Collision prevention device, collision prevention method, and collision prevention program

Abstract

To provide a collision prevention device, a collision prevention method, and a collision prevention program that are improved to be able to reduce a possibility that collision prevention support control is unnecessarily performed without requiring the presence of a preceding vehicle in a state where a movable body such as a train moves transversely on the level different from that of an own vehicle.SOLUTION: A collision prevention device includes: a radar device configured to detect a three-dimensional object approaching from the front side of an own vehicle to the front of the own vehicle; and a control device configured to execute collision prevention support control for reducing a possibility that the own vehicle collides with the three-dimensional object (S110) when determining that the own vehicle may collide with the three-dimensional object (S90). The control device suppresses the execution of collision prevention support control (S80, S100) when determining that the three-dimensional object is a group of movable bodies in rows with the number equal to or larger than a reference value (S30 to S50) and determining that no track for a track vehicle crossing at grade with a road on which the own vehicle runs is present in front of the own vehicle (S70).SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a collision prevention device, a collision prevention method, and a collision prevention program for a vehicle such as an automobile. [Background technology]

[0002] The collision prevention device includes a detection device that detects objects around the host vehicle, and a control device that, when it determines that the host vehicle is at risk of colliding with an object detected by the detection device, performs collision prevention assistance control such as issuing an alarm and automatically decelerating the vehicle to avoid the collision. The risk of collision is also determined for objects approaching the front of the host vehicle from the front side.

[0003] For example, the following Patent Document 1 describes a collision prevention device that uses a radar device to simultaneously detect one target ahead of the vehicle and another target traveling further ahead of the vehicle, and if the two targets do not intersect (the difference in the positions of both vehicles in the lateral direction relative to the traveling direction of the vehicle is less than a reference value), it is determined that there is no risk of collision between the one target and the vehicle. According to this type of collision prevention device, Upward In a situation where there is an elevated road in the vicinity of the target and the target is traveling on the elevated road, the possibility of unnecessary execution of collision prevention assist control can be reduced. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-218629 Summary of the Invention

[0005] [Problem to be solved by the invention] In conventional collision prevention devices such as the one described in Patent Document 1, if a preceding vehicle can move without colliding with other targets, it is determined that the host vehicle can also move without colliding with other targets. Therefore, in a situation where there is no preceding vehicle ahead of the host vehicle, it is not possible to determine whether the host vehicle is at risk of colliding with other targets. Therefore, even when a vehicle approaching from the side of the host vehicle is a train, monorail, or other vehicle traveling on an elevated track, the system may determine that the host vehicle is at risk of colliding with the other vehicle, resulting in unnecessary execution of collision prevention assistance control. This can lead to annoyance among occupants due to unnecessary alarms and unnecessary deceleration of the vehicle.

[0006] To avoid unnecessary execution of collision prevention assist control, it is conceivable to equip the vehicle with a radar device capable of detecting the height of other vehicles. However, such a radar device must be an expensive radar device with antenna elements arranged at multiple positions at different heights, which inevitably makes the collision prevention device expensive.

[0007] The present invention provides an improved collision prevention device, collision prevention method, and collision prevention program that can reduce the risk of unnecessary collision prevention support control being performed when a moving object such as a train is moving across at a different height from the vehicle itself, without requiring the presence of a preceding vehicle.

[0008] [Means for solving the problems and effects of the invention] According to the present invention, there is provided a collision prevention device (100) including a radar device (radar sensor 14) that detects a three-dimensional object (74) approaching the front of the host vehicle (102) from the front side of the host vehicle, and a control device (driving assistance ECU 10) that, when it is determined that there is a risk of the host vehicle colliding with the three-dimensional object (S90), executes collision prevention assistance control (S110) to reduce the risk of the host vehicle colliding with the three-dimensional object.

[0009] The control device (driving assistance ECU 10) includes a determination device (camera sensor 12, driving assistance ECU 10) that determines whether or not there is a track (74A to 74C) for a track vehicle that intersects at grade with a road (80) on which the vehicle is traveling ahead of the vehicle, and the control device radar equipment Based on the detection results, the reliability (Dr) of the detected three-dimensional object is calculated (S20), and it is determined that the three-dimensional objects are a group of moving objects in formation with a number equal to or greater than a reference value (S30 to S50). When the determination device determines that there is no track for a tracked vehicle ahead of the vehicle (S70), the reliability is reduced so that it becomes smaller as the probability that there is no track for a tracked vehicle increases (S80), and when the reliability is less than the reference value, the execution of collision prevention support control is suppressed (S100).

[0010] Furthermore, according to the present invention, there is provided a collision prevention method including a step (S10) of detecting a three-dimensional object (74) approaching the front of the vehicle (102) from the front side of the vehicle, and a step (S110) of executing collision prevention support control to reduce the risk of the vehicle colliding with the three-dimensional object when it is determined (S90) that there is a risk of the vehicle colliding with the three-dimensional object.

