Conflict Avoidance Support Device

Abstract

To provide an improved collision avoidance assistance device that not only can avoid a vehicle colliding with an obstacle at the end of a T-junction, but also can reduce the possibility of another vehicle traveling on the main line colliding with a stopped vehicle.SOLUTION: A collision avoidance assistance device includes a driver assistance ECU configured to stop a vehicle by automatic braking with an automatic braking device when it is determined, based on information acquired by a surrounding information acquisition device such as an object marker information acquisition device and a navigation device, that the vehicle may collide with an obstacle ahead. The driver assistance ECU stops the vehicle at a position before a T-junction by automatic braking by the automatic braking device (S60-S80) when determining, based on information obtained by an ambient information acquisition device, that the vehicle is traveling on a branch line and approaching the T-junction and that the vehicle may collide with an obstacle at the end of the T-junction (S150).SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a collision avoidance assistance device for a vehicle such as an automobile. [Background technology]

[0002] One known collision avoidance assistance device is configured to avoid collision with an obstacle by automatically braking the vehicle to slow down and stop it when it is determined that there is a risk of collision with an obstacle in front of the vehicle.

[0003] For example, Patent Document 1 listed below describes a collision avoidance assistance device that recognizes the shape of a road, estimates the vehicle's path based on the shape of the road, and, when it determines that the vehicle is at risk of colliding with an obstacle and that collision avoidance is necessary, performs collision avoidance by automatic braking. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-091789 Summary of the Invention

[0005] [Problem to be solved by the invention] When a vehicle equipped with a collision avoidance support device such as the collision avoidance support device described in Patent Document 1 travels on a branch road and approaches a T-junction, and it is determined that the vehicle is at risk of colliding with an obstacle at the end of the T-junction, the vehicle is automatically braked to a stop, thereby preventing the vehicle from colliding with the obstacle at the end of the T-junction.

[0006] However, since the vehicle stops just before the obstacle at the end of the T-junction, i.e., on the main lane of the T-junction, there is a risk that other vehicles traveling on the main lane will collide with the stopped vehicle. Conventional collision avoidance assistance devices such as the collision avoidance assistance device described in Patent Document 1 cannot reduce the risk of other vehicles traveling on the main lane colliding with the stopped vehicle.

[0007] To provide an improved collision avoidance support device that can not only prevent a vehicle from colliding with an obstacle at the end of a T-junction, but also reduce the risk of another vehicle traveling on the main road colliding with a stopped vehicle.

[0008] [Means for solving the problems and effects of the invention] According to the present invention, there is provided a collision avoidance assistance device (100) including a surrounding information acquisition device (target object information acquisition device 16, navigation device 80) that acquires information about the surroundings of a vehicle (102), an automatic braking device (34) that automatically brakes the vehicle, and a control unit (driving assistance ECU 10) configured to stop the vehicle by automatic braking using the automatic braking device when it is determined that the vehicle is at risk of colliding with an obstacle ahead based on the information acquired by the surrounding information acquisition device.

[0012] system The control unit (driving assistance ECU 10) is configured to stop the vehicle at a position just before the T-junction (S60 to S80) by automatic braking using the automatic braking device (34), when it determines (S30) that there is no traffic light at the T-junction (110) based on information acquired by the surrounding information acquisition device (16, 80), and determines that the vehicle (102) is traveling on the branch line (108) and is approaching the T-junction and that there is a risk of the vehicle colliding with an obstacle (112) at the end of the T-junction (S50).

[0013] the above Configuration According to this law, when there is no traffic light at a T-junction, a vehicle is traveling on a branch line and is approaching the T-junction, and it is determined that there is a risk of the vehicle colliding with an obstacle at the end of the T-junction, the vehicle is stopped at a position just before the T-junction by automatic braking by an automatic braking device.

[0014] Therefore, even if there is no traffic light installed at the T-junction, not only can the vehicle be prevented from colliding with an obstacle at the end of the T-junction, but the vehicle can be stopped on the main lane of the T-junction, reducing the risk of other vehicles traveling on the main lane colliding with the vehicle.

[0015] Furthermore, according to the present invention The control unit (driving assistance ECU 10) is configured to determine, based on information acquired by the surrounding information acquisition device (16, 80), that a traffic light is installed at the T-junction (110) (S30), and determine that the traffic light (116) on the branch line (108) side is green (S90), and when it determines that the vehicle (102) is traveling on the branch line and approaching the T-junction and that there is a risk of the vehicle colliding with an obstacle (112) at the end of the T-junction (S120), to stop the vehicle at a position just before the obstacle at the end of the T-junction by automatic braking using the automatic braking device (34) (S130 to S150).

