JP7776009B2 - Vehicle driving assistance method and driving assistance device - Google Patents

Description

The present invention relates to a vehicle driving assistance method and driving assistance device.

A driving assistance device is known that includes a lane keeping unit that assists in steering the vehicle so that the vehicle stays within the driving lane, and a lane changing unit that assists in steering the vehicle so that the vehicle changes lanes from the driving lane to another lane, and that determines whether to discontinue steering assistance by the lane keeping unit or steering assistance by the lane changing unit based on the driver's steering amount (Patent Document 1). This driving assistance device discontinues steering assistance by the lane keeping unit when the driver's steering amount exceeds a lane keeping discontinuation threshold, and discontinues steering assistance by the lane changing unit when the driver's steering amount exceeds a lane change discontinuation threshold that is greater than the lane keeping discontinuation threshold.

Japanese Patent Application Laid-Open No. 2015-205558

However, the above-mentioned conventional technology does not describe when to change the threshold for discontinuing steering assistance to a larger value, so steering assistance may be discontinued even in driving situations where autonomous lane change control should continue.

The problem that this invention aims to solve is to provide a vehicle driving assistance method and driving assistance device that can prevent the driver's steering operation from causing autonomous steering control to be discontinued in driving situations where autonomous lane change control should be continued.

The present invention provides a method for executing autonomous steering control including a first autonomous steering control for maintaining the vehicle traveling along its own lane, and a second autonomous steering control for changing lanes from the own lane to another lane, by setting a predetermined stop condition for the first autonomous steering control, and stopping the first autonomous steering control if a steering operation of the driver input during execution of the first autonomous steering control satisfies the predetermined stop condition for the first autonomous steering control, and stopping the second autonomous steering control after the start of the second autonomous steering control and before the vehicle starts moving in the width direction of the own lane , under conditions that are less likely to be stopped than the predetermined stop condition for the first autonomous steering control. The above problem is solved by setting a predetermined condition for stopping the autonomous steering control , and if a steering operation is detected after the second autonomous steering control is started and before the vehicle starts moving in the width direction of the own lane, determining whether the steering operation satisfies the predetermined condition for stopping the second autonomous steering control, and stopping the second autonomous steering control if it is determined that the steering operation satisfies the predetermined condition for stopping the second autonomous steering control , and correcting the lane change driving operation by the second autonomous steering control based on the steering operation if it is determined that the steering operation does not satisfy the predetermined condition for stopping the second autonomous steering control.

According to the present invention, it is possible to prevent the driver's steering operation from causing the autonomous steering control to be discontinued in driving situations where autonomous lane change control should be continued.

1 is a block diagram showing a driving assistance system including a driving assistance device according to the present invention; 2 is a plan view showing an example of a driving scene in which driving assistance is performed by the driving assistance system shown in FIG. 1 . 1. FIG. 4 is a plan view (part 1) showing another example of a driving scene in which driving assistance is performed by the driving assistance system shown in FIG. FIG. 2 is a plan view showing another example of a driving scene in which driving assistance is performed by the driving assistance system shown in FIG. 1 (part 2). 1. FIG. 4 is a plan view showing still another example of a driving scene in which driving assistance is performed by the driving assistance system shown in FIG. FIG. 2 is a block diagram showing state transitions of autonomous driving control in the driving assistance device of FIG. 1 . 2 is a flowchart showing an example of a processing procedure in the driving assistance system of FIG. 1 (part 1); 10 is a flowchart showing an example of a processing procedure in the driving assistance system of FIG. 1 (part 2);

Embodiments of the present invention will be described below with reference to the drawings. The following description is based on the assumption that vehicles drive on the left side of the road in countries with left-hand traffic regulations. In countries with right-hand traffic regulations, vehicles drive on the right side of the road, so the left and right in the following description should be interpreted as symmetrical.

[Configuration of driving assistance system]
FIG. 1 is a block diagram showing a driving assistance system 10 according to the present invention. The driving assistance system 10 is an in-vehicle system that drives a vehicle to a destination set by the vehicle's occupants (including the driver) through autonomous driving control. Autonomous driving control refers to autonomously controlling the vehicle's driving behavior using a driving assistance device (described later). The driving behavior includes all driving behaviors, such as acceleration, deceleration, starting, stopping, steering to the right or left, changing lanes, and pulling over. Furthermore, autonomously controlling driving behavior refers to the driving assistance device controlling the driving behavior using a vehicle's device. The driving assistance device controls these driving behaviors within a predetermined range, and driving behaviors not controlled by the driving assistance device are manually operated by the driver. In this embodiment, autonomous driving using autonomous driving control to change lanes from the vehicle's own lane to a lane other than the vehicle's own lane (e.g., an adjacent lane) is specifically referred to as autonomous lane change control, and lanes other than the vehicle's own lane are also referred to as other lanes.

The vehicles mentioned above include not only private vehicles but also vehicles dispatched by ride-hailing services. A ride-hailing service refers to the allocation and dispatch of a vehicle to a user to transport the user from their boarding location to their disembarking location. Examples include the dispatch of manned and unmanned taxis, the dispatch of vehicles used for shuttle services at airports, stations, and hotels, and the dispatch of vehicles used for rental cars and ride-sharing services. Hereinafter, the "own vehicle" will also be referred to simply as the "vehicle."

As shown in Figure 1, the driving assistance system 10 comprises an imaging device 11, a distance measuring device 12, a vehicle state detection device 13, map information 14, a vehicle position detection device 15, a navigation device 16, a vehicle control device 17, a display device 18, and a driving assistance device 19. The devices that make up the driving assistance system 10 are connected via a CAN (Controller Area Network) or other in-vehicle LAN, and can exchange information with each other.

The imaging device 11 is a device that recognizes objects around the vehicle using images, and is, for example, a camera equipped with an imaging element such as a CCD, an ultrasonic camera, or an infrared camera. Multiple imaging devices 11 can be installed on a single vehicle, and can be placed, for example, near the front grille, the bottom of the left and right door mirrors, and the rear bumper. This reduces blind spots when recognizing objects around the vehicle.

The ranging device 12 is a device for calculating the relative distance and relative speed between the vehicle and an object, and is, for example, a radar device or sonar such as laser radar, millimeter-wave radar (such as LRF), a LiDAR (light detection and ranging) unit, or ultrasonic radar. Multiple ranging devices 12 can be installed on a single vehicle, and can be placed, for example, at the front, right side, left side, and rear of the vehicle. This allows the relative distance and relative speed between the vehicle and surrounding objects to be accurately calculated.

Objects detected by the imaging device 11 and distance measuring device 12 include road lane boundaries, center lines, road markings, medians, guardrails, curbs, highway sidewalls, road signs, traffic lights, crosswalks, construction sites, accident sites, traffic restrictions, etc. Objects also include obstacles that may affect the vehicle's travel, such as automobiles (other vehicles) other than the vehicle itself, motorcycles, bicycles, pedestrians, etc. The detection results of the imaging device 11 and distance measuring device 12 are obtained by the driving assistance device 19 at predetermined time intervals as necessary.

In addition, the detection results of the imaging device 11 and the ranging device 12 can be integrated or synthesized (so-called sensor fusion) by the driving assistance device 19, thereby supplementing missing information about detected objects. For example, the driving assistance device 19 can calculate the position information of an object using the vehicle's self-position information, which is the position where the vehicle is traveling, obtained by the vehicle position detection device 15, and the relative position (distance and direction) between the vehicle and the object. The calculated position information of the object is integrated by the driving assistance device 19 with multiple pieces of information, such as the detection results of the imaging device 11 and the ranging device 12 and the map information 14, to become information about the driving environment around the vehicle. In addition, the detection results of the imaging device 11 and the ranging device 12 and the map information 14 can be used to recognize objects around the vehicle and predict their movement.

The vehicle state detection device 13 is a device for detecting the vehicle's driving state, and may include a vehicle speed sensor, acceleration sensor, yaw rate sensor (e.g., gyro sensor), steering angle sensor, inertial measurement unit, etc. There are no particular limitations on these devices, and known devices can be used. Furthermore, the placement and number of these devices can be set appropriately within a range that allows appropriate detection of the vehicle's driving state. The detection results of each device are obtained by the driving assistance device 19 at predetermined time intervals as necessary.

Map information 14 is information used for generating driving routes, controlling driving operations, etc., and includes road information, facility information, and their attribute information. Road information and road attribute information include information such as road width, road curvature radius, roadside structures, road traffic regulations (speed limits, whether lane changes are permitted), road merging and branching points, and locations where the number of lanes increases or decreases. Map information 14 is high-definition map information that allows for understanding the movement trajectory for each lane, and includes two-dimensional and/or three-dimensional position information at each map coordinate, road/lane boundary information at each map coordinate, road attribute information, lane incline/decline information, lane identification information, and destination lane information. High-precision maps are also called HD (High-Definition) maps.

Road/lane boundary information in high-resolution map information indicates the boundaries between the lane on which a vehicle travels and other roads. A lane on which a vehicle travels is a road along which the vehicle travels, and there are no particular restrictions on the form of the lane. Boundaries exist on both the left and right sides of the vehicle's direction of travel, and there are no particular restrictions on the form. Boundaries are, for example, road markings or road structures. Road markings include lane boundaries and center lines, and road structures include medians, guardrails, curbs, tunnels, and highway sidewalls. At points where lane boundaries cannot be clearly identified, such as within intersections, boundaries are set for the lane in advance. These boundaries are imaginary and are not actually existing road markings or road structures.

The map information 14 is stored in a readable state on a recording medium provided in the driving assistance device 19, an in-vehicle device, or a server on the network. The driving assistance device 19 acquires the map information 14 as needed.

The vehicle position detection device 15 is a positioning system for detecting the current position of the vehicle, and is not particularly limited and any known system can be used. The vehicle position detection device 15 calculates the current position of the vehicle, for example, from radio waves received from a GPS (Global Positioning System) satellite. The vehicle position detection device 15 may also estimate the current position of the vehicle from vehicle speed information and acceleration information obtained from the vehicle state detection device 13, which includes a vehicle speed sensor, acceleration sensor, and gyro sensor, and compare the estimated current position with the map information 14 to calculate the current position of the vehicle.

The navigation device 16 is a device that refers to map information 14 and calculates a driving route from the current position of the vehicle detected by the vehicle position detection device 15 to a destination set by the occupants (including the driver). The navigation device 16 uses road information, facility information, etc. from the map information 14 to search for a driving route for the vehicle to reach the destination from its current position. The driving route includes at least information on the road the vehicle is traveling on, the driving lane, and the vehicle's driving direction, and is displayed, for example, linearly. Depending on the search conditions, there may be multiple driving routes. The driving route calculated by the navigation device 16 is output to the driving assistance device 19.

