Driving Support Devices

Abstract

To provide a driving support device capable of reducing a sense of incongruity given to a driver by a deceleration support when turning right or left at an intersection.SOLUTION: A driving support device that supports deceleration of the own vehicle when turning right or left at an intersection comprises: an adjacent vehicle recognition unit that detects an adjacent vehicle traveling in an adjacent lane which is adjacent to a lane on which the own vehicle is traveling; an adjacent vehicle travel determination unit that determines whether or not the adjacent vehicle turns in the same direction as the own vehicle at the intersection based on adjacent vehicle information acquired through inter-vehicle communication with the adjacent vehicle or a detection result of an external sensor when the adjacent vehicle is detected by the adjacent vehicle recognition unit and the own vehicle turns left or right at the intersection; and a deceleration support execution unit that executes deceleration support so that the inter-vehicle distance between the own vehicle and the adjacent vehicle in the traveling direction of the own vehicle becomes greater than when it is not determined that the adjacent vehicle turns in the same direction as the own vehicle in the case that the adjacent vehicle traveling determination unit determines that the adjacent vehicle turns in the same direction as the own vehicle.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to a driving assistance device. [Background technology]

[0002] Japanese Patent Application Laid-Open Publication No. 2010-221858 is a known technical document relating to a driving support device. This publication discloses a driving support device that performs deceleration support for a vehicle from a predetermined distance before an intersection so that the vehicle passes through the intersection at a set appropriate speed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-221858 A Summary of the Invention [Problem to be solved by the invention]

[0004] When a vehicle enters an intersection from a road with multiple lanes and makes a right or left turn, there may be an adjacent vehicle entering the intersection. In this case, if a uniform deceleration support is performed without taking into account the presence of the adjacent vehicle, the driver may feel uncomfortable. [Means for solving the problem]

[0005] According to one aspect of the present invention, a vehicle deceleration support system is provided for supporting a vehicle in decelerating when the vehicle turns right or left at an intersection. cormorantA driving assistance device comprising: an adjacent vehicle recognition unit that recognizes an adjacent vehicle traveling in an adjacent lane adjacent to a driving lane of the host vehicle based on detection results from an external sensor of the host vehicle; an adjacent vehicle travel determination unit that, when the adjacent vehicle is recognized by the adjacent vehicle recognition unit and the host vehicle turns right or left at an intersection, determines whether the adjacent vehicle will turn in the same direction as the host vehicle at the intersection based on adjacent vehicle information acquired by vehicle-to-vehicle communication with the adjacent vehicle or detection results from the external sensor; a deceleration assistance execution unit that, when it is determined by the adjacent vehicle travel determination unit that the adjacent vehicle will turn in the same direction as the host vehicle, executes deceleration assistance so that the inter-vehicle distance between the host vehicle and the adjacent vehicle in the traveling direction of the host vehicle becomes equal to or greater than a predetermined adjacent vehicle target inter-vehicle distance, compared to when it is not determined that the adjacent vehicle will turn in the same direction as the host vehicle; The vehicle is equipped with a driving operation detection unit that detects the driving operations of both drivers, and an accelerator operation judgment unit that determines whether the driver's accelerator release timing for turning right or left at an intersection is earlier than a first timing threshold based on the position of the vehicle on a map, map information, and the detection results of the driver's driving operation by the driving operation detection unit, and when the accelerator operation judgment unit determines that the accelerator release timing is earlier than the first timing threshold, the deceleration assistance execution unit lowers the target vehicle speed for deceleration assistance compared to when the accelerator release timing is not determined to be earlier than the first timing threshold, and the inter-vehicle distance between the vehicle and an adjacent vehicle in the direction of travel of the vehicle is the inter-vehicle distance between the vehicle and the adjacent vehicle projected onto the travel route of the vehicle when turning right or left at an intersection.

[0006] According to a driving assistance device of one aspect of the present invention, when it is determined that an adjacent vehicle is turning in the same direction as the host vehicle when the host vehicle is turning right or left at an intersection, deceleration assistance is performed so that the distance between the host vehicle and the adjacent vehicle in the host vehicle's direction of travel is equal to or greater than the target adjacent vehicle distance. This reduces the discomfort felt by the driver due to the deceleration assistance compared to when deceleration assistance is performed without taking the adjacent vehicle into consideration.

[0007] In one embodiment of the driving assistance device of the present invention, the device further includes a preceding vehicle recognition unit that recognizes a preceding vehicle traveling in front of the vehicle based on detection results from an external sensor, and a large vehicle determination unit that, when a preceding vehicle is recognized by the preceding vehicle recognition unit, determines whether the preceding vehicle is a large vehicle or not based on preceding vehicle information obtained through vehicle-to-vehicle communication with the preceding vehicle or the detection results from the external sensor, and the deceleration assistance execution unit may perform deceleration assistance when the preceding vehicle is determined to be a large vehicle by the large vehicle determination unit so that the inter-vehicle distance between the vehicle and the preceding vehicle in the direction of travel of the vehicle is larger than when the preceding vehicle is not determined to be a large vehicle. According to this driving assistance device, when the vehicle ahead is determined to be a large vehicle when turning right or left at an intersection, deceleration assistance is performed so that the distance between the vehicle ahead and the vehicle ahead in the vehicle's direction of travel is increased compared to when the vehicle ahead is not determined to be a large vehicle. This reduces the discomfort that the deceleration assistance gives to the driver compared to when deceleration assistance is performed without considering whether the vehicle ahead is a large vehicle or not.

[0008] In a driving assistance device according to one aspect of the present invention, a visibility condition determination unit is further provided that determines whether or not the surroundings of the host vehicle are in a poor visibility condition based on at least one of an image captured by an external camera of the host vehicle, the wiper operation status of the host vehicle, the high beam headlight status of the host vehicle, weather information about the surroundings of the host vehicle obtained from a communication network, and traffic-related information about the surroundings of the host vehicle obtained from the communication network, and the deceleration assistance execution unit may lower the target vehicle speed in deceleration assistance when the visibility condition determination unit determines that the surroundings of the host vehicle are in a poor visibility condition compared to when it is not determined that the surroundings of the host vehicle are in a poor visibility condition. According to this driving assistance device, when the visibility condition determination unit determines that the surroundings of the vehicle are in a state of poor visibility, the target vehicle speed for deceleration assistance is lowered compared to when it is not determined that the surroundings of the vehicle are in a state of poor visibility. This reduces the discomfort felt by the driver due to deceleration assistance compared to when the poor visibility condition is not taken into consideration.

[0009] In one aspect of the present invention, a driving assistance device further includes a crosswalk determination unit that determines whether a crosswalk is present up ahead of the host vehicle's right or left turn based on at least one of the host vehicle's position on a map and map information, detection results from an external sensor, and traffic-related information around the host vehicle obtained from a communication network, and the deceleration assistance execution unit may lower the target vehicle speed in deceleration assistance when the crosswalk determination unit determines that a crosswalk is present up ahead of the host vehicle's right or left turn compared to when it is not determined that a crosswalk is present up ahead of the host vehicle's right or left turn. According to this driving assistance device, when the crosswalk determination unit determines that a crosswalk exists up ahead of the vehicle's right or left turn, the target vehicle speed for deceleration assistance is lowered compared to when it is not determined that a crosswalk exists up ahead of the vehicle's right or left turn, so that the deceleration assistance can cause less discomfort to the driver compared to when the presence of a crosswalk is not taken into consideration.

[0010] In one aspect of the present invention, a driving assistance device further includes an obstacle determination unit that determines whether or not an obstacle is present ahead of the host vehicle when the host vehicle makes a right or left turn based on at least one of the detection results of an external sensor, surrounding environment information obtained from vehicle-to-vehicle communication with other vehicles around the host vehicle, and traffic-related information around the host vehicle obtained from a communication network, and when the obstacle determination unit determines that an obstacle is present ahead of the host vehicle when the host vehicle makes a right or left turn, the deceleration assistance execution unit may lower the target vehicle speed in deceleration assistance compared to when it is not determined that an obstacle is present ahead of the host vehicle when the obstacle determination unit determines that an obstacle is present. According to this driving assistance device, when the obstacle determination unit determines that an obstacle is present ahead of the vehicle when turning right or left, the target vehicle speed for deceleration assistance is lowered compared to when it is not determined that an obstacle is present ahead of the vehicle when turning right or left. This reduces the discomfort felt by the driver when deceleration assistance is performed compared to when the presence of an obstacle is not taken into consideration.

[0012] In one aspect of the present invention, a driving assistance device includes: The driving operation detection unit includes: Detecting at least the operation of a turn signal as a driving operation by the driver of the vehicle death,and a direction indication timing determination unit that determines whether or not the timing of the driver's turn indicator operation for turning right or left at an intersection is earlier than a second timing threshold based on the position of the host vehicle on the map, the map information, and a detection result of the driver's turn indicator operation by the driving operation detection unit, and the deceleration support execution unit lowers the target vehicle speed in deceleration support when the direction indication operation determination unit determines that the turn indicator operation timing is earlier than the second timing threshold, compared to when the turn indicator operation timing is not determined to be earlier than the second timing. , and no guidance is given to drivers regarding the timing of turn signal operation. This is also fine. According to this driving assistance device, when the turn indicator operation determination unit determines that the turn indicator operation timing is earlier than the second timing threshold, the target vehicle speed for deceleration assistance is lowered compared to when the turn indicator operation timing is not determined to be earlier than the second timing. Therefore, the deceleration assistance can reduce the discomfort that it causes to the driver compared to when the turn indicator operation timing is not taken into consideration.