[0011] Collision prevention methods include: A step (S20) of calculating the reliability of the detected three-dimensional object; a step (S70) of determining whether or not there is a track (74A-74C) for track vehicles that intersects at grade with the road (80) on which the vehicle is traveling ahead of the vehicle; and when it is determined that the number of three-dimensional objects is equal to or greater than a reference value and that the three-dimensional objects are a group of moving objects forming a formation (S30-S50) and it is determined that there is no track for track vehicles ahead of the vehicle (S70), A step (S80) of reducing the reliability so that the reliability decreases as the probability that a track for a rail vehicle does not exist increases; and when the reliability is less than a reference value, Step of suppressing execution of collision prevention assistance control (S100) and,

[0012] Furthermore, according to the present invention, there is provided a collision prevention program that causes an electronic control unit (driving assistance ECU 10) mounted on the host vehicle to execute the following steps: a step (S10) of detecting a three-dimensional object (74) approaching the front of the host vehicle (102) from the front side of the host vehicle; and a step (S110) of executing collision prevention assistance control to reduce the risk of the host vehicle colliding with the three-dimensional object when it is determined (S90) that the host vehicle is at risk of colliding with the three-dimensional object.

[0013] The collision prevention program A step (S20) of calculating the reliability of the detected three-dimensional object; a step (S70) of determining whether or not there is a track (74A-74C) for track vehicles that intersects at grade with the road (80) on which the vehicle is traveling ahead of the vehicle; and when it is determined that the number of three-dimensional objects is equal to or greater than a reference value and that the three-dimensional objects are a group of moving objects forming a formation (S30-S50) and it is determined that there is no track for track vehicles ahead of the vehicle (S70), A step (S80) of reducing the reliability so that the reliability decreases as the probability that a track for a rail vehicle does not exist increases; and when the reliability is less than a reference value, Step of suppressing execution of collision prevention assistance control (S100) and,

[0014] According to the above-described collision prevention device, collision prevention method, and collision prevention program, The reliability of the detected three-dimensional object is calculated, It is determined whether there is a track for track vehicles ahead of the vehicle that intersects with the road on which the vehicle is traveling at grade. Furthermore, When it is determined that the number of three-dimensional objects is equal to or greater than a reference value and that a group of moving objects is in a formation, and it is determined that there is no track for a tracked vehicle ahead of the vehicle, The reliability is reduced so that the reliability becomes smaller as the probability that the track for the track vehicle does not exist increases, and when the reliability is less than a reference value, The execution of collision prevention assistance control is suppressed.

[0015] Therefore, even in a situation where it is determined that there is a risk of the vehicle colliding with a three-dimensional object, if the three-dimensional objects are a group of moving objects such as trains or monorails that form a line with a number equal to or greater than a reference value and are moving at a position at a different height from the vehicle, When the reliability is reduced and the reliability is below the reference value, The execution of the collision prevention assist control is suppressed, and therefore, the risk of the collision prevention assist control being executed unnecessarily can be reduced. In particular, the confidence level can be decreased so that it becomes smaller the more certain it is that the track for the rail vehicle does not exist.

[0016] Note that suppression of the execution of the collision prevention assist control may be achieved by reducing the control amount of the collision prevention assist control, or by reducing the control amount of the collision prevention assist control to 0. In the latter case, the execution of the collision prevention assist control is prevented, and adverse effects caused by the execution of the collision prevention assist control can be prevented.

[0017] Furthermore, when it is determined that the number of three-dimensional objects is equal to or greater than a reference value and that a track for track vehicles is present ahead of the host vehicle, the execution of the collision prevention assist control is executed without suppression. Therefore, in a situation where the host vehicle approaches a railroad crossing or the like and a train or the like is about to cross in front of the host vehicle, the collision prevention assist control can prevent the host vehicle from colliding with the train or the like.

[0018] [Mode of the Invention] In one aspect of the present invention, the control device (driving assistance ECU 10) is configured to determine that the three-dimensional objects are a group of moving bodies in a formation with a number equal to or greater than a reference value when the number of moving bodies is equal to or greater than a reference value and the distance between each moving body is equal to or less than a reference distance.

[0019] According to the above aspect, when a number of moving bodies equal to or greater than a reference value are moving in the same direction at the same speed and the distance between the moving bodies is equal to or less than a reference distance, the three-dimensional object is determined to be a group of moving bodies in a formation with a number equal to or greater than a reference value. Therefore, it is possible to accurately determine whether the three-dimensional object is a group of moving bodies in a formation with a number equal to or greater than a reference value, compared to when a number of moving bodies equal to or greater than a reference value are moving in the same direction at the same speed or the distance between the moving bodies is equal to or less than a reference distance, and the three-dimensional object is determined to be a group of moving bodies such as trains.

