Route generation method and route generation device

Abstract

To provide a route generation method and a route generation device with which it is possible to suppress the host vehicle from becoming unable to pass through an intersection and stopping in the intersection.SOLUTION: A processor generates a travel route R1 which a host vehicle V1 travels along by autonomous travelling control, extracts a non-priority intersection among intersections on the travel route R1 where other vehicles have the priority of traveling, when the traveling direction of the host vehicle V1 traveling along the travel route R1 crosses the traveling direction of the other vehicles, determines whether or not an alternative route R2 for the non-priority route can be generated, and generates the alternative route R2 for the non-priority route when it is determined that the alternative route R2 can be generated. The alternative route R2 is such that the non-priority intersection is exited along the traveling direction in which the host vehicle V1 has the priority of traveling when the traveling direction of other vehicles is crossed, traveling is continued in a lane in which the host vehicle V1 has the priority of traveling when the travelling direction of the host vehicle V1 and the traveling direction of other vehicles cross, and the same lane is entered as the one that the host vehicle V1 enters when the non-priority intersection is passed along the travel route R1.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a route generation method and a route generation device. [Background technology]

[0002] A known driving route setting device acquires traffic information related to the driving route, performs route search, and sets a new driving route to the destination, prioritizing the currently driving automatic driving section, when at least a part of the driving route corresponds to an automatic driving section and the vehicle is driving automatically through the automatic driving section (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-189528 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned conventional technology, because a new driving route is searched for with priority given to the autonomous driving section in which the vehicle is currently traveling, when the vehicle turns right at an intersection ahead of the autonomous driving section, even if the acquired traffic information indicates that a traffic jam of oncoming vehicles turning left at the intersection has occurred, the vehicle will enter the intersection without changing its driving route. As a result, the vehicle will be unable to enter the lane where it is about to turn right and will end up stopping at the intersection.

[0005] The problem to be solved by the present invention is to provide a route generation method and a route generation device that can prevent a host vehicle from being unable to pass through an intersection and having to stop at the intersection. [Means for solving the problem]

[0006] The present invention solves the above problem by generating a driving route for the vehicle to travel on using autonomous driving control, and extracting, from among the intersections on the driving route, a non-priority intersection where the direction of travel of the vehicle traveling along the driving route intersects with the direction of travel of another vehicle, and determining whether a detour route can be generated for the non-priority intersection.If it is determined that a detour route can be generated, the present invention generates a detour route for the non-priority intersection. [Effects of the Invention]

[0007] According to the present invention, it is possible to prevent the host vehicle from being unable to pass through an intersection and coming to a stop in the intersection. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a block diagram showing a driving assistance system including a driving assistance device according to the present invention. [Figure 2] 2 is a plan view showing an example of a travel route created by the driving assistance system shown in FIG. 1 and an example of a travel route created by a driving assistance system according to a comparative example. FIG. [Figure 3] FIG. 3 is a plan view showing whether or not traffic congestion occurring at an intersection can be bypassed when traveling along the travel route shown in FIG. 2. [Figure 4] 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. FIG. [Figure 5A] 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. [Figure 5B] 1. FIG. 4 is a plan view (part 2) showing another example of a driving scene in which driving assistance is performed by the driving assistance system shown in FIG. [Figure 6] 2 is a flowchart showing an example of a processing procedure in the driving assistance system of FIG. 1. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The following description is based on the assumption that vehicles are driven on the left side of the road in countries with laws stipulating left-hand traffic. In countries with laws stipulating right-hand traffic, vehicles are driven on the right side of the road, so the left and right in the following description should be interpreted as symmetrical.

[0010] [Driver assistance system configuration] 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), and 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 device in the vehicle. In other words, the driving assistance device intervenes in and controls these driving behaviors within a predetermined range. Driving behaviors that are not intervened in are manually controlled by the driver.

[0011] As shown in Fig. 1, a driving assistance system 10 includes 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. Also, as shown in Fig. 1, the driving assistance device 19 includes, as a part thereof, a route generation device having a route generation function. The devices that make up the driving assistance system 10 are connected by a CAN (Controller Area Network) or other in-vehicle LAN, and can exchange information with each other.

[0012] 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. A single vehicle can be provided with multiple imaging devices 11, and they can be located, for example, near the front grille, under the left and right door mirrors, and near the rear bumper. This reduces blind spots when recognizing objects around the vehicle.

[0013] The distance measuring 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 a laser radar, a millimeter wave radar (such as LRF), a LiDAR (light detection and ranging) unit, or an ultrasonic radar. A plurality of distance measuring devices 12 can be provided on one vehicle, and can be arranged, 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 objects around it to be accurately calculated.

[0014] The objects detected by the imaging device 11 and the 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. The 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 the distance measuring device 12 are acquired by the driving assistance device 19 at predetermined time intervals as necessary.

[0015] Furthermore, the detection results of the imaging device 11 and the distance measuring device 12 can be integrated or synthesized (so-called sensor fusion) by the driving assistance device 19, thereby supplementing missing information about the detected object. For example, the driving assistance device 19 can calculate the position information of the object based on the self-position information, which indicates the position where the vehicle is traveling and is acquired 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 distance measuring device 12 and the map information 14, to become information about the driving environment around the vehicle. Furthermore, the detection results of the imaging device 11 and the distance measuring device 12 and the map information 14 can be used to recognize objects around the vehicle and predict their movements.