The vehicle control device 17 is an on-board computer such as an electronic control unit (ECU), which electronically controls on-board equipment that governs the vehicle's driving. The vehicle control device 17 includes a speed control device 171 that controls the vehicle's driving speed, and a steering control device 172 that controls the vehicle's steering operation. The speed control device 171 and the steering control device 172 autonomously control the operation of these drive devices and steering devices in response to control signals input from the driving assistance device 19. This allows the vehicle to drive autonomously along a set driving route. Information required for autonomous control by the speed control device 171 and the steering control device 172, such as the vehicle's driving speed, acceleration, steering angle, and attitude, is obtained from the vehicle state detection device 13.

The drive devices controlled by the speed control device 171 include electric motors and/or internal combustion engines that serve as driving sources for driving, power transmission devices including drive shafts and automatic transmissions that transmit output from these driving sources to the drive wheels, and drive devices that control the power transmission devices. Furthermore, the braking devices controlled by the speed control device 171 are, for example, braking devices that brake the wheels. The speed control device 171 receives control signals from the driving assistance device 19 that correspond to the set driving speed. The speed control device 171 generates signals to control these drive devices based on the control signals received from the driving assistance device 19, and transmits these signals to the drive devices, thereby autonomously controlling the vehicle's driving speed.

On the other hand, the steering device controlled by the steering control device 172 is a steering device that controls the steered wheels according to the rotation angle of the steering wheel, and examples include a steering actuator such as a motor attached to the steering column shaft. Based on control signals input from the driving assistance device 19, the steering control device 172 autonomously controls the operation of the steering device so that the vehicle travels while maintaining a predetermined lateral position (the left-right position of the vehicle) relative to the set travel route. This control uses at least one of the detection results of the imaging device 11 and the distance measuring device 12, the vehicle's travel state acquired by the vehicle state detection device 13, and information on the map information 14 and the current position of the vehicle acquired by the vehicle position detection device 15.

The display device 18 is a device for providing necessary information to vehicle occupants, and may be, for example, a liquid crystal display mounted on the instrument panel, a projector such as a head-up display (HUD), or the like. The display device 18 may also include an input device for vehicle occupants to input instructions to the driving assistance device 19. Examples of input devices include a touch panel that receives input by the user's finger or a stylus pen, a microphone that receives instructions by voice from the user, and switches attached to the vehicle's steering wheel. The display device 18 may also include a speaker as an output device.

The driving assistance device 19 is a device that controls the driving of the vehicle by controlling and coordinating the devices that make up the driving assistance system 10, and drives the vehicle to a set destination. The destination is set, for example, by the vehicle's occupants. The driving assistance device 19 is, for example, a computer, and includes a CPU (Central Processing Unit) 191, which is a processor, a ROM (Read Only Memory) 192 in which programs are stored, and a RAM (Random Access Memory) 193, which functions as an accessible storage device. The CPU 191 is an operating circuit that executes the programs stored in the ROM 192 and realizes the functions of the driving assistance device 19.

The driving assistance device 19 has a driving assistance function that drives the vehicle to a set destination through autonomous driving control. The driving assistance functions of the driving assistance device 19 include a route generation function that generates a driving route, an environmental recognition function that recognizes the driving environment around the vehicle, and a driving control function that generates a driving trajectory and drives the vehicle along the driving trajectory. The driving control function includes a vehicle speed control function that autonomously controls the vehicle's driving speed, and a steering control function that autonomously controls the steering of the vehicle. In addition, the driving assistance device 19 has a determination function that determines whether the driver's steering operation satisfies a predetermined cancellation condition.

The programs stored in ROM 192 include programs for realizing the functions described above, and these functions are realized by CPU 191 executing the programs stored in ROM 192. Figure 1 conveniently shows the functional blocks that realize each function.

[Functions of each function block]
The functions of the respective functional blocks of the support unit 20, the generation unit 21, the recognition unit 22, the control unit 23, and the determination unit 24 shown in FIG. 1 will be described below.

The assistance unit 20 has a driving assistance function that drives the vehicle to a set destination through autonomous driving control. Figure 2 is a plan view showing an example of a driving scene in which the driving assistance device 19 autonomously controls the vehicle's driving using the driving assistance function of the assistance unit 20. In the driving scene shown in Figure 2, a two-lane road extends vertically on the drawing, and the vehicle drives on the road from the bottom to the top of the drawing. As shown in Figure 2, the lane on the left side of the driving direction is lane L1, and the lane on the right side of the driving direction is lane L2.

In the driving scene shown in Figure 2, vehicle V is traveling at position P1 on lane L1, heading toward destination X, which is located ahead on lane L2 and has been set by the occupant of vehicle V. In this case, the driving assistance device 19 generates a driving route toward destination X using the driving assistance function of the assistance unit 20, and drives vehicle V along the generated driving route using autonomous driving control. This autonomous driving control is mainly controlled by the functions of the generation unit 21, recognition unit 22, control unit 23, and judgment unit 24.

The generation unit 21 has a route generation function that generates a driving route for the vehicle to travel from the current position to the destination. The generation unit 21 also has a function that sets lanes for the vehicle to travel along the driving route. The driving assistance device 19 uses the navigation device 16, through the route generation function of the generation unit 21, to generate a driving route for the vehicle to travel by autonomous driving control from the current position to the destination. The driving assistance device 19 also sets lanes for traveling along the generated driving route. The driving assistance device 19 obtains information on the generated driving route and the set lanes from the navigation device 16 as necessary.

In the driving scene shown in Figure 2, the driving assistance device 19 obtains position P1, which is the current position of the vehicle V, from the vehicle position detection device 15, obtains road network data from the map information 14, and uses the navigation device 16 to search for a route to travel from position P1 to destination X. If multiple routes are found, the route with the shortest driving time or driving distance is selected.

The recognition unit 22 has an environmental recognition function that recognizes the driving environment around the vehicle. The driving assistance device 19 recognizes the driving environment around the vehicle using the imaging device 11 and distance measuring device 12, using the environmental recognition function of the recognition unit 22. The driving environment is information used to determine whether the vehicle can maintain its current driving state or whether it needs to change its driving state, and includes information such as the type and position of objects, the type and position of obstacles (if any), road conditions such as road surface conditions, and weather. The driving assistance device 19 recognizes the driving environment by performing appropriate processing such as pattern matching and sensor fusion on the detection results of the imaging device 11 and distance measuring device 12.

Alternatively or in addition, the driving assistance device 19 may acquire image data from cameras installed on traffic lights, telephone poles, road signs, etc., and recognize obstacles that exist within a range that cannot be detected by the vehicle's imaging device 11. The driving assistance device 19 may also connect to a server that provides traffic information such as the occurrence of congestion, accidents, and road closures, and recognize obstacles from information acquired from the server. Furthermore, the driving assistance device 19 may use vehicle-to-vehicle communication with other vehicles traveling around the vehicle to recognize obstacles that exist within a range that cannot be detected by the vehicle's imaging device 11.

In the driving scene shown in Figure 2, there are no obstacles around vehicle V. Therefore, the driving assistance device 19 recognizes from the detection results of the imaging device 11 and the distance measuring device 12 that no obstacles are detected around vehicle V, and that the driving environment is one in which there are no objects that obstruct the driving of vehicle V.

The control unit 23 has a driving control function that generates a driving trajectory for driving the vehicle V along the generated driving route and controls the driving operation of the vehicle V so that it follows the generated driving trajectory. The driving assistance device 19 uses the driving control function of the control unit 23 to generate a driving trajectory for driving the vehicle V along the driving route and autonomously controls the driving operation of the vehicle via the vehicle control device 17 (particularly the speed control device 171 and the steering control device 172) so that the vehicle V follows the generated driving trajectory. The generation of the driving trajectory takes into account information such as the shape, width, and curvature of the road contained in the map information 14, as well as the overall length and width of the vehicle body and the minimum turning radius of the vehicle V.

The control unit 23 has a vehicle speed control function that autonomously controls the traveling speed of the vehicle V and a steering control function that autonomously controls the steering of the vehicle V, with the vehicle speed control function being mainly realized by the speed control unit 231 and the steering control function being mainly realized by the steering control unit 232. Hereinafter, the autonomous control of the traveling speed by the speed control unit 231 will also be referred to simply as autonomous speed control, and the autonomous control of the steering by the steering control unit 232 will also be referred to simply as autonomous steering control.

When the driving assistance device 19 detects a preceding vehicle, it causes the vehicle V to follow the preceding vehicle using the vehicle speed control function of the speed control unit 231, while performing vehicle-to-vehicle distance control to maintain a vehicle-to-vehicle distance according to the driving speed, with the upper limit set by the driver. On the other hand, when no preceding vehicle is detected, it performs constant speed driving at the driving speed set by the driver. The former is called vehicle-to-vehicle distance control, and the latter is called constant speed control. Note that the driving assistance device 19 may use the imaging device 11, using its vehicle speed control function, to detect the speed limit of the road being traveled on from road signs or obtain the speed limit from map information 14, and automatically set that speed limit as the driving speed.

To activate the vehicle speed control function of the speed control unit 231, the driver first operates a switch on the steering wheel to input the desired driving speed. For example, if the switch is pressed while the vehicle V is traveling at 70 km/h, the current driving speed will be set as is, but if the desired driving speed is other than this, the switch can be operated to increase or decrease the set speed. The driver's desired following distance can also be selected from multiple settings, such as short distance, medium distance, or long distance, by operating a switch (e.g., a following distance adjustment switch).

Constant speed control is performed when no preceding vehicle is detected ahead of the vehicle V in the lane it is traveling in, for example, by the forward radar of the distance measuring device 12. In constant speed control, the speed control device 171 controls the operation of drive mechanisms such as the engine and brakes while feeding back vehicle speed information from the vehicle speed sensor, which is the vehicle state detection device 13, to maintain the set traveling speed.

Distance control is performed when a preceding vehicle is detected in front of the vehicle V in the lane it is traveling in, for example, by the forward radar of the distance measuring device 12. In distance control, the speed control device 171 controls the operation of the drive mechanism while feeding back the distance data detected by the forward radar so as to maintain the set distance between vehicles, with the set travel speed as the upper limit.