[0016] the above Configuration According to this system, when the traffic light on the branch line side is green, a vehicle is traveling on the branch line and approaching a T-junction, and it is determined that the vehicle is at risk of colliding with an obstacle at the end of the T-junction, the automatic braking device automatically brakes the vehicle and stops it at a position just before the obstacle at the end of the T-junction.

[0017] This prevents the vehicle from colliding with an obstacle at the end of the T-junction. In this case, the vehicle stops on the main lane of the T-junction, but since the traffic light on the main lane is red, other vehicles will not collide with the vehicle. Furthermore, compared to when the vehicle stops just before the T-junction, the risk of a following vehicle colliding with the vehicle from behind can be reduced.

[0018] Furthermore, the present invention According to The control unit (driving assistance ECU 10) is configured to determine, based on information acquired by the surrounding information acquisition device (16, 80), that a traffic light is installed at the T-junction (110) (S30), and determine that the traffic light (116) on the branch line (108) side is not green (S90), and when it determines that the vehicle (102) is traveling on the branch line and approaching the T-junction and that there is a risk of the vehicle colliding with an obstacle at the end of the T-junction (S50), to stop the vehicle at a position just before the T-junction by automatic braking using an automatic braking device (S40 to S80).

[0019] the above Configuration According to this system, when it is determined that the traffic light on the branch line side is not green, and that a vehicle is traveling on the branch line and approaching a T-junction, and that there is a risk of the vehicle colliding with an obstacle at the end of the T-junction, the vehicle is stopped at a position just before the T-junction by automatic braking by an automatic braking device.

[0020] Therefore, when the traffic light on the branch line is not green, not only can it be prevented that the vehicle will collide with an obstacle at the end of the T-junction, but it can also reduce the risk of the vehicle stopping on the main line of the T-junction and other vehicles traveling on the main line colliding with the vehicle.

[0021] [Mode of the Invention] One of the present invention In this aspect, the control unit (driving assistance ECU 10) is configured to calculate a target deceleration (Gxbt) of the vehicle (102) based on the distance (Lx, Ly) from the current position of the vehicle (102) to the position where the vehicle is to be stopped and the current vehicle speed (V) of the vehicle (S60, S130), and to control the automatic braking device (34) so ​​that the deceleration (Gxb) of the vehicle becomes the target deceleration (S70, S140).

[0022] According to the above aspect, it is possible to calculate the target deceleration of the vehicle to stop the vehicle at the position where the vehicle is to be stopped, and by controlling the automatic braking device so that the deceleration of the vehicle becomes the target deceleration, the vehicle can be stopped at the position where the vehicle is to be stopped.

[0023] 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]

[0024] [Figure 1] 1 is a schematic configuration diagram showing a collision avoidance assistance device according to an embodiment; [Figure 2] 4 is a flowchart showing a collision avoidance assistance control routine according to the embodiment. [Figure 3] 10 is a flowchart showing a modified collision avoidance assist control routine. [Figure 4] FIG. 1 shows a situation in which a vehicle is traveling on a branch line and is approaching a T-junction without traffic lights. [Figure 5] FIG. 10 is a diagram showing an example in which a vehicle travels on a branch line and stops by automatic braking just before a T-junction where no traffic lights are installed. [Figure 6] Figure 1A shows a situation in which a vehicle is traveling on a branch line and approaching a T-junction with a traffic light, and Figure 1B shows an example in which a vehicle is traveling on a branch line and stops by automatic braking just before the T-junction with a traffic light. DETAILED DESCRIPTION OF THE INVENTION

[0025] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A collision avoidance assistance device according to an embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

[0026] <Configuration> As shown in Fig. 1, a collision avoidance assistance device 100 according to an embodiment of the present invention 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. ECU refers to an electronic control unit that includes a microcomputer as its main component. In the following description, the electric power steering will be referred to as EPS.

[0027] 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.

[0028] The driving assistance ECU 10 is a central control device that performs driving assistance control such as collision avoidance assistance control, adaptive cruise control, lane departure prevention control, etc. In the embodiment, the driving assistance ECU 10 cooperates with other ECUs to perform automatic braking control for collision avoidance assistance, as will be described in detail later.