[0016] The vehicle state detection device 13 is a device for detecting the running state of the vehicle, and includes a vehicle speed sensor, an acceleration sensor, a yaw rate sensor (e.g., a gyro sensor), a steering angle sensor, an inertial measurement unit, etc. These devices are not particularly limited, and known devices can be used. The arrangement and number of these devices can be set appropriately within a range that allows the running state of the vehicle to be appropriately detected. The detection results of each device are acquired by the driving assistance device 19 at predetermined time intervals as necessary.

[0017] 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, road shoulder structures, road traffic regulations (speed limit, 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-resolution map information that allows the movement trajectory of each lane to be grasped, and includes two-dimensional position information 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, connecting lane information, etc.

[0018] Road and lane boundary information in high-resolution map information is information that 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 the form of the lane is not particularly limited. Boundaries exist on both the left and right sides of the vehicle's direction of travel, and the form is not particularly limited. Boundaries are, for example, road markings or road structures. Examples of road markings include lane boundaries and center lines, and examples of road structures include medians, guardrails, curbs, tunnels, and highway sidewalls. Note that 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.

[0019] The map information 14 is stored in a readable state in a recording medium provided in the driving assistance device 19, an in-vehicle device, or a server on a network. The driving assistance device 19 acquires the map information 14 as needed.

[0020] 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 from, for example, radio waves received from a satellite for a GPS (Global Positioning System). Alternatively, the vehicle position detection device 15 may estimate the current position of the vehicle from vehicle speed information and acceleration information acquired from the vehicle state detection device 13, which includes a vehicle speed sensor, an acceleration sensor, and a gyro sensor, and compare the estimated current position with the map information 14 to calculate the current position of the vehicle.

[0021] 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 searches for a driving route for the vehicle to reach the destination from the current position using road information, facility information, etc. in the map information 14. The driving route includes at least information on the road on which the vehicle is traveling, the driving lane, and the vehicle's traveling direction, and is displayed, for example, as a linear diagram. There may be multiple driving routes depending on the search conditions. The driving route calculated by the navigation device 16 is output to the driving assistance device 19.

[0022] The vehicle control device 17 is an on-board computer such as an electronic control unit (ECU), and electronically controls on-board devices that govern the driving of the vehicle. The vehicle control device 17 includes a vehicle speed control device 171 that controls the driving speed of the vehicle, and a steering control device 172 that controls the steering operation of the vehicle. The vehicle 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 vehicle 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 host vehicle state detection device 13.

[0023] Examples of the drive devices controlled by the vehicle speed control device 171 include an electric motor and / or an internal combustion engine as a driving source for traveling, a power transmission device including a drive shaft and an automatic transmission that transmits the output from these driving sources for traveling to the driving wheels, and a drive device that controls the power transmission device. In addition, the braking device controlled by the vehicle speed control device 171 is, for example, a braking device that brakes the wheels. A control signal corresponding to a set traveling speed is input to the vehicle speed control device 171 from the driving assistance device 19. The vehicle speed control device 171 generates signals to control these drive devices based on the control signals input from the driving assistance device 19 and transmits the signals to the drive devices, thereby autonomously controlling the traveling speed of the vehicle.

[0024] 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 steering angle of the steering wheel, and an example of this is a steering actuator such as a motor attached to a steering column shaft. Based on a control signal 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 (position of the vehicle in the left-right direction) with respect to the set travel route. For this control, at least one of the detection results of the imaging device 11 and the distance measuring device 12, the vehicle travel state acquired by the host vehicle state detection device 13, the map information 14, and information on the current position of the vehicle acquired by the host vehicle position detection device 15 is used.

[0025] The display device 18 is a device for providing necessary information to vehicle occupants, and is, for example, a liquid crystal display provided on the instrument panel, a projector such as a head-up display (HUD), etc. The display device 18 may also include an input device for the vehicle occupant to input instructions to the driving assistance device 19. Examples of the input device include a touch panel that receives input by the user's finger or a stylus pen, a microphone that receives instructions by the user's voice, and switches attached to the steering wheel of the vehicle. The display device 18 may also include a speaker as an output device.

[0026] The driving assistance device 19 is a device that controls the driving of the vehicle by controlling and cooperating with 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 a vehicle occupant. The driving assistance device 19 is, for example, a computer, and includes a CPU (Central Processing Unit) 191 that is a processor, a ROM (Read Only Memory) 192 that stores programs, and a RAM (Random Access Memory) 193 that 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.

[0027] The driving assistance device 19 has a driving assistance function of driving the vehicle to a set destination by autonomous driving control. The driving assistance functions of the driving assistance device 19 include a route generation function of generating a driving route, an environment recognition function of recognizing the driving environment around the vehicle, and a driving control function of generating a driving trajectory and driving the vehicle along the driving trajectory. In addition, the driving assistance device 19 has an extraction function of extracting intersections on the driving route that satisfy predetermined conditions, and a detour function of generating a detour route to reach the set destination. In this embodiment, the driving assistance device 19 includes a route generation device as a part thereof. Of the functions of the driving assistance device 19, the route generation function, extraction function, and detour function are mainly provided by the route generation device.

[0028] The programs stored in the ROM 192 include programs for realizing the above-mentioned functions, and these functions are realized by the CPU 191 executing the programs stored in the ROM 192. Figure 1 conveniently shows functional blocks that realize each function.

[0029] [Functions of each function block] The functions of each functional block of the support unit 20, the generation unit 21, the extraction unit 22, the detouring unit 23, the recognition unit 24, and the control unit 25 shown in FIG. 1 will be described below with reference to FIG.