[0013] In a driving assistance device according to one aspect of the present invention, when the adjacent vehicle driving determination unit determines that an adjacent vehicle will turn in the same direction as the host vehicle at an intersection, it determines whether the host vehicle will turn on the outside or inside of the adjacent vehicle, and when it determines that the host vehicle will turn on the outside of the adjacent vehicle, it determines based on the detection results of the external sensor whether the host vehicle can pass through the intersection ahead of the adjacent vehicle at a speed that is equal to or lower than a predetermined target vehicle speed upper limit, and when the adjacent vehicle driving determination unit determines that the host vehicle can pass through the intersection ahead of the adjacent vehicle at a speed that is equal to or lower than the target vehicle speed upper limit, the deceleration assistance execution unit adjusts the target vehicle speed in deceleration assistance so that the host vehicle passes through the intersection ahead of the adjacent vehicle. According to this driving assistance device, when the adjacent vehicle driving determination unit determines that the host vehicle will turn around the outside of the adjacent vehicle, and the host vehicle is able to pass through the intersection ahead of the adjacent vehicle at a speed equal to or lower than the target vehicle speed upper limit, the target vehicle speed in deceleration assistance is adjusted so that the host vehicle passes through the intersection ahead of the adjacent vehicle, thereby reducing the obstruction to the driver's view caused by the adjacent vehicle getting ahead when the host vehicle turns around the outside of the adjacent vehicle. Effect of the Invention

[0014] According to one aspect of the present invention, it is possible to reduce the discomfort felt by the driver due to deceleration assistance when turning right or left at an intersection. [Brief description of the drawings]

[0015] [Figure 1] 1 is a block diagram showing a driving assistance device according to a first embodiment. [Diagram 2] FIG. 4 is a plan view for explaining recognition of adjacent vehicles. [Diagram 3] FIG. 2 is a plan view showing an example of a situation in which the host vehicle recognizes a preceding vehicle. [Figure 4] FIG. 11 is a plan view showing an example in which the preceding vehicle is a large vehicle. [Diagram 5] FIG. 11 is a plan view for explaining an example of a situation in which an adjacent vehicle turns in the same direction as the host vehicle. [Figure 6] FIG. 11 is a plan view for explaining an example of a situation in which an adjacent vehicle is traveling in a direction different from that of the host vehicle. [Figure 7] 10 is a flowchart illustrating an example of a deceleration support execution process. [Figure 8] 10 is a flowchart showing a continuation of the deceleration support execution process. [Figure 9] FIG. 4 is a block diagram showing a driving assistance device according to a second embodiment. [Figure 10] FIG. 11 is a plan view showing an example of a situation in which the host vehicle turns around the outside of an adjacent vehicle. [Figure 11] FIG. 2 is a plan view for explaining a situation in which the host vehicle turns at an intersection ahead of an adjacent vehicle. [Figure 12] FIG. 11 is a plan view for explaining an example of a situation in which the host vehicle turns inside an adjacent vehicle. [Figure 13] 10 is a flowchart showing a continuation of the deceleration support execution process according to the second embodiment; [Figure 14] 14(a) is a flowchart showing an example of a process for determining a poor visibility state, FIG. 14(b) is a flowchart showing an example of a process for determining a pedestrian crossing, and FIG. 14(c) is a flowchart showing an example of a process for determining an obstacle. [Figure 15] 10A is a flowchart showing an example of an accelerator release determination process, and FIG.10B is a flowchart showing an example of a direction indicator operation timing determination process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0017] [First embodiment] The driving support device 100 shown in Fig. 1 is a device mounted on a vehicle (host vehicle) such as a passenger car, and supports the driver in driving the host vehicle. The driving support device 100 performs deceleration support for the host vehicle when the host vehicle turns right or left at an intersection. The deceleration support is a driving support that decelerates the host vehicle depending on the situation.

[0018] Configuration of the driving assistance device according to the first embodiment The configuration of the driving assistance device 100 will be described below with reference to the drawings. As shown in FIG. 1, the driving assistance device 100 includes a driving assistance ECU (Electronic Control Unit) 10 that performs overall management of the device. The driving assistance ECU 10 is an electronic control unit having a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. In the driving assistance ECU 10, for example, various functions are realized by the CPU executing a program stored in the ROM. The driving assistance ECU 10 may be composed of multiple electronic units.

[0019] The driving assistance ECU 10 is connected to a GPS (Global Positioning System) receiving unit 1 , an external sensor 2 , an internal sensor 3 , a driving operation detecting unit 4 , a map database 5 , and an actuator 6 .

[0020] The GPS receiver 1 measures the position of the vehicle (for example, the latitude and longitude of the vehicle) by receiving signals from three or more GPS satellites. The GPS receiver 1 transmits the measured position information of the vehicle to the ECU 10. A GNSS [Global Navigation Satellite System] receiver may be used instead of the GPS receiver 1.

[0021] The external sensor 2 is a detection device that detects the situation around the vehicle. The external sensor 2 includes at least one of an external camera and a radar sensor. The external camera is an imaging device that captures the external situation of the vehicle. The external camera is provided, for example, on the back side of the windshield of the vehicle and captures an image in front of the vehicle. The external camera transmits imaging information related to the external situation of the vehicle to the driving assistance ECU 10. The external camera may be a monocular camera or a stereo camera.

[0022] A radar sensor is a detection device that detects objects around the vehicle using radio waves (e.g., millimeter waves) or light. Radar sensors include, for example, millimeter wave radars and LIDARs (Light Detection and Ranging). The radar sensor detects objects by transmitting radio waves or light to the surroundings of the vehicle and receiving the radio waves or light reflected by the objects. The radar sensor transmits information about the detected objects to the driving assistance ECU 10.

[0023] The internal sensor 3 is a detection device that detects the traveling state of the host vehicle. The internal sensor 3 includes a vehicle speed sensor, an acceleration sensor, and a yaw rate sensor. The vehicle speed sensor is a detector that detects the speed of the host vehicle. As the vehicle speed sensor, for example, a wheel speed sensor that is provided on the wheels of the host vehicle or a drive shaft that rotates integrally with the wheels and detects the rotation speed of the wheels is used. The vehicle speed sensor transmits the detected vehicle speed information (wheel speed information) to the driving assistance ECU 10.

[0024] The acceleration sensor is a detector that detects the acceleration of the host vehicle. The acceleration sensor includes, for example, a longitudinal acceleration sensor that detects the acceleration in the longitudinal direction of the host vehicle, and a lateral acceleration sensor that detects the lateral acceleration of the host vehicle. The acceleration sensor transmits, for example, acceleration information of the host vehicle to the driving assistance ECU 10. The yaw rate sensor is a detector that detects the yaw rate (rotational angular velocity) around the vertical axis of the center of gravity of the host vehicle. For example, a gyro sensor can be used as the yaw rate sensor. The yaw rate sensor transmits the detected yaw rate information of the host vehicle to the driving assistance ECU 10.

[0025] The driving operation detection unit 4 is a detection device that detects driving operations of the vehicle by the driver. The driving operation detection unit 4 includes an accelerator pedal sensor or a turn signal sensor. The driving operation detection unit 4 may include both an accelerator pedal sensor and a turn signal sensor, a steering sensor, a brake pedal sensor, or a shift lever sensor.

[0026] The accelerator pedal sensor is provided, for example, on the shaft portion of the accelerator pedal and detects the force or amount of depression of the accelerator pedal by the driver (accelerator pedal position). The turn signal sensor detects the operation (on / off operation) of the turn signal by the driver. The turn signal sensor can be provided, for example, on the operating lever of the turn signal.

[0027] The brake pedal sensor is provided, for example, on the shaft of the brake pedal and detects the brake pedal pressure or amount of depression (brake pedal position) by the driver. The steering sensor is provided, for example, on the steering shaft of the vehicle and detects the steering torque applied to the steering wheel by the driver. The shift lever sensor detects the gear position of the transmission.

[0028] The map database 5 is a database that stores map information. The map database 5 is formed, for example, in a storage device such as a HDD (Hard Disk Drive) mounted on the vehicle. The map information may include road position information, road shape information (e.g., curves, types of straight sections, curvature of curves, etc.), intersection and branch point position information, and structure position information. The map information may also include traffic regulation information such as legal speed limits associated with the position information. The map database 5 may be formed in a server that can communicate with the vehicle.

[0029] The actuator 6 is a device used to control the host vehicle. The actuator 6 includes at least a drive actuator and a brake actuator. The actuator 6 may include a steering actuator. The drive actuator controls the amount of air supplied to the engine (throttle opening) in response to a control signal from the driving assistance ECU 10, thereby controlling the driving force of the host vehicle. If the host vehicle is a hybrid vehicle, in addition to the amount of air supplied to the engine, a control signal from the driving assistance ECU 10 is input to a motor serving as a power source to control the driving force. If the host vehicle is an electric vehicle, a control signal from the driving assistance ECU 10 is input to a motor serving as a power source to control the driving force. The motor serving as a power source in these cases constitutes the actuator 6.

[0030] The brake actuator controls a brake system in response to a control signal from the driving assistance ECU 10, and controls the braking force applied to the wheels of the vehicle. For example, a hydraulic brake system can be used as the brake system. The steering actuator controls the drive of an assist motor that controls the steering torque of the electric power steering system in response to a control signal from the driving assistance ECU 10. In this way, the steering actuator controls the steering torque of the vehicle.

[0031] The communication unit 7 acquires various types of information via a communication network (e.g., the Internet, VICS [Vehicle Information and Communication System] (registered trademark), etc.). The communication unit 7 acquires traffic-related information by communicating with a computer in a facility such as an information management center that manages traffic information. The traffic-related information includes information on construction sections on the road, information on accidents on the road, information on road conditions due to snowfall, etc. The communication unit 7 may acquire road information by road-to-vehicle communication with a roadside transmitter / receiver (e.g., an optical beacon, an ITS [Intelligent Transport Systems] spot, etc.) installed on the side of the road. The communication unit 7 may have a vehicle-to-vehicle communication function.

[0032] Next, a functional configuration of the driving assistance ECU 10 will be described. As shown in Fig. 1, the driving assistance ECU 10 has an intersection right / left turn determination unit 11, an adjacent vehicle recognition unit 12, an adjacent vehicle travel determination unit 13, a preceding vehicle recognition unit 14, a large vehicle determination unit 15, and a deceleration assistance execution unit 16. Note that some of the functions of the driving assistance ECU 10 described below may be executed by a server capable of communicating with the vehicle itself.