[0029] The driving assistance ECU 10 is connected to a camera sensor 12, a radar sensor 14, and a switch 18. The camera sensor 12 and the radar sensor 14 each include a plurality of camera devices and a plurality of radar devices. The camera sensor 12 and the radar sensor 14 function as a target information acquisition device 16 that acquires information about targets around the vehicle 102.

[0030] Although not shown in the figure, each camera device 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.

[0031] Each radar device 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 radio waves (hereinafter referred to as "millimeter waves") 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 supplies 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. to the driving assistance ECU 10 at predetermined time intervals 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. Note that a LiDAR (Light Detection and Ranging) may be used instead of or in addition to the radar sensor 14.

[0032] The switch 18 is provided in a position operable by the driver, such as on a steering wheel (not shown in Fig. 1), and is configured to be switched on and off by the driver. When the switch 18 is on, a signal indicating this is supplied to the driving assistance ECU 10, and automatic braking control for collision avoidance assistance is executed.

[0033] The drive ECU 20 is connected to a drive device 22 that accelerates the vehicle 102 by applying drive force to drive wheels not shown in Fig. 1. Under normal circumstances, the drive ECU 20 controls the drive device 22 so that the drive force generated by the drive device 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 device 22 based on the command signal.

[0034] 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.

[0035] 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 by braking. 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. Thus, the brake ECU 30 and the brake device 32 function as an automatic brake device 34.

[0036] 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 70, 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.

[0037] An alarm device 52 is connected to the meter ECU 50. The alarm device 52 is activated when it is determined that the vehicle 102 is at risk of colliding with an obstacle, and issues an alarm, i.e., issues an alarm that the vehicle 102 is at risk of colliding with an obstacle. The alarm device 52 may be any of an alarm device that issues a visual alarm such as a display or an alarm lamp, an alarm device that issues an auditory alarm such as an alarm buzzer, an alarm device that issues a tactile alarm such as seat vibration, or any combination thereof.

[0038] The driving operation sensors 60 and the vehicle condition sensors 70 are connected to the CAN 104. Information detected by the driving operation sensors 60 and the vehicle condition sensors 70 (referred to as sensor information) is transmitted to the CAN 104. The sensor information transmitted to the CAN 104 can be used appropriately by 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.

[0039] 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.

[0040] The vehicle state sensor 70 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, a roll angular acceleration sensor that detects the roll angular acceleration of the vehicle, and a yaw rate sensor that detects the yaw rate of the vehicle.

[0041] Furthermore, the navigation device 80 is also connected to the CAN 104. The navigation device 80 includes a GPS receiver that detects the position of the vehicle 102, a storage device that stores map information and road information, and a communication device that acquires the latest map information and road information from an external device. The navigation device 80 functions as a device that acquires information about the current location of the vehicle 102, and outputs a signal indicating the current location of the vehicle on the map and information about its surroundings to the driving assistance ECU 10.

[0042] As can be seen from the above description, in the embodiment, the target information acquisition device 16 and the navigation device 80 function as a surrounding information acquisition device that acquires information about the roads around the vehicle 102 and the like.

[0043] In this embodiment, a collision avoidance assistance control program is stored in the ROM of the driving assistance ECU 10. This control program corresponds to the flowchart shown in Fig. 2, and the collision avoidance assistance control is executed in accordance with this control program.

[0044] <Collision Avoidance Assist Control Program (Figure 2)> Next, the collision avoidance assist control in this embodiment will be described with reference to the flowchart shown in Fig. 2. The collision avoidance assist control according to the flowchart shown in Fig. 2 is repeatedly executed at predetermined time intervals by the CPU of the driving assist ECU 10 while the switch 18 is on, and ends when the switch 18 is turned off. In the following description, the collision avoidance assist control will be referred to as "this control."

[0045] First, in step S10, the CPU determines whether or not there is an intersection ahead of the vehicle 102 based on an image acquired by the front camera device of the camera sensor 12 and / or information from the navigation device 80. If the CPU makes a negative determination, it temporarily terminates this control, and if the CPU makes a positive determination, it proceeds to step S20.

[0046] In step S20, the CPU determines whether the vehicle 102 is traveling on a branch road and approaching a T-junction, as shown in Fig. 4, based on an image acquired by the front camera device of the camera sensor 12 and / or information from the navigation device 80. If the CPU makes a negative determination, the control proceeds to step S100, and if the CPU makes a positive determination, the control proceeds to step S30. In Fig. 4, the main road 106 is a priority road, the branch road 108 is a non-priority road, and reference numeral 110 denotes a T-junction.

