Driving assistance device

Abstract

A driving assist device configured to execute deceleration assist for a host vehicle when the host vehicle makes a right turn or a left turn at an intersection, is configured to: identify a neighboring vehicle traveling on a neighboring lane adjacent to a travel lane of the host vehicle based on a detection result from an external sensor of the host vehicle; when the neighboring vehicle is identified and the host vehicle makes a right turn or a left turn at the intersection, determine whether the neighboring vehicle turns in a same direction as the host vehicle at the intersection based on the detection result from the external sensor; and when the driving assist device determines that the neighboring vehicle turns in the same direction, execute the deceleration assist to bring an inter-vehicle distance between the host vehicle and the neighboring vehicle to a distance equal to or greater than a target host-vehicle-and-neighboring-vehicle inter-distance.

Description

TECHNICAL FIELD

[0001] The present application relates to a driving assist device. BACKGROUND

[0002] Japanese Laid-Open Patent Application Publication No. 2010-221858 (JP 2010-221858 A) is known as a technical document related to a driving assist device. JP 2010-221858 A discloses a driving assist device that assists deceleration of a driver's vehicle at a point a predetermined distance behind an intersection so that the driver's vehicle passes through the intersection at a set proper speed. SUMMARY

[0003] When the driver's vehicle enters an intersection from a road having a plurality of lanes and makes a right turn or a left turn, a neighboring vehicle can enter the intersection. When deceleration is assisted without considering the presence of the neighboring vehicle, the driver can feel discomfort.

[0004] A first aspect of the present application relates to a driving assist device configured to perform deceleration assistance for a driver's vehicle when the driver's vehicle makes a right turn or a left turn at an intersection. The driving assist device includes a neighboring vehicle recognizer configured to recognize a neighboring vehicle traveling on a neighboring lane adjacent to a travel lane of the driver's vehicle based on a detection result from an external sensor of the driver's vehicle; a neighboring vehicle travel determiner configured to determine, when the neighboring vehicle recognizer recognizes the neighboring vehicle and the driver's vehicle makes a right turn or a left turn at the intersection, whether the neighboring vehicle turns in the same direction as the driver's vehicle at the intersection based on neighboring vehicle information acquired through inter-vehicle communication with the neighboring vehicle or the detection result from the external sensor; and a deceleration assistance executor configured to execute, when the neighboring vehicle travel determiner determines that the neighboring vehicle turns in the same direction as the driver's vehicle, assistance deceleration to bring an inter-vehicle distance between the driver's vehicle and the neighboring vehicle in a travel direction of the driver's vehicle to a distance equal to or greater than a preset target driver's vehicle-to-neighboring vehicle distance.

[0005] According to the first aspect, when it is determined that the driver's vehicle makes a right turn or a left turn at the intersection while the neighboring vehicle turns in the same direction as the driver's vehicle, deceleration is assisted to bring the inter-vehicle distance between the driver's vehicle and the neighboring vehicle in the travel direction of the driver's vehicle to a distance equal to or greater than the target driver's vehicle-to-neighboring vehicle distance. Therefore, compared to a case where deceleration is assisted without considering the neighboring vehicle, discomfort of the driver to the deceleration assistance can be reduced.

[0006] In the first aspect, the driving assist device can include a preceding vehicle recognizer configured to recognize a preceding vehicle traveling ahead of a driver's vehicle based on a detection result from an external sensor, and a large vehicle determiner configured to determine whether the preceding vehicle is a large vehicle based on preceding vehicle information acquired through inter-vehicle communication with the preceding vehicle or the detection result from the external sensor when the preceding vehicle recognizer recognizes the preceding vehicle. A deceleration assist executor can be configured to execute assist deceleration to increase an inter-vehicle distance between the driver's vehicle and the preceding vehicle when the large vehicle determiner determines that the preceding vehicle is a large vehicle, as compared to when the large vehicle determiner does not determine that the preceding vehicle is a large vehicle.

[0007] According to the above-described configuration, when it is determined that the preceding vehicle is a large vehicle while the driver's vehicle is making a right turn or a left turn at an intersection, assist deceleration is executed to increase the inter-vehicle distance between the driver's vehicle and the preceding vehicle in the traveling direction of the driver's vehicle, as compared to when it is not determined that the preceding vehicle is a large vehicle. Therefore, as compared to when assist deceleration is executed without considering whether the preceding vehicle is a large vehicle, it is possible to reduce the discomfort of the driver with respect to the deceleration assist.

[0008] In the first aspect, the driving assist device can include a visibility condition determiner configured to determine whether a visibility deterioration situation occurs around a driver's vehicle based on at least one of an image captured by an external camera of the driver's vehicle, an operation state of a wiper of the driver's vehicle, a high beam illumination state of a headlamp of the driver's vehicle, weather information around the driver's vehicle acquired from a communication network, and traffic-related information around the driver's vehicle acquired from the communication network. A deceleration assist executor can be configured to reduce a target vehicle speed in deceleration assist when the visibility condition determiner determines that the visibility deterioration situation occurs around the driver's vehicle, as compared to when the visibility condition determiner does not determine that the visibility deterioration situation occurs around the driver's vehicle.

[0009] According to the above-described configuration, when the visibility condition determiner determines that the visibility deterioration situation occurs around the driver's vehicle, the driving assist device reduces the target vehicle speed in deceleration assist, as compared to when it is not determined that the visibility deterioration situation occurs around the driver's vehicle. Therefore, as compared to when deceleration assist is executed without considering the visibility deterioration situation, it is possible to reduce the discomfort of the driver with respect to the deceleration assist.

[0010] In the first aspect, the driving assist device can include a pedestrian crossing determiner configured to determine whether a pedestrian crossing exists at a location to be reached after a right turn or a left turn of the driver's vehicle based on at least one of a position of the driver's vehicle on a map and map information, a detection result from an external sensor, and traffic-related information around the driver's vehicle acquired from a communication network. The deceleration assist executor can be configured to lower a target vehicle speed in deceleration assist when the pedestrian crossing determiner determines that the pedestrian crossing exists at the location to be reached after the right turn or the left turn of the driver's vehicle, as compared to a case where the pedestrian crossing determiner does not determine that the pedestrian crossing exists at the location to be reached after the right turn or the left turn of the driver's vehicle.

[0011] According to the above-described configuration, the target vehicle speed in deceleration assist is lowered when the pedestrian crossing determiner determines that the pedestrian crossing exists at the location to be reached after the right turn or the left turn of the driver's vehicle, as compared to a case where the pedestrian crossing determiner does not determine that the pedestrian crossing exists at the location to be reached after the right turn or the left turn of the driver's vehicle. Therefore, the driver's discomfort with deceleration assist can be reduced as compared to a case where the existence of the pedestrian crossing is not taken into account.

[0012] In the first aspect, the driving assist device can include an obstacle determiner configured to determine whether an obstacle exists at a location to be reached after a right turn or a left turn of the driver's vehicle based on at least one of a detection result from an external sensor, surrounding environment information acquired through inter-vehicle communication with other vehicles around the driver's vehicle, and traffic-related information around the driver's vehicle acquired from a communication network. The deceleration assist executor can be configured to lower a target vehicle speed in deceleration assist when the obstacle determiner determines that the obstacle exists at the location to be reached after the right turn or the left turn of the driver's vehicle, as compared to a case where the obstacle determiner does not determine that the obstacle exists at the location to be reached after the right turn or the left turn of the driver's vehicle.

[0013] According to the above-described configuration, the target vehicle speed in deceleration assist is lowered when the obstacle determiner determines that the obstacle exists at the location to be reached after the right turn or the left turn of the driver's vehicle, as compared to a case where the obstacle determiner does not determine that the obstacle exists at the location to be reached after the right turn or the left turn of the driver's vehicle. Therefore, the driver's discomfort with deceleration assist can be reduced as compared to a case where the existence of the obstacle is not taken into account.

[0014] In the first aspect, the driving assistance device can include a driving operation detector configured to detect a driving operation of a driver of a driver's vehicle, and an accelerator operation determiner configured to determine whether an accelerator release timing of the driver at a crossing for a right turn or a left turn is earlier than a first timing threshold, based on a position of the driver's vehicle on a map, map information, and a result of detection of the driving operation of the driver by the driving operation detector. The deceleration assistance executor can be configured to lower a target vehicle speed in the deceleration assistance when the accelerator operation determiner determines that the accelerator release timing is earlier than the first timing threshold, as compared to a case where the accelerator operation determiner does not determine that the accelerator release timing is earlier than the first timing threshold.

[0015] According to the above-described configuration, the target vehicle speed in the deceleration assistance is lowered when the accelerator operation determiner determines that the accelerator release timing is earlier than the first timing threshold, as compared to a case where the accelerator operation determiner does not determine that the accelerator release timing is earlier than the first timing threshold. Therefore, the driver's discomfort with the deceleration assistance can be reduced as compared to a case where the accelerator release timing is not taken into account.

[0016] In the first aspect, the driving assistance device can include a driving operation detector configured to detect at least an operation with respect to a turn signal lamp as a driving operation of a driver of a driver's vehicle, and a turn signal lamp operation determiner configured to determine whether an operation timing of the turn signal lamp of the driver at a crossing for a right turn or a left turn is earlier than a second timing threshold, based on a position of the driver's vehicle on a map, map information, and a result of detection of the operation of the driver with respect to the turn signal lamp by the driving operation detector. The deceleration assistance executor can be configured to lower a target vehicle speed in the deceleration assistance when the turn signal lamp operation determiner determines that the operation timing of the turn signal lamp is earlier than the second timing threshold, as compared to a case where the turn signal lamp operation determiner does not determine that the operation timing of the turn signal lamp is earlier than the second timing threshold.

[0017] According to the above-described configuration, the target vehicle speed in the deceleration assistance is lowered when the turn signal lamp operation determiner determines that the operation timing of the turn signal lamp is earlier than the second timing threshold, as compared to a case where the turn signal lamp operation determiner does not determine that the operation timing of the turn signal lamp is earlier than the second timing threshold. Therefore, the driver's discomfort with the deceleration assistance can be reduced as compared to a case where the operation timing of the turn signal lamp is not taken into account.

[0018] In the first aspect, the adjacent vehicle travel determiner can be configured to determine whether the driver's vehicle is turning outside the adjacent vehicle or inside the adjacent vehicle when the adjacent vehicle travel determiner determines that the adjacent vehicle is turning in the same direction as the driver's vehicle at the intersection, and determine whether the driver's vehicle is expected to pass through the intersection ahead of the adjacent vehicle at a vehicle speed equal to or lower than a preset upper limit target vehicle speed based on a detection result from the external sensor when the adjacent vehicle travel determiner determines that the driver's vehicle is turning outside the adjacent vehicle. The deceleration assistance executor is configured to adjust the target vehicle speed in the deceleration assistance to cause the driver's vehicle to pass through the intersection ahead of the adjacent vehicle when the adjacent vehicle travel determiner determines that the driver's vehicle is expected to pass through the intersection ahead of the adjacent vehicle at a vehicle speed equal to or lower than the upper limit target vehicle speed.