[0033] The intersection right / left turn determination unit 11 recognizes (detects) an intersection ahead of the vehicle. The intersection right / left turn determination unit 11 recognizes the intersection ahead of the vehicle based on, for example, the position information of the vehicle measured by the GPS receiving unit 1 and the map information of the map database 5.

[0034] The intersection right / left turn determination unit 11 may recognize the position of the vehicle by SLAM [Simultaneous Localization and Mapping] technology using not only the position information of the vehicle itself measured by the GPS receiving unit 1, but also position information of structures (landmarks) such as utility poles included in the map information of the map database 5 and the detection results of the structures by the external sensor 2. Additionally, the intersection right / left turn determination unit 11 may recognize an intersection ahead of the vehicle by acquiring position information of the intersection from a communication network via the communication unit 7.

[0035] When an intersection ahead of the vehicle is recognized, the intersection right / left turn determination unit 11 determines whether the vehicle will turn right or left at the intersection. The intersection right / left turn determination unit 11 determines whether the vehicle will turn right or left at the intersection based on the driving operation of the driver detected by the driving operation detection unit 4. The driving operation includes, for example, the operation of a turn signal (on / off operation). The driving operation may include steering by the driver, accelerator release in which the driver releases the accelerator pedal, braking operation in which the driver depresses the brake pedal, and downshift operation.

[0036] The intersection right / left turn determination unit 11 may determine that the host vehicle will turn right or left at the intersection when the host vehicle is moving to the right or left as the driver steers the vehicle as it approaches the intersection. The intersection right / left turn determination unit 11 may determine that the host vehicle will turn right or left at the intersection when the host vehicle is moving to the right or left of the lane as the vehicle approaches the intersection, taking into account the accelerator release, brake operation, and downshift operation. The intersection right / left turn determination unit 11 recognizes whether the host vehicle will turn right or left at the intersection based on the operation of the turn signal or the driver's steering.

[0037] The adjacent vehicle recognition unit 12 recognizes adjacent vehicles traveling in an adjacent lane adjacent to the driving lane of the host vehicle based on the detection result of the external sensor 2. The adjacent vehicle recognition unit 12 recognizes, for example, other vehicles traveling in the same direction as the host vehicle on the side of the host vehicle within a preset adjacent vehicle recognition range based on the host vehicle as an adjacent vehicle.

[0038] The adjacent vehicle recognition range is set, for example, as a rectangular range based on the center of the front end of the host vehicle. The adjacent vehicle recognition range can be a range of a predetermined longitudinal distance and a predetermined lateral distance based on the center of the front end of the host vehicle. The adjacent vehicle recognition range does not necessarily have to be a rectangular range, and may be an elliptical range or another shape. The adjacent vehicle recognition range may be set based on the center of the host vehicle in a planar view, or may be set based on any position on the host vehicle.

[0039] The adjacent vehicle recognition unit 12 may use the position information and map information of the vehicle to identify adjacent lanes adjacent to the driving lane in which the vehicle is traveling. The adjacent vehicle recognition unit 12 combines the detection results of the external sensor 2 to recognize other vehicles traveling in adjacent lanes as adjacent vehicles.

[0040] Fig. 2 is a plan view for explaining the recognition of adjacent vehicles. Intersection T shown in Fig. 2 is an intersection where a three-lane road with lanes RA1 to RA3 intersects with a two-lane road with lanes RB1 and RB2. The remaining lanes on the two-lane road are indicated as RC1 and RC2.

[0041] FIG. 2 shows the host vehicle M, another vehicle N1, and another vehicle (two-wheeled vehicle) N2. The host vehicle M is traveling in lane RA1 (driving lane RA1) in the middle of a three-lane road. The other vehicle N1 is a four-wheeled vehicle traveling slightly ahead of the host vehicle M in lane RA2 (adjacent lane RA2) adjacent to the right side of lane RA1. The other vehicle N2 is a two-wheeled vehicle traveling behind the host vehicle M in lane RA3 (adjacent lane RA3) adjacent to the left side of lane RA1. FIG. 2 also shows the adjacent vehicle recognition range D of the host vehicle M.

[0042] In the situation shown in FIG. 2, the adjacent vehicle recognition unit 12 recognizes the other vehicle N2, which is traveling in lane RA2 and is partially included in the adjacent vehicle recognition range D of the host vehicle M, as an adjacent vehicle. The adjacent vehicle recognition unit 12 does not recognize the other vehicle N2, which is not included in the adjacent vehicle recognition range D, as an adjacent vehicle. Note that the adjacent vehicle recognition unit 12 does not necessarily need to recognize the adjacent vehicle using the adjacent vehicle recognition range. Various well-known methods can be adopted to recognize the adjacent vehicle.

[0043] When an adjacent vehicle is recognized by adjacent vehicle recognition unit 12 and the host vehicle turns right or left at an intersection, adjacent vehicle travel determination unit 13 determines whether the adjacent vehicle will turn in the same direction as the host vehicle at the intersection. Based on adjacent vehicle information acquired by vehicle-to-vehicle communication with the adjacent vehicle or the detection result of external sensor 2, adjacent vehicle travel determination unit 13 determines whether the adjacent vehicle will turn in the same direction as the host vehicle.

[0044] The adjacent vehicle information is information about adjacent vehicles obtained through vehicle-to-vehicle communication. The adjacent vehicle information includes at least one of the steering of the driver of the adjacent vehicle, the yaw rate of the adjacent vehicle, the lighting state of the turn signal, and navigation information (information about the driving route being guided by the navigation system). The adjacent vehicle driving determination unit 13 determines whether the adjacent vehicle will turn in the same direction as the vehicle itself based on the adjacent vehicle information and the lighting state of the turn signal of the adjacent vehicle.

[0045] The adjacent vehicle travel determination unit 13 may determine whether the adjacent vehicle turns in the same direction as the vehicle itself based on the detection result of the external sensor 2. The adjacent vehicle travel determination unit 13 may determine whether the adjacent vehicle turns in the same direction as the vehicle itself by, for example, recognizing the illumination of the turn signal of the adjacent vehicle from an image captured by an external camera. The adjacent vehicle travel determination unit 13 may determine whether the adjacent vehicle turns in the same direction as the vehicle itself based on a change in the direction or position of the adjacent vehicle detected by a radar sensor.

[0046] 2, the adjacent vehicle travel determination unit 13 determines that the adjacent vehicle N1 will turn in the same direction (right direction) as the host vehicle M by recognizing, for example, the illumination of the right turn signal of the adjacent vehicle N1 from an image captured by an external camera of the host vehicle M. In the situation shown in FIG. 2, the host vehicle M is planning to turn right from lane RA1 to lane RB1, and the adjacent vehicle N1 is planning to turn right from lane RA2 to lane RB2.

[0047] The preceding vehicle recognition unit 14 recognizes a preceding vehicle traveling in front of the host vehicle based on the detection result of the external sensor 2. The preceding vehicle recognition unit 14 recognizes the preceding vehicle by image recognition processing from an image of the area in front of the host vehicle captured by an external camera, for example. The preceding vehicle recognition unit 14 may recognize a preceding vehicle located in front of the host vehicle based on the detection result of a radar sensor. The preceding vehicle recognition unit 14 also recognizes the distance between the host vehicle and the preceding vehicle based on the image of the area in front of the host vehicle captured by the external camera or the detection result of the radar sensor.

[0048] Fig. 3 is a plan view showing an example of a situation in which a preceding vehicle is recognized. Fig. 3 shows a preceding vehicle N6 traveling in the same lane RA1 (driving lane RA1) as the host vehicle M, and a distance L6 between the host vehicle M and the preceding vehicle N6. In the situation shown in Fig. 3, the preceding vehicle recognition unit 14 recognizes the preceding vehicle N6 from the detection result of the external sensor 2, and also recognizes the distance L6 between the host vehicle M and the preceding vehicle N6.

[0049] When a preceding vehicle is recognized by the preceding vehicle recognition unit 14, the large vehicle determination unit 15 determines whether or not the preceding vehicle is a large vehicle based on preceding vehicle information acquired through vehicle-to-vehicle communication with the preceding vehicle or the detection result of the external sensor 2. A large vehicle is a vehicle such as a large truck. A large vehicle may be defined by the type of vehicle according to laws and regulations, or by its size.

[0050] The preceding vehicle information is information about the preceding vehicle obtained by vehicle-to-vehicle communication. The preceding vehicle information includes at least one of information about the type of vehicle, such as a large vehicle, and information about the size of the vehicle. The large vehicle determination unit 15 determines that the preceding vehicle is a large vehicle, for example, by recognizing the type of vehicle from the preceding vehicle information.

[0051] The large vehicle determination unit 15 may detect the license plate information of the preceding vehicle from the captured image of the external camera, thereby recognizing the type of vehicle and determining that the preceding vehicle is a large vehicle. The large vehicle determination unit 15 may estimate the area of ​​the rear surface of the preceding vehicle from the captured image of the external camera or the detection result of the radar sensor, and determine that the preceding vehicle is a large vehicle when the area of ​​the rear surface is equal to or greater than a predetermined threshold. The large vehicle determination unit 15 may determine that the preceding vehicle is a large vehicle when the width of the preceding vehicle is equal to or greater than a predetermined threshold or the height of the preceding vehicle is equal to or greater than a predetermined threshold, instead of the area of ​​the rear surface. The large vehicle determination unit 15 may determine that the preceding vehicle is a large vehicle by machine learning from the captured image of the external camera or the detection result of the radar sensor.