[0020] In another aspect of the present invention, the determination device includes an imaging device that captures an image of the area ahead of the vehicle, and is configured to determine whether a target indicating the presence of a track for a track vehicle exists ahead of the vehicle based on the image captured by the imaging device.

[0021] According to the above aspect, the determination device includes an imaging device that captures an image of the area ahead of the vehicle, and is configured to determine whether a target indicating the presence of a track for a track vehicle is present ahead of the vehicle based on the image captured by the imaging device. Thus, based on the image captured by the imaging device, it is possible to determine whether a track for a track vehicle exists ahead of the vehicle that intersects with the road on which the vehicle is traveling at grade.

[0022] In the above description, to facilitate understanding of the present invention, the names and / or symbols used in the embodiments described below are enclosed in parentheses for the configurations of the invention corresponding to those embodiments. However, each component of the present invention is not limited to the components of the embodiments corresponding to the names and / or symbols enclosed in parentheses. Other objects, features, and attendant advantages of the present invention will be easily understood from the following description of the embodiments of the present invention, which will be given with reference to the drawings. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a schematic configuration diagram showing an embodiment of a collision prevention device according to the present invention. [Figure 2] 4 is a flowchart illustrating a collision prevention control routine in the embodiment. [Figure 3] FIG. 10 is a diagram showing a situation in which a monorail as a three-dimensional object approaches the front of the vehicle from the front right side of the vehicle, crossing the direction of travel of the vehicle. [Figure 4] This figure shows a situation where there is a train track that intersects at grade with the road on which the vehicle is traveling, and a train, as a three-dimensional object, approaches the front of the vehicle from the right front side, crossing the direction of travel of the vehicle. [Figure 5] This figure shows a situation where there is a tram track that intersects at grade with the road on which the vehicle is traveling, and a tram, as a three-dimensional object, approaches the front of the vehicle from the right front side, crossing the direction of travel of the vehicle. [Figure 6]This figure shows a situation where there is an overpass above the road on which the vehicle is traveling, and a three-dimensional object consisting of a towing vehicle and a towed vehicle approaches the front right side of the vehicle along the overpass road. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, with reference to the accompanying drawings, a collision prevention device according to an embodiment of the present invention will be described. prevention equipment, collision prevention Methods and Conflicts prevention The program will be explained in detail.

[0025] As shown in FIG. 1, a collision according to an embodiment of the present invention prevention The device 100 is applied to a vehicle 102 and includes a driving assistance ECU 10. The vehicle 102 may be an autonomous vehicle, and includes a drive ECU 20, a braking ECU 30, an electric power steering ECU 40, and a meter ECU 50. The ECU refers to an electronic control unit that includes a microcomputer as its main component. In the following description, the vehicle 102 will be referred to as the host vehicle 102 as necessary to distinguish it from other vehicles, and the electric power steering will be referred to as EPS.

[0026] The microcomputer of each ECU includes a CPU, ROM, RAM, read / write non-volatile memory (N / M), and an interface (I / F). The CPU performs various functions by executing instructions (programs, routines) stored in the ROM. Furthermore, these ECUs are interconnected via a Controller Area Network (CAN) 104 to enable data exchange (communication). Therefore, the detected values ​​of sensors (including switches) connected to a specific ECU are transmitted to other ECUs.

[0027] The driving assistance ECU 10 preventionThe driving assistance ECU 10 is a central control device that performs driving assistance control such as vehicle speed control and lane keeping control. A camera sensor 12 and a radar sensor 14 are connected to the driving assistance ECU 10. The camera sensor 12 includes four camera sensors that capture images of the front, rear, right side, and left side, but the number of cameras is not limited to four. The radar sensor 14, which serves as a radar device, includes five radar sensors that detect three-dimensional objects in the front area, the right front area, the left front area, the right rear area, and the left rear area and acquire information about them, but the number of cameras is not limited to five. The camera sensor 12 and the radar sensor 14 function as a surrounding information acquisition device that acquires information about targets and the like around the vehicle 102.

[0028] Although not shown, each camera sensor of the camera sensor 12 includes a camera unit that captures images of the surroundings of the vehicle 102 and a recognition unit that analyzes image data captured by the camera unit to recognize targets such as white lines on the road and other vehicles. The recognition unit supplies information about the recognized targets to the driving assistance ECU 10 at predetermined time intervals.

[0029] Each radar sensor of the radar sensor 14 includes a radar transmitting / receiving unit and a signal processing unit (not shown). The radar transmitting / receiving unit emits millimeter-wave band radio waves (hereinafter referred to as "millimeter waves") ahead of the vehicle 102 and receives millimeter waves reflected by a three-dimensional object (e.g., another vehicle, a guardrail, etc.) within the emission range (i.e., reflected waves). The signal processing unit acquires information indicating the distance between the vehicle and the three-dimensional object, the relative speed between the vehicle and the three-dimensional object, the relative position (direction) of the three-dimensional object with respect to the vehicle, etc., based on the phase difference between the transmitted millimeter waves and the received reflected waves, the attenuation level of the reflected waves, the time from transmitting the millimeter waves to receiving the reflected waves, etc., at predetermined time intervals, and supplies the information to the driving assistance ECU 10. Note that a LiDAR (Light Detection and Ranging) may be used instead of or in addition to the radar sensor 14.

