Travel assistance method and travel assistance device for a vehicle

Abstract

According to the present application, there is provided a travel assistance method and a travel assistance device (19) for a vehicle, in which, after a first lane change by autonomous lane change control using autonomous travel control, in the case where a second lane change is performed in order to travel along a set travel path, it is determined whether a distance (D1) from a position at which the first lane change ends to a position at which the second lane change can be started is equal to or less than a predetermined distance, when it is determined that the distance (D1) is equal to or less than the predetermined distance, it is determined whether assistance based on autonomous lane change control is effective for the second lane change, when it is determined that the assistance based on autonomous lane change control is effective, it is determined whether a lane change from a lane in which the vehicle is traveling to an adjacent lane adjacent to the lane can be performed, when it is determined that the lane change from the lane to the adjacent lane can be performed, the second lane change is performed by autonomous lane change control, when it is determined that the lane change from the lane to the adjacent lane cannot be performed, the driver is notified of a situation in which the lane change based on autonomous lane change control cannot be performed, and when it is determined that the assistance based on autonomous lane change control is not effective, the driver is notified of a situation in which the lane change based on autonomous lane change control cannot be performed.

Description

TECHNICAL FIELD

[0001] The present application relates to a travel assistance method and a travel assistance device for a vehicle. BACKGROUND

[0002] There is known a device that determines a travel route using road network information corresponding to road map data, stores a restriction level that restricts a lane change, and the like, in correspondence with each lane of a road and a position on the lane, acquires a travel position of a vehicle, and based on the acquired travel position of the vehicle, prompts lane change information for traveling along the travel route in accordance with the restriction level in the travel route to assist the lane change (Patent Literature 1).

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Japanese Patent Application Publication No. 2021-76614

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] However, in the above-described prior art, there is no description of the relationship between whether the lane change using autonomous travel control can be performed and the information prompted to the driver. Therefore, in the above-described prior art, there is a problem that it is not known what information to notify to the driver depending on whether the lane change using autonomous travel control can be performed. SUMMARY

[0008] The present application relates to a travel assistance method and a travel assistance device for a vehicle.

[0009] The present application solves the above-described problem by the following processing: in a case where autonomous lane change control is performed based on a travel route up to a destination, in a scenario where a second lane change is performed after a first lane change in which the autonomous lane change control is performed in order to travel along the travel route, when assistance by the autonomous lane change control is not effective, as a rule, the second lane change based on the autonomous lane change control is not performed, and the driver is not notified of a situation where the lane change based on the autonomous lane change control cannot be performed, and even when the assistance by the autonomous lane change control is not effective, when it is determined that a distance from a position at which the first lane change ends to a position at which the second lane change can be started is equal to or less than a predetermined distance, as an exception to the rule, the second lane change based on the autonomous lane change control is not performed, and the driver is notified of the situation where the lane change based on the autonomous lane change control cannot be performed.

[0010] EFFECT OF THE INVENTION

[0011] According to the present invention, appropriate information can be notified to the driver depending on whether a lane change using autonomous driving control is possible. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a block diagram showing a driving assistance system including the driving assistance device of the present invention.

[0013] Figure 2 Yes Figure 1 A front view of a portion of an input device.

[0014] Figure 3 is a plan view showing lane changes based on autonomous lane change control.

[0015] Figure 4 It is a plan view showing a lane change to an adjacent lane based on overtaking assist control.

[0016] Figure 5 This is a plan view showing a lane change to the original driving lane based on autonomous lane change control.

[0017] Figure 6 This is a plan view showing lane changes based on lane-keeping assist control.

[0018] Figure 7 Yes Figure 1 Block diagram of the state transition of the driving assistance device.

[0019] Figure 8 Yes Figure 1 A flowchart showing an example of the information processing procedure of the driving assistance system.

[0020] Figure 9 Is to use Figure 1 The illustrated plan view is an example of a driving scene in which the driving assistance system performs autonomous driving control.

[0021] Figure 10 Yes Figure 8 Flowchart of an example of the subroutine of step S20 in FIG. DETAILED DESCRIPTION

[0022] The following describes an embodiment of the present invention with reference to the accompanying drawings. The following description assumes that vehicles are traveling on the left side of the road in countries with left-hand traffic laws. In countries with right-hand traffic laws, vehicles are traveling on the right side of the road. Therefore, the following description is symmetrical and interchangeable.

[0023] (Structure of driving assistance system)

[0024] Figure 1is a block diagram showing a travel assist system 1 of the present application. The travel assist system 1 of the present embodiment is a vehicle-mounted system which can be used not only for a private car that travels to a destination set by an occupant of the vehicle (hereinafter, also simply referred to as "vehicle") by autonomous travel control, but also for a vehicle dispatched in a vehicle dispatch service, for example. The vehicle dispatch service refers to a service in which a vehicle that transports a user from a boarding place to an alighting place is allocated to the user, and examples thereof include dispatch of a manned or unmanned taxi, dispatch of a vehicle used for a pick-up and drop-off service at an airport, a station, a hotel, and the like, and dispatch of a vehicle used for a car rental or sharing service. The user of the vehicle dispatch service is not particularly limited as long as the user can appropriately pay a reward for the service.

[0025] As shown in Figure 1 , the travel assist system 1 includes an imaging device 11, a distance measuring device 12, map information 13, a vehicle position detection device 14, a navigation device 15, a vehicle control device 16, an input device 17, an output device 18, and a travel assist device 19. The devices included in the travel assist system 1 are connected to each other by a CAN (Controller Area Network) or another vehicle-mounted LAN, and can transmit and receive information to and from each other.

[0026] The imaging device 11 is a device that images an object around the vehicle by image recognition, and is, for example, a video camera including an imaging element such as a CCD, an ultrasonic video camera, an infrared video camera, or the like. The imaging device 11 can be provided in plural on one vehicle, and can be disposed, for example, in the vicinity of the front grille portion of the vehicle, the lower portions of the left and right door mirrors, and the rear bumper. Thereby, it is possible to reduce a blind spot when an object around the vehicle is recognized. In addition, the imaging device 11 includes a driver monitor that images a driver.

[0027] The distance measuring device 12 is a device for calculating a relative distance and a relative speed between a vehicle and an object, and is, for example, a radar device such as a laser radar, a millimeter wave radar (LRF, etc.), a LiDAR (light detection and ranging) unit, an ultrasonic radar, or the like, or a sonar. The distance measuring device 12 can be provided in plural on one vehicle, and can be disposed, for example, in the front, right side, left side, and rear of the vehicle. Thereby, it is possible to correctly calculate a relative distance and a relative speed with respect to an object around the vehicle.

[0028] The objects detected by the camera 11 and the distance measuring device 12 are a lane boundary line, a center line, a pavement marking, a median strip, a guardrail, a curb, a side wall of an expressway, a road sign, a signal lamp, a pedestrian crossing, a work site, an accident site, a traffic restriction, and the like of a road. In addition, the objects include an obstacle such as a vehicle other than the host vehicle (another vehicle), a motorcycle, a bicycle, a pedestrian, and the like that can affect the travel of the host vehicle. The detection results of the camera 11 and the distance measuring device 12 are acquired by the travel assistance device 19 at predetermined time intervals.

[0029] In addition, the detection results of the camera 11 and the distance measuring device 12 can be synthesized or integrated by the travel assistance device 19, and thus, missing information of the detected objects can be supplemented. For example, based on the position at which the host vehicle travels, i.e., host vehicle position information, and the relative position (distance and direction) of the host vehicle to the objects, which are acquired by the host vehicle position detection device 14 described later, the position information of the objects can be calculated by the travel assistance device 19. The calculated position information of the objects is synthesized with the detection results of the camera 11 and the distance measuring device 12, the map information 13, and the like, and becomes the environmental information of the surroundings of the host vehicle. In addition, the objects in the surroundings of the host vehicle can be recognized using the detection results of the camera 11 and the distance measuring device 12 and the map information 13, and the movement thereof can be predicted.

[0030] The map information 13 is information for generation of a travel route and / or travel control, and includes road information, facility information, and attribute information thereof. The road information and the road attribute information include information such as the width of a road, the curvature and the radius of curvature of a road, the structure of a shoulder, the road traffic law (limit speed, whether or not lane changing is possible), the merging point and the branching point of a road, the position at which the number of lanes increases / decreases, and the like. The map information 13 of the present embodiment is high-precision map information that can grasp the movement trajectory of each lane, and includes two-dimensional position information and / or three-dimensional position information in each map coordinate, boundary information of a road / lane in each map coordinate, road attribute information, uplink / downlink information of a lane, lane identification information, connection destination lane information, and the like. In addition, the high-precision map is also referred to as an HD (High-Definition) map.

[0031] The boundary information of the road / lanes of the high-precision map information is information indicating a travel road on which the host vehicle travels and a boundary other than the same. The travel road on which the host vehicle travels refers to a road on which the host vehicle travels, and the form of the travel road is not particularly limited. The boundary exists to the left and right with respect to the advancing direction of the host vehicle, and the form of the boundary is not particularly limited. The boundary includes a road surface marking, a road structure, and the like, the road surface marking includes a lane boundary line, a center line, and the like, and the road structure includes a median, a guardrail, a curb, a tunnel, a side wall of an expressway, and the like. In addition, in a location where the boundary of the travel road cannot be clearly determined within an intersection, the boundary is set on the travel road in advance. The boundary is fictitious and is not an actually existing road surface marking or road structure.

[0032] The map information 13 is stored in a readable state in a recording medium on a server on a network or a vehicle-mounted device including the travel support device 19. The travel support device 19 acquires the map information 13 as needed.

[0033] The host vehicle position detection device 14 is a positioning system for detecting the current position of the host vehicle, and is not particularly limited and a publicly known device can be used. The host vehicle position detection device 14, for example, calculates the current position of the host vehicle from a radio wave received from a satellite for a GPS (Global Positioning System) or the like. In addition, the host vehicle position detection device 14 can also estimate the current position of the host vehicle from vehicle speed information acquired from a vehicle speed sensor and acceleration information acquired from an acceleration sensor and a gyro sensor, and calculate the current position of the host vehicle by collating the estimated current position with the map information 13.

[0034] The navigation device 15 is a device that calculates a travel route from the current position of the host vehicle detected by the host vehicle position detection device 14 to a destination set by the driver with reference to the map information 13. The navigation device 15, for example, uses road information and facility information of the map information 13 to search for a travel route for the host vehicle to travel from the current position to the destination. The travel route contains at least information of a road on which the host vehicle travels, a travel lane, and a travel direction of the host vehicle, and is displayed in a line shape, for example. According to the search conditions, there can be a plurality of travel routes. The travel route calculated by the navigation device 15 is output to the travel support device 19.