[0052] Fig. 4 is a plan view showing an example of a case where the preceding vehicle is a large vehicle. Fig. 4 shows a large vehicle N7 traveling in the same lane RA1 as the host vehicle M, and a distance L7 between the host vehicle M and the preceding vehicle N6. In the situation shown in Fig. 4, the large vehicle determination unit 15 recognizes the type of vehicle by detecting, for example, information on the license plate of the preceding vehicle from an image captured by an external camera, and determines that the preceding vehicle is a large vehicle.

[0053] The deceleration support execution unit 16 performs deceleration support for the host vehicle when the intersection right / left turn determination unit 11 determines that the host vehicle will turn right / left at the intersection. The deceleration support execution unit 16 realizes deceleration support by driving the brake actuator by transmitting a control signal to the actuator 6. For example, the deceleration support execution unit 16 performs deceleration support so that the vehicle speed of the host vehicle becomes a target vehicle speed. The target vehicle speed may be a value that is set in advance according to the situation of turning right / left at the intersection, or the value may change according to the distance between the vehicle and the preceding vehicle. The deceleration support execution unit 16 can change the content of the deceleration support by adjusting each parameter such as the target vehicle speed, the target deceleration, the target jerk, and the deceleration support start timing.

[0054] The deceleration support execution unit 16 changes the content of the deceleration support depending on various conditions such as the presence or absence of other vehicles in the vicinity, etc. First, the change of the deceleration support content depending on the adjacent vehicle will be described.

[0055] Specifically, when it is determined that the host vehicle will turn right or left at an intersection and the adjacent vehicle travel determination unit 13 determines that the adjacent vehicle will turn in the same direction as the host vehicle, the deceleration support execution unit 16 executes deceleration support so that the inter-vehicle distance between the host vehicle and the adjacent vehicle in the traveling direction of the host vehicle becomes equal to or greater than the adjacent vehicle target inter-vehicle distance. The deceleration support execution unit 16 executes deceleration support so that the inter-vehicle distance between the host vehicle and the adjacent vehicle becomes equal to or greater than the adjacent vehicle target inter-vehicle distance, using the position and speed of the adjacent vehicle acquired from the detection result of the external sensor 2. Note that the position of the adjacent vehicle may be the relative position of the adjacent vehicle with respect to the host vehicle, and the speed of the adjacent vehicle may be the relative speed of the adjacent vehicle with respect to the host vehicle.

[0056] The inter-vehicle distance between the host vehicle and the adjacent vehicle in the traveling direction of the host vehicle is, for example, the inter-vehicle distance between the host vehicle and the adjacent vehicle projected onto the traveling route of the host vehicle when turning right or left at an intersection. The inter-vehicle distance between the host vehicle and the adjacent vehicle in the traveling direction of the host vehicle may be the inter-vehicle distance between the host vehicle and the adjacent vehicle projected onto the longitudinal axis of the host vehicle with the host vehicle as a reference.

[0057] The target adjacent vehicle distance is a target vehicle distance that is set so that the driver of the host vehicle does not feel uncomfortable due to the deceleration support in relation to the adjacent vehicle when there is an adjacent vehicle turning in the same direction as the host vehicle at an intersection. The target adjacent vehicle distance can be a preset value.

[0058] The adjacent vehicle target inter-vehicle distance may be a different value when the host vehicle turns at an intersection ahead of the adjacent vehicle and when the adjacent vehicle turns at an intersection ahead of the host vehicle. The adjacent vehicle target inter-vehicle distance may be a different value when the host vehicle turns right and when the host vehicle turns left. The adjacent vehicle target inter-vehicle distance may be a different value when the host vehicle turns around the outside of the adjacent vehicle and when the host vehicle turns around the inside of the adjacent vehicle. The adjacent vehicle target inter-vehicle distance may be set to a different value depending on the vehicle speed of the host vehicle and the vehicle speed of the adjacent vehicle.

[0059] The deceleration support execution unit 16 may execute deceleration support so that the inter-vehicle distance between the preceding adjacent vehicle and the own vehicle becomes equal to or greater than the target adjacent vehicle inter-vehicle distance, or may execute deceleration support so that the inter-vehicle distance between the preceding own vehicle and the adjacent vehicle becomes equal to or greater than the target adjacent vehicle inter-vehicle distance. As long as an appropriate inter-vehicle distance between the own vehicle and the adjacent vehicle can be secured, the front-rear relationship between the own vehicle and the adjacent vehicle is not limited.

[0060] Fig. 5 is a plan view for explaining an example of a situation in which an adjacent vehicle turns in the same direction as the host vehicle. In Fig. 5, the host vehicle M and the adjacent vehicle N1 are about to turn right at an intersection T and proceed into lanes RB1 and RB2, respectively. Fig. 5 shows the travel route C of the host vehicle M and the inter-vehicle distance L1 between the host vehicle M and the adjacent vehicle N1 in the travel direction of the host vehicle M. The inter-vehicle distance L1 between the host vehicle M and the adjacent vehicle N1 in the travel direction of the host vehicle M is shown, as an example, as the inter-vehicle distance between the host vehicle M and the adjacent vehicle N1 projected onto the travel route C of the host vehicle M (the inter-vehicle distance along the travel route C of the host vehicle M).

[0061] In the situation shown in Figure 5, the deceleration support execution unit 16 determines that the host vehicle M will turn right at the intersection T, and the adjacent vehicle driving determination unit 13 determines that the adjacent vehicle N1 will turn in the same direction as the host vehicle M, so it performs deceleration support so that the inter-vehicle distance L1 between the host vehicle M and the adjacent vehicle N1 in the direction of travel of the host vehicle M is greater than or equal to the target adjacent vehicle inter-vehicle distance.

[0062] Fig. 6 is a plan view for explaining an example of a situation in which an adjacent vehicle moves in a different direction from the host vehicle. Fig. 6 shows an adjacent vehicle N3 going straight through an intersection T and an inter-vehicle distance L3 between the host vehicle M and the adjacent vehicle M3 in the traveling direction of the host vehicle M. In the situation shown in Fig. 6, the deceleration support execution unit 16 does not need to perform deceleration support to set the inter-vehicle distance L3 between the adjacent vehicle N3 to be equal to or larger than the adjacent vehicle target inter-vehicle distance, because the adjacent vehicle N3 does not turn in the same direction as the host vehicle M. Note that the deceleration support execution unit 16 may perform deceleration support due to right or left turns of the host vehicle M.

[0063] Next, a description will be given of changing the deceleration support content according to the preceding vehicle. When it is determined that the host vehicle is going to turn right or left at an intersection and the preceding vehicle recognition unit 14 recognizes a preceding vehicle traveling ahead of the host vehicle, the deceleration support execution unit 16 executes deceleration support so that the inter-vehicle distance between the host vehicle and the preceding vehicle becomes equal to or greater than the target inter-vehicle distance between the host vehicle and the preceding vehicle.

[0064] The target inter-vehicle distance from the preceding vehicle is a target inter-vehicle distance that is set so as not to cause discomfort to the driver of the own vehicle in relation to the preceding vehicle. The target inter-vehicle distance from the preceding vehicle includes a target inter-vehicle distance from the preceding vehicle for a normal vehicle and a target inter-vehicle distance from the preceding vehicle for a large vehicle, which will be described later. The target inter-vehicle distance from the preceding vehicle for a large vehicle is a target inter-vehicle distance that is larger than the target inter-vehicle distance from the preceding vehicle for a normal vehicle.

[0065] When the large vehicle determination unit 15 determines that the preceding vehicle is not a large vehicle, the deceleration support execution unit 16 executes deceleration support so that the inter-vehicle distance between the own vehicle and the preceding vehicle in the traveling direction of the own vehicle becomes larger compared to when the preceding vehicle is not determined to be a large vehicle.

[0066] Specifically, the deceleration support execution unit 16 executes deceleration support so that the distance between the host vehicle and the preceding vehicle becomes equal to or greater than the preceding vehicle target distance for normal vehicles (see FIG. 3). When the preceding vehicle is determined to be a large vehicle by the large vehicle determination unit 15, the deceleration support execution unit 16 executes deceleration support so that the distance between the host vehicle and the preceding vehicle becomes equal to or greater than the preceding vehicle target distance for large vehicles (see FIG. 4).

[0067] <Control of the driving assistance device according to the first embodiment> Next, the control (processing) of the driving support device 100 according to the first embodiment will be described with reference to the drawings. Fig. 7 is a flowchart showing an example of the deceleration support execution process. Fig. 8 is a flowchart showing the continuation of the deceleration support execution process. The deceleration support execution process shown in Figs. 7 and 8 is executed, for example, when the driving support of the host vehicle is in an ON state.

[0068] 7, in step S10, the driving assistance ECU 10 of the driving assistance device 100 recognizes an intersection ahead of the host vehicle by the intersection right / left turn determination unit 11. The intersection right / left turn determination unit 11 recognizes the intersection ahead of the host vehicle based on, for example, position information of the host vehicle measured by the GPS receiver 1 and map information in the map database 5.

[0069] In S11, the driving assistance ECU 10 recognizes a preceding vehicle ahead of the host vehicle by the preceding vehicle recognition unit 14. The preceding vehicle recognition unit 14 recognizes a preceding vehicle traveling ahead of the host vehicle based on the detection result of the external sensor 2. If a preceding vehicle is recognized (S11: YES), the driving assistance ECU 10 proceeds to S12. If a preceding vehicle is not recognized (S11: NO), the driving assistance ECU 10 proceeds to S15.

[0070] In S12, the driving assistance ECU 10 determines whether or not the preceding vehicle is a large vehicle using the large vehicle determination unit 15. The large vehicle determination unit 15 determines whether or not the preceding vehicle is a large vehicle based on preceding vehicle information acquired through vehicle-to-vehicle communication with the preceding vehicle or the detection result of the external sensor 2. If the driving assistance ECU 10 determines that the preceding vehicle is a large vehicle (S12: YES), the driving assistance ECU 10 proceeds to S13. If the driving assistance ECU 10 does not determine that the preceding vehicle is a large vehicle (S12: NO), the driving assistance ECU 10 proceeds to S14.