[0019] According to the above-described configuration, the target vehicle speed in the deceleration assistance is adjusted to cause the driver's vehicle to pass through the intersection ahead of the adjacent vehicle when the adjacent vehicle travel determiner determines that the driver's vehicle is turning outside the adjacent vehicle and is expected to pass through the intersection ahead of the adjacent vehicle at a vehicle speed equal to or lower than the upper limit target vehicle speed. Therefore, it is possible to reduce the occurrence of a situation in which the visibility of the driver of the driver's vehicle is obstructed by the adjacent vehicle traveling in front of the driver's vehicle when the driver's vehicle is turning outside the adjacent vehicle.

[0020] According to the first aspect of the present application, it is possible to reduce the discomfort of the driver with the deceleration assistance when right- or left-turning at an intersection. BRIEF DESCRIPTION OF DRAWINGS

[0021] Features, advantages, and technical and industrial significance of exemplary embodiments of the present application will be described below with reference to the accompanying drawings, wherein the same reference numerals denote the same elements, and wherein:

[0022] Figure 1 is a block diagram illustrating a driving assistance device according to a first embodiment;

[0023] Figure 2 is a plan view illustrating a case in which a preceding vehicle is a large vehicle;

[0024] Figure 3 is a plan view illustrating an example of a case in which the driver's vehicle recognizes a preceding vehicle;

[0025] Figure 4 is a plan view illustrating an example of a case in which the preceding vehicle is a large vehicle;

[0026] Figure 5 is a plan view illustrating an example of a case in which the adjacent vehicle is turning in the same direction as the driver's vehicle;

[0027] Figure 6is a plan view showing an example of a situation in which an adjacent vehicle is traveling in a direction different from that of the driver's vehicle;

[0028] Figure 7 is a flowchart showing an example of deceleration assistance execution processing;

[0029] Figure 8 is a flowchart showing a continuation of deceleration assistance execution processing;

[0030] Figure 9 is a block diagram showing a driving assistance device according to a second embodiment;

[0031] Figure 10 is a plan view showing an example of a situation in which the driver's vehicle turns outside of an adjacent vehicle;

[0032] Figure 11 is a plan view showing an example of a situation in which the driver's vehicle turns at a crossing before an adjacent vehicle;

[0033] Figure 12 is a plan view showing an example of a situation in which the driver's vehicle turns inside of an adjacent vehicle;

[0034] Figure 13 is a flowchart showing a continuation of deceleration assistance execution processing according to the second embodiment;

[0035] Figure 14A is a flowchart showing an example of visibility deterioration situation determination processing;

[0036] Figure 14B is a flowchart showing an example of pedestrian crossing determination processing;

[0037] Figure 14C is a flowchart showing an example of obstacle determination processing;

[0038] Figure 15A is a flowchart showing an example of accelerator release determination processing; and

[0039] Figure 15B is a flowchart showing an example of steering signal lamp operation timing determination processing. DETAILED DESCRIPTION

[0040] Embodiments of the present application will be described below with reference to the accompanying drawings.

[0041] First Embodiment

[0042] Figure 1The drive assist device 100 shown in FIG. 1 is mounted on a vehicle (driver's vehicle) such as a passenger car and assists a driver in driving the driver's vehicle. When the driver's vehicle is right-turning or left-turning at an intersection, the drive assist device 100 assists the driver's vehicle in deceleration. The deceleration assist is a drive assist that decelerates the driver's vehicle according to the situation.

[0043] Configuration of the drive assist device of the first embodiment

[0044] The configuration of the drive assist device 100 will be described below with reference to the drawings. As shown in FIG. 1, the drive assist device 100 includes a drive assist electronic control unit (ECU) 10 that centrally manages the device. The drive assist ECU 10 is an electronic control unit that includes a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), and the like. The drive assist ECU 10 realizes various functions by, for example, the CPU executing a program stored in the ROM. The drive assist ECU 10 can be constituted by a plurality of electronic units. Figure 1

[0045] The drive assist ECU 10 is connected to a global positioning system (GPS) receiver 1, an external sensor 2, an internal sensor 3, a drive operation detector (drive operation detecting unit) 4, a map database 5, and an actuator 6.

[0046] The GPS receiver 1 measures the position of the driver's vehicle (e.g., the latitude and longitude of the driver's vehicle) by receiving signals from three or more GPS satellites. The GPS receiver 1 transmits information about the measured position of the driver's vehicle to the ECU 10. A global navigation satellite system (GNSS) receiver can be used instead of the GPS receiver 1.

[0047] The external sensor 2 is a detection device that detects the situation around the driver's 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 images the situation outside the driver's vehicle. For example, the external camera is disposed on the back side of the windshield of the driver's vehicle and images the scenery in front of the driver's vehicle. The external camera transmits imaging information about the situation outside the driver's vehicle to the drive assist ECU 10. The external camera can be a monocular camera or a stereo camera.

[0048] The radar sensor is a detection device that detects an object around the driver's vehicle by using radio waves (e.g., millimeter waves) or light. Examples of the radar sensor include a millimeter wave radar and a light detection and ranging (LIDAR) sensor. The radar sensor detects an object by transmitting radio waves or light to the surrounding environment of the driver's vehicle and receiving radio waves or light reflected by the object. The radar sensor transmits information about the detected object to the drive assist ECU 10.​

[0049] The internal sensor 3 is a detection device that detects a running state of the driver's 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 a speed of the driver's vehicle. Examples of the vehicle speed sensor include a wheel speed sensor that is provided on each wheel of the driver's vehicle or a drive shaft that rotates together with the wheel and detects a rotational speed of the wheel. The vehicle speed sensor transmits information about the detected vehicle speed (wheel speed) to the driving assistance ECU 10.

[0050] The acceleration sensor is a detector that detects an acceleration of the driver's vehicle. The acceleration sensor includes, for example, a longitudinal acceleration sensor that detects an acceleration in a front-rear direction of the driver's vehicle and a lateral acceleration sensor that detects a lateral acceleration of the driver's vehicle. The acceleration sensor transmits information about the acceleration of the driver's vehicle to the driving assistance ECU 10, for example. The yaw rate sensor is a detector that detects a yaw rate (rotational angular velocity) with respect to a vertical axis of the driver's vehicle. Examples of the yaw rate sensor include a gyro sensor. The yaw rate sensor transmits information about the detected yaw rate of the driver's vehicle to the driving assistance ECU 10.

[0051] The driving operation detector 4 is a detection device that detects a driving operation of the driver's vehicle by the driver. The driving operation detector 4 includes an accelerator pedal sensor or a turn signal lamp sensor. The driving operation detector 4 can include both the accelerator pedal sensor and the turn signal lamp sensor, or a steering sensor, a brake pedal sensor, or a shift lever sensor.

[0052] The accelerator pedal sensor is provided on a shaft of the accelerator pedal, for example, and detects a depression force or a depression amount (position of the accelerator pedal) of the accelerator pedal by the driver. The turn signal lamp sensor detects an operation (on / off operation) of the turn signal lamp by the driver. The turn signal lamp sensor can be provided on an operation lever of the turn signal lamp, for example.

[0053] The brake pedal sensor is provided on a shaft of the brake pedal, for example, and detects a depression force or a depression amount (position of the brake pedal) of the brake pedal by the driver. The steering sensor is provided on a steering shaft of the driver's vehicle, for example, and detects a steering torque applied to a steering wheel by the driver. The shift lever sensor detects a shift position of the transmission.

[0054] The map database 5 stores map information. The map database 5 is built in a storage device such as a hard disk drive (HDD) mounted on the driver's vehicle. The map information can include road position information, road shape information (e.g., types of curves, straight portions, curvatures of curves), position information of intersections and branch points, position information of buildings, and the like. The map information can include information on traffic regulations such as a legal speed associated with the position information. The map database 5 can be built in a server capable of communicating with the driver's vehicle.

[0055] The actuator 6 is a device for controlling the driver's vehicle. The actuator 6 includes at least a drive actuator and a brake actuator. The actuator 6 can include a steering actuator. The drive actuator controls a driving force of the driver's vehicle by controlling an amount of air to be supplied to an engine (throttle opening degree) in response to a control signal from the drive assist ECU 10. When the driver's vehicle is a hybrid electric vehicle, the driving force is controlled by inputting the control signal from the drive assist ECU 10 to a motor serving as a power source in addition to controlling the amount of air to be supplied to the engine. When the driver's vehicle is a battery electric vehicle, the driving force is controlled by inputting the control signal from the drive assist ECU 10 to the motor serving as the power source. In such a case, the motor serving as the power source constitutes the actuator 6.

[0056] The brake actuator controls a braking force applied to a wheel of the driver's vehicle by controlling a brake system in response to a control signal from the drive assist ECU 10. Examples of the brake system include a hydraulic brake system. The steering actuator controls a driving of an assist motor that controls a steering torque in an electric power steering system in response to a control signal from the drive assist ECU 10. Thus, the steering actuator controls a steering torque of the driver's vehicle.

[0057] The communicator 7 acquires various types of information via a communication network (e.g., the Internet or a vehicle information and communication system (VICS) (registered trademark)). The communicator 7 acquires traffic-related information by communicating with a computer of a facility such as an information management center that manages traffic information. The traffic-related information includes information on a construction section on a road, information on an accident on a road, information on a road condition due to snow, and the like. The communicator 7 can acquire road information by road-to-vehicle communication with a roadside transceiver (e.g., an optical beacon or an intelligent transportation system (ITS) point) provided on a roadside. The communicator 7 can have an inter-vehicle communication function.

[0058] Next, the functional configuration of the drive assist ECU 10 will be described. As Figure 1As shown in the figure, the drive assist ECU 10 includes a crossroad right / left turn determiner 11, a neighboring vehicle recognizer (neighboring vehicle recognition unit) 12, a neighboring vehicle travel determiner (neighboring vehicle travel determination unit) 13, a preceding vehicle recognizer (preceding vehicle recognition unit) 14, a large vehicle determiner (large vehicle determination unit) 15, and a deceleration assist executor (deceleration assist execution unit) 16. The functions of the drive assist ECU 10 described below can be partially executed in a server that can communicate with the driver's vehicle.

[0059] The crossroad right / left turn determiner 11 recognizes (detects) a crossroad in front of the driver's vehicle. The crossroad right / left turn determiner 11 recognizes the crossroad in front of the driver's vehicle based on, for example, position information of the driver's vehicle measured by the GPS receiver 1 and map information in the map database 5.