[0030] Furthermore, a setting operator 16 is connected to the driving assistance ECU 10, and the setting operator 16 is provided at a position where it can be operated by the driver. Although not shown in Fig. 1, the setting operator 16 includes a collision prevention control switch, and the driving assistance ECU 10 executes collision prevention control when the collision prevention control switch is on.

[0031] A drive unit 22 that accelerates the vehicle 102 by applying drive force to drive wheels not shown in Fig. 1 is connected to the drive ECU 20. Under normal circumstances, the drive ECU 20 controls the drive unit 22 so that the drive force generated by the drive unit 22 changes in response to the driving operation by the driver, and when a command signal is received from the driving assistance ECU 10, the drive ECU 20 controls the drive unit 22 based on the command signal.

[0032] The drive device 22 is not limited to a combination of an internal combustion engine and an automatic transmission. That is, the drive device 22 may be any drive device known in the art, such as a combination of an internal combustion engine and a continuously variable transmission, a so-called hybrid system which is a combination of an internal combustion engine and a motor, a so-called plug-in hybrid system, a combination of a fuel cell and a motor, or a motor.

[0033] The brake ECU 30 is connected to a brake device 32 that applies braking force to wheels (not shown in Fig. 1) to decelerate the vehicle 102. The brake ECU 30 normally controls the brake device 32 so that the braking force generated by the brake device 32 changes in response to the braking operation by the driver, and when it receives a command signal from the driving assistance ECU 10, it controls the brake device 32 based on the command signal to perform automatic braking. When braking force is applied to the wheels, a brake lamp (not shown in Fig. 1) is turned on.

[0034] An EPS device 42 is connected to the EPS-ECU 40. The EPS-ECU 40 controls the steering assist torque and reduces the driver's steering burden by controlling the EPS device 42 in a manner known in the art based on the steering torque Ts and vehicle speed V detected by a driving operation sensor 60 and a vehicle state sensor 62, which will be described later. The EPS-ECU 40 also controls the EPS device 42 to steer the steered wheels as needed. Therefore, the EPS-ECU 40 and the EPS device 42 function as an automatic steering device that automatically steers the steered wheels as needed.

[0035] A display 52 that displays a visual warning or the like indicating the status of control by the driving assistance ECU 10 and the risk of the host vehicle colliding with another vehicle, and a buzzer 54 that issues an audible warning, are connected to the meter ECU 50. The display 52 may be, for example, a head-up display or a multi-information display that displays meters and various information, or may be a display of a navigation device.

[0036] The driving operation sensors 60 and the vehicle state sensors 62 are connected to the CAN 104. Information detected by the driving operation sensors 60 and the vehicle state sensors 62 (referred to as sensor information) is transmitted to the CAN 104. The sensor information transmitted to the CAN 104 can be used appropriately in each ECU. Note that the sensor information may be information from a sensor connected to a specific ECU and transmitted to the CAN 104 from that specific ECU.

[0037] The driving operation sensor 60 includes a driving operation amount sensor that detects the amount of accelerator pedal operation, a braking operation amount sensor that detects the master cylinder pressure or the force applied to the brake pedal, a brake switch that detects whether the brake pedal is operated, a steering angle sensor that detects the steering angle θ, a steering torque sensor that detects the steering torque Ts, etc.

[0038] The vehicle state sensor 62 includes a vehicle speed sensor that detects the vehicle speed V of the vehicle 102, a longitudinal acceleration sensor that detects the longitudinal acceleration of the vehicle, a lateral acceleration sensor that detects the lateral acceleration of the vehicle, and a yaw rate sensor that detects the yaw rate of the vehicle.

[0039] In this embodiment, the ROM of the driving assistance ECU 10 stores a program for collision prevention control corresponding to the flowchart shown in Fig. 2, and the CPU executes the collision prevention control in accordance with the program. The collision prevention control method according to this embodiment is implemented by executing the collision prevention control. In the following description, the collision prevention control will be referred to as the present control.

[0040] <Collision Prevention Control Routine in the Embodiment> Next, a collision prevention control routine in this embodiment will be described with reference to the flowchart shown in Fig. 2. The collision prevention control according to the flowchart shown in Fig. 2 is executed by the CPU of the driving assistance ECU 10 when a collision prevention switch (not shown in Fig. 1) is turned on.

[0041] First, in step S10, the CPU determines, based on the detection result of the radar sensor 14, whether or not there is a three-dimensional object 74 approaching the front of the vehicle 102 from the front side thereof across the traveling direction 72 of the vehicle, as shown in Fig. 3 for example. If the CPU makes a negative determination, it proceeds to step S60, and if the CPU makes a positive determination, it proceeds to step S20.