If a preceding vehicle stops while driving under vehicle-to-vehicle distance control, the driving assistance device 19 stops vehicle V following the preceding vehicle. Furthermore, if the preceding vehicle starts moving, for example, within 30 seconds after vehicle V has stopped, the driving assistance device 19 starts vehicle V and resumes following driving under vehicle-to-vehicle distance control. If vehicle V has been stopped for more than 30 seconds, vehicle V will not automatically start moving even if the preceding vehicle starts moving, and will resume following driving under vehicle-to-vehicle distance control if the driver operates a switch on the steering wheel or presses the accelerator pedal after the preceding vehicle has started moving.

When a predetermined condition is met during the execution of the above-described autonomous speed control, the driving assistance device 19 controls the operation of the steering actuator with the steering control device 172 using the steering control function of the steering control unit 232 to perform autonomous steering control. Autonomous steering control includes lane keeping control and autonomous lane change control. In this embodiment, lane keeping control, which maintains the vehicle traveling along its own lane, is also referred to as first autonomous steering control, and autonomous lane change control, which changes lanes from the own lane to another lane (e.g., an adjacent lane), is also referred to as second autonomous steering control. The difference between the first autonomous steering control and the second autonomous steering control is whether or not a lane change is performed during autonomous steering control. In other words, the first autonomous steering control is autonomous steering control that keeps the vehicle traveling along its own lane without changing lanes, and the second autonomous steering control is autonomous steering control that changes lanes from the own lane to another lane (e.g., an adjacent lane). The first autonomous steering control is an autonomous steering control that sets a target position in the vehicle's own lane, and the second autonomous steering control is an autonomous steering control that sets a target position in another lane (for example, an adjacent lane).

The driving assistance device 19 uses lane keeping control to control the steering actuator with the steering control device 172 so that the vehicle V travels near the center of the lane, thereby assisting the driver in steering. The driving assistance device 19 also uses autonomous lane change control to change lanes through autonomous driving. In other words, the autonomous lane change control by the driving assistance device 19 is mainly realized by the steering control function of the steering control unit 232.

As an example, in the driving scene shown in Figure 2, assume that vehicle V travels from position P1 to position P2, and then the driver operates the turn signal lever at position P2. In this case, the autonomous lane change control of steering control unit 232 starts flashing the turn signal, and if a preset lane change initiation condition is met, the lane change operation (hereinafter also referred to as LCP), which is a series of processes for changing lanes using autonomous driving control, is started. Alternatively, the turn signal may be flashed and the LCP may be started when a button is operated to accept the start of autonomous lane change control, such as when a switch on the steering wheel is operated.

The driving assistance device 19 determines whether or not a lane change start condition is met based on the driving information acquired by the environment recognition function of the recognition unit 22. The lane change start condition is not particularly limited, but may be exemplified as the condition that all of the following conditions are met:
-Lane keeping mode in hands-on mode.
・Hands-on evaluation is currently underway.
- Driving at a speed of 60 km/h or more.
- There is a lane in the direction you are changing lanes.
- There is space to change lanes in the lane you are about to change lanes into.
- The type of lane marker allows lane change.
- The curvature radius of the road is 250m or more.
- Within one second after the driver operates the turn signal lever.

Note that the lane keeping mode of the hands-on mode, which will be described in more detail later, refers to a state in which the driving assistance device 19 is executing autonomous speed control by the speed control unit 231 and lane keeping control by the steering control unit 232, and the driver is detected as holding the steering wheel. Furthermore, "hands-on determination in progress" refers to a state in which the driver continues to hold the steering wheel.

In the driving scene shown in Figure 2, lane L2 exists to the right of straight lane L1, and there is space for vehicle V to enter lane L2. Therefore, the lane change start condition is met if the driving assistance device 19 is in lane keeping mode in hands-on mode, a hands-on determination is in progress, vehicle V is traveling at 60 km/h or more, a lane change from lane L1 to lane L2 is possible, and the turn signal lever is operated at position P2 within one second.

When lane change initiation conditions are met, the driving assistance device 19 initiates an LCP using autonomous lane change control. This LCP involves lateral movement of vehicle V into an adjacent lane (i.e., lane L2) and a lane change maneuver (hereinafter referred to as LCM) to actually move into lane L2. Specifically, the driving assistance device 19 generates the driving trajectory T1 shown in FIG. 2, follows the driving trajectory T1, and travels from position P2 to position P6 to change lanes from lane L1 to lane L2. The driving assistance device 19 initiates lateral movement into lane L2 at position P3 and initiates LCM at position P4. At position P5, the driving assistance device 19 turns off the turn signal and completes LCM. The LCP is then completed at position P6, and lane keeping control is initiated. During the LCP, the driving assistance device 19 displays information to the driver via the display device 18 indicating that a lane change is being performed using autonomous lane change control, urging the driver to pay attention to their surroundings.

In addition, the control unit 23 has the function of executing overtaking control that combines lane keeping control and autonomous lane change control. Overtaking control is autonomous lane change control in a driving scene in which the vehicle is overtaking a preceding vehicle. Figure 3A is a plan view showing an example of a driving scene in which the driving assistance device 19 executes overtaking control. The driving scene shown in Figure 3A is similar to the driving scene shown in Figure 2, except that there is another vehicle Y traveling at position Py on lane L1. As shown in Figure 3A, when there is another vehicle Y ahead on lane L1 that is slower than vehicle V and a predetermined overtaking suggestion condition is met, the driving assistance device 19 uses the display device 18 to present overtaking information to the driver.

Overtaking information is information that suggests to the driver that they overtake another vehicle Y, which is a preceding vehicle. Furthermore, the driving assistance device 19 starts the above-mentioned LCP when the driver accepts the overtaking information by operating a switch on the steering wheel (corresponding to consent input) and when preset overtaking start conditions are met. The consent input includes the driver operating the turn signal lever to the right or left.

The driving assistance device 19 determines whether the overtaking suggestion conditions and overtaking start conditions are met based on information acquired by the environmental recognition function of the recognition unit 22. Note that the overtaking assistance control may include a function to start an LCP for overtaking the preceding vehicle when the driver operates the turn signal lever, even if overtaking information is not presented.

The overtaking proposal condition is not particularly limited, but may be exemplified by the fact that all of the following conditions are met.
-Lane keeping mode in hands-off mode.
- Driving at a speed of 60 km/h or more.
- There is a lane in the direction you are changing lanes.
- There is space in the lane you are changing into that allows you to change lanes in 5 seconds.
- The type of lane marker allows lane change.
- The curvature radius of the road is 250m or more.
- The vehicle speed is more than 5 km/h slower than the set speed.
- The speed of the preceding vehicle is more than 10 km/h slower than the set speed.
The distance between the host vehicle and the preceding vehicle is below a threshold value that is set in advance based on the speed difference between the host vehicle and the preceding vehicle.
The speed of the preceding vehicle in the lane into which the lane is to be changed satisfies a predetermined condition.

Note that the lane-keeping mode of the hands-off mode, described in more detail below, refers to a mode in which autonomous speed control and lane-keeping control are active and the driver does not need to hold the steering wheel. Furthermore, the condition that the speed of the preceding vehicle in the destination lane must satisfy a predetermined condition varies depending on the type of destination lane. For example, when changing lanes from the left lane to the right lane on a multi-lane road with left-hand traffic, the speed of the vehicle in the left lane must be approximately 5 km/h or more faster than the speed of the preceding vehicle in the right lane. Conversely, when changing lanes from the right lane to the left lane on a multi-lane road with left-hand traffic, the speed difference between the vehicle and the preceding vehicle in the left lane must be within approximately 5 km/h. Note that this condition regarding the relative speed difference between the vehicle and the preceding vehicle is reversed on roads with right-hand traffic.

When the driver agrees to the presentation of overtaking information and a predetermined overtaking start condition is satisfied, the driving assistance device 19 flashes the turn signal by overtaking control and starts the LCP. The overtaking start condition is not particularly limited, but may be exemplified as the condition that all of the following conditions are satisfied:
-Lane keeping mode in hands-on mode.
・Hands-on evaluation is currently underway.
- Driving at a speed of 60 km/h or more.
- There is a lane in the direction you are changing lanes.
- There is space to change lanes in the lane you are about to change lanes into.
- The type of lane marker allows lane change.
- The curvature radius of the road is 250m or more.
- The vehicle's speed is more than 5 km/h slower than the set speed (when changing lanes to the right lane while driving on the left).
- The speed of the vehicle ahead is more than 10 km/h slower than the set speed (when changing lanes to the right lane while driving on the left).
The speed of the preceding vehicle in the lane into which the lane is to be changed satisfies a predetermined condition.
- Within 10 seconds of operating the switch (lane change assist switch) to consent to the start of autonomous lane change control.

The condition that the speed of the preceding vehicle is 10 km/h or more slower than the set speed can be changed by the driver, and the changed set speed becomes the overtaking start condition. For example, in addition to 10 km/h, 15 km/h and 20 km/h can be selected as the changeable speed. Furthermore, the condition that the speed of the preceding vehicle in the lane into which the lane is to be changed meets a specified condition is the same as the overtaking suggestion condition described above.

In the driving scene shown in Figure 3A, lane L2 exists to the right of straight lane L1, and there is space in lane L2 for vehicle V to enter, and that space still exists 5 seconds later. Therefore, if the vehicle is in hands-off lane keeping mode, vehicle V is traveling at 60 km/h or faster, is capable of changing lanes from lane L1 to lane L2, vehicle V's traveling speed is 5 km/h or slower than the set speed, other vehicle Y's traveling speed is 10 km/h or slower than the set speed, and the inter-vehicle distance between vehicle V and other vehicle Y is below a preset threshold based on the speed difference between vehicle V and other vehicle Y, the overtaking suggestion conditions are met. If the overtaking suggestion conditions are met, driving assistance device 19 presents overtaking information using display device 18 when vehicle V is traveling at position P1.

When the driver is presented with overtaking information and agrees to overtaking, the driving assistance device 19 determines whether the overtaking start conditions are met. In the driving scene of Figure 3A, the overtaking suggestion conditions are met, so a hands-on determination is in progress, and if it is within 10 seconds of operating the lane change assistance switch on the steering wheel, the overtaking start conditions are met. In the driving scene shown in Figure 3A, the driver inputs consent to the execution of overtaking control while vehicle V is traveling at position P2. If the overtaking start conditions are met, LCP is initiated by overtaking control, and lateral movement to an adjacent lane and LCM are performed.