[0047] In step S30, the CPU determines whether or not a traffic light is installed at the T-junction based on image information acquired by the front camera device of 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 S40.

[0048] In step S40, the CPU estimates the path of the vehicle 102 at the T-junction, i.e., whether to turn left or right, based on the operating status of the turn signal lamps (not shown) and information on the planned driving route from the navigation device 80.

[0049] In step S50, the CPU determines whether or not braking assistance is required to avoid a collision early. If the CPU determines that the answer is negative, it temporarily terminates this control, and if the CPU determines that the answer is positive, it proceeds to step S60.

[0050] In this case, when the following condition is met and there is a risk that the vehicle 102 will collide with an obstacle 112 at the end of the T-junction 110, as shown by the dashed line in Figure 4, it may be determined that early braking assistance to avoid the collision is necessary. (X1) The distance Lx (see FIG. 4) to the stop line 114 of the T-junction 110 is equal to or less than the reference value Lxc. The reference value Lxc is a positive value that is variably set according to the vehicle speed V so that it increases as the vehicle speed V increases. (X2) It is not possible to determine whether the vehicle 102 is turning left or right. (X3) The vehicle speed V is equal to or greater than a reference vehicle speed Vxc (a positive constant), and the driver is not performing a braking or steering operation.

[0051] 2, when the CPU makes a positive determination in step S50, it issues a warning by outputting a command signal to the meter ECU 50 to activate the warning device 52 until it makes a positive determination in step S80, which will be described later. The warning may include a message that the vehicle 102 needs to be braked and that automatic braking control will be performed.

[0052] In step S60, the CPU calculates a target deceleration Gxbt for the vehicle 102, which is traveling at a vehicle speed V, to stop the vehicle 102, for example, at the stop line 114 of a T-junction 110. The target deceleration Gxbt is calculated in a manner known in the art based on the distance from the current position of the vehicle to the position where the vehicle is to be stopped and the current speed of the vehicle. The same applies to step S130, which will be described later.

[0053] In step S70, the CPU outputs a command signal to the brake ECU 30 to control the automatic braking by the automatic braking device 34 so that the deceleration Gxb of the vehicle 102 becomes the target deceleration Gxbt.

[0054] In step S80, the CPU determines whether or not the vehicle 102 has stopped. If the CPU makes a negative determination, it returns this control to step S70, and if the CPU makes a positive determination, it temporarily terminates this control.

[0055] In step S90, the CPU determines whether the traffic light on the branch line 108 side of the T-junction 110 is green, as shown in Figure 6(A). If the CPU makes a positive determination, it proceeds to step S110, and if the CPU makes a negative determination, it proceeds to step S100.

[0056] In step S100, the CPU performs collision avoidance assistance control known in the art, such as the control by the collision avoidance assistance device described in the aforementioned Patent Document 1.

[0057] In step S110, similar to step S40, the CPU estimates the path of the vehicle 102 at the T-junction, i.e., whether to turn left or right, based on the operation status of the turn signal lamps (not shown) and information on the planned driving route from the navigation device 80.

[0058] In step S120, the CPU determines whether braking assistance to avoid a collision is necessary. If the CPU determines that the collision is necessary, it temporarily terminates this control, and if the CPU determines that the collision is necessary, it proceeds to step S130.

[0059] In this case, it may be determined that braking assistance to avoid a collision is necessary when the following condition is met: (Y1) The distance Ly (see FIG. 6A) to the obstacle 112 at the end of the T-junction 110 is equal to or less than the reference value Lyc. The reference value Lyc is a positive value that is variably set according to the vehicle speed V so that it increases as the vehicle speed V increases. (Y2) It is not possible to determine whether the vehicle 102 is turning left or right. (Y3) The vehicle speed V is equal to or greater than the reference vehicle speed Vyc (a positive constant), and the driver is not performing any braking or steering operation.

[0060] In step S130, the CPU calculates a target deceleration Gxbt of the vehicle for stopping the vehicle 102, which is traveling at a vehicle speed V, at a position just before the obstacle 112 at the end of the T-junction 110.

[0061] In step S140, similarly to step S70, the CPU outputs a command signal to the brake ECU 30 to control the automatic braking by the automatic braking device 34 so that the deceleration Gxb of the vehicle 102 becomes the target deceleration Gxbt.