[0042] In Fig. 3, 76R and 76L indicate the detection ranges of the radar sensor 14 for the right front area and the left front area, respectively, and 78R and 78L indicate the ranges for determining the presence or absence of a three-dimensional object 74. As shown in the figure, the ranges 78R and 78L for determining the presence or absence of a three-dimensional object 74 may be part of the detection range of the radar sensor. Note that in Fig. 3, 12A indicates an example of the imaging range of the camera sensor 12 that images the front, and 74A indicates the track of the three-dimensional object (monorail) 74.

[0043] In step S20, the CPU calculates the reliability Dr of the detected three-dimensional object 74 based on at least the detection result of the radar sensor 14. In this case, for example, the reliability Dr may be calculated to a higher value as the intensity of the millimeter waves reflected from the three-dimensional object increases, and the maximum value of the reliability Dr may be, for example, 100%.

[0044] In step S30, the CPU determines whether the detected three-dimensional object 74 is a group of moving objects with a number equal to or greater than a reference value, that is, whether the three-dimensional object 74 is a three-dimensional object made up of a number of moving objects 74i (i = -1, 2 ... n (n is a positive constant)) equal to or greater than a reference value. If the CPU makes a negative determination, the control proceeds to step S60, and if the CPU makes a positive determination, the control proceeds to step S40. The reference value may be a positive integer such as 2 or 3. Whether the three-dimensional object 74 is a three-dimensional object made up of a number of moving objects 74i equal to or greater than a reference value may be determined, for example, by determining whether the length of the three-dimensional object 74 is equal to or greater than a reference length (a positive constant) and whether there is a recess at the upper edge.

[0045] In step S40, the CPU determines whether all of the moving bodies 74i of the three-dimensional object 74 are moving in the same direction at the same speed. If the CPU makes a negative determination, it proceeds to step S60, and if the CPU makes a positive determination, it proceeds to step S50.

[0046] In step S50, the CPU determines whether all of the moving bodies 74i have substantially the same length and whether the intervals between all of the moving bodies are equal to or less than a reference interval (a positive constant). If the CPU determines yes, the control proceeds to step S70, and if the CPU determines no, the control proceeds to step S60. Note that if the reference value in step S30 is 2, the determination of whether the intervals between all of the moving bodies are equal to or less than the reference interval may be omitted.

[0047] Thus, in steps S30 to S50, it is determined whether the three-dimensional object 74 determined in step S10 to be approaching the front of the vehicle 102 from the front side across the direction of travel of the vehicle is a group of moving objects such as a monorail or train, which form a convoy with a number greater than a reference value.

[0048] In step S60, when there is a risk of the host vehicle 102 colliding with a three-dimensional object that is not part of a platoon of moving objects whose number is equal to or greater than a reference value, the CPU executes conventional collision prevention control to reduce the risk. The conventional collision prevention control may be any collision prevention control known in the art, such as the collision prevention control described in the aforementioned Patent Document 1.

[0049] In step S70, the CPU determines whether or not the camera sensor 12, which captures an image ahead of the host vehicle 102, has detected a target object indicating the presence of a track for a track vehicle that intersects at grade with the road on which the host vehicle is traveling. That is, the CPU determines whether or not a track for a track vehicle exists ahead of the host vehicle based on the image captured by the camera sensor 12. If the CPU makes a positive determination, it proceeds to step S90, and if the CPU makes a negative determination, it proceeds to step S80. Thus, the camera sensor 12 and the driving assistance ECU 10 (step S70) function as a determination device that determines whether or not a track for a track vehicle exists ahead of the host vehicle that intersects at grade with the road on which the host vehicle is traveling.

[0050] It may be determined that there is a track for a track vehicle that intersects at grade with the road on which the vehicle is traveling when the camera sensor 12 captures an image of a road sign that says "Railroad Crossing Ahead," a sign that says "Watch Out for Railroad Crossing," a traffic light indicating a railroad crossing, a barrier, or other landmark located ahead of the vehicle 102. Therefore, when a road sign that says "Railroad Crossing Ahead" or the like is not captured, it is considered that there is a track for a track vehicle at a higher position than the road on which the vehicle is traveling, and therefore a negative determination is made in step S70.

[0051] 4 shows a situation in which train tracks 74B intersect at grade with road 80 on which vehicle 102 is traveling, and train 82 as three-dimensional object 74 approaches the front of vehicle 102 from the front right side, crossing the direction of travel of vehicle 102. In this situation, a positive determination is made in steps S30 to S50, and since there is a railroad crossing 84 ahead of vehicle 102, a road sign 84A indicating "railroad crossing ahead," a railroad crossing traffic light 84B, and so on, a positive determination is made in step S70.

