted from each of the multiple vehicles 10, 12 is received and stored.

[0017] Next, in S2 corresponding to the object detection unit 34, the position Pt and the time period Tt of occurrence of the object Q suspected to be the obstacle 26 are detected. This is performed using a suitable method that is set in advance by design or experimentation, based on the accumulated vehicle driving information VI, determining the vehicle's evasive behavior based on the driver's operation of the steering, accelerator, brake, blinker, etc. and information on the behavior associated with the operation (acceleration / deceleration, front / rear / left / right acceleration, yaw acceleration, etc.), and concentrating on whether the vehicle's evasive behavior is observed in the same place and at the same time period.

[0018] Next, the control from S3 to S7 corresponding to the obstacle detection unit is carried out. In S3, the speed distribution of the vehicles 10 and 12 that traveled at the position Pt and the time period Tt detected in S2 is created by statistical processing.

[0019] 3 is a diagram comparing an example of vehicle behavior and speed distribution when avoiding an obstacle 26 at a position Pt and a time period Tt on the expressway 20, with an example of vehicle behavior and speed distribution when traveling toward an expressway exit 28. In FIG. 3, (a) shows the vehicle behavior when avoiding the obstacle 26, (b) shows the speed distribution in the case of (a), (c) shows the vehicle behavior when traveling toward the expressway exit 28, and (d) shows the speed distribution in the case of (c). The speed distributions in (b) and (d) were created by tallying up vehicles 10 and 12 that passed through the position Pt and the time period Tt, with the horizontal axis representing vehicle speed V (km / h) and the vertical axis representing the number of passing vehicles.

[0020] As shown in FIG. 3( a), when an obstacle 26 appears in one of the lanes of the expressway 20 (the driving lane 22 in this embodiment), the vehicle 10 traveling in the driving lane 22 temporarily decelerates and changes lanes to the passing lane 24 in order to avoid the obstacle 26. As the vehicle 10 changes lanes, the vehicle 12 traveling in the passing lane 24 decelerates by operating the accelerator. After avoiding the obstacle 26, the vehicles 10 and 12 accelerate again. In this way, when avoiding the obstacle 26, both the vehicle 10 and the vehicle 12 temporarily decelerate and travel in the passing lane 24, and therefore the speed distribution in FIG. 3( b) exhibits a single peak smoothed out by the vehicle speed V traveling in the passing lane 24. The same applies when, for example, the obstacle 26 appears in the passing lane 24; the speed distribution exhibits a single peak smoothed out by the vehicle speed V traveling in the driving lane 22.

[0021] In contrast, as shown in Figure 3(c), when traveling toward an expressway exit 28, vehicle 10 traveling in driving lane 22 decelerates significantly by braking in order to head toward the expressway exit 28, but vehicle 12 traveling in passing lane 24 is not significantly affected by the deceleration of vehicle 10. Therefore, the speed distribution in Figure 3(d) shows a bimodal distribution in which the vehicle speeds of vehicle 10 (driving lane 22) and vehicle 12 (passing lane 24) are distributed independently. This makes it possible to distinguish (determine) whether the vehicle behavior is when avoiding obstacle 26 or when traveling toward the expressway exit 28, i.e., whether object Q is an obstacle 26, based on whether the speed distribution shows a bimodal distribution.

[0022] 2, in S4 corresponding to the obstacle detection unit 36, it is determined whether the speed distribution created in S3 exhibits bimodal characteristics. If the determination in S4 is positive, in S5, the object Q is determined and detected as an obstacle 26, and then in S6, as shown by the dashed-dotted line in FIG. 1, the obstacle detection information is notified to the vehicles 10 and 12 traveling within a predetermined range from the obstacle 26, and this routine is then terminated.

[0023] If the judgment at S4 is negative, at S7 corresponding to the obstacle detection unit 36, it is judged that the object Q is not an obstacle 26, that is, it is judged that the vehicle is traveling toward the expressway exit 28, and control from S8 to S10 corresponding to the exit congestion judgment unit is carried out.

[0024] In S8, it is determined whether the center value Vd of the distribution on the low-speed side of the speed distribution is equal to or less than the threshold value Va. FIG. 3(d) shows that the center value on the low-speed side of the speed distribution (bimodal distribution) is the vehicle speed Vd at which the frequency (number of vehicles) reaches the maximum value Nd. The threshold value Va is a value that is set in advance by design or experiment for determining whether a traffic jam is occurring. If the determination in S8 is negative, this routine is terminated.

[0025] If the determination in S8 is positive, in S9 it is determined that the expressway exit 28 is congested, and then in S10, as shown by the dashed line in Figure 1, expressway exit congestion information is notified to vehicles 10, 12 traveling within a predetermined range from the expressway exit 28, and this routine is terminated.

[0026] As described above, according to the server 32 of this embodiment, the object detection unit 34 detects the position Pt and the time period Tt of the occurrence of an object Q suspected to be an obstacle from the vehicle travel information VI, and the obstacle detection unit 36 ​​determines whether the object Q is an obstacle 26 based on whether the speed distribution of the multiple vehicles 10, 12 that traveled at the position Pt and the time period Tt shows a bimodal distribution, and detects the obstacle 26. This allows for accurate obstacle detection.

[0027] Preferably, when the obstacle detection unit 36 ​​determines that the speed distribution is bimodal and that the object Q is not an obstacle 26, it is determined that the vehicle is traveling toward the expressway exit 28, and the exit congestion determination unit 38 further determines whether the median value Vd on the low-speed side of the speed distribution is equal to or less than a preset threshold value Va. When the median value Vd is equal to or less than the threshold value Va, it is determined that the expressway exit 28 is congested. This allows for accurate detection of congestion at the expressway exit 28. Furthermore, it is possible to notify the vehicles 10, 12 traveling within a predetermined range of the expressway exit 28 of expressway exit congestion information.

[0028] Although one embodiment of the present invention has been described above with reference to the drawings, the present invention can be embodied in other ways.

[0029] For example, in the above-described embodiment, communication was between the vehicles 10, 12 and the server 32 of the road information management center 30, but communication may also be via roadside devices installed along the expressway 20.

[0030] It should be noted that the above is merely one embodiment, and the present invention can be embodied in various forms with various modifications and improvements based on the knowledge of those skilled in the art. [Explanation of symbols]

[0031] 10, 12: Vehicle 20: Expressway 26: Obstacle 32: Server (Expressway obstacle detection system) 34: Object detection unit 36: Obstacle detection unit Pt: Position Q: Object Tt: Time period VI: Vehicle driving information

Claims

[Claim 1] An obstacle detection system for an expressway, which detects an obstacle on the expressway based on vehicle travel information transmitted from a plurality of vehicles traveling on the expressway, and notifies vehicles traveling within a predetermined range of the obstacle of the obstacle, an object detection unit that detects the position and time period of an object suspected to be an obstacle based on the vehicle travel information; an obstacle detection unit that determines whether the object is the obstacle based on whether or not the speed distribution of the plurality of vehicles that traveled at the location and in the time period shows a bimodal distribution, and detects the obstacle. An obstacle detection system for expressways.

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