[0030] The assistance unit 20 has a driving assistance function that drives the vehicle to a set destination through autonomous driving control. Fig. 2 is a plan view showing an example of a driving scene in which the driving assistance device 19 autonomously controls the driving of the vehicle using the driving assistance function of the assistance unit 20. In the driving scene shown in Fig. 2, roads A1, A2, and A3 extend in the vertical direction of the drawing, and roads B1, B2, and B3 extend in the horizontal direction of the drawing. Roads A1, A2, A3, and B3 are roads with one lane in each direction, and roads B1 and B2 are roads with one lane in each direction with a dedicated right-turn lane at the intersection. Lane Lr shown in Fig. 2 is a dedicated right-turn lane.

[0031] Intersections C1 and C2 exist where road A1 intersects with roads B1 and B2, respectively; intersections C3, C4, and C5 exist where road A2 intersects with roads B1, B2, and B3, respectively; and intersections C6, C7, and C8 exist where road A3 intersects with roads B1, B2, and B3, respectively. Each road shown in Figure 2 is left-hand traffic, and vehicles traveling on roads A1, A2, A3, and B3 can turn right, left, or go straight through an intersection. However, if there is no lane for a vehicle to enter after turning right at an intersection, the vehicle cannot turn right at that intersection. The same applies to left turns and going straight.

[0032] On the other hand, on roads B1 and B2, vehicles traveling in the lane on the left side of the road can turn left or go straight at the intersection, and vehicles traveling in the right-turn-only lane Lr can turn right at the intersection. However, if there is no lane for a vehicle to enter after turning left at an intersection, the vehicle cannot turn left at the intersection. The same applies to going straight. Also, although not shown, each intersection is equipped with traffic lights.

[0033] In the driving scene shown in Fig. 2, the host vehicle V1 travels at position P1 on road A1, heading toward destination X set by the driver of the host vehicle V1. 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 causes the host vehicle V1 to travel along the generated driving route using autonomous driving control. This autonomous driving control is mainly controlled by the functions of the generation unit 21, extraction unit 22, detouring unit 23, recognition unit 24, and control unit 25.

[0034] 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 from the current position to the destination by autonomous driving control. The driving assistance device 19 also sets lanes for traveling along the generated driving route. The driving assistance device 19 acquires information on the generated driving route and the set lanes from the navigation device 16 as necessary.

[0035] In the driving scene shown in FIG. 2, the driving assistance device 19 generates a driving route for driving from position P1, which is the current position of the vehicle V1, to destination X. Specifically, the driving assistance device 19 acquires the current position of the vehicle V1 from the vehicle position detection device 15, acquires road network data from map information 14, and uses the navigation device 16 to search for multiple routes for driving from the current position to destination X. Among the searched routes, the driving assistance device 19 then selects the route with the shortest driving time or driving distance. Assuming that the time required to pass through each intersection is the same, the driving assistance device 19 generates a driving route R1 from the position P1 to destination X that has the shortest driving time. The driving route R1 is a route that travels straight on road A1, travels straight through intersection C1, turns left at intersection C2 and enters road B2, turns right at intersection C4 and enters road A2, and travels along the road to destination X.

[0036] In addition, in the driving scene shown in Fig. 2, in addition to driving route R1, a route Rx according to a comparative example of the present invention can be generated as a route for traveling from position P1 to destination X. Route Rx has the same travel time to destination X as driving route R1, and is a route that turns left at intersection C1 onto road B1, turns right at intersection C3 onto road A2, goes straight through intersection C4, and travels along road A2 to reach destination X. In the driving scene shown in Fig. 2, there are no obstacles, so both driving route R1 and route Rx reach destination X in the same travel time.

[0037] In the driving scene shown in FIG. 2, the route condition is set to select the route with the shortest driving time, but the route condition is not limited to this. It may be set to select the route with the shortest driving distance or the route with the fewest number of right turns. Furthermore, while the driving route R1 shown in FIG. 2 was generated under the setting that the required time to pass through each intersection is the same, the set conditions may be changed for each intersection and each lane. Examples of set conditions include driving time, driving distance, and the risk of contact with an oncoming vehicle. For example, if it is known that traffic congestion is likely to occur at intersection C2 shown in FIG. 2, the driving time at intersection C2 (i.e., the required time to pass intersection C2) is set to be longer than the passing times at other intersections.

[0038] The extraction unit 22 has an extraction function of extracting, from among intersections on the driving route, non-priority intersections at which other vehicles have priority when the traveling direction of the vehicle traveling along the driving route intersects with the traveling direction of the other vehicles. The driving assistance device 19 extracts non-priority intersections from the intersections on the generated driving route using the extraction function of the extraction unit 22.

[0039] A non-priority intersection is, for example, an intersection where the host vehicle crosses an oncoming lane when traveling along the travel path. Specifically, it is an intersection where the host vehicle turns right if driving on the left side of the road, and where the host vehicle turns left if driving on the right side of the road. When the traveling direction of the host vehicle traveling along the travel path intersects with the traveling direction of another vehicle, it means that the host vehicle and the other vehicle will come into contact if the host vehicle continues traveling along the travel path without stopping. In such a case, in accordance with traffic laws and regulations, the host vehicle or the other vehicle must stop to avoid contact. At a non-priority intersection, if the host vehicle and the other vehicle come into contact when traveling along the travel path, the host vehicle must stop to avoid contact.

[0040] For example, on a road where traffic keeps to the left, when a vehicle is turning right at an intersection and an oncoming vehicle is approaching the vehicle, the oncoming vehicle has priority. Therefore, the vehicle must stop and wait for the oncoming vehicle to pass in front of the vehicle. On the other hand, when a vehicle is turning left at an intersection and an oncoming vehicle turning right is approaching the vehicle, the vehicle has priority, so the vehicle passes through the intersection without stopping. In other words, there is no need to stop and wait for the oncoming vehicle turning right to pass in front of the vehicle.