[0071] In S13, the driving assistance ECU 10 sets the target inter-vehicle distance for the large vehicle as the target inter-vehicle distance for deceleration assistance. After that, the driving assistance ECU 10 proceeds to S15.

[0072] In S14, the driving assistance ECU 10 sets the target inter-vehicle distance for the normal vehicle as the target inter-vehicle distance for deceleration assistance. The target inter-vehicle distance for the normal vehicle is a target inter-vehicle distance that is smaller than the target inter-vehicle distance for the large vehicle. After that, the driving assistance ECU 10 proceeds to S15.

[0073] In S15, the driving assistance ECU 10 recognizes an adjacent vehicle by the adjacent vehicle recognition unit 12. The adjacent vehicle recognition unit 12 recognizes, for example, another vehicle traveling in the same direction as the host vehicle on the side of the host vehicle within a preset adjacent vehicle recognition range based on the host vehicle as an adjacent vehicle. If an adjacent vehicle is recognized (S20: NO), the driving assistance ECU 10 proceeds to S18. If an adjacent vehicle is not recognized (S20: YES), the driving assistance ECU 10 proceeds to S16.

[0074] In S16, the driving assistance ECU 10 judges whether the host vehicle will turn right or left at the intersection by the intersection right / left turn judgment unit 11. The intersection right / left turn judgment unit 11 judges whether the host vehicle will turn right or left at the intersection based on the driving operation of the driver detected by the driving operation detection unit 4. The intersection right / left turn judgment unit 11 recognizes whether the host vehicle will turn right or left at the intersection. If it is judged that the host vehicle will turn right or left at the intersection (S16: YES), the driving assistance ECU 10 proceeds to S17. If it is not judged that the host vehicle will turn right or left at the intersection (S16: NO), the driving assistance ECU 10 ends this deceleration assistance execution process. After that, the driving assistance ECU 10 repeats the process from S10 again after a certain time has elapsed.

[0075] In S17, the driving assist ECU 10 executes deceleration assistance by the deceleration assistance execution unit 16. The deceleration assistance execution unit 16 executes deceleration assistance for the host vehicle turning right or left at the intersection by sending a control signal to the actuator 6. When a target vehicle distance between the preceding vehicle for a normal vehicle or a target vehicle distance between the preceding vehicle for a large vehicle is set, the deceleration assistance execution unit 16 executes deceleration assistance so that the vehicle distance between the preceding vehicle and the host vehicle becomes equal to or greater than the set target vehicle distance between the preceding vehicle. After that, the driving assist ECU 10 ends the current deceleration assistance execution process. The driving assist ECU 10 repeats the process from S10 again after a certain time has elapsed.

[0076] In S18, the driving assist ECU 10 sets the deceleration assist content when the adjacent vehicle turns right or left in the same direction by the deceleration assist execution unit 16. Assuming that the host vehicle turns right or left at the intersection and that the adjacent vehicle turns right or left in the same direction as the host vehicle, the deceleration assist execution unit 16 sets the deceleration assist content from the position and vehicle speed of the adjacent vehicle detected by the external sensor 2. The deceleration assist content includes a target vehicle speed and a target inter-vehicle distance for the deceleration assist. If a target inter-vehicle distance for a preceding vehicle for a normal vehicle or a target inter-vehicle distance for a large vehicle is set, the deceleration assist content includes the target inter-vehicle distance for a normal vehicle or the target inter-vehicle distance for a large vehicle.

[0077] By setting the deceleration support contents in advance in this way, the driving support ECU 10 can easily start deceleration support immediately after it is determined that the host vehicle turns right or left and that the adjacent vehicle turns right or left in the same direction. After that, the driving support ECU 10 proceeds to S19 shown in FIG.

[0078] As shown in Fig. 8, in S19, the driving assistance ECU 10 judges whether the host vehicle will turn right or left at the intersection by the intersection right / left turn judgment unit 11. The judgment process of S19 is the same as S16 in Fig. 7. If the driving assistance ECU 10 judges that the host vehicle will turn right or left at the intersection (S19: YES), the driving assistance ECU 10 proceeds to S20. If the driving assistance ECU 10 does not judge that the host vehicle will turn right or left at the intersection (S19: NO), the driving assistance ECU 10 ends this deceleration assistance execution process. After that, the driving assistance ECU 10 repeats the process from S10 again after a certain time has elapsed.

[0079] In S20, the driving assistance ECU 10 determines whether the adjacent vehicle will turn in the same direction as the host vehicle using the adjacent vehicle driving determination unit 13. The adjacent vehicle driving determination unit 13 determines whether the adjacent vehicle will turn in the same direction as the host vehicle based on adjacent vehicle information acquired through vehicle-to-vehicle communication with the adjacent vehicle or the detection result of the external sensor 2. If it is determined that the adjacent vehicle will turn in the same direction as the host vehicle (S20: YES), the driving assistance ECU 10 proceeds to S21. If it is not determined that the adjacent vehicle will turn in the same direction as the host vehicle (S20: NO), the driving assistance ECU 10 proceeds to S22.

[0080] In S21, the driving assistance ECU 10 executes deceleration assistance by the deceleration assistance execution unit 16 so that the inter-vehicle distance between the host vehicle and the adjacent vehicle in the traveling direction of the host vehicle becomes equal to or greater than the adjacent vehicle target inter-vehicle distance. The deceleration assistance execution unit 16 executes the deceleration assistance content preset in S18, for example, so that the inter-vehicle distance between the host vehicle and the adjacent vehicle becomes equal to or greater than the adjacent vehicle target inter-vehicle distance. Note that the deceleration assistance execution unit 16 may calculate the deceleration assistance content based on the current vehicle speed of the adjacent vehicle, etc., when the vehicle speed of the adjacent vehicle suddenly changes. Thereafter, the driving assistance ECU 10 ends the current deceleration assistance execution process. The driving assistance ECU 10 repeats the process from S10 again after a certain time has elapsed.

[0081] In S22, the driving assistance ECU 10 executes deceleration assistance by the deceleration assistance execution unit 16. When a target inter-vehicle distance for a normal vehicle or a target inter-vehicle distance for a large vehicle is set, deceleration assistance is executed so that the inter-vehicle distance between the preceding vehicle and the subject vehicle becomes equal to or greater than the set target inter-vehicle distance for the preceding vehicle. After that, the driving assistance ECU 10 ends the current deceleration assistance execution process. The driving assistance ECU 10 repeats the process from S10 again after a certain period of time has elapsed.

[0082] The deceleration support execution process is not limited to the above. For example, the determinations in S11 and S12 may be performed after it is determined that the vehicle is turning right or left at the intersection. The same applies to the determination of the adjacent vehicle in S15. In addition, it is not necessary to set the deceleration support content in S18 in advance, and the deceleration support content may be determined after it is determined that the adjacent vehicle is turning in the same direction as the vehicle.

[0083] According to the driving assistance device 100 of the first embodiment described above, when it is determined that an adjacent vehicle is turning in the same direction as the host vehicle when the host vehicle is turning right or left at an intersection, deceleration assistance is performed so that the inter-vehicle distance between the host vehicle and the adjacent vehicle in the host vehicle's direction of travel becomes equal to or greater than a target inter-vehicle distance. This reduces the discomfort felt by the driver due to the deceleration assistance compared to when deceleration assistance is performed without taking the adjacent vehicle into consideration.

[0084] Furthermore, according to the driving assistance device 100, when the vehicle is turning right or left at an intersection and it is determined that the preceding vehicle is a large vehicle, deceleration assistance is performed so that the inter-vehicle distance between the vehicle and the preceding vehicle in the vehicle's direction of travel is increased compared to when the preceding vehicle is not determined to be a large vehicle. This reduces the discomfort felt by the driver due to deceleration assistance compared to when deceleration assistance is performed without considering whether the preceding vehicle is a large vehicle or not.

[0085] [Second embodiment] Next, a driving assistance device according to a second embodiment will be described. The same or corresponding components as those in the first embodiment will be denoted by the same reference numerals, and duplicated descriptions will be omitted.

[0086] <Configuration of driving support device according to second embodiment> Fig. 9 is a block diagram showing a driving support device according to the second embodiment. The driving support ECU 20 of the driving support device 200 according to the second embodiment shown in Fig. 9 is different from the first embodiment in that an adjacent vehicle travel determination unit 21 and a deceleration support execution unit 27 have additional functions, and in that the driving support ECU 20 has a visibility condition determination unit 22, a pedestrian crossing determination unit 23, an obstacle determination unit 24, an accelerator operation determination unit 25, and a turn signal operation determination unit 26.

[0087] When it is determined that the adjacent vehicle is turning in the same direction as the host vehicle, adjacent vehicle travel determination unit 21 determines whether the host vehicle is turning on the outside or inside of the adjacent vehicle. Adjacent vehicle travel determination unit 21 makes the above determination based on the detection result of external sensor 2.

[0088] Fig. 10 is a plan view showing an example of a situation in which the host vehicle turns on the outside of an adjacent vehicle. Fig. 11 is a plan view for explaining a situation in which the host vehicle turns at an intersection ahead of an adjacent vehicle. As shown in Figs. 10 and 11, when the host vehicle M and adjacent vehicle N4 turn right at an intersection T, the host vehicle M traveling in lane RA1 (traveling lane RA1) located to the left of lane RA2 (adjacent lane RA2) in which the adjacent vehicle N4 is traveling will turn on the outside of the adjacent vehicle N4. Therefore, in the situation shown in Fig. 10, the adjacent vehicle travel determination unit 21 determines that the host vehicle M will turn on the outside of the adjacent vehicle N4.

[0089] When it is determined that the host vehicle will turn around the outside of the adjacent vehicle, the adjacent vehicle travel determination unit 21 determines whether the host vehicle can pass through the intersection ahead of the adjacent vehicle at a vehicle speed equal to or lower than the target vehicle speed upper limit. The target vehicle speed upper limit is a target vehicle speed upper limit that is set in advance in accordance with the purpose of deceleration support when turning right or left at an intersection. The adjacent vehicle travel determination unit 21 makes the above determination from the relative positions of the host vehicle and the adjacent vehicle and the relative vehicle speeds of the host vehicle and the adjacent vehicle based on the detection results of the external sensor 2.