[0060] The crossroad right / left turn determiner 11 can recognize the position of the driver's vehicle by simultaneous localization and mapping (SLAM) technology using not only the position information of the driver's vehicle measured by the GPS receiver 1 but also the position information of a building (landmark) such as a utility pole in the map information in the map database 5 and the detection result of the building by the external sensor 2. The crossroad right / left turn determiner 11 can recognize the crossroad in front of the driver's vehicle by the position information of the crossroad acquired from the communication network via the communicator 7.

[0061] When the crossroad in front of the driver's vehicle is recognized, the crossroad right / left turn determiner 11 determines whether the driver's vehicle is right-turning or left-turning at the crossroad. The crossroad right / left turn determiner 11 determines whether the driver's vehicle is right-turning or left-turning at the crossroad based on the driving operation of the driver detected by the driving operation detector 4. The driving operation includes, for example, the operation (on / off operation) of the turn signal lamp. The driving operation can include the steering by the driver, the accelerator release of the release of the accelerator pedal by the driver, the brake operation of the depression of the brake pedal by the driver, or the downshift operation.

[0062] When the driver's vehicle is moving rightward or leftward by the steering of the driver while approaching the crossroad, the crossroad right / left turn determiner 11 can determine that the driver's vehicle is right-turning or left-turning at the crossroad. When the driver's vehicle is moving to the right side of the lane or to the left side of the lane while approaching the crossroad, the crossroad right / left turn determiner 11 can determine that the driver's vehicle is right-turning or left-turning at the crossroad based on the accelerator release, the brake operation, or the downshift operation. The crossroad right / left turn determiner 11 recognizes which of the right turn and the left turn is made at the crossroad based on the operation of the turn signal lamp or the steering of the driver.

[0063] The adjacent vehicle recognizer 12 recognizes an adjacent vehicle traveling on an adjacent lane adjacent to the travel lane of the driver's vehicle on the basis of the detection result from the external sensor 2. For example, the adjacent vehicle recognizer 12 recognizes another vehicle traveling in the same direction as the driver's vehicle on the side of the driver's vehicle within a preset adjacent vehicle recognition range with respect to the driver's vehicle as an adjacent vehicle.

[0064] The adjacent vehicle recognition range is set to a rectangular range with respect to the center of the front end of the driver's vehicle, for example. The adjacent vehicle recognition range can be set to a range of a predetermined lateral distance and a predetermined front-rear distance with respect to the center of the front end of the driver's vehicle. The adjacent vehicle recognition range need not be a rectangular range, but can be a range having an elliptical or other shape. The adjacent vehicle recognition range can be set with respect to the center in a plan view or an arbitrary position in the driver's vehicle.

[0065] The adjacent vehicle recognizer 12 can determine the adjacent lane adjacent to the travel lane of the driver's vehicle by using the position information of the driver's vehicle and the map information. The adjacent vehicle recognizer 12 combines the detection results from the external sensor 2 to recognize another vehicle traveling on the adjacent lane as an adjacent vehicle.

[0066] Figure 2 is a plan view showing that an adjacent vehicle is recognized. Figure 2 The intersection T shown in FIG. 1 is an intersection at which a road having three lanes RA1 to RA3 on one side and a road having two lanes RB1 and RB2 on one side cross each other. The remaining lanes on the road having two lanes are denoted by RC1 and RC2.

[0067] Figure 2 The driver's vehicle M, another vehicle N1, and another vehicle (two-wheeled vehicle) N2 are shown. The driver's vehicle M is traveling on the middle lane RA1 (travel lane RA1) among the three lanes. The other vehicle N1 is a four-wheeled vehicle traveling on the lane RA2 (adjacent lane RA2) adjacent to the right side of the lane RA1 slightly ahead of the driver's vehicle M. The other vehicle N2 is a two-wheeled vehicle traveling on the lane RA3 (adjacent lane RA3) adjacent to the left side of the lane RA1 behind the driver's vehicle M. Figure 2 The adjacent vehicle recognition range D of the driver's vehicle M is also shown.

[0068] In Figure 2In the scenario shown, the adjacent vehicle identifier 12 will identify another vehicle N1 traveling in lane RA2 and partially included in the adjacent vehicle identification range D of the driver vehicle M as an adjacent vehicle. The adjacent vehicle identifier 12 will not identify another vehicle N2 that is not included in the adjacent vehicle identification range D as an adjacent vehicle. The adjacent vehicle identifier 12 does not necessarily need to use the adjacent vehicle identification range to identify adjacent vehicles. Various methods can be used to identify adjacent vehicles.

[0069] When the adjacent vehicle identifier 12 identifies an adjacent vehicle and the driver's vehicle turns right or left at the intersection, the adjacent vehicle driving determiner 13 determines whether the adjacent vehicle is turning in the same direction as the driver's vehicle at the intersection. The adjacent vehicle driving determiner 13 determines whether the adjacent vehicle is turning in the same direction as the driver's vehicle based on adjacent vehicle information obtained through inter-vehicle communication with the adjacent vehicle or detection results from external sensor 2.

[0070] Adjacent vehicle information is information related to adjacent vehicles obtained through vehicle-to-vehicle communication. Adjacent vehicle information includes at least one of the following: steering performed by the driver of the adjacent vehicle, the yaw rate of the adjacent vehicle, the illumination status of the turn signals, and navigation information (information related to the driving route guided by the navigation system). The adjacent vehicle driving determiner 13 determines whether the adjacent vehicle is turning in the same direction as the driver's vehicle based on adjacent vehicle information, such as the illumination status of the adjacent vehicle's turn signals.

[0071] The adjacent vehicle driving determiner 13 can determine whether an adjacent vehicle is turning in the same direction as the driver's vehicle based on detection results from the external sensor 2. The adjacent vehicle driving determiner 13 can determine whether an adjacent vehicle is turning in the same direction as the driver's vehicle, for example, by identifying the illumination of the adjacent vehicle's turn signal lights from an image captured by an external camera. The adjacent vehicle driving determiner 13 can also determine whether an adjacent vehicle is turning in the same direction as the driver's vehicle based on changes in the direction or position of the adjacent vehicle detected by a radar sensor.

[0072] exist Figure 2 In the scenario shown, the adjacent vehicle driving determiner 13 determines, for example, that the adjacent vehicle N1 is turning in the same direction (to the right) as the driver vehicle M by identifying the illumination of the right turn signal light of the adjacent vehicle N1 from an image captured by an external camera of the driver vehicle M. Figure 2 In the scenario shown, it is anticipated that driver vehicle M will turn right from lane RA1 to lane RB1, and it is anticipated that adjacent vehicle N1 will turn right from lane RA2 to lane RB2.

[0073] The preceding vehicle recognizer 14 recognizes a preceding vehicle traveling ahead of the driver's vehicle on the basis of the detection result from the external sensor 2. The preceding vehicle recognizer 14 recognizes the preceding vehicle through image recognition processing, for example, from an image captured by the external camera and showing a scene ahead of the driver's vehicle. The preceding vehicle recognizer 14 can recognize the preceding vehicle located ahead of the driver's vehicle on the basis of the detection result from the radar sensor. The preceding vehicle recognizer 14 recognizes the inter-vehicle distance between the driver's vehicle and the preceding vehicle from the image captured by the external camera and showing the scene ahead of the driver's vehicle or the detection result from the radar sensor.

[0074] Figure 3 is a plan view showing an example of a situation in which the preceding vehicle is recognized. Figure 3 The preceding vehicle N6 traveling on the same lane RA1 (traveling lane RA1) as the lane of the driver's vehicle M and the inter-vehicle distance L6 between the driver's vehicle M and the preceding vehicle N6 are shown. In the situation shown in Figure 3 In the situation shown in, the preceding vehicle recognizer 14 recognizes the preceding vehicle N6 and the inter-vehicle distance L6 between the driver's vehicle M and the preceding vehicle N6 on the basis of the detection result from the external sensor 2.

[0075] When the preceding vehicle recognizer 14 recognizes the preceding vehicle, the large vehicle determiner 15 determines whether the preceding vehicle is a large vehicle on the basis of the preceding vehicle information acquired through inter-vehicle communication or the detection result from the external sensor 2. The large vehicle is a vehicle such as a large truck. The large vehicle can be defined according to the type of vehicle in accordance with laws and regulations, or can be defined in terms of size.

[0076] The preceding vehicle information is information about the preceding vehicle acquired through inter-vehicle communication. It is assumed that 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 determiner 15 determines that the preceding vehicle is a large vehicle, for example, by recognizing the type of vehicle on the basis of the preceding vehicle information.

[0077] The large vehicle determiner 15 can recognize the type of the vehicle by detecting information about the license plate of the preceding vehicle from an image captured by the external camera, and determine that the preceding vehicle is a large vehicle. The large vehicle determiner 15 can estimate the area of the back of the preceding vehicle based on an image captured by the external camera or a detection result from the radar sensor, and determine that the preceding vehicle is a large vehicle when the area of the back is equal to or greater than a predetermined threshold. The large vehicle determiner 15 can 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, rather than the area of the back being equal to or greater than a predetermined threshold. The large vehicle determiner 15 can determine that the preceding vehicle is a large vehicle by machine learning from an image captured by the external camera or a detection result from the radar sensor.

[0078] Figure 4 is a plan view showing an example of a case where the preceding vehicle is a large vehicle. Figure 4 A large vehicle N7 traveling in the same lane RA1 as the driver's vehicle M, and an inter-vehicle distance L7 between the driver's vehicle M and the large vehicle N7 are shown. In the case shown in Figure 4 In the case shown in FIG. 1, the large vehicle determiner 15 recognizes the type of the vehicle by detecting information about the license plate of the preceding vehicle from an image captured by the external camera, for example, and determines that the preceding vehicle is a large vehicle.

[0079] The deceleration assistance executor 16 assists the driver's vehicle in deceleration when the intersection right / left turn determiner 11 determines that the driver's vehicle makes a right turn or a left turn at an intersection. The deceleration assistance executor 16 sends a control signal to the actuator 6, and drives the brake actuator or the like to implement deceleration assistance. For example, the deceleration assistance executor 16 assists deceleration so that the vehicle speed of the driver's vehicle reaches a target vehicle speed. As the target vehicle speed, a preset value can be used according to the situation of the right turn or the left turn at the intersection, or the value can be changed according to the inter-vehicle distance between the driver's vehicle and the preceding vehicle. In addition to the target vehicle speed, the deceleration assistance executor 16 can change the details of the deceleration assistance by adjusting each parameter such as a target deceleration, a target jerk, and a deceleration assistance start time.

[0080] The deceleration assistance executor 16 changes the details of the deceleration assistance according to various situations such as the presence or absence of other vehicles in the vicinity. First, the change in the details of the deceleration assistance according to adjacent vehicles will be described.