[0041] The driving assistance device 19 acquires road information from the map information 14, acquires a driving route from the navigation device 16, and extracts non-priority intersections from intersections on the driving route. In this extraction, for example, the location of the intersection is compared with information on traffic laws and regulations included in the road information to determine whether the intersection is a non-priority intersection. Alternatively or in addition, the driving assistance device 19 extracts from the navigation device 16 intersections along the driving route at which the vehicle should turn right if driving on the left side of the road, or at which the vehicle should turn left if driving on the right side of the road. Information on the extracted non-priority intersections, together with information on the locations of the non-priority intersections on the driving route, is output for processing by the detouring unit 23, which will be described later.

[0042] In the travel route R1 shown in Fig. 2, the host vehicle V1 turns right at intersection C4, so the driving assistance device 19 extracts intersection C4 as a non-priority intersection. In contrast, in the route Rx according to the comparative example, the host vehicle V1 turns right at intersection C3, so intersection C3 is extracted as a non-priority intersection. The extracted non-priority intersections are different between the travel route R1 and the route Rx according to the comparative example. The effect that this difference in non-priority intersections has on the travel of the host vehicle V1 will be described with reference to Fig. 3.

[0043] Fig. 3 is a plan view showing another example of a driving scene in which the driving assistance device 19 autonomously controls the driving of a vehicle. The driving scene shown in Fig. 3 is the same as the driving scene shown in Fig. 2, except that there is a traffic jam of left-turning vehicles at intersections C3 and C4. Specifically, there is a traffic jam of other vehicles Y1 to Y6 at intersection C3, and there is a traffic jam of other vehicles Y7 to Y12 at intersection C4. In this embodiment, a traffic jam refers to a situation in which multiple vehicles form a line of vehicles, and the vehicles in the line of vehicles are stopped or moving slowly. Moving slowly refers to a driving speed (for example, 1 to 10 km / h) that allows the vehicles to stop immediately.

[0044] In the driving scene shown in Figure 3, when traveling along driving route R1, the host vehicle V1 travels along driving trajectory Tx to turn right at intersection C4 and attempts to enter the lane on the left side of road A2 in the direction of travel from the right-turn lane. However, there is another vehicle Y4 ahead of the host vehicle V1 that is turning left at intersection C4, so the host vehicle V1 stops at intersection C4 to avoid contact with the other vehicle Y4. If the traveling direction of the host vehicle V1 turning right intersects with the traveling direction of a vehicle turning left at intersection C4, the left-turning vehicle has priority. Therefore, the host vehicle V1 will continue to stop at intersection C4 until the congestion of the other vehicles Y1 to Y6 is resolved, thereby obstructing the traveling of the other vehicles passing through intersection C4.

[0045] In this case, in order to prevent the vehicle from stopping at intersection C4, a route to destination X without turning right at intersection C4 is generated and the vehicle travels along this route. Therefore, the driving assistance device 19 of this embodiment selects a non-priority intersection at which a detour route can be generated, and generates a travel route that passes through the non-priority intersection. The generation of the detour route is realized by the function of the detour unit 23.

[0046] The detour unit 23 has a detour function that determines whether a detour route can be generated for the extracted non-priority intersection. The detour unit 23 also has a detour function that generates a detour route for the non-priority intersection when it is determined that a detour route can be generated. The driving assistance device 19 determines whether a detour route can be generated for the non-priority intersection using the detour function of the detour unit 23, and generates a detour route for the non-priority intersection when a detour route can be generated.

[0047] In this embodiment, the detour route is a route that 1) exits a non-priority intersection along the direction of travel that gives priority to the vehicle's own travel if the direction of travel intersects with that of another vehicle, 2) continues to travel in the lane that gives priority to the vehicle's own travel if the direction of travel of the vehicle and the direction of travel of another vehicle intersect, and 3) enters the same lane that the vehicle will enter if it passes through a non-priority intersection along its travel route.

[0048] Regarding 1), the traveling direction in which the own vehicle has priority when crossing the traveling direction of another vehicle is, for example, the direction in which the own vehicle passes through the intersection (exits the intersection) without crossing the oncoming lane. Specifically, if the own vehicle is driving on the left side of the road, it is the direction in which the own vehicle turns left or goes straight through the intersection, and if the own vehicle is driving on the right side of the road, it is the direction in which the own vehicle turns right or goes straight through the intersection. If the own vehicle is traveling along a detour route and approaches another vehicle, the other vehicle will stop to avoid contact. In other words, when traveling along a detour route and exiting a non-priority intersection, the own vehicle can continue traveling without stopping, but if the other vehicle approaches the own vehicle, it will have to stop and wait for the own vehicle to pass in front.

[0049] Regarding 2), a lane in which the host vehicle has priority when its direction of travel intersects with the direction of travel of another vehicle is, for example, a lane in which the host vehicle can travel without crossing an oncoming lane. Specifically, if the vehicle is driving on the left side of the road, it is a lane in which the host vehicle travels straight or a lane in which the host vehicle turns left at an intersection; if the vehicle is driving on the right side of the road, it is a lane in which the host vehicle travels straight or a lane in which the host vehicle turns right at an intersection. When the host vehicle is traveling on the lane along a detour route and approaches another vehicle, the other vehicle stops to avoid contact. In other words, unless an unavoidable obstacle is detected, the host vehicle can travel on the lane without stopping. When another vehicle entering the lane approaches the host vehicle, it must stop and wait for the host vehicle to pass in front of it. Furthermore, since the host vehicle continues traveling on the lane, it does not include lanes in which the other vehicle has priority when the host vehicle's direction of travel intersects with the direction of travel of the other vehicle along the detour route. For example, a lane in which the host vehicle crosses an oncoming lane is not included in the detour route.