Specifically, the driving assistance device 19 generates the driving trajectory T2 shown in Figure 3A, and changes lanes from lane L1 to lane L2 by following the driving trajectory T2 and traveling from position P3 to position P7. The driving assistance device 19 starts flashing the turn signal at position P3, starts lateral movement to lane L2 at position P4, and starts LCM at position P5. The driving assistance device 19 turns off the turn signal at position P6 and completes LCM. Then, at position P7, the driving assistance device 19 completes LCP and starts lane keeping control. Vehicle V travels in lane L2 using lane keeping control and overtakes another vehicle Y.

After overtaking another vehicle Y through overtaking control, if the overtaking suggestion conditions are met again, the driving assistance device 19 will suggest to the driver via the display device 18 that they return to the original lane L1. If the driver accepts this suggestion by operating a switch on the steering wheel and the overtaking start conditions are met, the driving assistance device 19 will start the LCP to return vehicle V to the original lane L1 through overtaking control, as shown in Figure 3B.

Specifically, if the overtaking suggestion conditions are met, the driving assistance device 19 presents overtaking information using the display device 18 when vehicle V is traveling at position P7. If the driver inputs consent to the execution of overtaking control while vehicle V is traveling at position P8, the driving assistance device 19 generates the driving trajectory T3 shown in FIG. 3B, follows driving trajectory T3, travels from position P9 to position P13, and changes lanes from lane L2 to the original lane L1. The driving assistance device 19 starts flashing the turn signal at position P9, starts lateral movement to lane L1 at position P10, and starts LCM at position P11. The driving assistance device 19 turns off the turn signal at position P12 and completes LCM. Then, at position P13, it completes LCP and starts lane keeping control.

In addition, the control unit 23 has the function of executing route driving control that combines lane keeping control and autonomous lane change control. The driving assistance device 19 drives the vehicle V along a set driving route through route driving control. When the set driving route includes a driving direction change point such as a branch point, merging point, exit, or toll gate, and the distance to the driving direction change point is within a predetermined distance and predetermined route driving suggestion conditions are met, the driving assistance device 19 presents route driving information through route driving control. As route driving information, the driving assistance device 19 suggests a lane change at the driving direction change point on the display device 18.

The driving assistance device 19 starts the LCP when the lane change suggestion is accepted by operating a switch on the steering wheel and when predetermined route driving start conditions are met. The switch operation may also be the driver operating a turn signal lever. The driving assistance device 19 determines whether the route driving suggestion conditions and route driving start conditions are met based on information (driving environment) acquired by the environmental recognition function of the recognition unit 22.

Note that if a driving route is set in the navigation device 16 but route driving control is not being executed or is disabled in the settings, normal navigation is executed by the navigation device 16 to guide the driving route. Route driving control may also include a function to start an LCP for driving along the driving route when the driver operates the turn signal lever, even if a lane change is not suggested by the route driving information.

Figure 4 is a plan view showing an example of a driving scene in which the driving assistance device 19 controls route driving. In the driving scene shown in Figure 4, a road with three lanes on each side extends vertically in the drawing, and the vehicle travels on the road from the bottom to the top of the drawing. As shown in Figure 4, the lane on the right side of the driving direction is lane L1, the center lane is lane L2, the lane on the left side of the driving direction is lane L3, and the branch lane leading to destination X is lane L4.

In the driving scene shown in Figure 4, vehicle V is traveling at position P1 on lane L1, heading toward destination X, which is located ahead on lane L4 and has been set by the occupant of vehicle V. In this case, the driving assistance device 19 uses route driving control to suggest a lane change from lane L1 to lane L2 when the vehicle is within a first predetermined distance from branch point Z (for example, approximately 2.5 km to 1.0 km before branch point Z) and the route driving suggestion conditions are met.

The first predetermined distance (also referred to as the proposed lane change section) is preset based on the number of lane changes required to reach the lane where the driving direction change point is located. For example, as shown in Figure 4, if two lane changes are required to move from lane L1 to lane L2 and then to lane L3, the first predetermined distance (proposed lane change section) is the section from approximately 2.5 km to 1.0 km before branch point Z, as shown in the example.

The route travel suggestion conditions are not particularly limited, but may be exemplified by the fact that all of the following conditions are met.
The destination is set in the navigation device 16.
-Lane keeping mode in hands-off mode.
- Driving at a speed of 60 km/h or more.
- There is a lane in the direction you are changing lanes.
- The type of lane marker allows lane change.
- The curvature radius of the road is 250m or more.

In addition, under the route driving suggestion conditions, route driving information is presented to notify the driver that a lane change along the driving route is necessary even if there is no space available for a lane change at the lane change destination.

In the driving scene shown in Figure 4, destination X is set, lane L2 exists to the left (lane change side) of straight lane L1, and there are no obstacles in lane L2. Therefore, if the vehicle is in lane keeping mode in hands-off mode, the vehicle V is traveling at 60 km/h or more, and the boundary between lane L1 and lane L2 allows for a lane change, the route driving suggestion conditions are met. In the driving scene shown in Figure 4, if the route driving suggestion conditions are met, route driving information is presented to the driver using display device 18 while traveling at position P1.

When the driver inputs consent to change lanes to head toward the branch point at position P1 and the route travel start conditions are met, the driving assistance device 19 turns on the turn signals and starts the LCP through route travel control. The route travel start conditions are not particularly limited, but may be exemplified by the fact that all of the following conditions are met:
-Lane keeping mode in hands-on mode.
・Hands-on evaluation is currently underway.
- Driving at a speed of 60 km/h or more.
- There is a lane in the direction you are changing lanes.
- There is space to change lanes in the lane you are about to change lanes into.
- The type of lane marker allows lane change.
- Driving in a section where a lane change is suggested.
- The curvature radius of the road is 250m or more.

In the driving scene shown in Figure 4, the route driving proposal conditions are met, so the vehicle is in lane keeping mode in hands-on mode, a hands-on determination is in progress, and if the road shown in Figure 4 is a lane change proposal section, the route driving start conditions are met. When the route driving start conditions are met, the driving assistance device 19 starts LCP using route driving control and executes lateral movement to lane L2 and LCM. For example, the driving assistance device 19 generates driving trajectory T4 shown in Figure 4 and autonomously controls the driving behavior of vehicle V so that it follows driving trajectory T4. When LCM is completed, the driving assistance device 19 turns off the turn signal and starts lane keeping control at position P3 on lane L2. Note that while the LCP is being executed, the driving assistance device 19 displays information to the driver on the display device 18 indicating that a lane change is being performed using route driving control, urging the driver to pay attention to their surroundings.

Furthermore, as shown in FIG. 6, while lane keeping control is being performed on lane L2, if the vehicle is within a second predetermined distance of branch point Z (for example, approximately 2.3 km to 700 m before the branch point) and the route driving start conditions are met, the driving assistance device 19 will turn on the turn signals through route driving assistance control to initiate a second LCP and change lanes from lane L2 to lane L3. For example, the driving assistance device 19 will generate driving trajectory T5 shown in FIG. 4 and drive vehicle V so that it follows driving trajectory T5, traveling from position P4 to position P5. When LCM is completed, the driving assistance device 19 will turn off the turn signals and initiate lane keeping control at position P5 on lane L3.

Furthermore, while performing lane keeping control on lane L3, the driving assistance device 19 turns on the turn indicators using route driving control when the vehicle is within a third predetermined distance from branch point Z (for example, approximately 800 m to 150 m before the branch point) and the route driving start conditions are met. Using route driving control, the driving assistance device 19 generates a driving trajectory T6 for entering lane L4. Then, at position P6 before branch point Z, the driving assistance device 19 starts autonomous steering control for entering lane L4, which is a branch line, and travels from position P6 to position P7 following the driving trajectory T6, entering lane L4 from lane L3. Once entry into lane L4 is complete, the driving assistance device 19 turns off the turn indicators and starts lane keeping control at position P7 on lane L4.

Next, Figure 5 is a block diagram showing the state transitions of each function established in the driving assistance device 19. The system shown in Figure 5 refers to the autonomous driving control system realized by the driving assistance device 19. When the main switch is turned ON from the system OFF state shown in Figure 5, the system enters a standby state. The main switch is a switch that turns ON/OFF the power supply to the system that realizes the vehicle speed control function and steering control function of the driving assistance device 19, and is provided, for example, on the steering wheel.

By turning on the set/coast switch or resume/accelerate switch from the standby state, autonomous speed control using the vehicle speed control function is initiated. This initiates the constant speed control or vehicle distance control described above, allowing the driver to drive the vehicle simply by operating the steering wheel, without having to step on the accelerator or brake. The resume/accelerate switch is a switch that, after stopping (turning off) autonomous speed control, resumes autonomous speed control at the speed set before turning it off, increases the set speed, or restarts the vehicle using the driving assistance device 19 after stopping to follow a preceding vehicle. The set/coast switch is a switch that starts autonomous speed control at the speed at which the vehicle was traveling, or decreases the set speed. These switches are located, for example, on the steering wheel.

When autonomous speed control is being performed, if condition (1) in Figure 5 is met, the system transitions to lane keeping mode of autonomous steering control/hands-on mode. An example of this condition (1) is when lane markers on both sides of the vehicle V are detected and the driver is holding the steering wheel.

Note that hands-on mode refers to a mode in which autonomous steering control by the autonomous steering control function does not operate unless the driver is holding the steering wheel, and hands-off mode refers to a mode in which autonomous steering control by the autonomous steering control function operates even if the driver takes their hands off the steering wheel. Note that whether the driver is holding the steering wheel is detected by a touch sensor in the vehicle state detection device 13.

If condition (2) in Figure 5 is met while the lane keeping mode of the autonomous steering control hands-on mode is being executed, the system will transition to the lane keeping mode of the autonomous steering control hands-off mode. An example of this condition (2) is when the host vehicle V is traveling on a highway with a high-precision map and the GPS signal is valid.

Conversely, if condition (3) in Figure 5 is met while the lane keeping mode of the autonomous steering control hands-off mode is being executed, the system will transition to lane keeping mode of the autonomous steering control hands-on mode. An example of this condition (3) is when the driving speed exceeds the speed limit.

If condition (4) in Figure 5 is met while the lane-keeping mode of the autonomous steering control/hands-off mode is being executed, the autonomous steering control will be stopped and the system will transition to autonomous speed control. An example of this condition (4) is when the driver is operating the steering wheel.

Furthermore, if condition (5) in Figure 5 is met while the lane-keeping mode of the autonomous steering control/hands-off mode is being executed, the autonomous steering control and autonomous speed control are stopped and the vehicle transitions to a standby state. An example of this condition (5) is when the driver operates the brakes.