[0090] The adjacent vehicle travel determination unit 21 may determine that the host vehicle can pass the intersection ahead of the adjacent vehicle at a speed equal to or less than the target vehicle speed upper limit when the host vehicle is ahead of the adjacent vehicle at a speed equal to or less than the target vehicle speed upper limit and the vehicle-to-vehicle distance between the host vehicle and the adjacent vehicle can be maintained at or greater than the adjacent vehicle target vehicle-to-vehicle distance. Alternatively, the adjacent vehicle travel determination unit 21 may determine that the host vehicle can pass the intersection ahead of the adjacent vehicle at a speed equal to or less than the target vehicle speed upper limit even if the vehicle-to-vehicle distance is less than the adjacent vehicle target vehicle-to-vehicle distance, if the host vehicle can pass the intersection ahead of the adjacent vehicle at a speed equal to or less than the target vehicle speed upper limit.

[0091] Fig. 12 is a plan view for explaining an example of a situation in which the host vehicle turns inside an adjacent vehicle. In Fig. 12, the lane RA3 (driving lane RA3) in which the host vehicle M is traveling is located to the left of the lane RA1 (adjacent lane RA1) in which the adjacent vehicle N5 is traveling.

[0092] 12, when the host vehicle M and adjacent vehicle N5 turn left at the intersection T, the host vehicle M traveling in the lane RA1 located to the left of the lane RA1 in which the adjacent vehicle N5 is traveling will turn on the inside of the adjacent vehicle N4. Therefore, in the situation shown in FIG 12, the adjacent vehicle travel determination unit 21 determines that the host vehicle M will turn on the inside of the adjacent vehicle N4.

[0093] The visibility condition determination unit 22 determines whether or not the visibility around the vehicle is poor. The visibility condition determination unit 22 makes the determination based on at least one of an image captured by an external camera of the vehicle, the wiper operation status of the vehicle, the high beam lighting status of the headlights of the vehicle, weather information around the vehicle acquired from a communication network, and traffic-related information around the vehicle acquired from a communication network.

[0094] The poor visibility situation is a situation in which the driver's visibility is deteriorated. The poor visibility situation includes at least one of bad weather conditions such as rain, snow, and typhoons, poor visibility due to an intersection having a poor visibility shape, backlight conditions due to the setting sun or road surface reflection, and darkness conditions due to nighttime or shadows of building structures.

[0095] The bad weather condition can be determined from at least one of an image captured by an external camera of the host vehicle, the operation status of the wipers of the host vehicle, and weather information around the host vehicle obtained from a communication network. The poor visibility condition can be determined from an image captured by an external camera of the host vehicle or traffic-related information around the host vehicle obtained from a communication network. The poor visibility condition may be determined using the position information and map information of the host vehicle. The backlight condition can be determined from an image captured by an external camera of the host vehicle. The dark condition can be determined from an image captured by an external camera of the host vehicle or the high beam lighting status of the headlights of the host vehicle.

[0096] The crosswalk determination unit 23 determines whether or not a crosswalk exists at the destination where the vehicle is to turn right or left. The crosswalk determination unit 23 makes the above determination based on at least one of the location of the vehicle on the map and the map information in the map database 5, the detection result of the external sensor 2, and traffic-related information around the vehicle acquired from the communication network. The external sensor recognizes the crosswalk at the destination where the vehicle is to turn right or left by, for example, image recognition using an external camera. The traffic-related information in this case is assumed to include information on elements such as the crosswalk at the intersection and traffic lights.

[0097] The obstacle determination unit 24 determines whether or not there is an obstacle ahead of the vehicle when the vehicle turns right or left. The obstacle determination unit 24 makes the above determination based on at least one of the detection results of the external sensor 2, surrounding environment information acquired from inter-vehicle communication with other vehicles around the vehicle, and traffic-related information around the vehicle acquired from a communication network. Obstacles include stationary vehicles (including vehicles stopped temporarily due to congestion) on the road ahead of the turn, parked vehicles, pedestrians, bicycles, etc.

[0098] The surrounding environment information acquired from vehicle-to-vehicle communication with other vehicles around the vehicle is, for example, image information of the surroundings of the preceding vehicle captured by an external camera of the preceding vehicle acquired from the preceding vehicle. The obstacle determination unit 24 may directly acquire information on obstacles recognized by the preceding vehicle, etc., as the surrounding environment information from vehicle-to-vehicle communication. In this case, the traffic-related information includes image information from an intersection imaging camera that captures an image of the intersection from above. Various other well-known methods can be adopted as a method for recognizing obstacles.

[0099] Accelerator operation determination unit 25 determines whether the driver releases the accelerator for turning right or left at an intersection earlier than a first timing threshold. Accelerator operation determination unit 25 makes the above determination based on the position of the host vehicle on the map, the map information in map database 5, and the detection result of the driver's driving operation by driving operation detection unit 4.

[0100] The accelerator release timing is the timing at which the driver releases the accelerator pedal before turning right or left at an intersection. The accelerator operation determination unit 25 determines the accelerator release timing based on the remaining time to the intersection or the remaining distance to the intersection. The remaining time to the intersection may be recognized as the TTC [Time to Collision] between the intersection and the vehicle.

[0101] The first timing threshold is a preset threshold value. For example, the first timing threshold may be a timing at which a statistically typical driver releases the accelerator pedal when turning right or left at an intersection. The first timing threshold may be a different value when the host vehicle turns right and when the host vehicle turns left.

[0102] The turn indicator operation determination unit 26 determines whether the timing of the driver's turn indicator operation for turning right or left at an intersection is earlier than a second timing threshold. The turn indicator operation determination unit 26 makes the above determination based on the position of the vehicle on the map, the map information in the map database 5, and the detection result of the driver's turn indicator operation by the driving operation detection unit 4.

[0103] The turn indicator operation timing is the timing when the driver operates the turn indicator before turning right or left at an intersection. The turn indicator operation determination unit 26 determines the turn indicator operation timing based on the remaining time or distance of the host vehicle to the intersection.

[0104] The second timing threshold is a threshold value that is set in advance. For example, the second timing threshold may be set to a timing at which a statistically typical driver operates a turn signal when turning right or left at an intersection. The second timing threshold may be set to a different value when the host vehicle turns right and when the host vehicle turns left.

[0105] When adjacent vehicle travel determination unit 21 determines that the host vehicle can pass the intersection ahead of the adjacent vehicle at a vehicle speed equal to or lower than the target vehicle speed upper limit, deceleration support execution unit 27 adjusts the target vehicle speed in deceleration support so that the host vehicle passes the intersection ahead of the adjacent vehicle. Specifically, deceleration support execution unit 27 adjusts the target vehicle speed in deceleration support in the situation shown in Fig. 10 to execute deceleration support so that the host vehicle M passes the intersection ahead of the adjacent vehicle N4, as shown in Fig. 11. Deceleration support execution unit 27 executes deceleration support so that the inter-vehicle distance L4 between the host vehicle M and adjacent vehicle N4 is equal to or greater than the adjacent vehicle target inter-vehicle distance.

[0106] The deceleration support execution unit 27 may prioritize the host vehicle M leading the adjacent vehicle N4 ahead of the adjacent vehicle N4 even if the vehicle distance L4 between the host vehicle M and the adjacent vehicle N4 shown in FIG. 11 is less than the adjacent vehicle target vehicle distance.

[0107] When the deceleration support execution unit 27 detects an accelerator operation by the driver, the deceleration support execution unit 27 may adjust the target vehicle distance for deceleration support by giving priority to the host vehicle being ahead of the adjacent vehicle target vehicle distance. When the deceleration support execution unit 27 does not detect an accelerator operation by the driver, the deceleration support execution unit 27 may allow the adjacent vehicle to be ahead of the host vehicle by giving priority to the vehicle distance between the host vehicle and the adjacent vehicle being equal to or greater than the adjacent vehicle target vehicle distance. The deceleration support execution unit 27 may give priority to the host vehicle being ahead compared to adjusting the target vehicle speed according to various conditions described later.

[0108] As shown in Figure 12, when the adjacent vehicle driving determination unit 21 determines that the host vehicle M will turn inside the adjacent vehicle N4, the deceleration assistance execution unit 27 performs deceleration assistance so that the inter-vehicle distance between the host vehicle M and the adjacent vehicle N4 is equal to or greater than the target inter-vehicle distance between the adjacent vehicle N4, since the driver of the host vehicle M's field of vision in the direction of travel is not obstructed by the preceding adjacent vehicle N4 and there is no need for the host vehicle M to be ahead of the adjacent vehicle N4.

[0109] When the visibility condition determination unit 22 determines that the visibility around the vehicle is poor, the deceleration support execution unit 27 lowers the target vehicle speed in deceleration support compared to when the visibility around the vehicle is not determined to be poor. The deceleration support execution unit 27 lowers the target vehicle speed by a preset fixed amount or a preset fixed rate. The deceleration support execution unit 27 may change the amount or rate of reduction in the target vehicle speed depending on the type of the visibility poor state.

[0110] When the crosswalk determination unit 23 determines that a crosswalk exists ahead of the vehicle's right or left turn, the deceleration support execution unit 27 lowers the target vehicle speed in deceleration support compared to when it is not determined that a crosswalk exists ahead of the vehicle's right or left turn. The deceleration support execution unit 27 lowers the target vehicle speed by a preset fixed amount or a preset fixed rate.

[0111] When the obstacle determination unit 24 determines whether or not there is an obstacle ahead of the vehicle where the vehicle is to turn right or left, the deceleration support execution unit 27 lowers the target vehicle speed in deceleration support compared to when it is not determined that there is an obstacle ahead of the vehicle where the vehicle is to turn right or left. The deceleration support execution unit 27 lowers the target vehicle speed by a preset fixed amount or a preset fixed rate. The deceleration support execution unit 27 may change the amount or rate of reduction in the target vehicle speed depending on the type of obstacle.