[0052] 5 shows a situation in which road 80 on which vehicle 102 is traveling and road 86 intersect at grade, road 86 has tram tracks 74C, and tram 88 as three-dimensional object 74 approaches the front of vehicle 102 from the front right side, crossing the direction of travel of vehicle 102. In this situation, too, a positive determination is made in steps S30 to S50, and since there is road sign 84C ahead of vehicle 102 indicating that a "tram" will cross the road, a positive determination is made in step S70.

[0053] In the situation shown in FIG. 5, if the three-dimensional object 74 is an articulated bus and there is a road sign or the like indicating that an "articulated bus" is crossing ahead of the vehicle 102, a positive determination may be made in step S70 even though there is no trajectory for the articulated bus.

[0054] In step S80, the CPU reduces the reliability Dr of the three-dimensional object 74, for example, by multiplying the reliability Dr of the three-dimensional object 74 by a correction coefficient K that is greater than 0 and less than 0.8. In this case, the correction coefficient K may be variably set so that it decreases as the probability that a track for a track vehicle does not exist increases based on the imaging results of the camera sensor 12. Note that the reduction of the reliability Dr is not limited to multiplying the reliability Dr of the three-dimensional object 74 by the correction coefficient K.

[0055] In step S90, the CPU determines whether or not there is a risk of the host vehicle 102 colliding with the three-dimensional object 74, using a method known in the art. If the CPU determines negative, it temporarily terminates this control, and if the CPU determines positive, it proceeds to step S100. For example, the CPU estimates a time ts when the leading edge of the three-dimensional object 74 starts to pass in front of the host vehicle 102 and a time te when the rear edge of the three-dimensional object 74 finishes passing in front of the host vehicle 102. Furthermore, the CPU estimates the minimum distance between the host vehicle 102 and the three-dimensional object 74 from time ts to time te, and if the minimum distance is equal to or less than a preset reference distance (a positive constant), it may determine that there is a risk of the host vehicle 102 colliding with the three-dimensional object 74.

[0056] In step S100, the CPU determines whether the reliability Dr is equal to or greater than a reference value Drc (e.g., a positive constant of about 80%), i.e., whether collision prevention assist control should be executed. If the CPU makes a negative determination, it temporarily terminates this control, and if the CPU makes a positive determination, it proceeds to step S110.

[0057] In step S110, the CPU executes collision prevention assistance control. Specifically, the CPU outputs a command signal to the meter ECU 50 to display a visual warning on the display 52 that the host vehicle 102 is at risk of colliding with a group of moving objects, which are three-dimensional objects, and also sounds the buzzer 54 to issue an audible warning that the host vehicle 102 is at risk of colliding with a group of moving objects. Furthermore, The CPU is By outputting a command signal to the brake ECU 30, the brake device 32 automatically brakes the host vehicle 102 to decelerate the host vehicle 102, thereby avoiding the host vehicle 102 from colliding with the group of moving objects. Note that if it is determined that it is better to accelerate the host vehicle 102 in order to avoid the collision, the host vehicle 102 may be accelerated by automatic acceleration by the drive device 22.

[0058] In this embodiment, if it is determined in step S10 that there is a three-dimensional object 74 approaching the front of the vehicle 102 from the front side across the traveling direction of the vehicle, then in step S20, the reliability Dr of the three-dimensional object 74 is calculated. If it is determined in steps S30 to S50 that the three-dimensional objects 74 are a group of moving objects forming a formation with a number equal to or greater than a reference value, then in step S70, it is determined whether there is a track for track vehicles that intersects at grade with the road on which the vehicle 102 is traveling.

[0059] <When the track for tracked vehicles is located higher than the road on which the vehicle is traveling> In step S70, it is determined that there is no track for a track vehicle that intersects at grade with the road 80 on which the host vehicle 102 is traveling, and therefore the reliability Dr is reduced in step S80. Even if it is determined in step S90 that there is a high risk that the host vehicle 102 will collide with the group of moving objects 74, it is determined in step S100 that the reliability Dr is less than the reference value Drc. Therefore, the collision prevention assist control in step S110 is not executed, and therefore it is possible to prevent the collision prevention assist control from being executed unnecessarily.

[0060] For example, as shown in Fig. 3, when a track 74A for track vehicles is located above the road 80 on which the host vehicle 102 is traveling and a group of moving objects 74 such as a monorail or train approaches in front of the host vehicle along the track 74A, the collision prevention assist control is not executed. The monorail may be either a straddle type or a suspended type.

[0061] <When the road on which your vehicle is traveling intersects with a track for rail vehicles at grade> In step S70, it is determined that there is a track for track vehicles that intersects at grade with the road 80 on which the host vehicle 102 is traveling, so the reliability Dr is not reduced in step S80. If it is determined in step S90 that there is a high risk that the host vehicle 102 will collide with the group of moving objects 74, it is determined in step S100 that the reliability Dr is equal to or greater than the reference value Drc. Therefore, in step S110, collision prevention assist control is executed, so that the risk of the host vehicle 102 colliding with the group of moving objects 74 can be reduced.