If condition (6) in Figure 5 is met while autonomous steering control/hands-on mode is in operation, autonomous steering control is discontinued and the system transitions to autonomous speed control. An example of this condition (6) is when the driver operates the turn signal lever.

Furthermore, if condition (7) in Figure 5 is met while autonomous steering control/hands-on mode is being executed, autonomous steering control and autonomous speed control will be stopped and the vehicle will transition to a standby state. An example of this condition (7) is when the driver operates the brakes.

If condition (8) in Figure 5 is met while autonomous speed control is being performed, the vehicle will transition to standby mode. An example of this condition (8) is when the driver operates a cancel switch to turn off autonomous speed control.

If condition (9) in Figure 5 is met while the lane keep mode of the autonomous steering control hands-off mode is being executed, the system will transition to lane change mode of the autonomous steering control hands-on mode. Examples of this condition (9) include the driver operating the lane change assist switch in response to a lane change suggestion from the driving assistance system 10, and the driver operating the turn signal lever to execute autonomous lane change control.

The lane change assist switch is a switch that instructs (agrees to) the driver to start a lane change when the driving assistance device 19 confirms with the driver that the driver wants to start a lane change. The lane change assist switch is provided, for example, on the steering wheel.

If condition (10) in Figure 5 is met while the lane change mode of the autonomous steering control hands-on mode is being executed, the system will transition to lane keeping mode of the autonomous steering control hands-on mode. An example of this condition (10) is when the driving speed exceeds the speed limit before the LCP starts.

In this embodiment, lane keep mode and lane change mode are set in autonomous steering control/hands-off mode, and autonomous lane change control can be performed in autonomous steering control/hands-off mode.

In addition, if the main switch is turned off while in autonomous steering control/hands-off mode, autonomous steering control/hands-on mode, autonomous speed control, or standby mode, the system will be turned off.

The determination unit 24 has the function of determining whether the steering operation input by the driver satisfies a predetermined cancellation condition while autonomous steering control is being executed, and canceling autonomous steering control if it is determined that the steering operation input by the driver satisfies the predetermined cancellation condition. The period during which autonomous lane change control is being executed refers, for example, to the period after autonomous lane change control has started and before the vehicle V starts moving in the width direction of the road (lateral movement) or before the vehicle V starts LCM. If the determination function of the determination unit 24 determines that the driver's steering operation satisfies the predetermined cancellation condition, the driving assistance device 19 cancels autonomous steering control.

Specifically, if the driving assistance device 19 determines that the driver's steering operation satisfies a predetermined cancellation condition while the first autonomous steering control is being executed, the driving assistance device 19 cancels the first autonomous steering control. Furthermore, if the driving assistance device 19 determines that the driver's steering operation satisfies a predetermined cancellation condition while the second autonomous steering control is being executed, the driving assistance device 19 cancels the second autonomous steering control or cancels the first autonomous steering control and the second autonomous steering control. If the second autonomous steering control is canceled, the vehicle transitions to the first autonomous steering control, and if the first autonomous steering control and the second autonomous steering control are canceled, the vehicle transitions to driving under manual operation by the driver.

A steering operation refers to an operation to point the steering wheels of vehicle V in the target direction of travel of vehicle V, for example, by turning the steering wheel. Steering operations are detected using a steering angle sensor, torque sensor, etc. of the vehicle state detection device 13. A predetermined cancellation condition is a condition under which the driving assistance device 19 cancels autonomous steering control, and examples include a condition under which the absolute value of the rotation angle of the steering wheel of vehicle V becomes greater than a predetermined angle, and a condition under which the absolute value of the steering torque input to the steering wheel by the driver becomes greater than a predetermined value. Steering torque is the torque that rotates the steering wheel. Note that the predetermined cancellation conditions are not limited to these, and the above-mentioned conditions can be combined as appropriate.

The rotation angle of the steering wheel is defined as 0° when the steered wheels (e.g., front wheels) of vehicle V are parallel to the fore-and-aft direction of vehicle V, and is a positive angle when the steering wheel is rotated clockwise and a negative angle when it is rotated counterclockwise. The steering torque input to the steering wheel is a positive value when the steering wheel is rotated clockwise and a negative value when the steering wheel is rotated counterclockwise. The rotation angle of the steering wheel and the steering torque input to the steering wheel are detected, for example, by a steering angle sensor and torque sensor of the vehicle state detection device 13.

The predetermined angle is a value that corresponds to the traveling speed of the vehicle V and can be set to an appropriate value within a range that does not cause discomfort to the occupants of the vehicle V when autonomous steering control is terminated. Specifically, the predetermined angle is approximately 5 to 10 degrees when the vehicle V is traveling at 80 to 100 km/h, and approximately 10 to 20 degrees when the vehicle V is traveling at 60 to 80 km/h. The predetermined value of the steering torque is approximately 5 to 15 Nm when the vehicle V is traveling at 80 to 100 km/h, and approximately 20 to 30 Nm when the vehicle V is traveling at 60 to 80 km/h. In order to suppress changes in the behavior of the vehicle V, it is preferable to set the predetermined angle and predetermined value to smaller values as the traveling speed of the vehicle V increases. Note that the predetermined angle and steering torque are not limited to the above-mentioned ranges, and can be used in any appropriate combination in the present invention.

If, after autonomous steering control has started, the driving assistance device 19 determines that the driver's steering operation meets a predetermined cancellation condition while autonomous steering control is being performed, the driving assistance device 19 cancels autonomous steering control and transitions to manual driving. In this case, the driving assistance device 19 enters the system OFF state shown in Figure 5, and the vehicle's driving is controlled by the driver's steering operation. Note that manual driving refers to the driving assistance device 19 not performing autonomous driving control of driving operations, but rather controlling the vehicle's driving through driver operation. This transition to manual driving is not an essential component of the present invention and may be added or omitted as needed.

Alternatively, if the driving assistance device 19 determines that the driver's steering operation satisfies a predetermined stop condition after the start of autonomous steering control while autonomous steering control is being executed, it may stop autonomous steering control and maintain autonomous speed control. In this case, the state of the driving assistance device 19 becomes the autonomous speed control state shown in Figure 5. Stopping autonomous steering control and maintaining autonomous speed control when it determines that the driver's steering operation satisfies a predetermined stop condition while autonomous steering control is being executed is not an essential configuration of the present invention, and may be added or omitted as needed.

In contrast, after the start of autonomous steering control, if the driving assistance device 19 determines that a steering operation detected during the execution of autonomous steering control does not satisfy a predetermined cancellation condition, it corrects the driving operation by the autonomous steering control based on the steering operation. For example, the driving assistance device 19 advances or delays the timing of executing the driving operation of changing lanes in the second autonomous steering control based on the steering operation that does not satisfy the predetermined cancellation condition. This correction of the driving operation is not an essential component of the present invention and may be added or omitted as needed. Alternatively, or in addition, the driving assistance device 19 may shorten or lengthen the time required to execute the driving operation of changing lanes in the second autonomous steering control based on the steering operation. Shortening or lengthening the time required to execute the driving operation of changing lanes is not an essential component of the present invention and may be added or omitted as needed. Alternatively, or in addition, the driving assistance device 19 may increase or decrease the speed in the width direction of the own lane (or road) when the vehicle V moves from the own lane to another lane (for example, an adjacent lane) in the second autonomous steering control based on the steering operation. Setting the speed in the width direction of the own lane to increase or decrease when the vehicle V moves from the own lane to another lane is not an essential configuration for the present invention, and may be added or omitted as necessary.

As an example, we will explain the correction of driving behavior using the autonomous lane change control (i.e., second autonomous steering control) shown in Figure 2. In the driving scene shown in Figure 2, vehicle V starts lateral movement toward lane L2 at position P3. In this case, if a steering torque that turns the steering wheel to the left is detected between positions P2 and P3 before the lateral movement starts, and the steering torque value is greater than a predetermined value, the second autonomous steering control is stopped as described above. In contrast, if the steering torque value is equal to or less than the predetermined value, the driving assistance device 19 changes the position at which vehicle V starts lateral movement toward lane L2 from position P3 to position P3a. In other words, the driving assistance device 19 delays the timing at which vehicle V starts lateral movement according to the steering torque input to the steering wheel.

As another example, in the driving scene shown in Figure 2, assume that a steering torque is detected that turns the steering wheel to the right between positions P2 and P3 before the vehicle V starts to move laterally into lane L2. In this case, if the value of the steering torque is greater than a predetermined value, the second autonomous steering control is stopped. In contrast, if the value of the steering torque is equal to or less than the predetermined value, the driving assistance device 19 changes the position at which the vehicle V starts to move laterally into lane L2 from position P3 to position P3b. In other words, the timing at which the vehicle V starts to move laterally is advanced.

If the timing at which vehicle V begins its lateral movement is changed, the position at which LCP is completed may be the position initially set, or the position at which LCP is completed may be changed to match the changed timing. For example, if vehicle V begins its lateral movement from position P3a, the position at which LCP is completed may be position P6, or may be a position forward of position P6 in the direction of travel. Also, if vehicle V begins its lateral movement from position P3b, the position at which LCP is completed may be position P6, or may be a position behind position P6 in the direction of travel.

Alternatively, the driving assistance device 19 may discontinue autonomous steering control if a steering torque below a predetermined value is continuously input to the steering wheel for a predetermined period of time or longer after the start of autonomous steering control. For example, in the autonomous lane change control (i.e., second autonomous steering control) shown in FIG. 2 , if torque that rotates the steering wheel to the left is continuously detected for a predetermined period of time or longer after the driving assistance device 19 suggests a lane change to the driver at position P1, the driving assistance device 19 discontinues the second autonomous steering control and transitions to driving under manual driver control. The predetermined period of time can be set to an appropriate value within a range that does not cause discomfort to the occupants of the vehicle V if the second autonomous steering control is discontinued, specifically, approximately 5 to 60 seconds. Discontinuing autonomous steering control when a steering torque below a predetermined value is continuously input to the steering wheel for a predetermined period of time or longer is not a required feature of the present invention and may be added or omitted as needed. Alternatively, if a steering operation that does not satisfy a predetermined cancellation condition is detected for a predetermined period of time or more after the start of autonomous steering control, the driving assistance device 19 may cancel the autonomous steering control and transition to driving under manual operation by the driver. Canceling autonomous steering control and transitioning to driving under manual operation by the driver is not an essential configuration of the present invention, and may be added or omitted as necessary.