[0050] Regarding 3), the lane into which the vehicle will enter when passing through a non-priority intersection along the travel route is the lane set by the route generation function so that the vehicle will enter after traveling along the travel route and passing through the non-priority intersection. By entering the same lane as the lane set to enter after passing through the non-priority intersection, the vehicle can head towards destination X while minimizing stopping within the intersection.

[0051] Figure 3 shows detour route R2, which is an example of a detour route in the driving scene shown in Figure 3. Detour route R2 is a route in which the vehicle travels in the left lane of road B2 in the driving direction, passes intersection C4 by going straight along driving trajectory Ty, turns left at intersection C7 to enter road A3, turns left at intersection C6 to enter road B1, turns left at intersection C3 to enter road A2, passes intersection C4 by going straight, and travels along the road to reach destination X.

[0052] When traveling along detour route R2, host vehicle V1 passes intersection C4, which is a non-priority intersection, by going straight and exits toward the right side of the drawing. After exiting intersection C4, host vehicle V1 turns left at intersection C7, turns left at intersection C6, and turns left at intersection C3 to reach intersection C4. In other words, after exiting intersection C4, host vehicle V1 travels to intersection C4 by combining going straight and turning left at intersections. Furthermore, similar to travel route R1 shown in FIG. 2, host vehicle V1 passes intersection C4 and enters the left lane of road A2 in the direction of travel. At this time, because traffic is controlled by traffic lights at intersection C4, the traveling direction of host vehicle V1 passing intersection C4 by going straight does not intersect with the traveling directions of other vehicles Y1 to Y6 turning left at intersection C4. This prevents host vehicle V1 from stopping at intersection C4.

[0053] On the other hand, when traveling along route Rx, the host vehicle V1 travels along travel trajectory Tz to turn right at intersection C3, and attempts to enter the lane on the left side of road A2 in the direction of travel from the right-turn-only lane. However, because there is another vehicle Y10 turning left at intersection C3 ahead of the host vehicle V1, the host vehicle V1 stops at intersection C3 to avoid contact with the other vehicle Y10. At intersection C3, as at intersection C4, left-turning vehicles have priority, so the host vehicle V1 continues to stop at intersection C3 until the congestion of the other vehicles Y7 to Y12 is resolved.

[0054] In this case, if an attempt is made to generate a detour route for intersection C3 in the same way as for intersection C4, a route that combines going straight and turning left, such as detour route R2, cannot be generated. This is because the host vehicle V1 cannot turn left at intersection C6, which it will enter after going straight through intersection C3. Therefore, if the host vehicle V1 travels along route Rx, it cannot avoid stopping at intersection C3.

[0055] Whether or not a detour route can be generated for a non-priority intersection depends on the connection relationship of the roads around the non-priority intersection. When determining whether or not a detour route can be generated for a non-priority intersection, the driving assistance device 19 uses the navigation device 16 to search for a detour route that satisfies the above-mentioned conditions 1) to 3). The search for a detour route is performed using road network data acquired from map information 14, the navigation device 16, etc., in the same way as the search for a driving route. If a route that satisfies all of the conditions 1) to 3) is found, it is determined that a detour route can be generated for the non-priority intersection, and the found route is output as the detour route. On the other hand, if a route that satisfies all of the conditions 1) to 3) is not found, it is determined that a detour route cannot be generated for the non-priority intersection.

[0056] Furthermore, a condition for searching for a detour route may be added that the length of the detour route must not exceed a predetermined distance longer than if the vehicle had passed through a non-priority intersection without traveling along the detour route. The predetermined distance can be set as an appropriate distance within a range that is acceptable to the occupants of the vehicle V1 for the time required to travel along the detour route, and may be, for example, 50 m to 1 km. The predetermined distance varies depending on the traffic conditions and traffic laws around destination X. For example, if the speed limit around destination X is high, the predetermined distance is set longer than when the speed limit is low. Furthermore, if there is constant congestion around destination X, the predetermined distance is set shorter than when there is no congestion.

[0057] When generating the detour route R2, the driving assistance device 19 extracts non-priority intersections on the driving route R1 at the same time as generating the driving route R1, determines whether a detour route can be generated for the non-priority intersection, and if a detour route can be generated, generates the detour route for the non-priority intersection. Alternatively, the driving assistance device 19 extracts non-priority intersections on the driving route R1 at the same time as generating the driving route R1 or before starting driving following the driving route R1, determines whether a detour route can be generated for the non-priority intersection, and if a detour route can be generated, generates the detour route for the non-priority intersection. Alternatively, the driving assistance device 19 extracts non-priority intersections on the driving route R1 at the same time as generating the driving route R1, and generates detour routes for non-priority intersections for which a detour route can be generated at the latest by the time of switching from autonomous driving control that follows the driving trajectory to autonomous driving control that drives along the detour route. In this case, the determination of whether a detour route can be generated for the non-priority intersection is made at an appropriate time between the extraction of the non-priority intersection and the generation of the detour route. Switching of autonomous driving control will be described later. Alternatively, the driving assistance device 19 extracts the non-priority intersection, determines whether a detour route can be generated, and generates the detour route for the non-priority intersection before passing the intersection just before the non-priority intersection for which a detour route can be generated.