[0062] For example, even if a positive determination is made in steps S30 to S50, a positive determination is made in step S70 if a train or streetcar track intersects at grade with the road 80 on which the host vehicle 102 is traveling, as shown in Figures 4 and 5. Therefore, when there is a high risk that the host vehicle 102 will collide with a group of moving objects 74 such as a train or streetcar, the risk of the host vehicle 102 colliding with the group of moving objects 74 can be reduced by automatic braking of the collision prevention assist control, etc.

[0063] 6, there is an overpass 90 above the road 80 on which the vehicle 102 is traveling, and a three-dimensional object 74 consisting of a towing vehicle 92 and a towed vehicle 94 is located on the road above the overpass 90. 96 This shows a situation where a vehicle approaches the front of the host vehicle along the road. In this situation, positive determinations are made in steps S30 and S40, but a negative determination is made in step S50. Therefore, the steps after step S70 are not executed, and conventional collision prevention control is executed in step S60.

[0064] As can be seen from the above description, according to the embodiment, The reliability of the detected three-dimensional object is calculated, It is determined whether there is a track for track vehicles ahead of the vehicle that intersects with the road on which the vehicle is traveling at grade. Furthermore, When it is determined that the number of three-dimensional objects is equal to or greater than a reference value and that a group of moving objects is in a formation, and it is determined that there is no track for a tracked vehicle ahead of the vehicle, The reliability is reduced so that the reliability becomes smaller as the probability that the track for the track vehicle does not exist increases, and when the reliability is less than a reference value, The execution of collision prevention assistance control is suppressed.

[0065] Therefore, even in a situation where it is determined that there is a risk of the vehicle colliding with a three-dimensional object, if the three-dimensional objects are a group of moving objects such as trains or monorails that form a line with a number equal to or greater than a reference value and are moving at a position at a different height from the vehicle, When the reliability is reduced and the reliability is below the reference value, The execution of the collision prevention assist control is suppressed, and therefore, the risk of the collision prevention assist control being executed unnecessarily can be reduced. In particular, the confidence level can be decreased so that it becomes smaller the more certain it is that the track for the rail vehicle does not exist.

[0066] Furthermore, when it is determined that the number of three-dimensional objects is equal to or greater than a reference value and that the group of moving objects 74 is in a formation (S30 to S50), and when it is determined that a track 74A for track vehicles or the like is present ahead of the host vehicle (S70), the execution of the collision prevention assist control is executed without suppression (S110). Therefore, for example, as shown in Fig. 4, in a situation where the host vehicle approaches a railroad crossing or the like and a train or the like is about to cross in front of the host vehicle, the collision prevention assist control can prevent the host vehicle from colliding with the train or the like.

[0067] In particular, according to the embodiment, if it is determined in step S100 that the reliability Dr is less than the reference value Drc, the collision prevention assist control is not executed in step S110. Therefore, it is possible to reliably reduce the risk of unnecessary execution of the collision prevention assist control compared to when the execution of the collision prevention assist control is suppressed by reducing the control amount of the collision prevention assist control.

[0068] In particular, according to the embodiment, the determinations of steps S30 to S50 are performed. Therefore, compared to when any of the determinations of steps S30 to S50 is not performed, it is possible to accurately determine whether the three-dimensional object is a group of moving objects, such as trains or monorails, that form a convoy with a number equal to or greater than a reference value. In other words, it is possible to reduce the risk that a three-dimensional object towing a towed vehicle is determined to be a group of moving objects that form a convoy with a number equal to or greater than a reference value.

[0069] Furthermore, there is no need for a radar device capable of detecting the height of a three-dimensional object such as a train or monorail, for example, an expensive radar device in which antenna elements are arranged at a plurality of positions at different heights, so it is possible to avoid the collision prevention device becoming expensive.

[0070] Although the present invention has been described in detail above with reference to specific embodiments and modifications, it will be apparent to those skilled in the art that the present invention is not limited to the above-described embodiments and modifications, and that various other embodiments are possible within the scope of the present invention.

[0071] For example, in the above-described embodiment, when it is determined that the number of three-dimensional objects is equal to or greater than a reference value and that the group is a group of moving objects forming a formation (S30 to S50), and it is determined that there is no track for a tracked vehicle ahead of the vehicle (S70), the collision avoidance support control (S110) is not executed. That is, an alarm is not issued and acceleration / deceleration control of the vehicle 102 is not executed, and processing equivalent to reducing the control amount of the collision avoidance support control to zero is executed.

[0072] However, the acceleration / deceleration control may be performed with a reduced control amount, in which case the amount of acceleration / deceleration of the vehicle that is not due to the driver's driving operation, i.e., the amount of vehicle speed fluctuation that is not intended by the driver, can be reduced.