[0035] The vehicle control device 16 is an on-vehicle computer such as an electronic control unit (ECU) and electronically controls on-vehicle equipment that restricts travel of the vehicle. The vehicle control device 16 is provided with a vehicle speed control device 161 that controls a travel speed of the host vehicle and a steering control device 162 that controls a steering operation of the host vehicle. The vehicle speed control device 161 and the steering control device 162 autonomously control actions of these driving devices and a steering device in accordance with a control signal input from the travel assistance device 19. Thereby, the host vehicle can autonomously travel in accordance with a set travel path.

[0036] The driving devices controlled by the vehicle speed control device 161 include a motor and / or an internal combustion engine that are travel driving sources, a power transmission device including a drive shaft and an automatic transmission that transmits outputs from these travel driving sources to driving wheels, a driving device that controls the power transmission device, and the like. In addition, the braking devices controlled by the vehicle speed control device 161 are, for example, braking devices that brake the wheels. A control signal corresponding to a set travel speed is input from the travel assistance device 19 to the vehicle speed control device 161. The vehicle speed control device 161 generates a signal that controls these driving devices on the basis of the control signal input from the travel assistance device 19 and transmits the signal to the driving devices, thereby autonomously controlling the travel speed of the vehicle.

[0037] On the other hand, the steering device controlled by the steering control device 162 includes a steering device that controls a rudder wheel in accordance with a steering angle of a steering wheel (so-called steering wheel) and a steering actuator such as a motor mounted on a column shaft of a steering wheel. The steering control device 162 autonomously controls actions of the steering device in a manner in which the host vehicle travels while maintaining a prescribed lateral position (a position in a right-left direction of the vehicle) with respect to a set travel path, using at least one of a detection result of the imaging device 11 and the distance measuring device 12, map information 13, and information of a current position acquired by the host vehicle position detection device 14, on the basis of a control signal input from the travel assistance device 19.

[0038] Information required for autonomous control of the vehicle speed control device 161 and the steering control device 162, such as a travel speed, an acceleration, a steering angle, and a posture of the host vehicle, is detected using an on-vehicle sensor 163 provided in the vehicle control device 16. The on-vehicle sensor 163 is a sensor for detecting a travel state of the vehicle and includes, for example, a vehicle speed sensor, an acceleration sensor, a gyro sensor, a rudder angle sensor, an inertial measurement unit (IMU), and the like. In addition, the on-vehicle sensor 163 includes a touch sensor (electrostatic capacitance sensor) that detects a driver's hold on the steering wheel. The vehicle control device 16 outputs a detection result of the on-vehicle sensor 163 to the travel assistance device 19 at a prescribed time interval.

[0039] The input device 17 is a device for the occupant of the vehicle to input an instruction to the travel assist device 19, and includes, for example, a touch panel that inputs by finger contact or a stylus, a microphone that acquires an instruction of the user's voice, a switch mounted on the steering wheel of the vehicle, and the like.

[0040] As an example of the input device 17, Figure 2 indicates a switch mounted on the steering wheel of the vehicle. Figure 2 is a front view of a part of the input device 17, and indicates a button switch group arranged on the spokes of the steering wheel. Figure 2 The input device 17 illustrated is a button switch used when turning on / off (ON / OFF) of the autonomous travel control function (autonomous speed control function and autonomous steering control function) provided by the travel assist device 19. The input device 17 is provided with a main switch 171, a resume / accelerate switch 172, a set / coast switch 173, a cancel switch 174, an inter-vehicle adjustment switch 175, and a lane change assist switch 176.

[0041] The main switch 171 is a switch that turns on / off the power supply of the system that realizes the autonomous speed control function and the autonomous steering control function of the travel assist device 19. The resume / accelerate switch 172 is a switch for resuming the autonomous speed control at the set speed before stop (OFF) after stopping the autonomous speed control, or increasing the set speed, or starting again by the travel assist device 19 after stopping following a preceding vehicle. The set / coast switch 173 is a switch for starting the autonomous speed control at the speed during travel, or decreasing the set speed. The cancel switch 174 is a switch for stopping (OFF) the autonomous speed control. The inter-vehicle adjustment switch 175 is a switch for setting the inter-vehicle distance from the preceding vehicle, and is a switch for selecting one from a plurality of levels such as short, medium, and long. The lane change assist switch 176 is a switch for instructing (confirming) the start of the lane change when the travel assist device 19 confirms the start of the lane change to the driver. In addition, after confirming the start of the lane change, by operating the lane change assist switch 176 for longer than a prescribed time, it is possible to cancel the confirmation of the lane change proposal by the travel assist device 19.

[0042] In addition, in addition to Figure 2In addition to the push button switch, a direction indicator lever of a direction indicator or a switch of another in-vehicle device can be used as the input device 17. For example, in a case where the travel assistance device 19 proposes whether to automatically perform a lane change, when the driver operates the direction indicator lever, the lane change is performed in a direction in which the direction indicator lever is operated, instead of the proposed lane change. The input device 17 outputs the inputted setting information to the travel assistance device 19. In addition, the autonomous travel control, the autonomous speed control, and the autonomous steering control will be described later in detail.

[0043] RETURN Figure 1 The output device 18 is a device for providing necessary information to an occupant of the vehicle, such as a projector like a head-up display (HUD), a liquid crystal display provided to an instrument panel, and a display incorporated in a rearview mirror in the vehicle. In addition, the output device 18 includes not only a device for providing information visually, but also a device for providing information audibly like a speaker of an audio device, a device for providing information by vibration like a seat in which a vibration body is embedded, and the like.

[0044] The travel assistance device 19 is a device for controlling the travel of the host vehicle by controlling and cooperating the devices included in the travel assistance system 1, and causing the host vehicle to travel to a destination set by an occupant of the vehicle or a user of a vehicle dispatch service. The travel assistance device 19 is, for example, a computer provided with a CPU (Central Processing Unit) 191 as a processor, a ROM (Read Only Memory) 192 in which a program is stored, and a RAM (Random Access Memory) 193 functioning as an accessible storage device. The CPU 191 is an action circuit for functioning as the travel assistance device 19 by executing the program stored in the ROM 192.

[0045] (Function of Control Section)

[0046] The program stored in the ROM 192 includes the control section 2 as a functional block for implementing the travel control of the host vehicle by the travel assistance device 19. The control section 2 has a function of causing the host vehicle to travel by autonomous travel control. The autonomous travel control means that the travel assistance device 19 autonomously controls the travel action of the host vehicle, the travel action including acceleration, deceleration, start, stop, turning to right or left, lane change, and the like. In addition, the autonomous control of the travel action means that the travel assistance device 19 controls the travel action using the devices of the host vehicle. That is, the control section 2 intervenes and controls these travel actions within a predetermined range. For the travel actions in which the control section 2 does not intervene, the driver performs manual operation.

[0047] As Figure 1As shown, the control section 2 includes an acquisition section 3, an assist section 4, a determination section 5, and a notification section 6. The assist section 4 includes a speed control section 41 and a steering control section 42, and the steering control section 42 includes a lane keeping section 421, a lane changing section 422, an overtaking section 423, and a route traveling section 424. Figure 1 For convenience, each section is extracted and indicated. Hereinafter, the functions implemented by each functional block of the control section 2 will be described.

[0048] The acquisition section 3 has a function of acquiring information related to the running state of the host vehicle (hereinafter, also referred to as "running information"). Hereinafter, the function of acquiring the running information is also referred to as "running information acquisition function". For example, the running assist device 19 acquires, as the running information, images of the outside of the vehicle taken by the front camera, the rear camera, and the side camera as the imaging device 11, by the running information acquisition function of the acquisition section 3. In addition, the running assist device 19 acquires, as the running information, the detection results of the front radar, the rear radar, and the side radar as the distance measuring device 12, by the running information acquisition function of the acquisition section 3. Instead of these or in addition to these, the running assist device 19 also acquires, as the running information, the running speed of the host vehicle detected by the vehicle speed sensor as the on-vehicle sensor 163, and image information of the driver's face taken by the in-vehicle camera.

[0049] The running assist device 19 acquires, as the running information, the current position information of the vehicle from the host position detection device 14, by the running information acquisition function of the acquisition section 3. In addition, the running assist device 19 acquires, as the running information, the set destination and the running route to the destination from the navigation device 15, by the running information acquisition function of the acquisition section 3. Instead of these or in addition to these, the running assist device 19 acquires, as the running information, position information such as a curved road and the size (for example, the curvature or the curvature radius) of the curved road, a merging point, a branching point, a toll station, a position of a reduction in the number of lanes, and the like, from the map information 13. Instead of these or in addition to these, the running assist device 19 acquires, as the running information, operation information input by the driver from the input device 17.

[0050] The assist section 4 has a function of autonomously controlling the running of the host vehicle independently of the operation of the driver. The assist section 4 includes the speed control section 41 having a function of autonomously controlling the running speed of the host vehicle, and the steering control section 42 having a function of autonomously controlling the steering of the host vehicle. Hereinafter, the autonomous control of the running of the host vehicle independently of the operation of the driver is also referred to as "autonomous running control". In addition, the autonomous control of the running speed of the host vehicle is also referred to as "autonomous speed control", and the autonomous control of the steering of the host vehicle is also referred to as "autonomous steering control".

[0051] When a preceding vehicle is detected, the driving assist device 19 uses autonomous speed control in the speed control unit 41, using the driver's set speed as the upper limit. The vehicle then performs inter-vehicle control, maintaining a distance between vehicles corresponding to the speed, and follows the preceding vehicle. On the other hand, when no preceding vehicle is detected, the vehicle maintains a constant speed at the speed set by the driver. The former is also referred to as inter-vehicle control, and the latter is also referred to as constant speed control. Furthermore, the speed control unit 41 may also have the function of detecting the speed limit of the road being traveled from road signs using the camera device 11, or obtaining the speed limit from map information 13, and automatically using that speed limit as the set speed.

[0052] To activate the autonomous speed control by the speed control unit 41, first, the driver operates Figure 2 The desired driving speed is input by using the resume / accelerate switch 172 or the set / coast switch 173 of the input device 17 shown. For example, if the set / coast switch 173 is pressed while the vehicle is traveling at 70 km / h, the current driving speed is directly set. However, if the driver's desired speed is 80 km / h, the set speed can be increased by pressing the resume / accelerate switch 172 multiple times. On the other hand, if the driver's desired speed is 60 km / h, the set speed can be decreased by pressing the set / coast switch 173 multiple times. In addition, the vehicle distance desired by the driver is set by the operator. Figure 2 The inter-vehicle adjustment switch 175 of the input device 17 shown in the figure can be selected from a plurality of settings such as short distance, medium distance, and long distance.