[0112] When the accelerator operation determination unit 25 determines that the driver's accelerator release timing for turning right or left at an intersection is earlier than the first timing threshold, the deceleration support execution unit 27 lowers the target vehicle speed in deceleration support compared to when the driver's accelerator release timing is not determined to be earlier than the first timing threshold. The deceleration support execution unit 27 lowers the target vehicle speed by a preset fixed amount or a preset fixed rate. The deceleration support execution unit 27 may set multiple thresholds to gradually lower the target vehicle speed.

[0113] When the turn signal operation determination unit 26 determines that the timing of the driver's turn signal operation for turning right or left at an intersection is earlier than the second timing threshold, the deceleration support execution unit 27 lowers the target vehicle speed in deceleration support, compared to when the driver's turn signal operation timing is not determined to be earlier than the second timing threshold. The deceleration support execution unit 27 lowers the target vehicle speed by a preset constant amount or a constant rate. The deceleration support execution unit 27 may set multiple thresholds and gradually lower the target vehicle speed. Note that the deceleration support execution unit 27 does not lower the target vehicle speed below a preset lower limit of the target vehicle speed.

[0114] In addition, the deceleration support execution unit 27 may lower the target vehicle speed in deceleration support when turning right or left from a road with many lanes to a road with fewer lanes based on the intersection shape, compared to when turning right or left from a road with fewer lanes to a road with more lanes.In addition, the deceleration support execution unit 27 may change the target inter-vehicle distance between the preceding vehicle and / or the target inter-vehicle distance between the adjacent vehicle to a larger value instead of lowering the target vehicle speed described above.

[0115] <Control of driving assistance device according to second embodiment> Next, the control (processing) of the driving support device 200 according to the second embodiment will be described with reference to the drawings. Fig. 13 is a flowchart showing the continuation of the deceleration support execution process according to the second embodiment. The flowchart shown in Fig. 13 is another example that is a continuation of the flowchart in Fig. 7.

[0116] As shown in Fig. 13, the driving assistance ECU 20 of the driving assistance device 200 determines whether the host vehicle will turn right or left at the intersection using the intersection right / left turn determination unit 11 in S30. If it is determined that the host vehicle will turn right or left at the intersection (S30: YES), the driving assistance ECU 10 proceeds to S31. If it is not determined that the host vehicle will turn right or left at the intersection (S30: NO), the driving assistance ECU 20 ends the current deceleration assistance execution process. After that, the driving assistance ECU 20 repeats the process from S10 (Fig. 7) again after a certain period of time has elapsed.

[0117] In S31, the driving assistance ECU 20 determines whether the adjacent vehicle is turning in the same direction as the host vehicle using the adjacent vehicle travel determination unit 21. If the driving assistance ECU 20 determines that the adjacent vehicle is turning in the same direction as the host vehicle (S31: YES), the driving assistance ECU 20 proceeds to S33. If the driving assistance ECU 20 does not determine that the adjacent vehicle is turning in the same direction as the host vehicle (S31: NO), the driving assistance ECU 20 proceeds to S32.

[0118] In S32, the driving assist ECU 20 executes deceleration assistance by the deceleration assistance execution unit 27. When the target inter-vehicle distance for a normal vehicle or the target inter-vehicle distance for a large vehicle is set, the deceleration assistance is executed so that the inter-vehicle distance between the preceding vehicle and the subject vehicle becomes equal to or greater than the set target inter-vehicle distance for the preceding vehicle. After that, the driving assist ECU 20 ends the current deceleration assistance execution process. The driving assist ECU 20 repeats the process from S10 again after a certain time has elapsed.

[0119] In S33, the driving assistance ECU 20 determines whether the host vehicle will turn around the outside or inside of the adjacent vehicle using the adjacent vehicle driving determination unit 21. The adjacent vehicle driving determination unit 21 makes the above determination based on the detection result of the external sensor 2. If the driving assistance ECU 20 determines that the host vehicle will turn around the outside of the adjacent vehicle (S33: YES), the driving assistance ECU 20 proceeds to S34. If the driving assistance ECU 20 does not determine that the host vehicle will turn around the outside of the adjacent vehicle (S33: NO), the driving assistance ECU 20 proceeds to S35.

[0120] In S34, the driving assistance ECU 20 determines whether or not the host vehicle can pass through the intersection ahead of the adjacent vehicle at a speed equal to or less than the target upper limit vehicle speed using the adjacent vehicle travel determination unit 21. The adjacent vehicle travel determination unit 21 makes the above determination from the relative positions of the host vehicle and the adjacent vehicle and the relative vehicle speeds of the host vehicle and the adjacent vehicle based on the detection results of the external sensor 2. If the driving assistance ECU 20 determines that the host vehicle can pass through the intersection ahead of the adjacent vehicle at a speed equal to or less than the target upper limit vehicle speed (S34: YES), the driving assistance ECU 20 proceeds to S36. If the driving assistance ECU 20 does not determine that the host vehicle can pass through the intersection ahead of the adjacent vehicle at a speed equal to or less than the target upper limit vehicle speed (S34: NO), the driving assistance ECU 20 proceeds to S35.

[0121] In S35, the driving assistance ECU 20 executes deceleration assistance by the deceleration assistance execution unit 27 so that the inter-vehicle distance between the host vehicle and the adjacent vehicle becomes equal to or greater than the target inter-vehicle distance between the adjacent vehicle. In this case, the host vehicle or the adjacent vehicle may be ahead. Thereafter, the driving assistance ECU 20 ends the current deceleration assistance execution process. After a certain period of time has elapsed, the driving assistance ECU 20 repeats the process from S10.

[0122] In S36, the driving assist ECU 20 executes deceleration assistance by the deceleration assistance execution unit 27 so that the inter-vehicle distance between the preceding host vehicle and the adjacent vehicle becomes equal to or greater than the adjacent vehicle target inter-vehicle distance. Note that the deceleration assistance execution unit 27 may prioritize the host vehicle being ahead over making the inter-vehicle distance equal to or greater than the adjacent vehicle target inter-vehicle distance. Thereafter, the driving assist ECU 20 ends the current deceleration assistance execution process. The driving assist ECU 20 repeats the process from S10 again after a certain period of time has elapsed.

[0123] Fig. 14(a) is a flowchart showing an example of a process for determining a poor visibility state. The process for determining a poor visibility state shown in Fig. 14(a) is executed, for example, when it is determined that the host vehicle will turn right or left at an intersection.

[0124] 14(a), the driving assistance ECU 20 determines whether or not the visibility around the host vehicle is poor by the visibility condition determination unit 22 in S40. If the driving assistance ECU 20 determines that the visibility around the host vehicle is poor (S40: YES), the driving assistance ECU 20 proceeds to S41. If the driving assistance ECU 20 determines that the visibility around the host vehicle is poor (S40: NO), the driving assistance ECU 20 ends this processing.

[0125] In S41, the driving assist ECU 20 reduces the target vehicle speed for deceleration assist by the deceleration assist execution unit 27. The deceleration assist execution unit 27 reduces the target vehicle speed by, for example, a preset fixed amount or a fixed rate.

[0126] Fig. 14(b) is a flowchart showing an example of a crosswalk determination process. The crosswalk determination process shown in Fig. 14(b) is executed, for example, when it is determined that the host vehicle will turn right or left at an intersection.

[0127] As shown in Fig. 14(b), in S50, the driving assistance ECU 20 determines whether or not a crosswalk exists ahead of the vehicle's right or left turn using the crosswalk determination unit 23. If it is determined that a crosswalk exists ahead of the vehicle's right or left turn (S50: YES), the driving assistance ECU 20 proceeds to S51. If it is determined that a crosswalk exists ahead of the vehicle's right or left turn (S50: NO), the driving assistance ECU 20 ends this processing.

[0128] In S51, the driving assist ECU 20 reduces the target vehicle speed for deceleration assist by the deceleration assist execution unit 27. The deceleration assist execution unit 27 reduces the target vehicle speed by, for example, a preset fixed amount or a fixed rate.

[0129] Fig. 14(c) is a flowchart showing an example of the obstacle determination process. The obstacle determination process shown in Fig. 14(c) is executed, for example, when it is determined that the host vehicle will turn right or left at an intersection.

[0130] 14(c), in S60, the driving assistance ECU 20 determines whether or not an obstacle exists ahead of the vehicle's right or left turn using the obstacle determination unit 24. If it is determined that an obstacle exists ahead of the vehicle's right or left turn (S60: YES), the driving assistance ECU 20 proceeds to S61. If it is determined that an obstacle exists ahead of the vehicle's right or left turn (S60: NO), the driving assistance ECU 20 ends this processing.

[0131] In S61, the driving assist ECU 20 reduces the target vehicle speed for deceleration assist by the deceleration assist execution unit 27. The deceleration assist execution unit 27 reduces the target vehicle speed by, for example, a preset fixed amount or a fixed rate.

[0132] Fig. 15(a) is a flow chart showing an example of an accelerator release determination process. The accelerator release determination process shown in Fig. 15(a) is executed, for example, when it is determined that the host vehicle will turn right or left at an intersection.

[0133] 15(a), in S70, the driving assistance ECU 20 determines whether the driver's accelerator release timing is earlier than a first timing threshold by the accelerator operation determination unit 25. If the driving assistance ECU 20 determines that the driver's accelerator release timing is earlier than the first timing threshold (S70: YES), the driving assistance ECU 20 proceeds to S71. If the driving assistance ECU 20 does not determine that the driver's accelerator release timing is earlier than the first timing threshold (S70: NO), the driving assistance ECU 20 ends this processing.