[0073] Furthermore, the amount of control of the warning may be reduced before the warning is issued. In the case of an audible warning, the amount of control of the warning may be reduced, for example, by reducing the volume of the warning, and in the case of a visual warning, the amount of control of the warning may be reduced, for example, by reducing the size or brightness of the characters in the warning. Furthermore, the amount of control of the warning may be reduced by reducing the number of types of warning, for example, by omitting either the audible warning or the visual warning. In these cases, the appeal of the warning is reduced, thereby reducing the risk of the occupant being annoyed by unnecessary warnings.

[0074] In the above embodiment, in step S50, it is determined whether all of the moving bodies 74i have substantially the same length and the intervals between all of the moving bodies are equal to or less than the reference interval. However, it may be determined whether all of the moving bodies 74i have substantially the same length and height and the intervals between all of the moving bodies are equal to or less than the reference interval. Furthermore, the determination of either all of the moving bodies 74i having substantially the same length or all of the intervals between all of the moving bodies being equal to or less than the reference interval may be omitted.

[0075] Furthermore, in the above-described embodiment, the collision prevention assist control is the issuance of an alarm and automatic acceleration / deceleration control, but it may be only one of the issuance of an alarm and automatic acceleration / deceleration control. [Explanation of symbols]

[0076] 10... driving assistance ECU, 12... camera sensor, 14... radar sensor, 20... drive ECU, 22... drive device, 30... braking ECU, 32... braking device, 40... EPS ECU, 42... EPS device, 50... meter ECU, 52... display, 54... buzzer, 60... driving operation sensor, 62... vehicle state sensor, 74... three-dimensional object (group of moving objects), 74A... track, 100... collision prevention device

Claims

1. A collision prevention device including a radar device that detects a three-dimensional object approaching the front of the vehicle from the front side of the vehicle, and a control device that, when it is determined that the vehicle is at risk of colliding with the three-dimensional object, executes collision prevention support control to reduce the risk of the vehicle colliding with the three-dimensional object, The control device includes a determination device that determines whether or not there is a track for a tracked vehicle ahead of the host vehicle that intersects at grade with the road on which the host vehicle is traveling, and the control device calculates the reliability of the detected three-dimensional objects based on the detection results of the radar device, and when it determines that the three-dimensional objects are a group of moving objects in formation with a number equal to or greater than a reference value and the determination device determines that there is no track for a tracked vehicle ahead of the host vehicle, the control device reduces the reliability so that it becomes smaller as the probability that there is no track for a tracked vehicle increases, and when the reliability is less than the reference value, the control device is configured to suppress the execution of the collision prevention assist control.

2. 2. The collision prevention device according to claim 1, wherein the control device is configured to determine that the three-dimensional objects are a group of moving bodies in formation with a number equal to or greater than the reference value when the number of moving bodies is equal to or greater than the reference value and the distance between each moving body is equal to or less than the reference distance.

3. 2. The collision prevention device according to claim 1, wherein the determination device includes an imaging device that images an area ahead of the vehicle, and is configured to determine whether or not a target indicating the presence of a track for the track vehicle exists ahead of the vehicle based on an image captured by the imaging device.

4. A collision prevention method including the steps of: detecting a three-dimensional object approaching from a front side of the host vehicle toward the front of the host vehicle; and, when it is determined that the host vehicle is at risk of colliding with the three-dimensional object, executing collision prevention assist control to reduce the risk of the host vehicle colliding with the three-dimensional object, A collision prevention method comprising: a step of calculating the reliability of a detected three-dimensional object; a step of determining whether or not there is a track for a track vehicle ahead of the host vehicle that intersects at grade with a road on which the host vehicle is traveling; a step of reducing the reliability so that the reliability becomes smaller as the probability that a track for a track vehicle does not exist increases, when it is determined that the three-dimensional objects are a group of moving objects forming a formation in number equal to or greater than a reference value and it is determined that there is no track for a track vehicle ahead of the host vehicle; and a step of suppressing execution of the collision prevention assist control when the reliability is less than the reference value.

5. A collision prevention program that causes an electronic control device mounted on a host vehicle to execute the following steps: detecting a three-dimensional object approaching from a front side of the host vehicle toward the front of the host vehicle; and, when it is determined that the host vehicle is at risk of colliding with the three-dimensional object, executing collision prevention support control to reduce the risk of the host vehicle colliding with the three-dimensional object, 1. A collision prevention program comprising: a step of calculating the reliability of a detected three-dimensional object; a step of determining whether or not there is a track for a track vehicle ahead of the vehicle that intersects at grade with a road on which the vehicle is traveling; a step of reducing the reliability so that the reliability becomes smaller as the probability that a track for a track vehicle does not exist increases, when it is determined that the three-dimensional objects are a group of moving objects in a formation with a number equal to or greater than a reference value and it is determined that there is no track for a track vehicle ahead of the vehicle; and a step of suppressing execution of the collision prevention assistance control when the reliability is less than the reference value.

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