In the driving assistance device 19 of this embodiment, the driver can correct or cancel both the first autonomous steering control and the second autonomous steering control by inputting a steering operation. However, even when the same steering operation is input, the driver's intention differs when the first autonomous steering control is being executed and when the second autonomous steering control is being executed. That is, when a steering operation is input while the first autonomous steering control (lane keeping control) is being executed, the driver intends to cancel the autonomous steering control (lane keeping control). In contrast, when a steering operation is input while the second autonomous steering control is being executed, the driver intends to correct the autonomous steering control. Therefore, the specified cancellation condition in this embodiment is a condition under which the second autonomous steering control is less likely to be canceled than the first autonomous steering control after the start of the second autonomous steering control, particularly before the vehicle V starts moving in the width direction of the host lane. This allows the lane-changing driving operation to be corrected to reflect the driver's intention before the vehicle starts moving in the width direction of the host lane while continuing the second autonomous steering control.

2, after starting the second autonomous steering control between positions P1 and P2, and before starting lateral movement into lane L2 at position P3, the driving assistance device 19 sets the predetermined cancellation condition to a condition that makes it less likely that the second autonomous steering control will be cancelled than the first autonomous steering control. The timing to start the second autonomous steering control is when the vehicle V reaches a point that serves as the starting point for starting a lane change, which is before the vehicle V starts lateral movement in the width direction of the own lane. Examples of timings that can be used include starting the LCP, suggesting a lane change to the driver, starting the blinking of the turn signal, detecting space for vehicle V to enter another lane (e.g., an adjacent lane), arriving at a point set as a point for starting the second autonomous steering control, and when the speed difference between vehicle V and a preceding vehicle in the own lane or another lane becomes equal to or less than a predetermined speed.

In this embodiment, the specified cancellation condition is a condition under which the second autonomous steering control is less likely to be cancelled than the first autonomous steering control after the start of the second autonomous steering control and before the vehicle V starts moving in the width direction of the host lane. This means that the second autonomous steering control is less likely to be cancelled than the first autonomous steering control, at least after the start of the second autonomous steering control and before the vehicle V starts moving in the width direction of the host lane. Preferably, the specified cancellation condition is set when the second autonomous steering control is started. Note that the specified condition can also be changed so that the second autonomous steering control is more likely to be cancelled when the vehicle V starts moving in the width direction of the host lane.

The driving assistance device 19 sets the predetermined angle for the second autonomous steering control, which is the rotation angle of the steering wheel at which autonomous steering control is discontinued, to be larger than the predetermined angle for the first autonomous steering control. For example, the predetermined angle for the first autonomous steering control is set to approximately 5 to 10°, and the predetermined angle for the second autonomous steering control is set to approximately 7.5 to 15°, which is 1.5 times the predetermined angle for the first autonomous steering control. Alternatively, or in addition, the driving assistance device 19 may set the predetermined value for the second autonomous steering control to be larger than the predetermined value for the first autonomous steering control, for the predetermined value of steering torque at which autonomous steering control is discontinued. For example, the predetermined value for the first autonomous steering control is set to approximately 5 to 15 Nm, and the predetermined value for the second autonomous steering control is set to approximately 10 to 30 Nm, which is twice the predetermined value for the first autonomous steering control. Regarding the predetermined angle, which is the rotation angle of the steering wheel at which autonomous steering control is stopped, setting the predetermined angle for the second autonomous steering control to be larger than the predetermined angle for the first autonomous steering control, and regarding the predetermined value of the steering torque at which autonomous steering control is stopped, setting the predetermined value for the second autonomous steering control to be larger than the predetermined value for the first autonomous steering control, are not essential configurations of the present invention and may be added or omitted as necessary.

In this embodiment, the driving assistance device 19 selectively executes the first autonomous steering control and the second autonomous steering control. Therefore, for example, if the predetermined angle for the first autonomous steering control is set to 10° and the predetermined angle for the second autonomous steering control is set to 15°, when the steering wheel rotation angle is detected to be 12°, the first autonomous steering control will be stopped if the first autonomous steering control is being executed, and the second autonomous steering control will be continued if the second autonomous steering control is being executed. In other words, even if the predetermined condition for stopping the first autonomous steering control is met while the second autonomous steering control is being executed, the first autonomous steering control will not be stopped, and the second autonomous steering control will continue.

Alternatively or additionally, the predetermined cancellation condition may be set to a condition that makes the second autonomous steering control less likely to be cancelled than the first autonomous steering control by changing the steering wheel operation setting without changing the predetermined angle of the steering wheel rotation angle and the predetermined value of the steering torque. For example, if the vehicle is equipped with a steering device in which the amount of steering wheel rotation required to change the steering angle of the steered wheels is variable, the amount of steering wheel rotation for the second autonomous steering control may be set to be greater than the amount of steering wheel rotation for the first autonomous steering control. Alternatively or additionally, the assist gain for the driver's steering input may be set low so that the torque required to rotate the steering wheel in the second autonomous steering control is greater than the torque required to rotate the steering wheel in the first autonomous steering control. This increases the amount of rotation and steering torque required to reach the predetermined angle, making it less likely that the second autonomous steering control will be cancelled. In addition, setting the specified cancellation condition to a condition in which the second autonomous steering control is less likely to be cancelled than the first autonomous steering control by changing the setting of the steering wheel operation without changing the specified angle of the steering wheel rotation angle and the specified value of the steering torque is not an essential configuration of the present invention, and may be added or omitted as necessary.

The driving assistance device 19 may set the amount of change in the steering angle of the steered wheels of the vehicle V relative to the amount of rotation of the steering wheel of the vehicle V in the second autonomous steering control to be smaller than the amount of change in the first autonomous steering control before the vehicle V starts moving in the width direction of the vehicle's lane. The steering angle is the angle indicating the inclination of the steered wheels relative to the fore-and-aft direction of the vehicle V, and may be the yaw angle of the vehicle V. The steering angle is defined as 0° when the steered wheels (e.g., front wheels) of the vehicle V are parallel to the fore-and-aft direction of the vehicle V, a positive angle when the steered wheels are tilted to the right of the vehicle, and a negative angle when the steered wheels are tilted to the left of the vehicle. The steering angle is determined from the detection results of the steering angle sensor of the vehicle state detection device 13. In other words, the steering angle corresponds to the amount of rotation (rotation angle) of the steering wheel, and can be determined using a correspondence relationship (e.g., a proportional relationship) between the steering angle and the amount of rotation (rotation angle). Alternatively, the yaw rate obtained from the yaw rate sensor may be integrated to obtain the yaw angle as the steering angle. Setting the amount of change in the second autonomous steering control to be smaller than the amount of change in the first autonomous steering control before the vehicle V starts moving in the width direction of the own lane is not an essential configuration of the present invention, and may be added or omitted as necessary.

After vehicle V starts moving in the width direction of the lane in which vehicle V is traveling, driving assistance device 19 sets the predetermined cancellation condition to a condition under which second autonomous steering control is more likely to be cancelled than first autonomous steering control. Alternatively, driving assistance device 19 may set the predetermined cancellation condition to a condition under which first autonomous steering control is cancelled after vehicle V starts moving in the width direction of the lane in which vehicle V is traveling. This makes it easier to reflect the driver's intentions in the driving of vehicle V, for example, when the driver wants to cancel autonomous steering control after vehicle V starts a lane change driving operation, or when the driver wants to increase the speed of movement in the width direction of the lane. Setting the specified cancellation condition to a condition in which the second autonomous steering control is more likely to be cancelled than the first autonomous steering control after the vehicle V starts moving in the width direction of the lane in which the vehicle V is traveling, and setting the specified cancellation condition to a condition in which the first autonomous steering control is cancelled after the vehicle V starts moving in the width direction of the lane in which the vehicle V is traveling, are not essential configurations of the present invention and may be added or omitted as necessary.

Furthermore, the driving assistance device 19 sets the predetermined cancellation condition to a condition under which the second autonomous steering control is more likely to be cancelled than the first autonomous steering control after one of the steered wheels of the vehicle V steered in the direction opposite to the direction in which the vehicle V is moving passes over a boundary line defining the vehicle's lane. Alternatively, the driving assistance device 19 may set the predetermined cancellation condition to a condition under which the first autonomous steering control is cancelled after one of the steered wheels of the vehicle V steered in the direction opposite to the direction in which the vehicle V is moving passes over a boundary line defining the vehicle's lane.

For example, in the driving scene shown in Figure 2, vehicle V changes lanes from lane L1 to lane L2 on the right, so the predetermined cancellation condition is set to a condition for canceling the first autonomous steering control after the left front wheel of vehicle V passes over the dashed boundary line that defines lane L1. The position of the left front wheel is estimated, for example, based on image data of the boundary line obtained from imaging device 11 and data on the distance to the road shoulder obtained from distance measuring device 12. Alternatively, or in addition, it may be determined whether the front wheel of vehicle V has passed over the boundary line based on the detection results of an acceleration sensor attached to the damper of vehicle V. This makes it easier to reflect the driver's intentions, such as canceling autonomous steering control or increasing the vehicle's lane width speed, in the driving of vehicle V. Setting the specified cancellation condition to a condition in which the second autonomous steering control is more likely to be cancelled than the first autonomous steering control after one of the steering wheels of vehicle V that is steered in the direction opposite to the direction in which vehicle V is moving passes over the boundary line defining the vehicle's lane, and setting the specified cancellation condition to a condition in which the first autonomous steering control is cancelled after one of the steering wheels of vehicle V that is steered in the direction opposite to the direction in which vehicle V is moving passes over the boundary line defining the vehicle's lane, are not essential configurations of the present invention and may be added or omitted as necessary.

After the second autonomous steering control starts flashing the turn indicators of vehicle V, the driving assistance device 19 may set the predetermined cancellation condition to a condition that makes it more difficult to cancel the second autonomous steering control than the first autonomous steering control. This makes it more difficult to cancel the second autonomous steering control after the turn indicators start flashing, and can accelerate the timing at which vehicle V starts moving in the width direction of the host lane, reflecting the driver's intention, in cases such as when a following vehicle traveling at a higher speed approaches vehicle V from behind. Setting the predetermined cancellation condition to a condition that makes it more difficult to cancel the second autonomous steering control than the first autonomous steering control after the second autonomous steering control starts flashing the turn indicators of vehicle V is not an essential configuration of the present invention and may be added or omitted as needed. Furthermore, after the second autonomous steering control starts flashing, the driving assistance device 19 may determine whether a driver's steering operation is detected before vehicle V starts moving in the width direction of the host lane, and if a driver's steering operation is detected, cause vehicle V's turn indicators to flash. This makes it possible to notify other vehicles around the vehicle V that the vehicle V is attempting to change lanes. Determining whether or not a steering operation by the driver has been detected before the vehicle V starts moving in the width direction of the own lane after the start of the second autonomous steering control, and flashing the turn indicators of the vehicle V when a steering operation by the driver has been detected, are not essential components of the present invention and may be added or omitted as necessary.