[0053] If the front radar of the distance measuring device 12 detects that there is no preceding vehicle in the vehicle's lane, constant speed control is executed. During constant speed control, vehicle speed data from the vehicle speed sensor, which is an onboard sensor 163, is fed back, and the operation of driving mechanisms such as the engine and brakes is controlled by the vehicle speed control device 161 to maintain the set driving speed.

[0054] In a case where it is detected by the front radar or the like of the distance measuring device 12 that a preceding vehicle exists in front of the subject vehicle, inter-vehicle control is executed. In the inter-vehicle control, the inter-vehicle distance data detected by the front radar is fed back with a set travel speed as an upper limit, and the operation of the driving mechanism such as the engine and the brake is controlled by the vehicle speed control device 161 to maintain the set inter-vehicle distance. In addition, in a case where the preceding vehicle stops while the subject vehicle is traveling with the inter-vehicle control, the subject vehicle also stops behind the preceding vehicle. In addition, after the subject vehicle stops, if the preceding vehicle starts within, for example, 30 seconds, the subject vehicle also starts and resumes the following travel based on the inter-vehicle control. In a case where the subject vehicle stops for more than 30 seconds, the subject vehicle does not automatically start even if the preceding vehicle starts, and after the preceding vehicle starts, if the resume / accelerator switch 172 is pressed or the accelerator pedal is depressed, the following travel based on the inter-vehicle control is resumed.

[0055] The autonomous steering control by the steering control section 42 is executed by controlling the operation of the steering actuator by the steering control device 162 in a case where the condition prescribed in the execution of the autonomous speed control described above is satisfied. The steering control section 42 includes, for example, a lane keeping section 421, a lane changing section 422, an overtaking section 423, and a route travel section 424.

[0056] The lane keeping section 421 has a function of assisting the steering operation of the driver by controlling the steering actuator by the steering control device 162 so that the subject vehicle travels near the center of the lane. In addition, the function possessed by the lane keeping section 421 is also referred to as a "lane keeping function" or a "lane width direction maintaining function". In addition, the control of the lane keeping section is also referred to as "lane keeping control".

[0057] The lane changing section 422 has a function of changing the lane by autonomous travel control. Hereinafter, the control of changing the lane from the subject lane in which the subject vehicle travels to an adjacent lane adjacent to the subject lane by autonomous travel based on autonomous travel control is also referred to as "autonomous lane changing control". As described above, the autonomous travel control is executed in a case where the condition prescribed in the execution of the autonomous speed control described above is satisfied. Figure 3When the driver operates the direction indicator lever, the travel assist device 19 turns on the direction indicator by the autonomous lane change control point of the lane change section 422, and starts a series of processes of lane change operation (hereinafter referred to as LCP) based on autonomous travel control, in the case where the pre-set lane change start condition is satisfied. Alternatively, the direction indicator can be turned on and the LCP can be started in the case where the button operation for starting the autonomous lane change control is performed, such as in the case where the lane change assist switch 176 of the input device 17 is operated. The travel assist device 19 determines whether the lane change start condition is satisfied based on various travel information acquired by the travel information acquisition function of the acquisition section 3, by the autonomous lane change control. As the lane change start condition, there is no particular limitation, and all of the following conditions can be exemplified as being satisfied.

[0058] • The lane keeping mode in the handheld mode.

[0059] • The handheld is determined.

[0060] • The vehicle is traveling at a speed of 60 km / h or more.

[0061] • There is a lane in the lane change direction.

[0062] • There is a space in which the lane change can be performed in the lane of the lane change destination.

[0063] • The type of the lane marking is lane changeable.

[0064] • The curvature radius of the road is 250 m or more.

[0065] • The driver operates the direction indicator lever within 1 second after the operation.

[0066] Further, the lane keeping mode in the handheld mode refers to the autonomous speed control of the speed control section 41 and the lane keeping control of the lane keeping section 421 being executed, and the state in which the driver holds the steering wheel is detected, which will be described later in detail. Further, the handheld is determined refers to the state in which the driver continues to hold the steering wheel.

[0067] In the case where the lane change start condition is satisfied, the travel assist device 19 starts the LCP by the autonomous lane change control of the lane change section 422. The LCP includes: the lateral movement of the host vehicle to the adjacent lane, and the lane change operation (hereinafter referred to as LCM) in which the actual movement to the adjacent lane is performed. During the execution of the LCP, the travel assist device 19 prompts the driver with information indicating that the lane change is automatically performed by the output device 18, in order to call attention to the surroundings. The travel assist device 19 turns off the direction indicator at the end of the LCM based on the autonomous lane change control, and starts the control based on the lane keeping section 421 on the adjacent lane.

[0068] The overtaking unit 423 has the function of overtaking the preceding vehicle by autonomous driving control. Hereinafter, the control for overtaking the preceding vehicle by autonomous driving based on autonomous driving control is also referred to as "overtaking assist control". Overtaking assist control is a type of autonomous lane change control, and is an autonomous lane change control in a driving scenario where the vehicle is overtaking the preceding vehicle. Figure 4 As shown, when there is a preceding vehicle slower than the vehicle in front of the present vehicle in the present lane and the predetermined overtaking proposal conditions are met, the driving assist device 19 prompts the driver with overtaking information through the output device 18 by means of the function of the overtaking unit 423. Here, the overtaking information refers to information used to propose to the driver to overtake the preceding vehicle. In addition, the driving assist device 19 starts the above-mentioned LCP when the driver confirms the prompt of the overtaking information by operating the lane change assist switch 176 of the input device 17 (equivalent to the confirmation input) and the predetermined overtaking start conditions are met. The confirmation input includes the driver operating the direction indicator lever to the right or left. The driving assist device 19 determines whether the overtaking proposal conditions and the overtaking start conditions are met based on the various driving information acquired by the acquisition unit 3. In addition, the overtaking assist control may also include a function of starting the LCP for overtaking the preceding vehicle when the driver operates the direction indicator lever even when the overtaking information is not prompted.

[0069] The transcending proposal condition is not particularly limited, and examples thereof include the condition that all of the following conditions are satisfied.

[0070] It is a lane keeping mode with hands-off mode.

[0071] Driving at a speed of 60 km / h or more.

[0072] There is a lane in the direction of the lane change.

[0073] There is room to change lanes after 5 seconds in the lane at the lane change destination.

[0074] The lane marking type is lane changeable.

[0075] The curvature radius of the road is more than 250m.

[0076] The vehicle's speed is more than 5 km / h slower than the set speed.

[0077] The speed of the preceding vehicle is more than 10 km / h slower than the set speed.

[0078] The inter-vehicle distance between the host vehicle and the preceding vehicle is smaller than a preset threshold value based on the speed difference between the host vehicle and the preceding vehicle.

[0079] The speed of the preceding vehicle in the lane at the lane change destination satisfies a predetermined condition.

[0080] The hands-off lane keeping mode refers to a mode in which autonomous speed control by the speed control unit 41 and lane keeping control by the lane keeping unit 421 are in effect, and the driver does not need to hold the steering wheel. This will be described in detail later. Furthermore, the requirement that the speed of the preceding vehicle in the lane of the lane change destination satisfies a prescribed condition varies depending on the type of lane of the lane change destination. For example, on a multi-lane road with left-hand traffic, when changing lanes from the left lane to the right lane, the condition is that the speed of the host vehicle in the left lane is at least approximately 5 km / h faster than the speed of the preceding vehicle in the right lane. Conversely, on a multi-lane road with left-hand traffic, when changing lanes from the right lane to the left lane, the condition is that the speed difference between the host vehicle and the preceding vehicle in the left lane is within approximately 5 km / h. Furthermore, the condition regarding the relative speed difference between the host vehicle and the preceding vehicle on right-hand traffic roads is reversed.

[0081] When the driver confirms the overtaking information and the predetermined overtaking start conditions are satisfied, the driving assistance device 19 illuminates the direction indicator and starts LCP through the overtaking assistance control of the overtaking unit 423. The overtaking start conditions are not particularly limited, but examples thereof include the following: all of the following conditions are satisfied.

[0082] It is a lane keeping mode in handheld mode.

[0083] ·Determine whether the item is in hand.

[0084] Driving at a speed of 60 km / h or more.

[0085] There is a lane in the direction of the lane change.

[0086] There is space for lane change in the lane at the lane change destination.

[0087] The lane marking type is lane changeable.

[0088] The curvature radius of the road is more than 250m.

[0089] The vehicle's speed is 5 km / h or more slower than the set speed (when changing lanes from left-hand traffic to the right lane).

[0090] The speed of the preceding vehicle is more than 10 km / h slower than the set speed (when changing lanes from left-hand traffic to the right lane).

[0091] The speed of the preceding vehicle in the lane at the lane change destination satisfies a predetermined condition.

[0092] Within 10 seconds after the lane change assist switch 176 is operated.

[0093] Furthermore, the driver can change the condition that the preceding vehicle's speed is at least 10 km / h slower than the set speed. The changed set speed becomes the overtaking initiation condition. For example, in addition to 10 km / h, other selectable speeds include 15 km / h and 20 km / h. Furthermore, the requirement that the preceding vehicle's speed in the lane at the lane change destination meets the specified conditions is the same as the overtaking proposal condition described above.

[0094] When the overtaking start condition is satisfied, the driving assist device 19 starts LCP through the overtaking assist control, and executes lateral movement and LCM to the adjacent lane. Through the overtaking assist control, the driving assist device 19 prompts the driver through the output device 18 a message indicating that a lane change is automatically performed during the execution of LCP, reminding the driver to pay attention to the surroundings. When LCM ends, the driving assist device 19 turns off the direction indicator and starts the lane keeping control of the lane keeping unit 421 in the adjacent lane. In addition, the overtaking unit 423 has a function of proposing to the driver to return to the original lane through the output device 18 when the overtaking proposal condition is satisfied again after overtaking the preceding vehicle. In response to this proposal, when the driver operates the lane change assist switch 176 of the input device 17 for confirmation and the overtaking start condition is satisfied, as shown in FIG. Figure 5 As shown, the driving assist device 19 starts LCP to return the host vehicle to the original lane through the overtaking assist control.

[0095] The lane driving unit 424 has the function of driving the vehicle along a set driving route. The lane driving unit 424 uses lane driving assistance control to drive the vehicle along the set driving route. Specifically, lane driving assistance control is a type of autonomous lane change control, specifically, autonomous lane change control in driving scenarios that causes the vehicle to drive along the set driving route. If the set driving route includes a driving direction change point, such as a branch point, a merge point, an exit, or a toll booth, and the distance to the driving direction change point is within a specified distance and specified lane driving proposal conditions are met, the driving assistance device 19, through the function of the lane driving unit 424, presents lane driving information via the output device 18 and proposes a lane change to the driving direction change point. Furthermore, the driving assistance device 19 initiates LCP when the lane change proposal is confirmed by operation of the lane change assist switch 176 and specified lane driving start conditions are met. The lane change assist switch 176 may also be operated by the driver using a direction indicator lever. The driving assistance device 19 determines whether or not a route driving suggestion condition and a route driving start condition are satisfied based on various types of driving information acquired by the driving information acquisition function of the acquisition unit 3 .