[0081] Specifically, when it is determined that the driver's vehicle is making a right turn or a left turn at the intersection and the adjacent vehicle turning determination device 13 determines that the adjacent vehicle is making a turn in the same direction as the driver's vehicle, the deceleration assistance executor 16 assists deceleration so that the inter-vehicle distance between the driver's vehicle and the adjacent vehicle in the travel direction of the driver's vehicle reaches a distance equal to or greater than the target driver's vehicle-to-adjacent vehicle distance. The deceleration assistance executor 16 assists deceleration so that the inter-vehicle distance between the driver's vehicle and the adjacent vehicle reaches a distance equal to or greater than the target driver's vehicle-to-adjacent vehicle distance, by using the vehicle speed and the position of the adjacent vehicle acquired on the basis of the detection result from the external sensor 2. The position of the adjacent vehicle can be the relative position of the adjacent vehicle to the driver's vehicle. The vehicle speed of the adjacent vehicle can be the relative vehicle speed of the adjacent vehicle to the driver's vehicle.

[0082] The inter-vehicle distance between the driver's vehicle and the adjacent vehicle in the travel direction of the driver's vehicle is, for example, the inter-vehicle distance between the driver's vehicle and the adjacent vehicle projected onto the travel course of the driver's vehicle during a right turn or a left turn at the intersection. The inter-vehicle distance between the driver's vehicle and the adjacent vehicle in the travel direction of the driver's vehicle can be the inter-vehicle distance between the driver's vehicle and the adjacent vehicle projected onto the longitudinal axis of the driver's vehicle with respect to the driver's vehicle.

[0083] The target driver's vehicle-to-adjacent vehicle distance is a target inter-vehicle distance set so that the driver of the driver's vehicle does not feel discomfort with respect to the deceleration assistance related to the adjacent vehicle when the adjacent vehicle makes a turn in the same direction as the driver's vehicle at the intersection. The target driver's vehicle-to-adjacent vehicle distance can be a preset value.

[0084] The target driver's vehicle-to-adjacent vehicle distance can be a different value depending on whether the driver's vehicle makes a turn at the intersection before the adjacent vehicle or the adjacent vehicle makes a turn at the intersection before the driver's vehicle. The target driver's vehicle-to-adjacent vehicle distance can be a different value depending on whether the driver's vehicle makes a right turn or a left turn. The target driver's vehicle-to-adjacent vehicle distance can be a different value depending on whether the driver's vehicle makes a turn on the outside of the adjacent vehicle or makes a turn on the inside of the adjacent vehicle. The target driver's vehicle-to-adjacent vehicle distance can be set to a different value depending on the vehicle speed of the driver's vehicle and the vehicle speed of the adjacent vehicle.

[0085] The deceleration assistance executor 16 can assist deceleration so that the inter-vehicle distance between the preceding adjacent vehicle and the driver's vehicle reaches a distance equal to or greater than the target driver's vehicle-to-adjacent vehicle distance, or so that the inter-vehicle distance between the driver's vehicle and the adjacent vehicle reaches a distance equal to or greater than the target driver's vehicle-to-adjacent vehicle distance. It is only necessary to appropriately ensure the inter-vehicle distance between the driver's vehicle and the adjacent vehicle. The front-rear relationship between the driver's vehicle and the adjacent vehicle is not limited.

[0086] Figure 5 is a plan view showing an example of a situation in which an adjacent vehicle turns in the same direction as the direction of the driver's vehicle. In Figure 5 , the driver's vehicle M and the adjacent vehicle N1 are about to turn right at the intersection T and proceed to the lanes RB1 and RB2, respectively. Figure 5 The running route C of the driver's vehicle M and the inter-vehicle distance LI between the driver's vehicle M and the adjacent vehicle N1 in the running direction of the driver's vehicle M are shown. The inter-vehicle distance LI between the driver's vehicle M and the adjacent vehicle N1 in the running direction of the driver's vehicle M is, for example, the inter-vehicle distance between the driver's vehicle M and the adjacent vehicle N1 projected onto the running route C of the driver's vehicle M (the inter-vehicle distance along the running route C of the driver's vehicle M).

[0087] In Figure 5 the situation shown, it is determined that the driver's vehicle M turns right at the intersection T, and the adjacent vehicle running determiner 13 determines that the adjacent vehicle N1 turns in the same direction as the direction of the driver's vehicle M. Therefore, the deceleration assistance executor 16 assists deceleration so that the inter-vehicle distance LI between the driver's vehicle M and the adjacent vehicle N1 in the running direction of the driver's vehicle M reaches a distance equal to or greater than the target driver's vehicle-to-adjacent vehicle distance.

[0088] Figure 6 is a plan view showing an example of a situation in which an adjacent vehicle turns in the same direction as the direction of the driver's vehicle. In Figure 6 , the running route C of the driver's vehicle M and the inter-vehicle distance LI between the driver's vehicle M and the adjacent vehicle N1 in the running direction of the driver's vehicle M are shown. The inter-vehicle distance LI between the driver's vehicle M and the adjacent vehicle N1 in the running direction of the driver's vehicle M is, for example, the inter-vehicle distance between the driver's vehicle M and the adjacent vehicle N1 projected onto the running route C of the driver's vehicle M (the inter-vehicle distance along the running route C of the driver's vehicle M). Figure 6 In the situation shown, the adjacent vehicle N3 does not turn in the same direction as the direction of the driver's vehicle M. Therefore, the deceleration assistance executor 16 does not need to assist deceleration so that the inter-vehicle distance L3 to the adjacent vehicle N3 reaches a distance equal to or greater than the target driver's vehicle-to-adjacent vehicle distance. The deceleration assistance executor 16 can assist deceleration caused by a right turn or a left turn of the driver's vehicle M.

[0089] Next, the details of the change in deceleration assistance depending on the preceding vehicle will be described. When it is determined that the driver's vehicle turns right or left at an intersection and the preceding vehicle recognizer 14 recognizes a preceding vehicle running ahead of the driver's vehicle, the deceleration assistance executor 16 assists deceleration so that the inter-vehicle distance between the driver's vehicle and the preceding vehicle reaches a distance equal to or greater than the target driver's vehicle-to-adjacent vehicle distance.

[0090] The target driver vehicle-to-vehicle distance is a target vehicle-to-vehicle distance set so that the driver of the driver vehicle does not have a feeling of discomfort with respect to the preceding vehicle. As described later, the target driver vehicle-to-vehicle distance includes a target driver vehicle-to-vehicle distance for a normal-type vehicle and a target driver vehicle-to-vehicle distance for a large-type vehicle. The target driver vehicle-to-vehicle distance for a large-type vehicle is greater than the target driver vehicle-to-vehicle distance for a normal-type vehicle.

[0091] When the large vehicle determiner 15 determines that the preceding vehicle is a large-type vehicle, the deceleration assistance executor 16 assists deceleration to increase the vehicle-to-vehicle distance between the driver vehicle and the preceding vehicle in the travel direction of the driver vehicle, as compared to a case where it is not determined that the preceding vehicle is a large-type vehicle.

[0092] Specifically, the deceleration assistance executor 16 assists deceleration so that the vehicle-to-vehicle distance between the driver vehicle and the preceding vehicle reaches a distance equal to or greater than the target driver vehicle-to-vehicle distance for a normal-type vehicle (see Figure 3 ). When the large vehicle determiner 15 determines that the preceding vehicle is a large-type vehicle, the deceleration assistance executor 16 assists deceleration so that the vehicle-to-vehicle distance between the driver vehicle and the preceding vehicle reaches a distance equal to or greater than the target driver vehicle-to-vehicle distance for a large-type vehicle (see Figure 4 ).

[0093] Control of the driving assistance device of the first embodiment

[0094] Next, the control (process) of the driving assistance device 100 according to the first embodiment will be described with reference to the drawings. Figure 7 is a flowchart showing an example of the deceleration assistance execution process. Figure 8 is a flowchart showing a continuation of the deceleration assistance execution process. For example, when the driving assistance of the driver vehicle is on, the deceleration assistance execution process shown in Figure 7 and Figure 8 is executed.

[0095] As shown in Figure 7 , in S10, the driving assistance ECU 10 of the driving assistance device 100 causes the intersection right turn / left turn determiner 11 to recognize an intersection ahead of the driver vehicle. The intersection right turn / left turn determiner 11 recognizes the intersection ahead of the driver vehicle based on, for example, position information of the driver vehicle measured by the GPS receiver 1 and map information in the map database 5.

[0096] In Sll, the drive assist ECU 10 causes the preceding vehicle recognizer 14 to recognize a preceding vehicle in front of the driver's vehicle. The preceding vehicle recognizer 14 recognizes a preceding vehicle traveling in front of the driver's vehicle on the basis of a detection result from the external sensor 2. When a preceding vehicle is recognized (Sll: YES), the drive assist ECU 10 proceeds to S12. When a preceding vehicle is not recognized (Sll: NO), the drive assist ECU 10 proceeds to S15.

[0097] In S12, the drive assist ECU 10 causes the large vehicle determiner 15 to determine whether the preceding vehicle is a large vehicle. The large vehicle determiner 15 determines whether the preceding vehicle is a large vehicle on the basis of preceding vehicle information acquired through inter-vehicle communication with the preceding vehicle or a detection result from the external sensor 2. When it is determined that the preceding vehicle is a large vehicle (S12: YES), the drive assist ECU 10 proceeds to S13. When it is not determined that the preceding vehicle is a large vehicle (S12: NO), the drive assist ECU 10 proceeds to S14.

[0098] In S13, the drive assist ECU 10 sets a target driver's vehicle-to-preceding vehicle distance for a large vehicle as a target inter-vehicle distance for deceleration assist. Then, the drive assist ECU 10 proceeds to S15.

[0099] In S14, the drive assist ECU 10 sets a target driver's vehicle-to-preceding vehicle distance for a normal vehicle as a target inter-vehicle distance for deceleration assist. The target driver's vehicle-to-preceding vehicle distance for a normal vehicle is a target inter-vehicle distance smaller than the target driver's vehicle-to-preceding vehicle distance for a large vehicle. Then, the drive assist ECU 10 proceeds to S15.

[0100] In S15, the drive assist ECU 10 causes the adjacent vehicle recognizer 12 to recognize an adjacent vehicle. For example, the adjacent vehicle recognizer 12 recognizes another vehicle traveling in the same direction as the driver's vehicle on one side of the driver's vehicle within a predetermined adjacent vehicle recognition range with respect to the driver's vehicle as an adjacent vehicle. When an adjacent vehicle is recognized (S15: YES), the drive assist ECU 10 proceeds to S18. When an adjacent vehicle is not recognized (S15: NO), the drive assist ECU 10 proceeds to S16.