Before starting to move to another lane (e.g., an adjacent lane) using the second autonomous steering control, the driving assistance device 19 uses the environmental recognition function of the recognition unit 22 to detect a space into which the vehicle V will enter the other lane from the detection results of the imaging device 11 and the distance measuring device 12. In this case, it determines whether the length of the detected space in the direction of travel of the vehicle V is longer than the overall length of the vehicle V and shorter than the length at which a lane change is determined to be possible under the second autonomous steering control. A space at which a lane change is determined to be possible under the second autonomous steering control is, for example, a space where the time between vehicles (THW) with an obstacle ahead of the vehicle V is 0.7 to 1.4 seconds or more, and the time between vehicles (THW) with an obstacle behind the vehicle V is 0.7 to 1.4 seconds or more.

If the length of the detected space in the direction of vehicle V's travel is longer than the overall length of vehicle V and shorter than the length at which a lane change is determined to be possible under the second autonomous steering control, the driving assistance device 19 sets the predetermined cancellation condition to a condition that makes it more difficult for the second autonomous steering control to be cancelled than the first autonomous steering control. This allows the second autonomous steering control to continue while the driver decides to change lanes. On the other hand, if the length of the detected space in the direction of vehicle V's travel is shorter than the overall length of vehicle V or longer than the length at which a lane change is determined to be possible under the second autonomous steering control, the driving assistance device 19 maintains the predetermined cancellation condition or sets the predetermined cancellation condition to a condition that makes it more likely for the second autonomous steering control to be cancelled than the first autonomous steering control. Detecting a space for vehicle V to enter another lane before starting to move to another lane using the second autonomous steering control, and determining whether the length of the detected space in the direction of vehicle V's travel is longer than the total length of vehicle V and shorter than the length at which lane change is determined to be possible using the second autonomous steering control, are not essential components of the present invention and may be added or omitted as necessary.

In addition, if the driving assistance device 19 is equipped with a steering device in which the amount of steering wheel rotation required to change the steering angle of the vehicle's steering wheels is variable, even if a steering operation of the same amount of rotation is input, the driving assistance device 19 may maintain first autonomous steering control (lane keeping control) if the input time is short, and execute second autonomous steering control (autonomous lane change control) if the input is continued. For example, if a rotation of the steering wheel to a rotation angle of 30° is input to the steering wheel, the first autonomous steering control will be maintained without rotating the steering wheels if the input time is approximately 0.5 to 5 seconds, and if the input time is longer than approximately 5 seconds, the steering wheels will be rotated in accordance with the steering operation and the second autonomous steering control will be executed.

[Processing in driving assistance system]
The procedure for information processing by the driving assistance device 19 will be described with reference to Figures 6A and 6B. Figures 6A and 6B are an example of a flowchart showing information processing executed in the driving assistance system 10 of this embodiment. The processing described below is executed at predetermined time intervals by the CPU 191, which is the processor of the driving assistance device 19. Note that the flowcharts shown in Figures 6A and 6B are based on the premise that the vehicle V is traveling on a road using lane keeping control.

First, in step S1 of FIG. 6A, the judgment function of the judgment unit 24 sets a predetermined cancellation condition for the first autonomous steering control (lane keeping control). This predetermined cancellation condition may be, for example, a condition under which the second autonomous steering control is more likely to be canceled than the first autonomous steering control, and may be a predetermined standard condition. In the following step S2, the vehicle V is caused to travel using the vehicle control device 17 through the first autonomous steering control (lane keeping control) of the steering control unit 232. Specifically, the traveling speed of the vehicle V is controlled using the speed control device 171 through vehicle distance control or constant speed control. Furthermore, the steering device of the vehicle V is controlled using the steering control device 172 so that the vehicle travels along its own lane through autonomous steering control.

In step S3, the environment recognition function of the recognition unit 22 acquires the current position of the vehicle V from the vehicle position detection device 15. In the following step S4, the driving control function of the control unit 23 acquires the driving route from the navigation device 16. In the following step S5, the environment recognition function of the recognition unit 22 recognizes the driving environment around the vehicle V from the detection results of the imaging device 11 and the distance measuring device 12.

In step S6, the judgment function of the judgment unit 24 determines whether or not the execution of second autonomous steering control is necessary based on the information acquired in steps S3 to S5. For example, if it is necessary to change lanes from the current vehicle lane to an adjacent lane that is a left-turn-only lane in order to turn left along the set driving route, it is determined that the execution of second autonomous steering control is necessary. On the other hand, if the destination can be reached by continuing driving along the current vehicle lane, it is determined that the execution of second autonomous steering control is not necessary.

If it is determined that the second autonomous steering control does not need to be executed, the process proceeds to step S7, and driving is maintained using the first autonomous steering control (lane keeping control). In the following step S8, the driving assistance function of the assistance unit 20 determines whether the vehicle V has arrived at the destination. If it is determined that the vehicle V has arrived at the destination, the autonomous driving control is stopped, and the driver is prompted to drive manually via the display device 18. On the other hand, if it is determined that the vehicle V has not arrived at the destination, the process proceeds to step S2, and the above-mentioned processing is repeated.

On the other hand, if it is determined in step S6 that the second autonomous steering control needs to be executed, the process proceeds to step S9, where the determination function of the determination unit 24 determines whether the lane change start condition is met. If it is determined that the lane change start condition is not met, the autonomous driving control is stopped and the driver is prompted to manually change lanes via the display device 18. On the other hand, if it is determined that the lane change start condition is met, the process proceeds to step S10, where the second autonomous steering control is started by the control unit 23. In the following step S11, the determination function of the determination unit 24 sets a predetermined stop condition for the second autonomous steering control. In other words, a predetermined stop condition is set that makes it more difficult to stop the second autonomous steering control than the first autonomous steering control.

Next, in step S12 of Figure 6B, the judgment function of the judgment unit 24 determines whether a steering operation by the driver has been detected. If it is determined that a steering operation by the driver has not been detected, the process proceeds to step S17, where the control unit 23 starts a lane change using the second autonomous steering control. Specifically, the LCP, LCM, and turn signal blinking or lateral movement in the width direction of the own lane is started. On the other hand, if a steering operation by the driver has been detected, the process proceeds to step S13. Note that if a lane change has already been started, step S17 shown in Figure 6B should be read as "continue lane change."

In step S13, the judgment function of the judgment unit 24 determines whether the input steering operation satisfies a predetermined cancellation condition. For example, if the absolute value of the steering torque acquired from the torque sensor (host vehicle state detection device 13) is greater than a predetermined value, it is determined that the predetermined cancellation condition is satisfied. On the other hand, if the steering wheel rotation angle acquired from the steering angle sensor (host vehicle state detection device 13) is equal to or less than a predetermined angle, it is determined that the predetermined cancellation condition is not satisfied.

If it is determined that the steering operation does not satisfy the predetermined cancellation condition, the process proceeds to step S14, where the lane-changing driving behavior is corrected according to the steering operation. For example, when changing lanes to the right of the traveling direction, if torque is detected that turns the steering wheel to the left of the traveling direction, the timing at which the vehicle V starts to move laterally is delayed.

In the following step S15, the judgment function of the judgment unit 24 determines whether a steering torque equal to or less than a predetermined value has been input to the steering wheel continuously for a predetermined period of time or more. If it is determined that a steering torque equal to or less than the predetermined value has not been input to the steering wheel continuously for a predetermined period of time or more, the process proceeds to step S17, where a lane change is performed based on the corrected driving operation.

In contrast, if it is determined that a steering torque equal to or less than a predetermined value has been input to the steering wheel continuously for a predetermined period of time or longer, the process proceeds to step S16, where the second autonomous steering control is discontinued. Also, if it is determined in step S13 that the input steering operation satisfies a predetermined discontinuation condition, the process proceeds to step S16, where the second autonomous steering control is discontinued. The driver is then prompted to drive manually via the display device 18.

After starting the lane change in step S17, in step S18, the judgment function of the judgment unit 24 determines whether the vehicle V has started moving in the width direction of the lane. For example, if the steering angle sensor or torque sensor detects rotation of the steering wheel, it is determined that the vehicle V has started moving in the width direction of the lane, and the process proceeds to step S22. On the other hand, if rotation of the steering wheel is not detected, it is determined that the vehicle V has not started moving in the width direction of the lane, and the process proceeds to step S19.

In step S19, the judgment function of the judgment unit 24 determines whether the steering wheel of vehicle V in the direction opposite to the direction in which vehicle V is moving has passed over the boundary line defining the current lane. For example, when vehicle V changes lanes to an adjacent lane on the left, it determines whether the right front wheel of vehicle V has passed over the boundary line defining the current lane. In this determination, for example, the position of the front wheel of vehicle V in the current lane is estimated based on image data of the boundary line obtained from the imaging device 11 and data on the distance to the shoulder obtained from the distance measuring device 12. If it is determined that the steering wheel in the direction opposite to the direction in which vehicle V is moving has passed over the boundary line defining the current lane, the process proceeds to step S22. On the other hand, if it is determined that the steering wheel in the direction opposite to the direction in which vehicle V is moving has not passed over the boundary line defining the current lane, the process proceeds to step S20.

In step S20, the environmental recognition function of the recognition unit 22 uses image data acquired from the imaging device 11 to detect a space for entering an adjacent lane to the own vehicle lane. In the following step S21, it is determined whether the length of the detected space in the direction of travel of the vehicle V is longer than the overall length of the vehicle V and shorter than the length at which a lane change is determined to be possible in the second autonomous steering control. If the length of the detected space in the direction of travel of the vehicle V is longer than the overall length of the vehicle V and shorter than the length at which a lane change is determined to be possible in the second autonomous steering control, the process proceeds to step S23. On the other hand, if the length of the detected space in the direction of travel of the vehicle V is less than the overall length of the vehicle V or is greater than the length at which a lane change is determined to be possible in the second autonomous steering control, the process proceeds to step S22.

In step S22, the judgment function of the judgment unit 24 changes the predetermined cancellation condition to a condition under which the first autonomous steering control is canceled. For example, the predetermined cancellation condition is changed to the condition set in step S1. Alternatively, the predetermined cancellation condition may be changed to a condition under which the second autonomous steering control is more likely to be canceled. Then, proceed to step S23.