[0096] Further, although the travel route set by the navigation device 15 is set, in a case where the route travel assist control by the route travel section 424 is not executed, or in a case where the setting becomes invalid, the usual navigation that guides the travel route is executed by the navigation device 15. Further, the route travel assist control can also include a function that starts the LCP for traveling along the travel route when the driver operates the direction indicator lever even in a case where the lane change is not proposed according to the route travel information.

[0097] In Figure 6 The example shown in FIG. 10 is an example in which the host vehicle is traveling in the right lane on a one-way 3-lane road on which the vehicles travel on the left side, and makes 2 lane changes in succession toward a branch point existing on the left lane, and moves toward a branch road (also referred to as a branch lane, hereinafter the same) extending to the left from the branch point. The travel assist device 19 proposes the lane change from the right lane to the center lane according to the route travel information by the route travel assist control by the route travel section 424 in a case where the distance to the branch point is within a first prescribed distance (for example, about 2.5 km to 1.0 km before the branch point), and the route travel proposal conditions are satisfied. Further, the first prescribed distance (also referred to as a lane change proposal interval) is set in advance according to the number of lane changes required to move to the lane where the travel direction change point is located. For example, as shown in FIG. 10, in a case where two lane changes are required from the right lane via the center lane to the left lane, the interval of about 2.5 km to 1.0 km before the branch point becomes the first prescribed distance (lane change proposal interval) as exemplified. Figure 6

[0098] Further, the route travel proposal conditions are not particularly limited, but all of the following conditions can be exemplified as being satisfied.

[0099] • The destination is set by the navigation device 15.

[0100] • The lane keeping mode is the hands-off mode.

[0101] • The vehicle is traveling at a speed of 60 km / h or more.

[0102] • There is a lane in the lane change direction.

[0103] • The type of the lane marking is lane changeable.

[0104] • The radius of curvature of the road is 250 m or more.

[0105] Further, in the route travel proposal conditions, even in a case where there is no space in which the lane change is possible at the lane change destination, the route travel information is prompted in order to notify the driver that the lane change along the travel route is required. ​

[0106] The travel assist device 19, in a case where the driver confirms the lane change toward the branch point and the route travel start condition is satisfied, turns on the direction indicator and starts the LCP by the route travel assist control of the route travel section 424. As the route travel start condition, there is no particular limitation, and all of the following conditions can be exemplified as being established.

[0107] • The lane keep mode is the handheld mode.

[0108] • The handheld is determined.

[0109] • The vehicle is traveling at a speed of 60 km / h or more.

[0110] • There is a lane in the lane change direction.

[0111] • There is a space available for the lane change in the lane of the lane change destination.

[0112] • The type of the lane marking is available for the lane change.

[0113] • The vehicle is traveling in the lane change proposal section.

[0114] • The radius of the road curvature is 250 m or more.

[0115] The travel assist device 19, in a case where the route travel start condition is satisfied, starts the LCP by the route travel assist control of the route travel section 424, performs the lateral movement to the center lane and the LCM. When the LCM ends, the travel assist device 19 turns off the direction indicator and starts the lane keep control of the lane keep section 421 on the center lane. The travel assist device 19, by the route travel assist control, prompts the driver by the output device 18 with information indicating that the lane change is automatically performed in the LCP execution, to alert the attention to the surroundings.

[0116] In addition, as shown in Figure 6 , the travel assist device 19, in the execution of the lane keep control on the center lane, in a case where the distance to the branch point is within a second prescribed distance (for example, about 2.3 km to 700 m before the branch point) and the route travel start condition is satisfied, turns on the direction indicator and starts the second LCP by the route travel assist control, and performs the lane change from the center lane to the left lane. When the second LCM ends, the travel assist device 19 turns off the direction indicator and starts the lane keep control of the lane keep section 421 on the left lane.

[0117] Further, the travel assist device 19, in the execution of the lane keeping control on the left lane, illuminates the turn signal by the route travel assist control when the distance from the branching point is within a third prescribed distance (for example, about 800 m to 150 m before the branching point) and the route travel start condition is satisfied. The travel assist device 19 starts the steering control from the point beyond the branching point to the branch road by the route travel assist control of the route travel section 424, and performs the lane change from the left lane to the branch road by the autonomous travel control. The autonomous steering control described above is used in this steering control. When the lane change to the branch road is completed, the travel assist device 19 turns off the turn signal, and starts the lane keeping control of the lane keeping section 421 on the branch road.

[0118] Figure 7 is a block diagram showing the state transition of each function established by the travel assist device 19. Figure 7 The system shown in FIG. 10 is an autonomous travel control system realized by the travel assist device 19. When the main switch 171 is turned on (ON) from the state shown in FIG. 10 Figure 7 , the system becomes a standby state. By turning on (ON) the set / slide switch 173 or the resume / accelerator switch 172 from this standby state Figure 2 , autonomous speed control based on the autonomous speed control function is started. Thereby, the constant speed control or the inter-vehicle control described above is started, and the driver can make the host vehicle travel only by operating the steering wheel without stepping on the accelerator or the brake. Figure 2

[0119] In the autonomous speed control execution, when the condition (1) is satisfied Figure 7 , the lane keeping mode of the autonomous steering control / hand-held mode is switched to. As this condition (1), although there is no particular limitation, all of the following conditions can be exemplified.

[0120] • The lane marks on both sides of the host vehicle are detected.

[0121] • The driver is holding the steering wheel.

[0122] • The host vehicle is traveling near the center of the lane.

[0123] • The turn signal is not operating.

[0124] • The wiper is not operating at high speed (HI).

[0125] • In the case of a high-precision map, there is no toll gate, exit, merging point, intersection, or lane number reduction point within about 200 m ahead.

[0126] ​In addition, the hand-held mode is a mode in which autonomous steering control based on the autonomous steering control function does not act if the driver does not hold the steering wheel, and the hand-away mode is a mode in which autonomous steering control based on the autonomous steering control function acts even if the driver moves his hand away from the steering wheel. In addition, the driver's holding of the steering wheel is detected by a touch sensor of the in-vehicle sensor 163.

[0127] In the lane keeping mode execution of the autonomous steering control / hand-held mode, when Figure 7 condition (2) is satisfied, the lane keeping mode of the autonomous steering control / hand-away mode is switched to. As this condition (2), all of the following conditions can be exemplified as being satisfied, and the like.

[0128] • The host vehicle is traveling on a road other than an automobile exclusive road.

[0129] • The host vehicle is traveling on a road on which the opposite lane is structurally separated.

[0130] • The host vehicle is traveling on a road on which a high-precision map is available.

[0131] • The host vehicle is traveling at a vehicle speed lower than a limit speed.

[0132] • A GPS signal is available.

[0133] • The driver is holding the steering wheel.

[0134] • The driver is facing forward.

[0135] • There is no toll gate, exit, merging point, intersection, or lane number reduction point within about 800 m ahead.

[0136] • There is no sharp turn of 100 R or less within about 500 m ahead.

[0137] • The host vehicle is not traveling in a tunnel more than 500 m from a tunnel entrance.

[0138] • The accelerator pedal is not depressed.

[0139] In addition, for example, whether or not the driver is facing forward is determined based on a captured image of a driver monitoring camera of the camera 11.

[0140] On the contrary, in the lane keeping mode execution of the autonomous steering control / hand-away mode, when Figure 7 condition (3) is satisfied, the lane keeping mode of the autonomous steering control / hand-held mode is switched to. As this condition (3), although not particularly limited, any one of the following conditions can be exemplified as being satisfied, and the like.

[0141] • The host vehicle is traveling on a road other than an automobile exclusive road.

[0142] • The host vehicle is traveling on an opposite travel section.

[0143] Driving on roads without high-precision maps.

[0144] Driving at a speed exceeding the speed limit.

[0145] ·GPS signal cannot be received.

[0146] The driver does not face forward within 5 seconds after the forward look alarm is activated.

[0147] The driver monitoring camera cannot detect the driver.

[0148] About 800 meters ahead, there is a toll booth, an exit, a merge, or a lane reduction.

[0149] When driving at a speed of less than approximately 40 km / h, there is a sharp curve of less than 100R within approximately 200 meters ahead.

[0150] When driving at a speed of approximately 40 km / h or higher, there is a sharp curve with a radius of less than 170° within approximately 200 meters ahead.

[0151] Driving in a tunnel more than 500m from the tunnel entrance.

[0152] The driver holds the steering wheel and steps on the accelerator pedal.

[0153] The proximity alarm is operating.

[0154] In lane keeping mode of autonomous steering control / hands-off mode, when Figure 7 When the condition (4) is satisfied, the autonomous steering control is terminated and the vehicle is switched to the autonomous speed control. Although the condition (4) is not particularly limited, it can be exemplified by the following conditions being satisfied.

[0155] The lane markings on both sides of the vehicle are not detected for a certain period of time.

[0156] The driver is operating the steering wheel.

[0157] The wipers operate at high speed (HI).

[0158] In addition, the driver's operation of the steering wheel is determined by detecting the torque applied to the steering wheel using the vehicle-mounted sensor 163.

[0159] In addition, when the lane keeping mode of the autonomous steering control / hands-off mode is executed, Figure 7 When the condition (5) is satisfied, the autonomous steering control and the autonomous speed control are stopped and the vehicle is switched to the standby state. Although the condition (5) is not particularly limited, it can be exemplified by the following conditions being satisfied.

[0160] • The driver operated the brake.

[0161] • The driver operated the cancel switch 174. Figure 2

[0162] • The door of the host vehicle is opened.

[0163] • The seat belt of the driver's seat is released.

[0164] • The driver is detected by the seat sensor to have left the driver's seat.

[0165] • The shift lever is in a position other than "D" or "M".

[0166] • The parking brake is operated.

[0167] • The vehicle's side slip prevention device is turned OFF.

[0168] • The side slip prevention device is operated.

[0169] • The snow mode is turned ON.

[0170] • The emergency brake is operated.

[0171] • The vehicle is stopped by the vehicle speed control, and the stopped state continues for about 3 minutes.

[0172] • It is detected that the front camera cannot correctly recognize the object due to dirt, backlight, rain / fog, etc.

[0173] • The front radar detects shielding or radio wave failure.

[0174] • The front radar detects axis deviation.

[0175] • The side radar detects shielding or radio wave failure.

[0176] • The side radar detects axis deviation.