[0101] In S16, the drive assist ECU 10 causes the intersection right / left turn determiner 11 to determine whether the driver's vehicle is right turning or left turning at the intersection. The intersection right / left turn determiner 11 determines whether the driver's vehicle is right turning or left turning at the intersection based on the driver's driving operation detected by the driving operation detector 4. The intersection right / left turn determiner 11 identifies which one of right turning and left turning the driver's vehicle is making at the intersection. When it is determined that the driver's vehicle is right turning or left turning at the intersection (S16: YES), the drive assist ECU 10 proceeds to S17. When it is not determined that the driver's vehicle is right turning or left turning at the intersection (S16: NO), the drive assist ECU 10 terminates the current deceleration assist execution processing. Then, after a predetermined period elapses, the drive assist ECU 10 repeats the processing starting from S10.

[0102] In S17, the drive assist ECU 10 causes the deceleration assist executor 16 to assist deceleration. The deceleration assist executor 16 sends a control signal to the actuator 6 to assist deceleration of the driver's vehicle right turning or left turning at the intersection. When the target driver's vehicle-to-lead vehicle distance for the normal-type vehicle or the target driver's vehicle-to-lead vehicle distance for the large-type vehicle is set, the deceleration assist executor 16 assists deceleration to bring the inter-vehicle distance between the lead vehicle and the driver's vehicle to a distance equal to or greater than the set target driver's vehicle-to-lead vehicle distance. Then, the drive assist ECU 10 terminates the current deceleration assist execution processing. After a predetermined period elapses, the drive assist ECU 10 repeats the processing starting from S10.

[0103] In S18, the drive assist ECU 10 causes the deceleration assist executor 16 to set the details of deceleration assist for the case where the adjacent vehicle is right turning or left turning in the same direction as the driver's vehicle. Assuming that the driver's vehicle is right turning or left turning at the intersection and the adjacent vehicle is right turning or left turning in the same direction as the driver's vehicle, the deceleration assist executor 16 sets the details of deceleration assist based on the position and vehicle speed of the adjacent vehicle detected by the external sensor 2. The details of deceleration assist include the target vehicle speed of deceleration assist and the target driver's vehicle-to-adjacent vehicle distance. When the target driver's vehicle-to-lead vehicle distance for the normal-type vehicle or the target driver's vehicle-to-lead vehicle distance for the large-type vehicle is set, the details of deceleration assist include the target driver's vehicle-to-lead vehicle distance for the normal-type vehicle or the target driver's vehicle-to-lead vehicle distance for the large-type vehicle.

[0104] By presetting the details of deceleration assist in this way, the drive assist ECU 10 can easily start deceleration assist immediately after determining right turning or left turning of the driver's vehicle and right turning or left turning of the adjacent vehicle in the same direction. Then, the drive assist ECU 10 proceeds to Figure 8S19 shown in FIG. 6.

[0105] In Figure 8 In S19, the intersection right / left turn determiner 11 is caused by the drive assist ECU 10 to determine whether the driver's vehicle is right turning or left turning at the intersection. The determination process of S19 is the same as the determination process of S16. Figure 7 When it is determined that the driver's vehicle is right turning or left turning at the intersection (S19: YES), the drive assist ECU 10 proceeds to S20. When it is not determined that the driver's vehicle is right turning or left turning at the intersection (S19: NO), the drive assist ECU 10 terminates the current deceleration assist execution process. Then, after a predetermined period elapses, the drive assist ECU 10 repeats the process starting from S10.

[0106] In S20, the adjacent vehicle traveling determiner 13 is caused by the drive assist ECU 10 to determine whether the adjacent vehicle is turning in the same direction as the direction of the driver's vehicle. The adjacent vehicle traveling determiner 13 determines whether the adjacent vehicle is turning in the same direction as the direction of the driver's vehicle based on the adjacent vehicle information acquired through the inter-vehicle communication with the adjacent vehicle or the detection result from the external sensor 2. When it is determined that the adjacent vehicle is turning in the same direction as the direction of the driver's vehicle (S20: YES), the drive assist ECU 10 proceeds to S21. When it is not determined that the adjacent vehicle is turning in the same direction as the direction of the driver's vehicle (S20: NO), the drive assist ECU 10 proceeds to S22.

[0107] In S21, the deceleration assist executor 16 is caused by the drive assist ECU 10 to assist deceleration so that the inter-vehicle distance between the driver's vehicle and the adjacent vehicle in the direction of travel of the driver's vehicle reaches a distance equal to or greater than the target driver's vehicle-to-adjacent vehicle distance. For example, the deceleration assist executor 16 implements the details of the deceleration assist set in S18 to assist deceleration so that the inter-vehicle distance between the driver's vehicle and the adjacent vehicle reaches a distance equal to or greater than the target driver's vehicle-to-adjacent vehicle distance. When the vehicle speed of the adjacent vehicle suddenly changes, the deceleration assist executor 16 can calculate the details of the deceleration assist based on, for example, the current vehicle speed of the adjacent vehicle. Then, the drive assist ECU 10 terminates the current deceleration assist execution process. After a predetermined period elapses, the drive assist ECU 10 repeats the process starting from S10.

[0108] In S22, the drive assist ECU 10 assists deceleration by the deceleration assist actuator 16. When the target driver-vehicle-to-lead-vehicle distance for a normal vehicle or the target driver-vehicle-to-lead-vehicle distance for a large vehicle is set, the deceleration is assisted so that the inter-vehicle distance between the lead vehicle and the driver vehicle becomes a distance equal to or greater than the set target driver-vehicle-to-lead-vehicle distance. Then, the drive assist ECU 10 terminates the current deceleration assist execution process.

[0109] After a predetermined period of time elapses, the drive assist ECU 10 repeats the process starting from S10.

[0110] The deceleration assist execution process is not limited to the details described above. For example, the determinations of Sll and S12 can be made after determining that the driver vehicle is making a right turn or a left turn at the intersection. The same applies to the determination regarding the adjacent vehicle in S15. It is not always necessary to preset the details of the deceleration assist in S18. The details of the deceleration assist can be determined after determining that the adjacent vehicle is turning in the same direction as the driver vehicle.

[0111] According to the drive assist device 100 of the first embodiment described above, when it is determined that the adjacent vehicle is turning in the same direction as the driver vehicle while the driver vehicle is making a right turn or a left turn at the intersection, the deceleration is assisted so that the inter-vehicle distance between the driver vehicle and the adjacent vehicle in the direction of travel of the driver vehicle becomes a distance equal to or greater than the target inter-vehicle distance. Thus, compared to a case where the deceleration is assisted without taking the adjacent vehicle into account, it is possible to reduce the discomfort of the driver to the deceleration assist.

[0112] According to the drive assist device 100, compared to a case where the lead vehicle is not determined to be a large vehicle, when the lead vehicle is determined to be a large vehicle while the driver vehicle is making a right turn or a left turn at the intersection, the deceleration is assisted to increase the inter-vehicle distance between the driver vehicle and the lead vehicle in the direction of travel of the driver vehicle. Thus, compared to a case where the deceleration assist is performed without taking into account whether the lead vehicle is a large vehicle, it is possible to reduce the discomfort of the driver to the deceleration assist.

[0113] Second Embodiment

[0114] Next, a drive assist device according to a second embodiment will be described. Components that are the same as or correspond to those in the first embodiment are denoted by the same reference numerals, and repetitive description will be omitted.

[0115] Configuration of the drive assist device of the second embodiment

[0116] Figure 9 is a block diagram illustrating a drive assist device according to the second embodiment. According to the second embodiment, the drive assist device 100 is configured to determine whether the adjacent vehicle is turning in the same direction as the driver vehicle while the driver vehicle is making a right turn or a left turn at the intersection. When it is determined that the adjacent vehicle is turning in the same direction as the driver vehicle while the driver vehicle is making a right turn or a left turn at the intersection, the deceleration is assisted so that the inter-vehicle distance between the driver vehicle and the adjacent vehicle in the direction of travel of the driver vehicle becomes a distance equal to or greater than the target inter-vehicle distance. Figure 9The driving assistance ECU 20 of the driving assistance device 200 of the second embodiment shown in FIG. 2 differs from the driving assistance ECU according to the first embodiment in that the adjacent vehicle traveling determiner (adjacent vehicle traveling determination unit) 21 and the deceleration assistance executor (deceleration assistance execution unit) 27 have additional functions, and the driving assistance ECU 20 includes a visibility condition determiner (visibility condition determination unit) 22, a pedestrian crossing determiner (pedestrian crossing determination unit) 23, an obstacle determiner (obstacle determination unit) 24, an accelerator operation determiner (accelerator operation determination unit) 25, and a turn signal lamp operation determiner (turn signal lamp operation determination unit) 26.

[0117] When it is determined that the adjacent vehicle is turning in the same direction as the direction of the driver's vehicle, the adjacent vehicle traveling determiner 21 determines whether the driver's vehicle is turning on the outside of the adjacent vehicle or on the inside of the adjacent vehicle. The adjacent vehicle traveling determiner 21 makes the above determination based on the detection results from the external sensor 2.

[0118] Figure 10 is a plan view showing an example of a situation in which the driver's vehicle turns on the outside of the adjacent vehicle. Figure 11 is a plan view showing a situation in which the driver's vehicle turns at a crossing before the adjacent vehicle. As Figure 10 and Figure 11 When the driver's vehicle M and the adjacent vehicle N4 turn right at the crossing T, as shown in FIG. 2, the driver's vehicle M traveling on the lane RA1 (traveling lane RA1) on the left side of the lane RA2 (adjacent lane RA2) on which the adjacent vehicle N4 travels turns on the outside of the adjacent vehicle N4. Therefore, in the situation shown in FIG. 2, the adjacent vehicle traveling determiner 21 determines that the driver's vehicle M turns on the outside of the adjacent vehicle N4. Figure 10

[0119] When it is determined that the driver's vehicle turns on the outside of the adjacent vehicle, the adjacent vehicle traveling determiner 21 determines whether the driver's vehicle is expected to pass through the crossing before the adjacent vehicle at a vehicle speed equal to or lower than an upper limit target vehicle speed. The upper limit target vehicle speed is preset in accordance with the purpose of the deceleration assistance during right or left turns at the crossing. The adjacent vehicle traveling determiner 21 makes the above determination by using the relative position and the relative vehicle speed of the driver's vehicle and the adjacent vehicle based on the detection results from the external sensor 2.

[0120] ​When the driver's vehicle is traveling at a speed equal to or lower than the upper limit target vehicle speed in front of the adjacent vehicle and the inter-vehicle distance between the driver's vehicle and the adjacent vehicle can be maintained at a distance equal to or greater than the target driver's vehicle-to-adjacent vehicle distance, the adjacent vehicle travel determiner 21 can determine that the driver's vehicle is expected to pass through the intersection ahead of the adjacent vehicle at a speed equal to or lower than the upper limit target vehicle speed. Alternatively, when the driver's vehicle is able to travel in front of the adjacent vehicle at a speed equal to or lower than the upper limit target vehicle speed, the adjacent vehicle travel determiner 21 can determine that the driver's vehicle is expected to pass through the intersection ahead of the adjacent vehicle at a speed equal to or lower than the upper limit target vehicle speed despite the inter-vehicle distance being less than the target driver's vehicle-to-adjacent vehicle distance.