[0062] In step S150, the CPU determines whether or not the vehicle 102 has stopped, similarly to step S80. If the CPU makes a negative determination, it returns this control to step S140, and if the CPU makes a positive determination, it temporarily terminates this control.

[0063] <Operation of the embodiment> Next, the operation of the embodiment will be explained for the cases where the vehicle 102 is traveling on the branch line 108 and approaches the T-junction 110, and there is no traffic light at the T-junction (C1), and there is a traffic light at the T-junction (C2). (C1) When there are no traffic lights at the T-junction (Figure 4, Figure 5)

[0064] In steps S10 and S20, a positive determination is made, and in step S30, a negative determination is made. When the above conditions X1 to X3 are satisfied, early braking assistance to avoid a collision is necessary, so in step S50, a positive determination is made, and in step S60, a target deceleration Gxbt of the vehicle for stopping the vehicle 102 at, for example, the stop line 114 of the T-junction 110 is calculated.

[0065] Furthermore, automatic braking control is executed in steps S70 and S80 until the vehicle 102 stops at the stop line of the T-junction, for example. Therefore, even if a traffic light is not installed at the T-junction, it is possible to prevent the vehicle 102 from colliding with an obstacle 112 such as a wall or guardrail at the end of the T-junction, and also to prevent the vehicle 102 from stopping on the main lane 106 of the T-junction 110 and another vehicle 118 traveling on the main lane from colliding with the vehicle 102.

[0066] If any of the above conditions X1 to X3 is not satisfied, braking assistance for early collision avoidance is not required, and a negative determination is made in step S50. Therefore, steps S60 to S80 are not executed, and deceleration and temporary stop of the vehicle 102 are performed by the driver's driving operation.

[0067] (C2) When a traffic light is installed at a T-junction (Figure 6) (C2-1) When the signal light on the branch line is green (Figure 6(A)) In steps S10 to S30 and step S90, affirmative determinations are made. When the above conditions Y1 to Y3 are met, braking assistance to avoid a collision is necessary, so an affirmative determination is made in step S120, and in step S130, a target deceleration Gxbt of the vehicle for stopping the vehicle 102 at a position just before the obstacle 112 at the end of the T-junction 110 is calculated.

[0068] Furthermore, automatic braking control is executed in steps S140 and S150 until the vehicle 102 stops in front of the obstacle 112 at the end of the T-junction 110. This prevents the vehicle 102 from colliding with the obstacle 112 at the end of the T-junction. In this case, the vehicle 102 stops on the main lane 106 of the T-junction 110, but because the traffic light 120 on the main lane side is red, the other vehicle 118 will not collide with the vehicle 102. Furthermore, compared to when the vehicle 102 stops in front of the T-junction 110, the risk of a following vehicle colliding with the vehicle 102 from behind can be reduced.

[0069] If any of the above conditions Y1 to Y3 is not satisfied, braking assistance for collision avoidance is not required, and a negative determination is made in step S120. Therefore, steps S130 to S150 are not executed, and deceleration and temporary stop of the vehicle 102 are performed by the driver's driving operation.

[0070] (C2-2) When the traffic light on the branch line is not green (Figure 6(B)) In steps S10 to S30, a positive determination is made, and in step S90, a negative determination is made. Therefore, steps S110 to S150 are not executed, and in step S100, collision avoidance assistance control known in the art is performed.

[0071] As can be seen from the above explanation, according to the embodiment, even if there is no traffic light at the T-junction, or even if there is a traffic light at the T-junction and the traffic light on the branch line is green, it is possible to prevent a vehicle from colliding with an obstacle at the end of the T-junction, and it is also possible to stop the vehicle on the main line of the T-junction, thereby reducing the risk of other vehicles traveling on the main line colliding with the vehicle.

[0072] Furthermore, according to the embodiment and the modified example described below, the target deceleration Gxbt of the vehicle is calculated based on the distances Lx and Ly from the current position of the vehicle 102 to the position where the vehicle is to be stopped and the current vehicle speed V of the vehicle, and the automatic braking device 34 is controlled so that the deceleration Gxb of the vehicle becomes the target deceleration.

[0073] Therefore, it is possible to calculate the target deceleration of the vehicle to stop the vehicle at the desired position, and by controlling the automatic braking device so that the deceleration of the vehicle becomes the target deceleration, the vehicle can be stopped at the desired position.