[0177] In the autonomous steering control / handheld mode execution, when the condition (6) is established, the autonomous steering control is suspended and switched to autonomous speed control. As the condition (6), although not particularly limited, any one of the following conditions can be exemplified, etc. Figure 7 • The lane marks on both sides of the host vehicle cannot be detected.

[0178] • The driver operates the steering wheel.

[0179] • The driver operates the direction indicator lever.

[0180] • The driver operates the direction indicator lever.

[0181] ​• The wiper is operating at high speed (HI).

[0182] • The section of the toll gate is recognized with high accuracy.

[0183] • The field of view of the front camera is not good for recognizing an object due to dirt, backlight, rain / fog, etc.

[0184] In addition, in the autonomous steering control / handheld mode execution, when the condition (7) is satisfied, the autonomous steering control and the autonomous speed control are suspended and the standby state is switched to. As the condition (7), although not particularly limited, any one of the following conditions can be exemplified as being satisfied, etc. Figure 7

[0185] • The driver operates the brake.

[0186] • The driver operates the cancel switch 174 of the Figure 2

[0187] • The door of the vehicle is opened.

[0188] • The seat belt of the driver's seat is released.

[0189] • The driver is detected by the seat sensor to have left the driver's seat.

[0190] • The shift lever is in a position other than "D" or "M".

[0191] • The parking brake is operated.

[0192] • The vehicle's side slip prevention device is turned off (OFF).

[0193] • The side slip prevention device is operated.

[0194] • The snow mode is turned on (ON).

[0195] • The emergency brake is operated.

[0196] • After the vehicle is stopped by the vehicle speed control, the stopped state continues for about 3 minutes.

[0197] • The front radar detects a blockage or a radio failure.

[0198] • The front radar detects an axis deviation.

[0199] In the autonomous speed control execution, when the condition (8) is satisfied, the standby state is switched to. As the condition (8), although not particularly limited, any one of the following conditions can be exemplified as being satisfied, etc. Figure 7

[0200] • The driver operates the brake. ​​​

[0201] The driver operated Figure 2 The cancel switch 174 is provided.

[0202] The vehicle's door is open.

[0203] The driver's seat belt was unfastened.

[0204] The seating sensor detects that the driver has left the driver's seat.

[0205] The selector lever is in a position other than "D" or "M".

[0206] The parking brake is applied.

[0207] The vehicle's anti-skid system is OFF.

[0208] The anti-skid device has been activated.

[0209] Snow mode is turned ON.

[0210] The emergency brake is applied.

[0211] After the vehicle was stopped by speed control, it remained stopped for approximately 3 minutes.

[0212] The forward radar detected obstruction or radio wave failure.

[0213] The forward radar detected an axis deviation.

[0214] In lane keeping mode of autonomous steering control / hands-off mode, when Figure 7 When the condition (9) is satisfied, the mode is switched to the lane change mode of the autonomous steering control / handheld mode. The condition (9) is not particularly limited, and any one of the following conditions can be exemplified.

[0215] The system proposes a lane change based on the overtaking assist control of the overtaking unit 423 or the lane travel assist control of the lane travel unit 424 , and the driver operates the lane change assist switch 176 .

[0216] The driver operated the turn signal lever to execute autonomous lane change control.

[0217] During lane change execution in autonomous steering control / handheld mode, when Figure 7 When the condition (10) is satisfied, the mode is switched to the lane keeping mode of the autonomous steering control / handheld mode. Although the condition (10) is not particularly limited, it can be exemplified by the following conditions being satisfied.

[0218] The speed limit was exceeded before LCP started.

[0219] Before the LCP starts, the driver holds the steering wheel and depresses the accelerator pedal.

[0220] If the lane change assist switch 176 is pressed during a lane change proposal with a slower vehicle ahead, LCP will not start within 10 seconds.

[0221] After the lane change assist switch 176 is pressed during a lane change proposal for following the driving route, the LCP cannot be started and the vehicle approaches the branch point too close.

[0222] After LCP is activated, LCM cannot be started within 5 seconds.

[0223] Start LCP and the vehicle speed is less than approximately 50 km / h before starting LCM.

[0224] After LCP maneuvering, before starting LCM, the space in the adjacent lane required for lane change is no longer available.

[0225] The driver canceled the LCM operation before it started.

[0226] Lane markings were not detected before LCM started.

[0227] Before LCM starts, it is determined that there is no adjacent lane in the lane change direction, or that there is no adjacent lane within a certain distance ahead.

[0228] Before LCM starts, it is determined that there is a curve with a curvature radius of more than 250 meters within a certain distance ahead.

[0229] Before LCM starts, it is determined that there is a lane-dividing line within a certain distance ahead where lane changes to the adjacent lane are prohibited.

[0230] Before LCM starts, the side radar detects shielding or radio wave obstruction.

[0231] Before LCM starts, the side radar detects axis deviation.

[0232] Handheld alarm action.

[0233] The driver stopped the direction indicator.

[0234] The LCP has ended.

[0235] In addition, the handheld alarm will be activated when any of the following conditions are met.

[0236] The driver does not hold the steering wheel within approximately 2 seconds after LCP is activated.

[0237] • The lane change assist switch 176 was pressed in a lane change proposal in a case where there is a slow vehicle ahead, and the driver did not hold the steering wheel within about 2 seconds.

[0238] • The lane change assist switch 176 was pressed in a lane change proposal for traveling along a travel path, and the driver did not hold the steering wheel within about 2 seconds.

[0239] In addition, if the main switch 171 is turned off (OFF) in any one of the autonomous steering control / hand-off mode, the autonomous steering control / hand-hold mode, the autonomous speed control, and the standby state, the system is turned off (OFF)

[0240] Next, the travel control processing of the present embodiment will be described with reference to Figure 8 The travel control processing of the present embodiment will be described. Figure 8 is an example of a flowchart showing the travel control processing of the present embodiment. In addition, the travel assist device 19 executes the travel control processing described below at a prescribed time interval. In addition, in the following description, the travel assist device 19 executes autonomous speed control by the function of the speed control section 41 and autonomous steering control by the function of the steering control section 42. In addition, the travel assist device 19 executes lane change assist control by the function of the lane change section 422, overtaking assist control by the function of the overtaking section 423, and route travel assist control by the function of the route travel section 424.

[0241] First, in step S1 of the flowchart of Figure 8 , it is determined whether the main switch 171 of the travel assist device 19 is turned on (ON), and in a case where the main switch 171 is turned off (OFF), step S1 is repeated until it is turned on. In a case where the main switch 171 is turned on, step S2 is entered, and it is determined whether a travel speed is set by the driver. In a case where the travel speed is not set, step S1 is returned to, and steps S1 and S2 are repeated until the travel speed is set. In addition, the setting of the travel speed by the driver is performed by the driver operating the resume / accelerate switch 172 or the set / coast switch 173 of the input device 17 shown in FIG. 1 and inputting a desired travel speed. Figure 2

[0242] After the travel speed is set, autonomous speed control is started. In step S3, it is detected by the front radar as the distance measuring device 12 whether there is a preceding vehicle in front of the lane in which the host vehicle is traveling, and in a case where there is a preceding vehicle, step S4 is entered, and inter-vehicle control is executed. In a case where there is no preceding vehicle, step S5 is entered, and constant speed control is executed. Thus, the driver can make the host vehicle travel at a desired speed without depressing the accelerator and the brake, by operating the steering wheel.

[0243] ​During the inter-vehicle control of step S4 or the constant speed control of step S5, in step S6, it is determined whether or not the condition (1) for switching to the lane keeping mode of the autonomous steering control / hand-held mode described above is satisfied. In the case where the condition (1) is satisfied, step S7 is entered, and in the case where the condition (1) is not satisfied, step S3 is returned to.

[0244] In step S7, it is detected whether or not there is a preceding vehicle in front of the lane in which the host vehicle is traveling, using the front radar (distance measuring device 12) that detects an obstacle in front of the host vehicle. In the case where there is a preceding vehicle, step S8 is entered, and the inter-vehicle control / lane keeping mode is executed. In the case where there is no preceding vehicle, step S9 is entered, and the constant speed control / lane keeping mode is executed.

[0245] In step S7, it is detected whether or not there is a preceding vehicle in front of the lane in which the host vehicle is traveling, using the front radar (distance measuring device 12) that detects an obstacle in front of the host vehicle. In the case where there is a preceding vehicle, step S8 is entered, and the inter-vehicle control / lane keeping mode is executed. In the case where there is no preceding vehicle, step S9 is entered, and the constant speed control / lane keeping mode is executed.

[0246] In step S14, it is determined whether or not the driver has operated the direction indicator lever. In the case where the direction indicator lever has been operated, the condition (9) for switching to the lane changing mode of the autonomous steering control / hand-held mode is satisfied, and step S15 is entered. In step S15, the lane change assist control is executed. After the lane change assist control of step S15 is ended, step S3 is returned to. In the case where the driver has not operated the direction indicator lever in step S14, step S16 is entered.

[0247] In step S16, it is determined whether or not there is a preceding vehicle that is slower than the set speed. In the case where there is a preceding vehicle that is slower than the set speed, it is determined whether or not the condition (9) is satisfied, and in the case where the condition (9) is satisfied, the lane changing mode of the autonomous steering control / hand-held mode is switched to, and step S17 is entered. In step S17, the overtaking assist control is executed. After the overtaking assist control of step S17 is ended, step S3 is returned to. In the case where there is no preceding vehicle that is slower than the set speed in step S16, step S18 is entered.

[0248] In step S18, it is determined whether a driving route to the destination is set in the navigation device 15. If no driving route is set, the process returns to step S1. In step S18, if a driving route to the destination is set in the navigation device 15, the process proceeds to step S19. In step S19, it is determined whether the specified distance from the driving direction change point, such as a branch point on the driving route, has been reached. If the specified distance from the driving direction change point has been reached in step S19, it is determined whether condition (9) is met. If condition (9) is met, the process switches to the lane change mode of the autonomous steering control / handheld mode and the process proceeds to step S20. In step S20, route driving assist control is executed. After the route driving assist control in step S20 is completed, the process returns to step S3. If the specified distance from the driving direction change point has not been reached in step S19, the process returns to step S1.

[0249] In addition, Figure 8 In the flowchart, whether lane change assist control, overtaking assist control, and route driving assist control are needed is judged in turn, but in fact, whether each control is needed is judged in parallel. When other auxiliary controls need to be executed during the execution of any auxiliary control, it is necessary to adjust whether to execute them among the auxiliary controls and determine the auxiliary control to be executed first.