[0121] Figure 12 is a plan view showing an example of a case where the driver's vehicle turns inside the adjacent vehicle. In Figure 12 , the lane RA3 (traveling lane RA3) in which the driver's vehicle M is traveling is located to the left of the lane RA1 (adjacent lane RA1) in which the adjacent vehicle N4 is traveling.

[0122] In Figure 12 , when the driver's vehicle M and the adjacent vehicle N4 make a left turn at the intersection T, the driver's vehicle M traveling on the lane RA3 located to the left of the lane RA1 in which the adjacent vehicle N4 is traveling turns inside the adjacent vehicle N4. Thus, in Figure 12 , the adjacent vehicle travel determiner 21 determines that the driver's vehicle M turns inside the adjacent vehicle N4.

[0123] The visibility condition determiner 22 determines whether a visibility deterioration case occurs around the driver's vehicle. The visibility condition determiner 22 makes the above determination based on at least one of an image captured by an external camera of the driver's vehicle, a wiper operation state of the driver's vehicle, a high beam illumination state of a headlamp of the driver's vehicle, weather information around the driver's vehicle acquired from a communication network, and traffic-related information around the driver's vehicle acquired from the communication network.

[0124] The visibility deterioration case is a case where the level of visibility of the driver decreases. The visibility deterioration case includes at least one of a severe weather condition such as rain, snow, or a typhoon, a poor view due to the shape of the intersection, a backlight condition due to sunset or road reflection, and a dark condition due to nighttime or a shadow of a building structure.

[0125] The adverse weather condition can be determined based on at least one of an image captured by an external camera of the driver's vehicle, an operation state of a wiper of the driver's vehicle, and weather information around the driver's vehicle acquired from a communication network. The poor visibility condition can be determined based on an image captured by an external camera of the driver's vehicle or traffic-related information around the driver's vehicle acquired from a communication network. The poor visibility condition can be determined by using position information of the driver's vehicle and map information. The backlight condition can be determined based on an image captured by an external camera of the driver's vehicle. The darkness condition can be determined based on an image captured by an external camera of the driver's vehicle or a high beam lighting state of a headlamp of the driver's vehicle.

[0126] The pedestrian crossing determiner 23 determines whether a pedestrian crossing exists at a place to be reached after the right turn or the left turn of the driver's vehicle. The pedestrian crossing determiner 23 makes the above determination based on at least one of the position of the driver's vehicle on a map and map information in the map database 5, a detection result from the external sensor 2, and traffic-related information around the driver's vehicle acquired from a communication network. The external sensor identifies a pedestrian crossing at a place to be reached after the right turn or the left turn by, for example, using image recognition of an external camera. In this case, the traffic-related information includes information about elements such as a pedestrian crossing at an intersection and a traffic signal.

[0127] The obstacle determiner 24 determines whether an obstacle exists at a place to be reached after the right turn or the left turn of the driver's vehicle. The obstacle determiner 24 makes the above determination based on at least one of a detection result from the external sensor 2, surrounding environment information acquired by inter-vehicle communication with other vehicles around the driver's vehicle, and traffic-related information around the driver's vehicle acquired from a communication network. Examples of the obstacle include a stationary vehicle (including a vehicle temporarily stopped due to traffic congestion), a parked vehicle, a pedestrian, and a bicycle on a road to be reached after the right turn or the left turn.

[0128] The surrounding environment information acquired by the inter-vehicle communication with other vehicles around the driver's vehicle is, for example, image information around a preceding vehicle ahead of the driver's vehicle acquired from the preceding vehicle and obtained from an external camera of the preceding vehicle. The obstacle determiner 24 can directly acquire information about an obstacle identified by the preceding vehicle or the like as the surrounding environment information acquired by the inter-vehicle communication. In this case, the traffic-related information includes image information obtained by an intersection imaging camera that images an intersection from above. Various other methods can be employed to identify an obstacle.

[0129] The accelerator operation determiner 25 determines whether or not the accelerator release timing of the right turn or the left turn of the driver at the intersection is earlier than a first timing threshold. The accelerator operation determiner 25 makes the above determination based on the position of the driver's vehicle on the map, the map information in the map database 5, and the detection result of the driving operation of the driver by the driving operation detector 4.

[0130] The accelerator release timing is the timing at which the driver releases the accelerator pedal before the right turn or the left turn at the intersection. The accelerator operation determiner 25 determines the accelerator release timing based on the remaining arrival period required for the driver's vehicle to reach the intersection or the arrival distance of the driver's vehicle to the intersection. The remaining arrival period can be identified as the time to collision (TTC) for the intersection.

[0131] The first timing threshold is a preset threshold. For example, the first timing threshold can be the timing at which a statistically average driver releases the accelerator pedal at the intersection for the right turn or the left turn. The first timing threshold can be a different value depending on whether the driver's vehicle is right turning or left turning.

[0132] The turn signal operation determiner 26 determines whether or not the turn signal operation timing of the right turn or the left turn of the driver at the intersection is earlier than a second timing threshold. The turn signal operation determiner 26 makes the above determination based on the position of the driver's vehicle on the map, the map information in the map database 5, and the detection result of the turn signal operation of the driver by the driving operation detector 4.

[0133] The turn signal operation timing is the timing at which the driver operates the turn signal before the right turn or the left turn at the intersection. The turn signal operation determiner 26 determines the turn signal operation timing based on the remaining arrival period required for the driver's vehicle to reach the intersection or the arrival distance of the driver's vehicle to the intersection.

[0134] The second timing threshold is a preset threshold. For example, the second timing threshold can be the timing at which a statistically average driver operates the turn signal at the intersection for the right turn or the left turn. The second timing threshold can be a different value depending on whether the driver's vehicle is right turning or left turning.

[0135] When the adjacent vehicle travel determiner 21 determines that the driver's vehicle is expected to pass through the intersection prior to the adjacent vehicle at a vehicle speed equal to or lower than the upper limit target vehicle speed, the deceleration assist executor 27 adjusts the target vehicle speed in the deceleration assist so that the driver's vehicle passes through the intersection prior to the adjacent vehicle. Specifically, the deceleration assist executor 27 assists deceleration by adjusting the target vehicle speed in the deceleration assist so that the driver's vehicle M passes through the intersection prior to the adjacent vehicle N4 in the situation shown in Figure 10 Figure 11 ​The deceleration assistance executor 27 assists deceleration so that the inter-vehicle distance L4 between the driver's vehicle M and the adjacent vehicle N4 reaches a distance equal to or greater than the target driver's vehicle-to-adjacent vehicle distance, as shown in FIG. 6. The deceleration assistance executor 27 can give priority to the front travel of the driver's vehicle M over the target driver's vehicle-to-adjacent vehicle distance. That is, even if the inter-vehicle distance L4 between the driver's vehicle M and the adjacent vehicle N4 is less than the target driver's vehicle-to-adjacent vehicle distance, the deceleration assistance executor 27 can give priority to the driver's vehicle M to turn in front of the adjacent vehicle N4.

[0136] The deceleration assistance executor 27 can give priority to the front travel of the driver's vehicle over the target driver's vehicle-to-adjacent vehicle distance. That is, even if the inter-vehicle distance L4 between the driver's vehicle M and the adjacent vehicle N4 is less than the target driver's vehicle-to-adjacent vehicle distance, the deceleration assistance executor 27 can give priority to the driver's vehicle M to turn in front of the adjacent vehicle N4. Figure 11

[0137] When the accelerator operation of the driver is detected, the deceleration assistance executor 27 can adjust the target inter-vehicle distance of the deceleration assistance while giving priority to the front travel of the driver's vehicle over the target driver's vehicle-to-adjacent vehicle distance. When the accelerator operation of the driver is not detected, the deceleration assistance executor 27 can give priority to the case where the inter-vehicle distance between the driver's vehicle and the adjacent vehicle reaches a distance equal to or greater than the target driver's vehicle-to-adjacent vehicle distance while the adjacent vehicle travels in front of the driver's vehicle. The deceleration assistance executor 27 can give priority to the front travel of the driver's vehicle over the adjustment of the target vehicle speed in various situations to be described later.

[0138] As shown in FIG. 6, when the adjacent vehicle travel determiner 21 determines that the driver's vehicle M turns inside the adjacent vehicle N4, the driver's vehicle M does not need to travel in front of the adjacent vehicle N4 because the front travel of the adjacent vehicle N4 does not obstruct the visibility of the driver of the driver's vehicle M in the travel direction. Therefore, the deceleration assistance executor 27 assists deceleration so that the inter-vehicle distance between the driver's vehicle M and the adjacent vehicle N4 reaches a distance equal to or greater than the target driver's vehicle-to-adjacent vehicle distance. Figure 12

[0139] When the visibility condition determiner 22 determines that the visibility deterioration situation occurs around the driver's vehicle, the deceleration assistance executor 27 lowers the target vehicle speed in the deceleration assistance, as compared to the case where it is not determined that the visibility deterioration situation occurs around the driver's vehicle. The deceleration assistance executor 27 lowers the target vehicle speed by a predetermined fixed amount or at a predetermined fixed rate. The deceleration assistance executor 27 can change the lowering amount or the lowering rate of the target vehicle speed depending on the type of the visibility deterioration situation.

[0140] When the pedestrian crossing determiner 23 determines that the pedestrian crossing exists at the location to be reached after the right turn or the left turn of the driver's vehicle, the deceleration assistance executor 27 lowers the target vehicle speed in the deceleration assistance, as compared to the case where it is not determined that the pedestrian crossing exists at the location to be reached after the right turn or the left turn of the driver's vehicle. The deceleration assistance executor 27 lowers the target vehicle speed by a predetermined fixed amount or at a predetermined fixed rate.​​

[0141] When the obstacle determiner 24 determines that there is an obstacle at the location to be reached after the driver's vehicle turns right or left, the deceleration assist execution part 27 lowers the target vehicle speed in the deceleration assist, compared to the case where it is not determined that there is an obstacle at the location to be reached after the driver's vehicle turns right or left. The deceleration assist execution part 27 lowers the target vehicle speed by a preset fixed amount or at a preset fixed rate. The deceleration assist execution part 27 can change the amount of lowering or the rate of lowering of the target vehicle speed depending on the type of the obstacle.