[0058] On the other hand, if the driving assistance device 19 determines that a detour route cannot be generated for a non-priority intersection, it changes the setting conditions for the non-priority intersection to make it more difficult to pass through the non-priority intersection when generating a driving route. Specifically, it changes the setting conditions for the non-priority intersection in route generation so that it is more difficult to pass through the non-priority intersection than when a driving route that has already undergone processing to extract the non-priority intersection was generated. Then, the driving assistance device 19 generates a new driving route based on the changed setting conditions using the route generation function of the generation unit 21.

[0059] As an example of changing the setting conditions for route generation to make it harder to pass through non-priority intersections, for example, the setting of the time required to pass through a non-priority intersection is changed to set it to a longer time. As a result, if the non-priority intersection is passed, the time required to reach destination X will be longer, so when searching for a travel route with a shorter travel time, another travel route will be selected with priority. Alternatively or in addition to this, the setting of the travel distance required to pass through a non-priority intersection is changed to set it to a longer travel distance. As a result, if the non-priority intersection is passed, the travel distance to reach destination X will be longer, so when searching for a travel route with a shorter travel distance, another travel route will be selected with priority.

[0060] The change of settings and generation of a driving route are repeated until the driving route does not include any non-priority intersections for which a detour route cannot be generated. However, if the change of settings and generation of a driving route are repeated a predetermined number of times (for example, 3 to 20 times) and a driving route that does not include any non-priority intersections for which a detour route cannot be generated cannot be generated, a driving route that includes the non-priority intersections for which a detour route cannot be generated is output, and the vehicle travels along that driving route.

[0061] Furthermore, to prevent an increase in the number of repetitions of setting changes and route generation, route generation setting conditions may be set in advance so that non-priority intersections for which a detour route can be generated are easier to pass through than non-priority intersections for which a detour route cannot be generated. For example, the time required to pass through a non-priority intersection for which a detour route can be generated is set in advance to be shorter than the time required to pass through a non-priority intersection for which a detour route cannot be generated. Alternatively or in addition, the driving distance for passing through a non-priority intersection for which a detour route can be generated is set in advance to be shorter than the driving distance for passing through a non-priority intersection for which a detour route cannot be generated. By setting route generation setting conditions at the time of initial route generation so that non-priority intersections for which a detour route cannot be generated are difficult to pass through, a route that does not pass through non-priority intersections for which a detour route cannot be generated can be generated with a relatively small number of repetitions.

[0062] Furthermore, the driving assistance device 19 may accumulate information about the surrounding driving environment acquired by the environment recognition function of the driving assistance device 19 when the host vehicle and / or other vehicles have traveled in the past, and calculate the probability of a traffic jam occurring at a non-priority intersection where an oncoming vehicle is waiting to change direction, based on the accumulated past information. In this embodiment, a change in direction refers to a change in the vehicle's direction of travel, including a right turn, a left turn, a turnaround, or entering a branch lane. If the probability is equal to or less than a predetermined value, the host vehicle is unlikely to stop at the intersection, so a new driving route is not generated, and the previously generated driving route is output and the host vehicle is caused to travel along that driving route. On the other hand, if the probability exceeds a predetermined value, the host vehicle is likely to stop at the intersection, so a new driving route is generated. The acquired information about the surrounding driving environment is accumulated in an on-board memory unit or an external server. The predetermined value can be set appropriately within a range (e.g., 1% or less) in which the host vehicle is unlikely to encounter a traffic jam of oncoming vehicles.

[0063] The recognition unit 24 has an environment 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 the distance measuring device 12 through the environment recognition function of the recognition unit 24. The driving environment is information used to determine whether the vehicle can maintain its current driving state or 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 the distance measuring device 12.

[0064] Alternatively or in addition, the driving assistance device 19 acquires image data from cameras installed on traffic lights, telephone poles, road signs, etc., and recognizes 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 recognize obstacles that exist within a range that cannot be detected by the vehicle's imaging device 11, using vehicle-to-vehicle communication with other vehicles traveling around the vehicle.

[0065] Furthermore, the driving assistance device 19 determines whether an intersection exists within a predetermined distance ahead of the vehicle using the environment recognition function of the recognition unit 24. The predetermined distance can be set to an appropriate value within a range in which the driver is not confused as to whether the guidance from the driving assistance device 19 is appropriate. The predetermined distance is, for example, 100 to 1500 m. If the predetermined distance is set longer than this, the driving distance to reach the branch point will be longer, and the driver will be confused as to whether the guidance from the driving assistance device 19 is appropriate, which will cause discomfort. If the predetermined distance is set shorter than this, the driver will not have enough time to understand the guidance from the driving assistance device 19, which will cause discomfort. The intersections detected by the driving assistance device 19 are particularly non-priority intersections.

[0066] The control unit 25 has a driving control function that generates a driving trajectory for driving the vehicle along the generated driving route or detour route, and controls the driving operation of the vehicle so as to follow the generated driving trajectory. The driving assistance device 19 generates a driving trajectory for driving the vehicle along the driving route or detour route using the driving control function of the control unit 25, and autonomously controls the driving operation of the vehicle via the vehicle control device 17 (particularly, the vehicle speed control device 171 and the steering control device 172) so that the vehicle follows the generated driving trajectory. The generation of the driving trajectory takes into consideration information such as the shape, width, and curvature of the road included in the map information 14, as well as the overall length and overall width of the body of the host vehicle V1 and the minimum turning radius of the host vehicle V1.