[0250] (Route Driving Assist Control)

[0251] use Figure 9 The route-based driving assist control according to the present embodiment will be described. Figure 9 It is a plan view showing an example of a driving scene in which autonomous driving control is performed using the driving support system 1 . Figure 9 The direction of travel of vehicles on the road shown is determined by Figure 9 The direction indicated by the lower right arrow A is from the lower side toward the upper side of the drawing. Figure 9 The road shown has lane L1 on the right side of the travel direction and lane L2 on the left side of the travel direction. Lane L2 branches at branch point B1 into lane L2 as the main lane and lane L3 as the branch lane. Lane L3 as the branch lane also branches at branch point B2 into lane L3 and lane L4.

[0252] exist Figure 9In the driving scenario shown, it is assumed that the host vehicle V is traveling at position P1 in lane L2. Furthermore, it is assumed that the driver's set destination Px is located ahead of the driving direction of lane L4, and a driving route toward destination Px is set by the navigation device 15. In this case, in order to travel along the driving route, the host vehicle V needs to change lanes from lane L2 to lane L3, entering lane L3, which is a branch lane, and then change lanes from lane L3 to lane L4, entering lane L4. To cause the host vehicle V to enter lane L4, the driving assistance device 19 causes the host vehicle V to travel from position P1 to position P2 along trajectory T1, initiates the first LCP at position P2 in lane L2, causes the host vehicle V to travel along trajectory T2, terminates the LCP at position P3 in lane L3, initiates the second LCP at position P3 in lane L3, causes the host vehicle V to travel along trajectory T3, and terminates the LCP at position P4 in lane L4.

[0253] In this way, when entering a branch lane (such as Figure 9 Branch lane L3) further branches out to other branch lanes (such as Figure 9 In the case of a branch lane L4, two (or three or more) consecutive lane changes are required. If all lane changes can be assisted by autonomous lane change control, the driving assistance device 19 can simply execute lane changes using autonomous lane change control in sequence. However, if, for example, two lane changes are performed consecutively and only the second lane change cannot be assisted by autonomous lane change control, the second lane change is performed solely through manual operation by the driver. Hereinafter, lane changes using autonomous lane change control will also be referred to as "autonomous lane changes."

[0254] As situations where autonomous lane change control cannot assist in lane changes, two situations can be considered. That is, (a) the conditions for enabling autonomous lane change control (autonomous lane change control activation) have been met, but the lane change itself cannot be performed due to reasons such as the presence of an obstacle in the lane of the lane change destination; (b) the conditions for enabling autonomous lane change control are not met. In case (a), since the driver expects to perform an autonomous lane change, the driving assistance device 19 notifies the driver that the autonomous lane change cannot be performed when it determines that the lane change cannot be performed due to an obstacle, etc. This notification is made using the output device 18. The driver who is notified that the autonomous lane change cannot be performed can attempt a second lane change (from lane L3 to lane L4) through manual operation.

[0255] In contrast, in case (b), even if the driving assistance device 19 determines that the autonomous lane change cannot be executed, it does not notify the driver of this impossibility. If the conditions for enabling autonomous lane change control (autonomous lane change control activation) are not met, assistance based on autonomous lane change control, which is based on the functions of the lane change unit 422, overtaking unit 423, and line driving unit 424 of the driving assistance device 19, is already ineffective. Therefore, the driver is not notified of whether the autonomous lane change can be executed. Furthermore, in such a situation, the driver generally does not intend to execute an autonomous lane change. In other words, if a driver who does not intend to execute an autonomous lane change is notified of the impossibility of the autonomous lane change, the driver may be confused as to why they were notified of something that should be taken for granted, which may lead to a feeling of discomfort or unhappiness.

[0256] However, in Figure 9 In the driving scenario shown, when a vehicle enters lane L4 from lane L2, which is the main lane, via lane L3, the driver may also expect to use autonomous lane change control to perform a second lane change (from lane L3 to lane L4) even after the first lane change (from lane L2 to lane L3) has been executed using autonomous lane change control. In particular, in driving scenarios where lane changes are repeated over a short period of time, it is difficult to notify the driver whether autonomous lane changes are possible each time the vehicle changes. Therefore, even if the conditions for enabling autonomous lane change control are not met, the driver may expect to use autonomous lane change control to perform the second lane change, similar to the first lane change.

[0257] On the other hand, if the conditions for enabling autonomous lane change control are not met, the driving assistance device 19 does not notify the driver that autonomous lane change is not possible, in order to avoid notifying the driver of a situation that would be unavoidable. Furthermore, the lane keeping control performed by the lane keeping unit 421 causes the vehicle V, which is traveling in lane L3, to proceed straight ahead. Therefore, even after passing the branch point B2, the vehicle V continues to travel straight ahead in lane L3, and a second lane change (from lane L3 to lane L4) is not performed unless the driver manually operates the lane change. Furthermore, even if the driver recognizes the need for a second lane change through manual operation after the vehicle V passes the branch point B2, the driving distance required for the lane change cannot be guaranteed, and the second lane change cannot be completed.

[0258] Thus, in the route travel assist control of the present embodiment, in addition to the functions of the acquisition section 3 and the assist section 4, the functions of the determination section 5 and the notification section 6 are used, whereby the driver's sense of discomfort due to a discrepancy between the autonomous travel control expected by the driver (particularly, a lane change based on autonomous lane change control) and the actual autonomous travel control is suppressed. Hereinafter, the functions of the determination section 5 and the notification section 6 will be described.

[0259] The determination section 5 has a function of determining whether a second lane change is needed for traveling along the set travel path after a first lane change by autonomous lane change control using autonomous travel control in a travel scenario in which multiple lane changes are successively performed, such as a travel scenario in which a further branched lane is branched from a certain branched lane. Successively performing multiple lane changes means performing multiple lane changes in succession, and does not necessarily have to be continuous movement of the vehicle in a direction perpendicular to the direction of travel (hereinafter, also referred to as "lateral direction"). That is, straight travel using lane keeping control by the lane keeping section 421 can be included between a certain lane change and the next lane change. Also, the first lane change can be a lane change for traveling along the set travel path.

[0260] The travel path for the host vehicle V to travel to the destination is generated by the navigation device 15. The travel assist device 19 acquires the travel path from the navigation device 15 by the function of the determination section 5. Then, based on the acquired travel path, the map information 13, and information of the current position of the host vehicle V acquired from the host position detection device 14, it is determined whether a lane change is needed.

[0261] Specifically, first, based on the road information of the map information 13 and the information of the current position of the host vehicle V, it is determined whether the number of lanes of the road ahead of the travel direction of the road on which the host vehicle V is traveling increases. For example, in a case where the road on which the host vehicle V is traveling branches into a main lane and a branched lane ahead of the current position of the host vehicle V, it is determined that the number of lanes of the road increases. As another example, in a case where another lane merges with the main lane on which the host vehicle V is traveling ahead of the current position of the host vehicle V, it is determined that the number of lanes of the road increases. Also, as another example, in a case where a crossroad exists ahead of the host vehicle V, in a case where the lane on which the host vehicle V is traveling branches into a straight-only lane and a right-turn-only lane just before the crossroad, it is determined that the number of lanes of the road increases. In contrast, in a case where a bridge exists ahead of the host vehicle V, when the lane on which the host vehicle V is traveling merges with the adjacent lane just before the bridge as the width decreases, it is determined that the number of lanes of the road decreases. Also, in a case where there is no branching position and no merging position of lanes ahead of the current position of the host vehicle V, it is determined that the number of lanes of the road does not change.

[0262] Next, the travel assist device 19 determines whether the added lane is directed to a different place from other lanes in a case where the number of lanes of the road on which the host vehicle V travels in front of the host vehicle V is increased. For example, in a case where an automobile exclusive road on which the host vehicle V travels branches into a main lane that straight travels on the automobile exclusive road and a branch lane that exits from the automobile exclusive road in front of the current position of the host vehicle V, the place to which the added lane, i.e., the branch lane is directed is a general road, and is directed to a different place from the main lane that is an automobile exclusive road. Thus, it is determined that the added lane, i.e., the branch lane is directed to a different place from other lanes, i.e., the main lane. In contrast, in a case where other lanes merge with the main lane on which the host vehicle V travels in front of the current position of the host vehicle V on the automobile exclusive road, the place to which the other lanes that are added lanes and the main lane that is other lanes are directed is the same. Thus, it is determined that the added lanes and the main lane are directed to the same place.

[0263] Next, the travel assist device 19 determines whether the host vehicle V needs to enter the added lane in order to be directed to the set destination, based on the information of the current position of the host vehicle V acquired from the host position detection device 14 and the travel route acquired from the navigation device 15. For example, in a case where the road on which the host vehicle V travels branches into a main lane and a branch lane in front of the current position of the host vehicle V, when a travel route on which the host vehicle V travels on the main lane is set, it is determined that the host vehicle V does not need to enter the added lane. In contrast, in a case where the road on which the host vehicle V travels branches into a main lane and a branch lane in front of the current position of the host vehicle V, when a travel route on which the host vehicle V enters the branch lane is set, it is determined that the host vehicle V needs to enter the added lane, i.e., the branch lane.

[0264] In Figure 9 In the travel scenario shown in FIG. 10, since the host vehicle V travels at the position PI of the lane L2, the road on which the host vehicle V travels branches into the main lane L2 and the branch lane L3 at the branch position Bl in front of the current position, i.e., the position PI, of the host vehicle V. Thus, the number of lanes of the road is increased. In addition, since the added lane, i.e., the branch lane L3 is directed to a different place from the lane L2, the main lane L2 and the branch lane L3 are directed to different places. Further, the travel route to the destination Px is set to need to enter the branch lane L3. Thus, the travel assist device 19 determines that the host vehicle V needs to make a lane change from the lane L2 to the lane L3.

[0265] The above-mentioned method for determining whether a lane change is necessary is applicable to either the first lane change or the second lane change. For example, if the vehicle V performs the first LCP along the trajectory T2 and ends the LCP at position P3, then since the vehicle V is traveling at position P3 in lane L3, the road on which the vehicle V is traveling branches into lane L3 and branch lane L4 at the branch position B2 in front of the current position of the vehicle V, i.e., position P3. Therefore, the number of lanes on the road increases. In addition, since the added lane, branch lane L4, faces a different location from lane L3, lane L3 and branch lane L4 face different locations. Furthermore, the driving path toward the destination Px is set to require entering branch lane L4. Therefore, the driving assistance device 19 determines that the vehicle V needs to change lanes from lane L3 to lane L4.

[0266] The determination unit 5 has a function of determining whether the distance from the position where the first lane change ends to the position where the second lane change can start is less than a predetermined distance, especially in the second lane change. Hereinafter, the position where the first lane change ends is also referred to as the "first position", and the position where the second lane change can start is also referred to as the "second position". Specifically, the first position is the position where the LCM or LCP of the first lane change ends. Figure 9 In the driving scenario shown, the position P3 where the first LCP ends is the first position. In addition, the first position can also be any position between the position where the LCM ends and the position where the LCP ends. On the other hand, the second position is the position of the LCM or LCP where the second lane change can be started. Figure 9 In the driving scenario shown, the branch position B2 is the second position. Alternatively, the second position may be the position where the number of lanes on the road increases, the position where the road width begins to increase in the case of a road branch, or the position where the lanes begin to branch in the case of a lane branch.