[0142] When the accelerator operation determiner 25 determines that the accelerator release timing of the driver at the intersection for right or left turn is earlier than the first timing threshold, the deceleration assist execution part 27 lowers the target vehicle speed in the deceleration assist, compared to the case where it is not determined that the accelerator release timing of the driver is earlier than the first timing threshold. The deceleration assist execution part 27 lowers the target vehicle speed by a preset fixed amount or at a preset fixed rate. The deceleration assist execution part 27 can gradually lower the target vehicle speed by setting a plurality of thresholds.

[0143] When the turn signal operation determiner 26 determines that the turn signal operation timing of the driver at the intersection for right or left turn is earlier than the second timing threshold, the deceleration assist execution part 27 lowers the target vehicle speed in the deceleration assist, compared to the case where it is not determined that the turn signal operation timing of the driver is earlier than the second timing threshold. The deceleration assist execution part 27 lowers the target vehicle speed by a preset fixed amount or at a preset fixed rate. The deceleration assist execution part 27 can gradually lower the target vehicle speed by setting a plurality of thresholds. The deceleration assist execution part 27 does not lower the target vehicle speed to a value equal to or lower than a preset lower limit target vehicle speed.

[0144] When the deceleration assist execution part 27 can lower the target vehicle speed in the deceleration assist when right or left turning from a road with a small number of lanes to a road with a large number of lanes, compared to the case where right or left turning is made from a road with a large number of lanes to a road with a small number of lanes based on the shape of the intersection. The deceleration assist execution part 27 can change the target driver vehicle-to-leading vehicle distance and / or the target driver vehicle-to-adjacent vehicle distance to a larger value, instead of lowering the target vehicle speed as described above.

[0145] Control of the driving assist device of the second embodiment

[0146] Next, the control (process) of the driving assist device 200 according to the second embodiment will be described with reference to the drawings. Figure 13 is a flowchart showing the continuation of the deceleration assist execution process according to the second embodiment. Figure 13 The flowchart shown in is another example of the flowchart of Figure 7 is the continuation of the flowchart of

[0147] InFigure 13 In S30, the drive assist ECU 20 of the drive assist device 200 causes the intersection right / left turn determiner 11 to determine whether the driver's vehicle is right turning or left turning at the intersection. When it is determined that the driver's vehicle is right turning or left turning at the intersection (S30: YES), the drive assist ECU 20 proceeds to S31. When it is not determined that the driver's vehicle is right turning or left turning at the intersection (S30: NO), the drive assist ECU 20 terminates the current deceleration assist execution processing. Then, after a predetermined period elapses, the drive assist ECU 20 repeats the processing starting from S10 Figure 7 ) again.

[0148] In S31, the drive assist ECU 20 causes the adjacent vehicle traveling determiner 21 to determine whether the adjacent vehicle is turning in the same direction as the direction of the driver's vehicle. When it is determined that the adjacent vehicle is turning in the same direction as the direction of the driver's vehicle (S31: YES), the drive assist ECU 20 proceeds to S33. When it is not determined that the adjacent vehicle is turning in the same direction as the direction of the driver's vehicle (S31: NO), the drive assist ECU 20 proceeds to S32.

[0149] In S32, the drive assist ECU 20 causes the deceleration assist executor 27 to assist deceleration. When the target driver's vehicle-to-lead vehicle distance for a normal-type vehicle or the target driver's vehicle-to-lead vehicle distance for a large-type vehicle is set, deceleration is assisted so that the inter-vehicle distance between the lead vehicle and the driver's vehicle reaches a distance equal to or greater than the set target driver's vehicle-to-lead vehicle distance. Then, the drive assist ECU 20 terminates the current deceleration assist execution processing. After a predetermined period elapses, the drive assist ECU 20 repeats the processing starting from S10.

[0150] In S33, the drive assist ECU 20 causes the adjacent vehicle traveling determiner 21 to determine whether the driver's vehicle is turning outside the adjacent vehicle or turning inside the adjacent vehicle. The adjacent vehicle traveling determiner 21 makes the above determination based on the detection result from the external sensor 2. When it is determined that the driver's vehicle is turning outside the adjacent vehicle (S33: YES), the drive assist ECU 20 proceeds to S34. When it is not determined that the driver's vehicle is turning outside the adjacent vehicle (S33: NO), the drive assist ECU 20 proceeds to S35.

[0151] In S34, the driver assistance ECU 20 instructs the adjacent vehicle driving determiner 21 to determine whether the driver's vehicle is expected to pass through the intersection before the adjacent vehicle at a speed equal to or lower than the upper limit target speed. The adjacent vehicle driving determiner 21 makes this determination based on the detection results from the external sensor 2, using the relative position and relative speed of the driver's vehicle and the adjacent vehicle. When it is determined that the driver's vehicle is expected to pass through the intersection before the adjacent vehicle at a speed equal to or lower than the upper limit target speed (S34: Yes), the driver assistance ECU 20 proceeds to S36. When it is not determined that the driver's vehicle is expected to pass through the intersection before the adjacent vehicle at a speed equal to or lower than the upper limit target speed (S34: No), the driver assistance ECU 20 proceeds to S35.

[0152] In S35, the driver assistance ECU 20 causes the deceleration assist actuator 27 to assist in deceleration, so that the inter-vehicle distance between the driver's vehicle and the adjacent vehicle reaches a distance equal to or greater than the target distance between the driver's vehicle and the adjacent vehicle. In this case, either the driver's vehicle or the adjacent vehicle may be traveling ahead. Then, the driver assistance ECU 20 terminates the current deceleration assist execution process. After a predetermined period of time, the driver assistance ECU 20 repeats the process that started from S10.

[0153] In S36, the driver assistance ECU 20 activates the deceleration assist actuator 27 to assist in deceleration, so that the inter-vehicle distance between the advancing driver vehicle and the adjacent vehicle reaches a distance equal to or greater than the distance between the target driver vehicle and the adjacent vehicle. The deceleration assist actuator 27 prioritizes the forward movement of the driver vehicle over the situation where the inter-vehicle distance is equal to or greater than the distance between the target driver vehicle and the adjacent vehicle. Then, the driver assistance ECU 20 terminates the current deceleration assist execution process. After a predetermined period of time, the driver assistance ECU 20 repeats the process that began in S10.

[0154] Figure 14A This is a flowchart illustrating an example of the process for determining when visibility is impaired. For instance, when it is determined that a driver's vehicle is turning right or left at an intersection, the following steps are executed: Figure 14A The visibility degradation situation shown is handled in the diagram.

[0155] like Figure 14A As shown, the driver assistance ECU 20 causes the visibility condition determiner 22 to determine in S40 whether a situation of deteriorated visibility has occurred around the driver's vehicle. When it is determined that a situation of deteriorated visibility has occurred around the driver's vehicle (S40: Yes), the driver assistance ECU 20 proceeds to S41. When it is not determined that a situation of deteriorated visibility has occurred around the driver's vehicle (S40: No), the driver assistance ECU 20 terminates the current processing.

[0156] In S41, the deceleration assistance executor 27 is caused by the drive assist ECU 20 to lower the target vehicle speed in the deceleration assistance. For example, the deceleration assistance executor 27 lowers the target vehicle speed by a preset fixed amount or at a preset fixed rate.

[0157] Figure 14B is a flowchart illustrating an example of the pedestrian crossing determination process. For example, when it is determined that the driver's vehicle is to make a right turn or a left turn at an intersection, the pedestrian crossing determination process illustrated in Figure 14B is executed.

[0158] As illustrated in Figure 14B , the drive assist ECU 20 causes the pedestrian crossing determiner 23 to determine in S50 whether or not there is a pedestrian crossing at a location to be reached after the driver's vehicle makes a right turn or a left turn. When it is determined that there is a pedestrian crossing at the location to be reached after the driver's vehicle makes a right turn or a left turn (S50: YES), the drive assist ECU 20 proceeds to S51. When it is not determined that there is a pedestrian crossing at the location to be reached after the driver's vehicle makes a right turn or a left turn (S50: NO), the drive assist ECU 20 terminates the current process.

[0159] In S51, the deceleration assistance executor 27 is caused by the drive assist ECU 20 to lower the target vehicle speed in the deceleration assistance. For example, the deceleration assistance executor 27 lowers the target vehicle speed by a preset fixed amount or at a preset fixed rate.

[0160] Figure 14C is a flowchart illustrating an example of the obstacle determination process. For example, when it is determined that the driver's vehicle is to make a right turn or a left turn at an intersection, the obstacle determination process illustrated in Figure 14C is executed.

[0161] As illustrated in Figure 14C , the drive assist ECU 20 causes the obstacle determiner 24 to determine in S60 whether or not there is an obstacle at a location to be reached after the driver's vehicle makes a right turn or a left turn. When it is determined that there is an obstacle at the location to be reached after the driver's vehicle makes a right turn or a left turn (S60: YES), the drive assist ECU 20 proceeds to S61. When it is not determined that there is an obstacle at the location to be reached after the driver's vehicle makes a right turn or a left turn (S60: NO), the drive assist ECU 20 terminates the current process.

[0162] In S61, the deceleration assistance executor 27 is caused by the drive assist ECU 20 to lower the target vehicle speed in the deceleration assistance. For example, the deceleration assistance executor 27 lowers the target vehicle speed by a preset fixed amount or at a preset fixed rate.

[0163] Figure 15Ais a flowchart showing an example of the accelerator release determination process. For example, when it is determined that the driver turns right or left at the intersection, the Figure 15A accelerator release determination process shown in

[0164] As shown in Figure 15A , the drive assist ECU 20 causes the accelerator operation determiner 25 to determine whether or not the accelerator release timing of the driver is earlier than the first timing threshold in S70. When it is determined that the accelerator release timing of the driver is earlier than the first timing threshold (S70: YES), the drive assist ECU 20 proceeds to S71. When it is not determined that the accelerator release timing of the driver is earlier than the first timing threshold (S70: NO), the drive assist ECU 20 terminates the current process.

[0165] In S71, the drive assist ECU 20 causes the deceleration assist executor 27 to lower the target vehicle speed in the deceleration assist. For example, the deceleration assist executor 27 lowers the target vehicle speed by a preset fixed amount or at a preset fixed rate.

[0166] Figure 15B is a flowchart showing an example of the turn signal lamp operation timing determination process. For example, when it is determined that the driver turns right or left at the intersection, the Figure 15B turn signal lamp operation timing determination process shown in

[0167] As shown in Figure 15B , the drive assist ECU 20 causes the turn signal lamp operation determiner 26 to determine whether or not the turn signal lamp operation timing of the driver is earlier than the second timing threshold in S80. When it is determined that the turn signal lamp operation timing of the driver is earlier than the second timing threshold (S80: YES), the drive assist ECU 20 proceeds to S81. When it is not determined that the turn signal lamp operation timing of the driver is earlier than the second timing threshold (S80: NO), the drive assist ECU 20 terminates the current process.