[0067] While the driving assistance device 19 is traveling following the generated traveling trajectory, the driving assistance device 19 performs a process of recognizing the traveling environment around the vehicle V1 from the detection results of the imaging device 11 and the distance measuring device 12 at predetermined time intervals using the environment recognition function of the recognition unit 24. The predetermined time interval can be set to an appropriate value depending on the processing capacity of the CPU 191 within a range in which the vehicle V1 can avoid contact with an obstacle. In particular, when passing through a non-priority intersection, the driving assistance device 19 detects obstacles present at the non-priority intersection from the detection results of the imaging device 11 and the distance measuring device 12, as well as image information from fixed cameras installed at traffic lights, information obtained from an external server that provides traffic information, information obtained through vehicle-to-vehicle communication with other vehicles traveling around the vehicle V1, and the like.

[0068] The driving assistance device 19 then uses the driving control device of the control unit 25 to predict whether the host vehicle V1 will stop at a non-priority intersection to avoid contact with the detected obstacle. If the driving assistance device 19 predicts that the host vehicle V1 will stop at the non-priority intersection to avoid contact with the obstacle, it switches from autonomous driving control that follows the driving trajectory to autonomous driving control that travels along a detour route. On the other hand, if no obstacle is detected at the non-priority intersection and it is predicted that the host vehicle V1 will not stop at the non-priority intersection, it continues autonomous driving control that follows the driving trajectory. When detecting an obstacle, the driving assistance device 19 uses, in addition to the detection results of the imaging device 11 and the distance measuring device 12, image information from fixed cameras installed at traffic lights, etc., information obtained from a server external to the driving assistance system 10 that provides traffic information, information obtained through vehicle-to-vehicle communication with other vehicles traveling around the host vehicle V1, and the like.

[0069] Specifically, if the driving assistance device 19 detects that congestion has occurred in the lane into which the host vehicle V1 will enter after passing through a non-priority intersection along the driving route, the driving assistance device 19 predicts that the host vehicle V1 will stop at the non-priority intersection. On the other hand, if congestion has not been detected in the lane into which the host vehicle V1 will enter after passing through a non-priority intersection along the driving route, the driving assistance device 19 predicts that the host vehicle V1 will be able to pass through the non-priority intersection without stopping at the intersection.

[0070] 3, when traveling along travel route R1, there is congestion of other vehicles Y1 to Y4 in the lane on the left side of road A2 in the travel direction, into which the host vehicle V1 enters after passing through intersection C4 along travel route R1. Therefore, the driving assistance device 19 detects congestion in the lane into which the host vehicle V1 enters after passing through intersection C4, and predicts that the host vehicle V1 will stop at intersection C4.

[0071] Alternatively or in addition, the driving assistance device 19 sets a congestion detection range having a predetermined length in the oncoming lane of the lane in which the host vehicle V1 is traveling at the non-priority intersection, where the host vehicle V1 turns in the same direction as when exiting the non-priority intersection along the driving route. If the driving assistance device 19 detects a line of vehicles longer than the congestion detection range in the lane in which the host vehicle V1 turns in the same direction as when exiting the non-priority intersection along the driving route, the driving assistance device 19 predicts that the host vehicle V1 will stop at the non-priority intersection. On the other hand, if the driving assistance device 19 detects a line of vehicles with the same length as or shorter than the congestion detection range in the lane in which the host vehicle V1 turns in the same direction as when exiting the non-priority intersection along the driving route, the driving assistance device 19 predicts that the host vehicle V1 will pass through the non-priority intersection without stopping at the intersection.

[0072] In the driving scene shown in Figure 3, when driving along driving route R1, a congestion detection range Z having a predetermined length D is set in the oncoming lane at intersection C4 that turns in the same direction as the host vehicle V1 turning right at intersection C4, that is, the lane that turns left at intersection C4 in the direction of destination X. Specifically, the congestion detection range Z is set in the lane where other vehicles Y5 and Y6 are waiting to turn left. In this case, a line of other vehicles Y5 and Y6 that is longer than the congestion detection range Z is detected, so it is predicted that the host vehicle V1 will stop at intersection C4.

[0073] The predetermined length D is the length of the congestion detection range along the driving direction of the road, and can be set to an appropriate value within a range in which multiple other vehicles that are stopped or moving slowly can be detected. The predetermined length D may also be set according to the distance between the non-priority intersection and another intersection located ahead of the lane into which the host vehicle V1 will enter after passing through the non-priority intersection along the driving route. If congestion is detected in the lane into which the host vehicle V1 will enter after passing through the non-priority intersection, the predetermined length of the congestion detection range may be set shorter than when no congestion occurs, according to the length of the line of vehicles in the congestion. This is because the host vehicle V1 will be stopped in the intersection unless the congestion in the lane into which the host vehicle V1 will enter is resolved, so shortening the predetermined length makes it easier to determine that a congestion exists.

[0074] In the driving scene shown in FIG. 3, the predetermined length D is set according to the distance between intersection C4, which is a non-priority intersection, and intersection C5, which is ahead in the lane the vehicle enters after passing intersection C4 along driving route R1. That is, when the distance between intersections C4 and C5 is short, the predetermined length D of the congestion detection range Z is set shorter than when the distance between intersections C4 and C5 is long. When the distance between intersections is short, vehicles that turn left at intersection C4 are likely to get stuck between the intersections, so the predetermined length D is set shorter to make it easier to determine that a congestion has occurred. Also, in the driving scene shown in FIG. 3, other vehicles Y1 to Y3 form a congested line of vehicles between intersections C4 and C5. However, when other vehicles Y1 and Y2 form a congested line of vehicles between intersections C4 and C5, the congested line of vehicles is short, so the length of the congestion detection range is set longer than the predetermined length D shown in FIG. 3.