[0267] The distance from the first position to the second position is, for example, Figure 7 The distance D1 shown here is the distance along the direction of travel of the road on which the vehicle V is traveling (the direction of arrow A). The prescribed distance can be set to an appropriate value within a range that allows the driver to appropriately recognize that a driving scenario involves multiple lane changes. The prescribed distance is, for example, 500 to 1000 meters. If the prescribed distance is set longer than this, the driving distance from the end of the first lane change to the start of the second lane change will be longer, and the driver will not be able to recognize that two lane changes have been made in succession, which may cause discomfort.

[0268] When the determination section 5 determines that the distance Dl from the first position to the second position exceeds the prescribed distance, the assist section 4 causes the host vehicle V to travel straight ahead using the lane keeping control of the lane keeping section 421. In contrast, when the determination section 5 determines that the distance Dl from the first position to the second position is equal to or less than the prescribed distance, the assist section 4 determines whether the assistance based on the autonomous lane change control is effective for the second lane change. Specifically, for the second lane change, it is determined whether the condition for making the assistance based on the autonomous lane change control effective (i.e., the autonomous lane change control is activated) is satisfied.

[0269] The condition for making the assistance based on the autonomous lane change control effective refers to a condition for performing the lane change without causing the occupants including the driver to feel discomfort or unpleasantness, and is a condition for not causing the front-rear direction and the left-right direction of the host vehicle V to change greatly in the execution of the autonomous lane change. This condition is, for example, the condition (1) for switching to the autonomous steering control / handling mode and the condition (9) for switching to the lane change mode shown in FIG. 6. Figure 9

[0270] ​The conditions for making the assistance for the autonomous lane change control effective include, for example, detecting lane marks on both sides of the host vehicle V, the driver holding the steering wheel, the host vehicle V traveling near the center of the lane, the turn signal not being operated, the wiper not being operated at high speed (HI) (i.e., no strong rain or snow is observed around the host vehicle V), the road on which the host vehicle V travels being a road on which a high-precision map can be used (particularly, a road on which the host vehicle V travels from the start of the autonomous lane change to the end can use a high-precision map), no toll gate, exit, merging point, intersection, or lane number reduction point being present within about 200 km ahead in the case where a high-precision map can be used, the road on which the host vehicle V travels from the start of the autonomous lane change to the end not being registered in the high-precision map information as a road on which autonomous lane change cannot be performed, the host vehicle V traveling at a travel speed within a prescribed range (e.g., a travel speed of 1 to 30 km / h or more and 40 to 70 km / h or less), the GPS signal being valid, the radius of curvature of the road on which the host vehicle V travels from the start of the autonomous lane change to the end being a prescribed value (e.g., 200 to 1000 m) or more, no sharp turn of 100 R or less being present within about 500 m ahead, the host vehicle V not traveling in a tunnel more than 500 m from the tunnel entrance, the host vehicle V not traveling on a route proposed by the route travel assistance control of the route travel section 424, and the driver operating the lane change assistance switch 176. The driver operating the direction indicator lever or the like in order to execute the autonomous lane change control. Specifically, the assistance section 4 determines that the assistance based on the autonomous lane change control is effective in the case where the high-precision map information can be used for the road on which the host vehicle V travels from the start of the lane change based on the autonomous lane change control to the end. In this embodiment, the space for the host vehicle V to enter the adjacent lane can also not be included in the conditions for making the assistance for the autonomous lane change control effective in the case where the adjacent lane exists. In this case, whether or not the space for the host vehicle V to enter the adjacent lane is determined separately as whether or not the lane change is possible.

[0271] Alternatively, the assistance unit 4 may determine that assistance based on autonomous lane change control is effective based on the following conditions: the radius of curvature of the road on which the host vehicle V is traveling from the start to the end of the lane change based on autonomous lane change control is greater than or equal to a predetermined value; the road is not registered in the high-precision map information as a road where lane change based on autonomous lane change control is not permitted; the speed of the host vehicle V is within a predetermined range; and the behavior of the host vehicle V during the lane change based on autonomous lane change control is within a range that can be controlled by autonomous lane change control. The speed of the host vehicle V being within the predetermined range means that the speed of the host vehicle V is within a range in which autonomous steering control by the steering control unit 42 can be performed. For example, the speed of the host vehicle V is between 10 and 30 km / h or higher and between 60 and 80 km / h or lower. Furthermore, the range within which the behavior of the host vehicle V can be controlled by autonomous lane change control is defined by at least one of the acceleration, deceleration, and lateral acceleration of the host vehicle V. Appropriate values ​​can be set for each of these values ​​within a range that does not cause discomfort to occupants, including the driver. Furthermore, since the behavior of the host vehicle V may deviate from the range within which it can be controlled by autonomous lane change control due to the shape of the road on which the host vehicle V is traveling, roads where the behavior of the host vehicle V varies significantly can be pre-registered in the high-precision map information as roads where autonomous lane change control is not possible.

[0272] Furthermore, the conditions for enabling the assistance based on autonomous lane change control include: the distance from the first position to the position where the second lane change cannot be performed is longer than the driving distance required for executing LCP or LCM (for example, 700 to 1500 meters). Figure 9 In the driving scenario shown, position B3 is where lanes L3 and L4 are separated. The distance from the first position to the position where the second lane change cannot be performed is Figure 9 The distance D2 shown is along the travel direction (direction of arrow A) of the road on which the host vehicle V is traveling. After passing position B3, a lane change from lane L3 to lane L4 is not possible. Therefore, the host vehicle V needs to change lanes before reaching position B3.

[0273] Furthermore, changing lanes before reaching position B3 means that, when viewed from above, the entire body of the vehicle V is contained within lane L4 before the rear end of the vehicle V reaches position B3. In other words, LCM only needs to be completed before the rear end of the vehicle V reaches position B3; LCP does not necessarily need to be completed. Distances D1 and D2 can be set to appropriate values. Distance D1 is set to be shorter than distance D2.

[0274] If the assistance unit 4 determines that the aforementioned conditions for enabling autonomous lane change control assistance are met, it determines that autonomous lane change control assistance is valid for the second lane change. Then, the lane-traveling unit 424 performs lane-traveling assistance control, executing the autonomous lane change as the second lane change. In contrast, if the conditions for enabling autonomous lane change control assistance are determined not to be met, it determines that autonomous lane change control assistance is invalid for the second lane change. In this case, the second lane change is performed manually by the driver. In this case, to urge the driver to manually change lanes, the notification unit 6 notifies the driver that the autonomous lane change is not possible. This notification is made using an output device 18, such as a display or speaker within the instrument panel.

[0275] In addition, when the assistance unit 4 determines that the assistance based on the autonomous lane change control is effective for the second lane change, it determines whether the lane change can be made from the host lane to the adjacent lane (that is, whether the host vehicle V can actually enter the adjacent lane). Figure 10 In the illustrated driving scenario, lane L3, in which the host vehicle V is traveling, is the host lane, and lane L4, adjacent to lane L3, is the adjacent lane. When determining whether the host vehicle V can change lanes from lane L3 to lane L4, the acquisition unit 3 uses the camera 11 and the distance measuring device 12 to detect a space for the host vehicle V to enter the adjacent lane (i.e., lane L4). This space is sufficient to ensure at least the distance required for the host vehicle V to complete the LCM.

[0276] If the driving assistance device 19 can detect space for the vehicle V to enter the adjacent lane (lane L4) through the function of the acquisition unit 3, it determines that a lane change from the vehicle V's lane (lane L3) to the adjacent lane (lane L4) is possible. Then, the autonomous lane change is performed through the function of the assistance unit 4 (particularly the path-traveling unit 424). In contrast, if the driving assistance device 19 cannot detect such space, it determines that a lane change from the vehicle V's lane (lane L3) to the adjacent lane (lane L4) is not possible. In this case, the driving assistance device 19 notifies the driver of the impossibility of an autonomous lane change through the function of the notification unit 6.

[0277] Next, refer to Figure 10 , explaining the processing in route driving assistance control. Figure 8 yes Figure 10 The subroutine of step S20 in the flowchart shown. ​ The subroutine shown is merely an example and is not limited thereto. The CPU (processor) 191 of the driving assistance device 19 executes the processing described below at predetermined time intervals.

[0278] First, in step S31, the travel route generated by the navigation device 15 is acquired by the function of the acquisition section 3, and is set as the travel route. In the next step S32, the host vehicle V is caused to travel along the travel route by the function of the route travel section 424 using the vehicle control device 16. In the next step S33, it is determined whether the number of lanes of the road ahead in the travel direction of the road on which the host vehicle V is traveling increases using the map information 13 and the host vehicle position detection device 14 by the function of the route travel section 424. In the case where it is determined that the number of lanes of the road ahead in the travel direction of the road on which the host vehicle V is traveling increases, step S34 is entered. In contrast, in the case where it is determined that the number of lanes of the road ahead in the travel direction of the road on which the host vehicle V is traveling does not change or decreases, step S3 is returned to.

[0279] In step S34, it is determined whether the added lane is directed toward a location different from the other lanes using the map information 13. In the case where it is determined that the added lane is directed toward a location different from the other lanes, step S35 is entered. In contrast, in the case where it is determined that the added lane is directed toward a location the same as the other lanes, step S3 is returned to.

[0280] In step S35, it is determined whether the host vehicle V needs to enter the added lane in order to head toward the set destination based on the information of the current position of the host vehicle V and the travel route. In the case where it is determined that the host vehicle V needs to enter the added lane, step S36 is entered. In contrast, in the case where it is determined that the host vehicle V does not need to enter the added lane, step S3 is returned to.

[0281] In step S36, it is determined whether the lane change can be assisted by autonomous lane change control by the function of the assistance section 4, particularly the route travel section 424. The detection results of the map information 13 and the on-vehicle sensor 163 are used in this determination. In the case where it is determined that the lane change can be assisted by autonomous lane change control, step S37 is entered, and autonomous lane change is executed. The lane change of step S37 corresponds to the first lane change. Also, in step S37, it is premised that the space for the host vehicle V to enter the adjacent lane can be detected, but in the case where the space cannot be detected, autonomous lane change is not executed and step S3 is returned to. In contrast, in the case where it is determined that the lane change cannot be assisted by autonomous lane change control, step S3 is returned to.

[0282] After autonomous lane change is executed in step S37, step S38 is entered, and it is determined whether the number of lanes of the road ahead in the travel direction of the road on which the host vehicle V is traveling increases in the same manner as in step S33. Also, since steps S38 to S40 are the same processing as steps S33 to S35, respectively, the explanation is omitted.