[0168] In S81, the drive assist ECU 20 causes the deceleration assist executor 27 to lower the target vehicle speed in the deceleration assist. For example, the deceleration assist executor 27 lowers the target vehicle speed by a preset fixed amount or at a preset fixed rate.

[0169] According to the drive assist apparatus 200 of the above-described second embodiment, when the adjacent vehicle traveling determiner 21 determines that the driver vehicle turns on the outside of the adjacent vehicle and that the driver vehicle is expected to pass the intersection earlier than the adjacent vehicle at a vehicle speed equal to or lower than the upper limit target vehicle speed, the target vehicle speed in the deceleration assist is adjusted so that the driver vehicle passes the intersection earlier than the adjacent vehicle. Thus, it is possible to reduce the occurrence of a situation in which the front of the adjacent vehicle obstructs the driver's view when the driver vehicle turns on the outside of the adjacent vehicle.

[0170] According to the driving assist device 200, when the visibility condition determiner 22 determines that the visibility deterioration situation occurs around the driver's vehicle, the target vehicle speed in the deceleration assist is reduced, as compared with the case where it is not determined that the visibility deterioration situation occurs around the driver's vehicle. Therefore, as compared with the case where the visibility deterioration situation is not taken into consideration, it is possible to reduce the driver's discomfort with the deceleration assist.

[0171] According to the driving assist device 200, when the pedestrian crossing determiner 23 determines that the pedestrian crossing exists at the location to be reached after the right turn or the left turn of the driver's vehicle, the target vehicle speed in the deceleration assist is reduced, as compared with the case where it is not determined that the pedestrian crossing exists at the location to be reached after the right turn or the left turn of the driver's vehicle. Therefore, as compared with the case where the existence of the pedestrian crossing is not taken into consideration, it is possible to reduce the driver's discomfort with the deceleration assist.

[0172] According to the driving assist device 200, when the obstacle determiner 24 determines that the obstacle exists at the location to be reached after the right turn or the left turn of the driver's vehicle, the target vehicle speed in the deceleration assist is reduced, as compared with the case where it is not determined that the obstacle exists at the location to be reached after the right turn or the left turn of the driver's vehicle. Therefore, as compared with the case where the existence of the obstacle is not taken into consideration, it is possible to reduce the driver's discomfort with the deceleration assist.

[0173] According to the driving assist device 200, when the accelerator operation determiner 25 determines that the accelerator release timing is earlier than the first timing threshold, the target vehicle speed in the deceleration assist is reduced, as compared with the case where it is not determined that the accelerator release timing is earlier than the first timing threshold. Therefore, as compared with the case where the accelerator release timing is not taken into consideration, it is possible to reduce the driver's discomfort with the deceleration assist.

[0174] According to the driving assist device 200, when the turn signal operation determiner 26 determines that the turn signal operation timing is earlier than the second timing threshold, the target vehicle speed in the deceleration assist is reduced, as compared with the case where it is not determined that the turn signal operation timing is earlier than the second timing threshold. Therefore, as compared with the case where the turn signal operation timing is not taken into consideration, it is possible to reduce the driver's discomfort with the deceleration assist.

[0175] Although the embodiments of the present application have been described above, the present application is not limited to the above-described embodiments. The present application can be implemented in various forms having various changes and improvements based on the knowledge of those skilled in the art, including the above-described embodiments.

[0176] The driving assist devices 100 and 200 do not necessarily determine whether the preceding vehicle is a large vehicle. The driving assist devices 100 and 200 can assist deceleration by using the same target driver-vehicle-to-preceding-vehicle distance regardless of the size of the preceding vehicle. The driving assist devices 100 and 200 do not necessarily assist deceleration in consideration of the presence of the preceding vehicle. In this case, the driving assist ECUs 10 and 20 do not necessarily have the preceding vehicle recognizer 14 and the large vehicle determiner 15.

[0177] The driving assist device 200 does not necessarily have the visibility condition determiner 22, the pedestrian crossing determiner 23, the obstacle determiner 24, the accelerator operation determiner 25, and the turn signal lamp operation determiner 26. The driving assist device 200 can have or not have any of the visibility condition determiner 22, the pedestrian crossing determiner 23, the obstacle determiner 24, the accelerator operation determiner 25, and the turn signal lamp operation determiner 26.

Claims

1. A driving assist device configured to perform deceleration assist for a driver's vehicle when the driver's vehicle makes a right turn or a left turn at an intersection, characterized by, The driving assist device includes: an adjacent vehicle recognizer configured to recognize an adjacent vehicle traveling on an adjacent lane adjacent to a travel lane of the driver's vehicle, based on a detection result from an external sensor of the driver's vehicle; an adjacent vehicle travel determiner configured to determine whether the adjacent vehicle turns at the intersection in the same direction as the driver's vehicle, based on adjacent vehicle information acquired through inter-vehicle communication with the adjacent vehicle or a detection result from the external sensor, when the adjacent vehicle recognizer recognizes the adjacent vehicle and the driver's vehicle makes a right turn or a left turn at the intersection; and a deceleration assist executor configured to execute the deceleration assist to bring an inter-vehicle distance between the driver's vehicle and the adjacent vehicle in a travel direction of the driver's vehicle to a distance equal to or greater than a preset target driver's vehicle and adjacent vehicle inter-distance, when the adjacent vehicle travel determiner determines that the adjacent vehicle turns in the same direction as the driver's vehicle; a driving operation detector configured to detect a driving operation of a driver of the driver's vehicle, and at least detect an operation of a turn signal lamp as the driving operation of the driver of the driver's vehicle; and an accelerator operation determiner configured to determine whether an accelerator release timing of the driver at the intersection for a right turn or a left turn is earlier than a first timing threshold, based on a position of the driver's vehicle on a map, map information, and a detection result of the driving operation of the driver by the driving operation detector; a turn signal lamp operation determiner configured to determine a turn signal lamp operation timing based on a remaining arrival period until the driver's vehicle reaches the intersection or an arrival distance of the driver's vehicle to the intersection, and determine whether the turn signal lamp operation timing of the driver at the intersection for a right turn or a left turn is earlier than a second timing threshold, based on the position of the driver's vehicle on the map, the map information, and the detection result of the operation of the driver with respect to the turn signal lamp by the driving operation detector, wherein the deceleration assist executor is configured to lower a target vehicle speed in the deceleration assist when the accelerator operation determiner determines that the accelerator release timing is earlier than the first timing threshold, as compared to a case where the accelerator operation determiner does not determine that the accelerator release timing is earlier than the first timing threshold, and lower the target vehicle speed in the deceleration assist when the turn signal lamp operation determiner determines that the turn signal lamp operation timing is earlier than the second timing threshold, as compared to a case where the turn signal lamp operation determiner does not determine that the turn signal lamp operation timing is earlier than the second timing threshold; the adjacent vehicle travel determiner is configured to: when the adjacent vehicle travel determiner determines that the adjacent vehicle turns at the intersection in the same direction as the host vehicle, determining whether the host vehicle turns outside of the adjacent vehicle or inside of the adjacent vehicle, and when the adjacent vehicle travel determiner determines that the host vehicle turns outside of the adjacent vehicle, determining, based on the detection result from the external sensor, whether the host vehicle is expected to pass through the intersection ahead of the adjacent vehicle at a vehicle speed equal to or lower than an upper limit target vehicle speed set in advance; and the deceleration assistance implementer is configured to adjust the target vehicle speed in the deceleration assistance so that the host vehicle passes through the intersection ahead of the adjacent vehicle when the adjacent vehicle travel determiner determines that the host vehicle is expected to pass through the intersection ahead of the adjacent vehicle at a vehicle speed equal to or lower than the upper limit target vehicle speed.

2. The driving assist apparatus according to claim 1, characterized by Further comprising: a preceding vehicle recognizer configured to recognize a preceding vehicle traveling ahead of the host vehicle based on a detection result from the external sensor; and a large vehicle determiner configured to determine, when the preceding vehicle recognizer recognizes the preceding vehicle, whether the preceding vehicle is a large vehicle based on preceding vehicle information acquired through inter-vehicle communication with the preceding vehicle or a detection result from the external sensor, wherein the deceleration assistance implementer is configured to implement the deceleration assistance to increase an inter-vehicle distance between the host vehicle and the preceding vehicle when the large vehicle determiner determines that the preceding vehicle is a large vehicle, as compared to when the large vehicle determiner does not determine that the preceding vehicle is a large vehicle.

3. The drive assist apparatus according to claim 1 or 2, characterized by Further comprising: a visibility condition determiner configured to determine whether a visibility deterioration situation occurs around the host vehicle based on at least one of an image captured by an external camera of the host vehicle, a wiper operation state of the host vehicle, a high beam lighting state of a headlamp 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 the communication network, wherein the deceleration assistance implementer is configured to lower the target vehicle speed in the deceleration assistance when the visibility condition determiner determines that the visibility deterioration situation occurs around the host vehicle, as compared to when the visibility condition determiner does not determine that the visibility deterioration situation occurs around the host vehicle.

4. The drive assist apparatus according to claim 1 or 2, characterized by Further comprising: a pedestrian crossing determiner configured to determine whether a pedestrian crossing exists at a location to be reached after a right turn or a left turn of the host vehicle based on at least one of a position of the host vehicle on a map and map information, a detection result from the external sensor, and traffic-related information around the host vehicle acquired from a communication network, wherein the deceleration assistance implementer is configured to implement the deceleration assistance to increase an inter-vehicle distance between the host vehicle and the preceding vehicle when the pedestrian crossing determiner determines that the pedestrian crossing exists at the location to be reached after the right turn or the left turn of the host vehicle, as compared to when the pedestrian crossing determiner does not determine that the pedestrian crossing exists at the location to be reached after the right turn or the left turn of the host vehicle. The deceleration assistance executor is configured to lower a target vehicle speed in the deceleration assistance when the pedestrian crossing determiner determines that the pedestrian crossing exists at a location to be reached after the driver's vehicle turns right or left, as compared to a case where the pedestrian crossing determiner does not determine that the pedestrian crossing exists at the location to be reached after the driver's vehicle turns right or left.

5. The drive assist apparatus according to claim 1 or 2, characterized by Further included are: an obstacle determiner configured to determine whether an obstacle exists at a location to be reached after the driver's vehicle turns right or left, based on at least one of a detection result from the external sensor, surrounding environment information acquired through inter-vehicle communication with other vehicles around the driver's vehicle, and traffic-related information around the driver's vehicle acquired from a communication network, wherein the deceleration assistance executor is configured to lower a target vehicle speed in the deceleration assistance when the obstacle determiner determines that the obstacle exists at the location to be reached after the driver's vehicle turns right or left, as compared to a case where the obstacle determiner does not determine that the obstacle exists at the location to be reached after the driver's vehicle turns right or left.

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