[0134] In S71, the driving assist ECU 20 reduces the target vehicle speed for deceleration assist by the deceleration assist execution unit 27. The deceleration assist execution unit 27 reduces the target vehicle speed by, for example, a preset fixed amount or a preset fixed rate.

[0135] Fig. 15(b) is a flowchart showing an example of a turn indicator operation timing determination process. The turn indicator operation timing determination process shown in Fig. 15(b) is executed, for example, when it is determined that the host vehicle will turn right or left at an intersection.

[0136] 15(b), in S80, the driving assistance ECU 20 determines whether the timing of the driver's turn indicator operation is earlier than the second timing threshold by the turn indicator operation determination unit 26. If the driving assistance ECU 20 determines that the timing of the driver's turn indicator operation is earlier than the second timing threshold (S80: YES), the driving assistance ECU 20 proceeds to S71. If the driving assistance ECU 20 does not determine that the driver's turn indicator operation is earlier than the second timing threshold (S80: NO), the driving assistance ECU 20 ends this processing.

[0137] In S81, the driving assist ECU 20 reduces the target vehicle speed for deceleration assist by the deceleration assist execution unit 27. The deceleration assist execution unit 27 reduces the target vehicle speed by, for example, a preset fixed amount or a fixed rate.

[0138] According to the driving assistance device 200 of the second embodiment described above, when the adjacent vehicle driving determination unit 21 determines that the host vehicle will turn around the outside of the adjacent vehicle, and the host vehicle is able to pass through the intersection ahead of the adjacent vehicle at a vehicle speed equal to or lower than the target vehicle speed upper limit, the target vehicle speed in deceleration assistance is adjusted so that the host vehicle passes through the intersection ahead of the adjacent vehicle. This reduces the obstruction of the driver's view caused by the adjacent vehicle getting ahead when the host vehicle turns around the outside of the adjacent vehicle.

[0139] Furthermore, according to the driving assistance device 200, when the visibility condition determination unit 22 determines that the surroundings of the vehicle are in a poor visibility condition, the target vehicle speed for deceleration assistance is lowered compared to when it is not determined that the surroundings of the vehicle are in a poor visibility condition. This reduces the discomfort felt by the driver due to deceleration assistance compared to when the poor visibility condition is not taken into consideration.

[0140] Furthermore, according to the driving assistance device 200, when the crosswalk determination unit 23 determines that a crosswalk exists up ahead of the vehicle's right or left turn, the target vehicle speed in deceleration assistance is lowered compared to when it is not determined that a crosswalk exists up ahead of the vehicle's right or left turn, so that the deceleration assistance can reduce the discomfort felt by the driver compared to when the presence of a crosswalk is not taken into consideration.

[0141] Furthermore, according to the driving assistance device 200, when the obstacle determination unit 24 determines that an obstacle is present ahead of the vehicle when turning right or left, the target vehicle speed for deceleration assistance is lowered compared to when it is not determined that an obstacle is present ahead of the vehicle when turning right or left. This reduces the discomfort felt by the driver due to deceleration assistance compared to when the presence of an obstacle is not taken into consideration.

[0142] Furthermore, according to the driving assistance device 200, when the accelerator operation determination unit 25 determines that the accelerator release timing is earlier than the first timing threshold, the target vehicle speed in deceleration assistance is lowered compared to when the accelerator release timing is not determined to be earlier than the first timing threshold, so that the sense of discomfort felt by the driver due to deceleration assistance can be reduced compared to when the accelerator release timing is not taken into consideration.

[0143] Furthermore, according to the driving assistance device 200, when the turn indicator operation determination unit 26 determines that the turn indicator operation timing is earlier than the second timing threshold, the target vehicle speed in deceleration assistance is lowered compared to when the turn indicator operation timing is not determined to be earlier than the second timing. Therefore, it is possible to reduce the discomfort felt by the driver due to deceleration assistance compared to when the turn indicator operation timing is not taken into consideration.

[0144] Although the embodiment of the present invention has been described above, the present invention is not limited to the above-mentioned embodiment. The present invention can be embodied in various forms including the above-mentioned embodiment and various modifications and improvements based on the knowledge of those skilled in the art.

[0145] The driving assistance devices 100, 200 do not necessarily need to determine whether the preceding vehicle is a large vehicle or not. The driving assistance devices 100, 200 may perform deceleration assistance using the same target inter-vehicle distance to the preceding vehicle regardless of the size of the preceding vehicle. Furthermore, the driving assistance devices 100, 200 do not necessarily need to perform deceleration assistance taking into account the presence of a preceding vehicle. In this case, the driving assistance ECUs 10, 20 do not necessarily need to include the preceding vehicle recognition unit 14 and the large vehicle determination unit 15.

[0146] The driving support device 200 does not need to have the visibility condition determination unit 22, the crosswalk determination unit 23, the obstacle determination unit 24, the accelerator operation determination unit 25, and the turn signal operation determination unit 26. The driving support device 200 may have any one of the visibility condition determination unit 22, the crosswalk determination unit 23, the obstacle determination unit 24, the accelerator operation determination unit 25, and the turn signal operation determination unit 26, or may not have all of them. [Explanation of symbols]

[0147] 1...GPS receiver unit, 2...external sensor, 3...internal sensor, 4...driving operation detection unit, 5...map database, 6...actuator, 7...communication unit, 10,20...driving assistance ECU, 11...intersection right / left turn determination unit, 12...adjacent vehicle recognition unit, 13,21...adjacent vehicle driving determination unit, 14...preceding vehicle recognition unit, 15...large vehicle determination unit, 16,27...deceleration assistance execution unit, 22...visibility condition determination unit, 23...pedestrian crossing determination unit, 24...obstacle determination unit, 25...accelerator operation determination unit, 26...turn signal operation determination unit, 100,200...driving assistance device.

Claims

1. A driving assistance device that assists a vehicle in decelerating when the vehicle turns right or left at an intersection, an adjacent vehicle recognition unit that recognizes adjacent vehicles traveling in an adjacent lane adjacent to the driving lane of the host vehicle based on a detection result of an external sensor of the host vehicle; an adjacent vehicle travel determination unit that, when the adjacent vehicle is recognized by the adjacent vehicle recognition unit and the host vehicle turns right or left at the intersection, determines whether the adjacent vehicle will turn in the same direction as the host vehicle at the intersection based on adjacent vehicle information acquired through vehicle-to-vehicle communication with the adjacent vehicle or the detection result of the external sensor; a deceleration support execution unit that, when it is determined by the adjacent vehicle travel determination unit that the adjacent vehicle is turning in the same direction as the host vehicle, executes the deceleration support so that an inter-vehicle distance between the host vehicle and the adjacent vehicle in the traveling direction of the host vehicle becomes equal to or larger than a preset target inter-vehicle distance between the host vehicle; A driving operation detection unit that detects a driving operation of a driver of the vehicle; an accelerator operation determination unit that determines whether or not an accelerator release timing of the driver for turning right or left at the intersection is earlier than a first timing threshold value based on a position of the host vehicle on a map, map information, and a detection result of the driving operation of the driver by the driving operation detection unit, when the accelerator operation determination unit determines that the accelerator release timing is earlier than the first timing threshold, the deceleration support execution unit lowers a target vehicle speed in the deceleration support compared to when the accelerator release timing is not determined to be earlier than the first timing threshold, A driving assistance device, wherein the inter-vehicle distance between the host vehicle and the adjacent vehicle in the direction of travel of the host vehicle is the inter-vehicle distance between the host vehicle and the adjacent vehicle projected onto the travel route of the host vehicle when turning right or left at the intersection.

2. a preceding vehicle recognition unit that recognizes a preceding vehicle traveling ahead of the host vehicle based on a detection result of the external sensor; a large vehicle determination unit that, when the preceding vehicle is recognized by the preceding vehicle recognition unit, determines whether the preceding vehicle is a large vehicle based on preceding vehicle information acquired through vehicle-to-vehicle communication with the preceding vehicle or a detection result of the external sensor, 2. The driving assistance device according to claim 1, wherein when the large vehicle determination unit determines that the preceding vehicle is a large vehicle, the deceleration assistance execution unit executes the deceleration assistance so that the inter-vehicle distance between the host vehicle and the preceding vehicle becomes larger compared to when the preceding vehicle is not determined to be a large vehicle.

3. a visibility condition determination unit that determines whether or not the visibility around the host vehicle is poor based on at least one of an image captured by an external camera of the host vehicle, a wiper operation status of the host vehicle, a high beam lighting status of the headlights of the host vehicle, weather information around the host vehicle acquired from a communication network, and traffic-related information around the host vehicle acquired from a communication network; 3. The driving assistance device according to claim 1, wherein the deceleration assistance execution unit lowers a target vehicle speed in the deceleration assistance when the visibility condition determination unit determines that the surroundings of the host vehicle are in the deteriorated visibility condition, compared to when the surroundings of the host vehicle are not determined to be in the deteriorated visibility condition.

4. a crosswalk determination unit that determines whether or not a crosswalk exists ahead of a right or left turn of the vehicle based on at least one of the position of the vehicle on a map and map information, the detection result of the external sensor, and traffic-related information around the vehicle acquired from a communication network; The driving support device according to any one of claims 1 to 3, wherein when the crosswalk determination unit determines that the crosswalk exists ahead of the vehicle to turn right or left, the deceleration support execution unit lowers the target vehicle speed in the deceleration support compared to when it is not determined that the crosswalk exists ahead of the vehicle to turn right or left.

5. an obstacle determination unit that determines whether or not an obstacle is present ahead of a right or left turn of the host vehicle based on at least one of a detection result of the external sensor, surrounding environment information acquired from inter-vehicle communication with other vehicles around the host vehicle, and traffic-related information around the host vehicle acquired from a communication network; The driving support device according to any one of claims 1 to 4, wherein when the obstacle determination unit determines that the obstacle exists ahead of the vehicle to turn right or left, the deceleration support execution unit lowers the target vehicle speed in the deceleration support compared to when it is not determined that the obstacle exists ahead of the vehicle to turn right or left.

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