[0283] In step S41, it is determined by the function of the determination section 5 whether the distance Dl from the first position at which the first lane change is ended to the second position at which the second lane change can be started is equal to or less than a prescribed distance. In the case where it is determined that the distance Dl is equal to or less than the prescribed distance, step S42 is entered. In contrast, in the case where it is determined that the distance Dl exceeds the prescribed distance, step S3 is returned to.

[0284] In step S42, it is determined by the function of the assistance section 4 whether a condition for making the autonomous lane change control effective (activated) for the second lane change is satisfied. In the case where it is determined that the autonomous lane change control effective condition is satisfied, step S43 is entered. In contrast, in the case where it is determined that the autonomous lane change control effective condition is not satisfied, step S45 is entered, and the driver is notified by the function of the notification section 6 that the lane change cannot be performed by the autonomous lane change control.

[0285] In step S43, the space for the host vehicle V to enter the adjacent lane is detected by the function of the acquisition section 3 using the camera 11 and the distance measuring device 12. In the case where the space for the host vehicle V to enter the adjacent lane can be detected (i.e., the space exists, and the host vehicle V can enter the adjacent lane), step S44 is entered, and the autonomous lane change is performed. The lane change of step S44 corresponds to the second lane change. In contrast, in the case where the space for the host vehicle V to enter the adjacent lane cannot be detected (i.e., the space does not exist, and the host vehicle V cannot enter the adjacent lane), step S45 is entered. Then, when the processing of step S44 and step S45 is ended, step S3 is returned to.

[0286] (Embodiment of the Invention)

[0287] As described above, according to the present embodiment, a travel assistance method of a vehicle is provided, in which, in a travel assistance method of a vehicle using autonomous lane change control that performs lane changing by autonomous travel control, which is executed by a processor, in a case where second lane changing is performed for traveling along a set travel path after first lane changing using the autonomous lane change control, it is determined whether a distance Dl from a position at which the first lane changing ends to a position at which the second lane changing can be started is equal to or less than a predetermined distance, in a case where it is determined that the distance is equal to or less than the predetermined distance, it is determined whether assistance based on the autonomous lane change control is effective for the second lane changing, in a case where it is determined that the assistance based on the autonomous lane change control is effective, it is determined whether lane changing from a current lane in which the vehicle is traveling to an adjacent lane adjacent to the current lane is possible, in a case where it is determined that the lane changing from the current lane to the adjacent lane is possible, the second lane changing is performed by the autonomous lane change control, in a case where it is determined that the lane changing from the current lane to the adjacent lane is not possible, the driver is notified that lane changing based on the autonomous lane change control is not possible, and in a case where it is determined that the assistance based on the autonomous lane change control is not effective, the driver is notified that lane changing based on the autonomous lane change control is not possible. Thus, the driver can be appropriately informed of whether lane changing using autonomous travel control is possible or not. In addition, the driver's discomfort due to a discrepancy between autonomous travel control (particularly, autonomous lane changing) expected by the driver and actual autonomous travel control can be suppressed.

[0288] In addition, in the travel assistance method of a vehicle according to the present embodiment, in a case where it is determined whether lane changing from the current lane to the adjacent lane is possible, a space for entering the adjacent lane by the vehicle is detected, in a case where the space can be detected, it is determined that lane changing from the current lane to the adjacent lane is possible, and in a case where the space cannot be detected, it is determined that lane changing from the current lane to the adjacent lane is not possible. Thus, whether lane changing is possible or not can be more correctly determined.

[0289] In addition, in the travel assistance method of a vehicle according to the present embodiment, in a case where high-precision map information can be used for a road on which the vehicle travels from the start of lane changing based on the autonomous lane change control to the end, it is determined that assistance based on the autonomous lane change control is effective. Thus, whether autonomous lane changing is possible or not can be more correctly determined.

[0290] Further, in the travel assistance method for a vehicle of the present embodiment, the range is set by at least one of an acceleration, a deceleration, and a lateral acceleration of the vehicle. Thus, it is possible to more correctly determine whether autonomous lane change can be performed.

[0291] Further, in the travel assistance method for a vehicle of the present embodiment, the range is set by at least one of an acceleration, a deceleration, and a lateral acceleration of the vehicle. Thus, it is possible to more correctly determine whether autonomous lane change can be performed.

[0292] Further, according to the present embodiment, a travel assistance device 19 for a vehicle is provided, which includes: a determination section 5 that determines whether a distance Dl from a position at which a first lane change ends to a position at which a second lane change can be started is equal to or less than a predetermined distance, in a case where the second lane change is performed in order to travel along a set travel path after the first lane change is performed by autonomous lane change control that performs lane change by using autonomous travel control; an assistance section 4 that determines whether assistance based on the autonomous lane change control is effective for the second lane change when the determination section 5 determines that the distance Dl is equal to or less than the predetermined distance, and determines whether lane change from a current lane in which the vehicle travels to an adjacent lane adjacent to the current lane is possible when it is determined that assistance based on the autonomous lane change control is effective, and performs the second lane change by the autonomous lane change control when it is determined that lane change from the current lane to the adjacent lane is possible; and a notification section 6 that notifies a driver of a situation in which lane change based on the autonomous lane change control is not possible when the assistance section 4 determines that lane change from the current lane to the adjacent lane is not possible, and notifies the driver of a situation in which lane change based on the autonomous lane change control is not possible when the assistance section 4 determines that assistance based on the autonomous lane change control is not effective for the second lane change. Thus, it is possible to notify the driver of appropriate information depending on whether lane change using autonomous travel control can be performed. Further, it is possible to suppress a sense of discomfort of the driver due to inconsistency between autonomous travel control (particularly, autonomous lane change) expected by the driver and actual autonomous travel control.

[0293] Explanation of Symbols

[0294] 1: Travel assist system

[0295] 11: Imaging device

[0296] 12: Distance measuring device

[0297] 13: Map information

[0298] 14: Host vehicle position detection device

[0299] 15: Navigation device

[0300] 16: Vehicle control device

[0301] 161: Vehicle speed control device

[0302] 162: Steering control device

[0303] 163: Onboard sensor

[0304] 17: Input device

[0305] 171: Main switch

[0306] 172: Recovery / acceleration switch

[0307] 173: Set / slide switch

[0308] 174: Cancel switch

[0309] 175: Inter-vehicle adjustment switch

[0310] 176: Lane change assist switch

[0311] 18: Output device

[0312] 19: Travel assist device

[0313] 191: CPU (processor)

[0314] 192: ROM

[0315] 193: RAM

[0316] 2: Control section

[0317] 3: Acquisition section

[0318] 4: Assist section

[0319] 41: Speed control section

[0320] 42: Steering control section

[0321] 421: Lane keeping section

[0322] 422: Lane changing section

[0323] 423: Overtaking section

[0324] 424: Route traveling section

[0325] 5: Determining section

[0326] 6: Notifying section

[0327] A: Arrow (direction of travel)

[0328] B1, B2: Branching position

[0329] B3: Position

[0330] D1, D2: Distance

[0331] L1, L2, L3, L4: Lane

[0332] P1, P2, P3, P4: Position

[0333] Px: Destination

[0334] T1, T2, T3: Trajectory

[0335] V: Own vehicle

Claims

1. A vehicle driving assistance method using a processor that performs autonomous lane change control based on a driving route to a destination obtained from a navigation device, wherein: The processor performs the following processing: In order to travel along the driving route, when a second lane change is performed after a first lane change is performed by the autonomous lane change control, determining whether a distance from a position where the first lane change ends to a position where the second lane change can be started is less than or equal to a predetermined distance; determining whether the assistance based on the autonomous lane change control is effective for the second lane change; If it is determined that the assistance based on the autonomous lane change control is invalid for the second lane change, the second lane change based on the autonomous lane change control is not performed as a principle, and the driver is not notified that the lane change based on the autonomous lane change control is not possible. Even when it is determined that the assistance based on the autonomous lane change control is invalid for the second lane change, when it is determined that the distance is less than the prescribed distance, as an exception to the principle, the second lane change based on the autonomous lane change control is not performed, and the driver is notified that the lane change based on the autonomous lane change control cannot be performed.

2. The vehicle driving assistance method according to claim 1, wherein: The processor performs the following processing: When determining whether a lane change from a lane in which the vehicle is traveling to an adjacent lane adjacent to the lane is possible, detecting a space for the vehicle to enter the adjacent lane, When the space can be detected, it is determined that a lane change from the own lane to the adjacent lane is possible. If the space cannot be detected, it is determined that a lane change from the own lane to the adjacent lane is not possible.

3. The vehicle driving assistance method according to claim 1 or 2, wherein: If high-precision map information is available for the road on which the vehicle travels from the start to the end of the lane change by the autonomous lane change control, it is determined that the assistance by the autonomous lane change control is valid.

4. The vehicle driving assistance method according to any one of claims 1 to 3, wherein: The conditions for determining that the assistance based on the autonomous lane change control is valid are as follows: the curvature radius of the road on which the vehicle is traveling is greater than or equal to a predetermined value from the start to the end of the lane change based on the autonomous lane change control; The road is not registered in high-precision map information as a road on which lane change by the autonomous lane change control is not possible; The driving speed of the vehicle is within the prescribed range; During execution of the lane change based on the autonomous lane change control, the behavior of the vehicle is within a range controllable by the autonomous lane change control.

5. The vehicle driving assistance method according to claim 4, wherein: The range is set based on at least one of acceleration, deceleration, and lateral acceleration of the vehicle.

6. A driving assistance device for a vehicle that performs autonomous lane change control based on a driving route to a destination acquired from a navigation device, wherein: The driving assistance device of the vehicle comprises: a determination unit configured to determine whether, when a second lane change is performed after a first lane change is performed by autonomous lane change control in order to travel along the driving route, a distance from a position where the first lane change is completed to a position where the second lane change can be started is less than or equal to a predetermined distance; an assisting unit configured to determine whether assistance based on the autonomous lane change control is effective for the second lane change; a notification unit configured to notify the driver that the lane change based on the autonomous lane change control cannot be performed, When the assist unit determines that the assistance based on the autonomous lane change control is invalid for the second lane change, the assist unit does not perform the second lane change based on the autonomous lane change control as a principle, and the notification unit does not notify the driver that the lane change based on the autonomous lane change control is not possible. Even when the assist unit determines that the assistance based on the autonomous lane change control is invalid for the second lane change, when the determining unit determines that the distance is less than the prescribed distance, the assist unit does not perform the second lane change based on the autonomous lane change control as an exception to the principle, and the notification unit notifies the driver that the lane change based on the autonomous lane change control cannot be performed.

Images