In step S23, the driving control function of the assistance unit 20 determines whether the lane change has been completed. Specifically, it determines whether the LCM or LCP has been completed. If it is determined that the lane change has not been completed, the process proceeds to step S12 and the above-mentioned processing is repeated. On the other hand, if it is determined that the lane change has been completed, the second autonomous steering control is terminated and the process proceeds to step S8 in Figure 6A.

[Embodiments of the present invention]
As described above, according to the present embodiment, a vehicle driving assistance method is provided, which is executed by a processor to execute autonomous steering control including a first autonomous steering control for maintaining vehicle V traveling along its own lane and a second autonomous steering control for changing lanes from the own lane to another lane, and to terminate the autonomous steering control if a driver's steering operation input during execution of the autonomous steering control satisfies a predetermined termination condition. The predetermined termination condition is a condition under which the second autonomous steering control is less likely to be terminated than the first autonomous steering control after the second autonomous steering control has started and before the vehicle starts moving in the width direction of the own lane. This prevents the driver's steering operation from terminating the autonomous steering control in a driving scenario where autonomous lane change control should be continued. Furthermore, even if the driver checks the surrounding driving environment and steers when a lane change is possible, the lane change can be initiated while the autonomous steering control is continued. Therefore, the driver can start the lane change driving action at the desired timing, and after starting the lane change driving action, the vehicle can drive using autonomous steering control.

Furthermore, according to the vehicle driving assistance method of this embodiment, the processor may set the predetermined cancellation condition to a condition that makes the second autonomous steering control less likely to be cancelled than the first autonomous steering control after the second autonomous steering control has started and before the vehicle starts moving in the width direction of the host lane. This makes it possible to prevent the autonomous steering control from being cancelled against the driver's intention due to the driver's steering operation.

Furthermore, according to the vehicle driving assistance method of this embodiment, the processor may set the amount of change in the steering angle of the steered wheels of the vehicle relative to the amount of rotation of the steering wheel of the vehicle in the second autonomous steering control to be smaller than the amount of change in the first autonomous steering control before the vehicle starts moving in the width direction of the host lane. This increases the amount of rotation required to reach the specified angle, making it less likely that the second autonomous steering control will be terminated.

Furthermore, according to the vehicle driving assistance method of this embodiment, the processor may set the predetermined cancellation condition to a condition for canceling the first autonomous steering control after the vehicle starts moving in the width direction of the own lane. This makes it easier to reflect the driver's intentions in the driving of the vehicle V, for example, when the driver wants to cancel the autonomous steering control after the vehicle V starts a driving operation to change lanes, or when the driver wants to increase the speed of movement in the width direction of the own lane.

Furthermore, according to the vehicle driving assistance method of this embodiment, the processor may set the predetermined cancellation condition to a condition for canceling the first autonomous steering control after one of the vehicle's steering wheels, which is steered in a direction opposite to the direction in which the vehicle is moving, passes over a boundary line that defines the vehicle's own lane. This makes it easier to reflect the driver's intentions, such as canceling autonomous steering control or increasing the vehicle's speed in the width direction of the lane, in the driving of the vehicle V.

Furthermore, according to the vehicle driving assistance method of this embodiment, after the processor starts flashing the vehicle's turn indicators through the second autonomous steering control, the processor may set the predetermined cancellation condition to a condition under which the second autonomous steering control is less likely to be cancelled than the first autonomous steering control. This makes it possible to accelerate the timing at which vehicle V starts moving in the width direction of its own lane, reflecting the driver's intentions, for example, when a following vehicle traveling at a higher speed approaches vehicle V from behind.

Furthermore, according to the vehicle driving assistance method of this embodiment, the processor may flash the turn indicators of the vehicle if the steering operation is detected after the start of the second autonomous steering control and before the vehicle starts moving in the width direction of the own lane. This allows other vehicles around vehicle V to be informed that vehicle V is attempting to change lanes.

Furthermore, according to the vehicle driving assistance method of this embodiment, the processor detects a space where the vehicle can enter the other lane, and if the length of the detected space in the direction of travel of the vehicle is longer than the overall length of the vehicle and shorter than the length at which it is determined that a lane change is possible under the second autonomous steering control, the predetermined cancellation condition may be set to a condition under which the second autonomous steering control is less likely to be cancelled than the first autonomous steering control. This allows the driver to change lanes at their discretion while continuing the second autonomous steering control.

Furthermore, according to this embodiment, a vehicle driving assistance device 19 is provided, which includes a control unit 23 that executes autonomous steering control, including first autonomous steering control to maintain vehicle V traveling along its own lane and second autonomous steering control to change lanes from the own lane to another lane, and a determination unit 24 that terminates the autonomous steering control if a driver's steering operation input during execution of the autonomous steering control satisfies a predetermined termination condition, wherein the predetermined termination condition is a condition under which the second autonomous steering control is less likely to be terminated than the first autonomous steering control after the second autonomous steering control has started and before the vehicle begins moving in the width direction of the own lane. This prevents the driver's steering operation from terminating autonomous steering control in driving situations where autonomous lane change control should be continued. Furthermore, even if the driver checks the surrounding driving environment and steers when a lane change is possible, the lane change can be initiated while autonomous steering control is continued. Therefore, the driver can start the lane change driving action at the desired timing, and after starting the lane change driving action, the vehicle can drive using autonomous steering control.

In the vehicle driving assistance method and driving assistance device 19 of this embodiment, the configurations described in the above-mentioned embodiments may be freely combined and used, and there are no particular limitations on the combinations. Furthermore, in the vehicle driving assistance method and driving assistance device 19 of this embodiment, the configurations described in the above-mentioned embodiments are not limited to the configurations described in the above-mentioned embodiments, and there are no particular limitations on the combinations.

DESCRIPTION OF SYMBOLS 10... Driving assistance system 11... Imaging device 12... Distance measuring device 13... Vehicle state detection device 14... Map information 15... Vehicle position detection device 16... Navigation device 17... Vehicle control device 171... Speed control device 172... Steering control device 18... Display device 19... Driving assistance device 191... CPU (processor)
192...ROM
193...RAM
20... Support unit 21... Generation unit 22... Recognition unit 23... Control unit 231... Speed control unit 232... Steering control unit 24... Determination unit L1, L2, L3, L4... Lanes P1, P2, P3, P3a, P3b, P4, P5, P6, P7, P8, P9, P10, P11, P12, P13, Py... Positions T1, T2, T3, T4, T5, T6... Travel trajectory V... Vehicle (host vehicle)
X: Destination Y: Other vehicle Z: Branch point

Claims (7)

A vehicle driving assistance method executed by a processor, comprising:
The processor:
Execute autonomous steering control including a first autonomous steering control for maintaining the vehicle traveling along its own lane, and a second autonomous steering control for changing lanes from the own lane to another lane;
setting a predetermined cancellation condition for the first autonomous steering control;
If a steering operation of the driver input during execution of the first autonomous steering control satisfies a predetermined condition for canceling the first autonomous steering control , cancel the first autonomous steering control;
After the second autonomous steering control is started and before the vehicle starts moving in the width direction of the own lane , a predetermined stop condition for the second autonomous steering control is set, the predetermined stop condition being a condition that is less likely to be stopped than the predetermined stop condition for the first autonomous steering control ;
If the steering operation is detected between the start of the second autonomous steering control and the start of the vehicle moving in the width direction of the own lane, determine whether the steering operation satisfies a predetermined stop condition for the second autonomous steering control ;
When it is determined that the steering operation satisfies a predetermined condition for stopping the second autonomous steering control, the second autonomous steering control is stopped;
A vehicle driving assistance method that, if it is determined that the steering operation does not satisfy a predetermined condition for canceling the second autonomous steering control , corrects the lane change driving operation performed by the second autonomous steering control based on the steering operation. 2. The vehicle driving assistance method of claim 1, wherein the processor sets the amount of change in the steering angle of the vehicle's steering wheels relative to the amount of rotation of the vehicle's steering wheel in the second autonomous steering control to be smaller than the amount of change in the first autonomous steering control before the vehicle starts moving in the width direction of the vehicle's lane. 3. A vehicle driving assistance method as described in claim 1 or 2, wherein the processor sets the predetermined termination condition of the second autonomous steering control to the same condition as the predetermined termination condition of the first autonomous steering control after the vehicle starts moving in the width direction of the own lane. 3. A vehicle driving assistance method as described in claim 1 or 2, wherein the processor sets the predetermined termination condition of the second autonomous steering control to the same condition as the predetermined termination condition of the first autonomous steering control after one of the steering wheels of the vehicle that is steered in a direction opposite to the direction in which the vehicle is moving passes over a boundary line that defines the vehicle's own lane. 3. A vehicle driving assistance method as described in claim 1 or 2, wherein the processor sets a predetermined termination condition for the second autonomous steering control that is less likely to be terminated than the predetermined termination condition for the first autonomous steering control after starting to flash the vehicle's turn indicators through the second autonomous steering control . The processor:
detecting a space for the vehicle to enter the other lane;
A vehicle driving assistance method as described in claim 1 or 2, wherein if the length of the detected space in the direction of travel of the vehicle is longer than the overall length of the vehicle and shorter than the length at which a lane change is determined to be possible by the second autonomous steering control, a predetermined termination condition for the second autonomous steering control is set that is less likely to be terminated than the predetermined termination condition for the first autonomous steering control . a control unit that executes autonomous steering control including a first autonomous steering control for maintaining the vehicle traveling along its own lane, and a second autonomous steering control for changing lanes from the own lane to another lane;
a determination unit that sets a predetermined cancellation condition for the first autonomous steering control, and cancels the first autonomous steering control if a steering operation of the driver input during execution of the first autonomous steering control satisfies the predetermined cancellation condition for the first autonomous steering control,
The determination unit
After the second autonomous steering control is started and before the vehicle starts moving in the width direction of the own lane , a predetermined stop condition for the second autonomous steering control is set, the predetermined stop condition being a condition that is less likely to be stopped than the predetermined stop condition for the first autonomous steering control ;
If the steering operation is detected between the start of the second autonomous steering control and the start of the vehicle moving in the width direction of the own lane, determine whether the steering operation satisfies a predetermined stop condition for the second autonomous steering control ;
The control unit
When the determination unit determines that the steering operation satisfies a predetermined condition for stopping the second autonomous steering control, the second autonomous steering control is stopped,
A vehicle driving assistance device that corrects the lane change driving operation by the second autonomous steering control based on the steering operation when the judgment unit determines that the steering operation does not satisfy a predetermined condition for stopping the second autonomous steering control.