[0074] Although the present invention has been described in detail above with reference to specific embodiments, it will be apparent to those skilled in the art that the present invention is not limited to the above-described embodiments, and that various other embodiments are possible within the scope of the present invention.

[0075] For example, in the above embodiment, when a negative determination is made in step S90, that is, when it is determined that the traffic light on the branch line 108 side of the T-junction 110 is not green, In step S100, collision avoidance assistance control known in the art is performed. However, as shown as a modified example in Fig. 3, if a negative determination is made in step S90, the control may proceed to step S40, and the same control as that in the case where no traffic light is installed at the T-junction 110 may be performed.

[0076] According to this modification, when the traffic light on the branch line 108 side is not green, the vehicle 102 can be stopped before the T-junction 110. Therefore, in both cases where there is no traffic light at the T-junction and where there is a traffic light and the traffic light on the branch line side is not green, not only can the vehicle 102 be prevented from colliding with the obstacle 112 at the end of the T-junction, but the vehicle 102 can also be prevented from stopping on the main line 106 at the T-junction 110 and from colliding with another vehicle 118 traveling on the main line.

[0077] In the above-described embodiment, the target information acquisition device 16 and the navigation device 80 function as a surrounding information acquisition device that acquires information about the surroundings of the vehicle 102. However, for example, the navigation device 80 may be omitted. [Explanation of symbols]

[0078] 10... driving assistance ECU, 12... camera sensor, 14... radar sensor, 16... target information acquisition device, 18... switch, 20... drive ECU, 22... drive device, 30... braking ECU, 32... braking device, 40... EPS ECU, 42... EPS device, 50... meter ECU, 52... warning device, 60... driving operation sensor, 70... vehicle status sensor, 80... navigation device, 100... collision avoidance assistance device, 102... vehicle, 108... branch line, 110... T-junction

Claims

1. A collision avoidance support device including a surrounding information acquisition device that acquires information about the surroundings of a vehicle, an automatic braking device that automatically brakes the vehicle, and a control unit configured to stop the vehicle by automatic braking by the automatic braking device when it is determined that the vehicle is at risk of colliding with an obstacle ahead based on the information acquired by the surrounding information acquisition device, The control unit determines, based on information acquired by the surrounding information acquisition device, that there is no traffic light at the T-junction, and when it determines that the vehicle is traveling on a branch line and approaching the T-junction and that there is a risk of the vehicle colliding with an obstacle at the end of the T-junction, the control unit is configured to stop the vehicle at a position just before the T-junction by automatic braking using the automatic braking device.

2. A collision avoidance assistance device including a surrounding information acquisition device that acquires information about the surroundings of a vehicle, an automatic braking device that automatically brakes the vehicle, and a control unit configured to stop the vehicle by automatic braking using the automatic braking device when it is determined that the vehicle is at risk of colliding with an obstacle ahead based on the information acquired by the surrounding information acquisition device, The control unit determines, based on information acquired by the surrounding information acquisition device, that a traffic light is installed at the T-junction, and that the traffic light on the branch line is green. When the control unit determines that a vehicle is traveling on the branch line and approaching the T-junction and that there is a risk of the vehicle colliding with an obstacle at the end of the T-junction, the control unit automatically brakes the vehicle using the automatic braking device to stop the vehicle at a position just before the obstacle at the end of the T-junction.

3. A collision avoidance assistance device including a surrounding information acquisition device that acquires information about the surroundings of a vehicle, an automatic braking device that automatically brakes the vehicle, and a control unit configured to stop the vehicle by automatic braking using the automatic braking device when it is determined that the vehicle is at risk of colliding with an obstacle ahead based on the information acquired by the surrounding information acquisition device, The control unit determines, based on information acquired by the surrounding information acquisition device, that a traffic light is installed at the T-junction, and that the traffic light on the branch line side is not green. When the control unit determines that a vehicle is traveling on the branch line and approaching the T-junction and that there is a risk of the vehicle colliding with an obstacle at the end of the T-junction, the control unit is configured to stop the vehicle at a position just before the T-junction by automatically braking using the automatic braking device.

4. 4. A collision avoidance assistance device according to claim 1, wherein the control unit is configured to calculate a target deceleration of the vehicle based on a distance from the current position of the vehicle to a position where the vehicle is to be stopped and the current speed of the vehicle, and to control the automatic braking device so that the deceleration of the vehicle becomes the target deceleration.

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