[0075] Furthermore, when there are multiple oncoming lanes at the non-priority intersection, the driving assistance device 19 detects congestion occurring in a lane among the multiple oncoming lanes that turns in the same direction as the direction in which the host vehicle V1 exits the non-priority intersection along the travel route. Furthermore, when the host vehicle can choose between going straight or turning in the same direction as the direction in which the host vehicle exits the non-priority intersection along the travel route in the oncoming lane at the non-priority intersection, the driving assistance device 19 sets the predetermined length shorter as the proportion of vehicles traveling in the oncoming lane that turn is higher.

[0076] In the driving scene shown in FIG. 3, the intersection C4 has an oncoming lane that includes a right-turn-only lane and a lane that allows either straight travel or a left turn. In this case, the driving assistance device 19 detects congestion occurring in a lane that allows a left turn in the same direction as the host vehicle V1 making a right turn. That is, the driving assistance device 19 detects congestion in the lane where other vehicles Y5 and Y6 are waiting to turn left, but does not detect congestion in the right-turn-only lane that is adjacent to the lane. This is because the traveling direction of the host vehicle V1 making a right turn at the intersection C4 does not intersect with the traveling direction of oncoming vehicles making a right turn. Furthermore, since the lane where other vehicles Y5 and Y6 are waiting to turn left allows either straight travel or a left turn, the higher the proportion of vehicles traveling in this lane that make a left turn, the shorter the predetermined length D is set. That is, the higher the proportion of vehicles turning left, the easier it is to determine that the host vehicle V1 will stop at the intersection C4. This proportion is calculated, for example, from accumulated information about the surrounding driving environment acquired when the host vehicle and / or other vehicles have traveled in the past. Alternatively or additionally, the ratio of vehicles that are flashing their left turn indicators among the vehicles traveling in the lane where the other vehicles Y5 and Y6 are waiting to turn left is calculated.

[0077] Furthermore, when the driving assistance device 19 determines that a non-priority intersection exists within a predetermined distance ahead, it determines whether or not the host vehicle V1 needs to change lanes before the non-priority intersection in order to pass through the non-priority intersection. If it determines that a lane change is necessary before the non-priority intersection, it switches to autonomous driving control for traveling along a detour route before the host vehicle V1 reaches a position where the host vehicle V1 starts changing lanes (hereinafter also referred to as the lane change start position). This avoids a situation where the host vehicle V1 is unable to enter a lane for traveling along the detour route and is unable to travel along the detour route. On the other hand, when it determines that a lane change is not necessary before the non-priority intersection, it continues traveling along the travel route, and if it is predicted that the host vehicle V1 will stop at the non-priority intersection, it switches to traveling along the detour route.

[0078] Alternatively, the driving assistance device 19 takes into consideration the time required to switch the autonomous driving control, and switches from autonomous driving control for driving along the driving route to autonomous driving control for driving along the detour route by the time the host vehicle V1 reaches a position a distance before the lane change start position that corresponds to the time required to switch from autonomous driving control for driving along the driving route to autonomous driving control for driving along the detour route. Alternatively, the driving assistance device 19 switches to autonomous driving control for driving along the detour route by the time the host vehicle V1 reaches a position where the turn signal starts flashing for lane change.

[0079] Hereinafter, a case where the host vehicle V1 autonomously travels along the travel route R1 and the detour route R2 using the environment recognition function of the recognition unit 24 and the travel control device of the control unit 25 will be described with reference to FIG. 4 and FIGS. 5A to 5B.

[0080] 4 is a plan view showing the driving scene in which the host vehicle V1 travels along a driving route R1 in the driving scene shown in FIG. 2. The driving lanes for traveling along the driving route R1 are set when the driving route R1 is generated. For example, as shown in FIG. 4, lanes L1 and L2 of road A1, lane L3 and right-turn-only lane L4 of road B2, and lane L5 of road A2 are set as driving lanes on the driving route R1. The driving assistance device 19 generates a driving trajectory for traveling along the set driving lanes using a driving control device of the control unit 25.

[0081] First, the driving assistance device 19 generates a driving trajectory T1 that travels from position P1 on lane L1, passes through intersection C1, and travels to position P2 on lane L2. The driving assistance device 19 causes the host vehicle V1 to travel along the driving trajectory T1 using the driving control device of the control unit 25. While traveling along the driving trajectory T1, the driving assistance device 19 recognizes the surrounding driving environment (particularly obstacles) from the detection results of the imaging device 11 and the distance measuring device 12 using the environment recognition function of the recognition unit 24. In the driving scene shown in FIG. 4, no obstacles are detected on lanes L1, L2, or intersection C1, so the host vehicle V1 continues traveling along the driving trajectory T1.

[0082] Next, the driving assistance device 19 generates a traveling trajectory T2 that travels from position P2 on lane L2, turns left at intersection C2, and travels to position P3 on lane L3. In the traveling scene shown in Fig. 4, since no obstacle is detected at intersection C2, the host vehicle V1 follows the traveling trajectory T2, turns left at intersection C2, and travels to position P3.

[0083] Next, the driving assistance device 19 detects an obstacle at intersection C4, which is a non-priority intersection. The obstacle detection may be performed using, in addition to the detection results of the imaging device 11 and the distance measuring device 12, image information from fixed cameras installed at traffic lights, information obtained from a server external to the driving assistance system 10 that provides traffic information, and information obtained through vehicle-to-vehicle communication with other vehicles traveling around the host vehicle V1. The driving control device of the control unit 25 then predicts whether the host vehicle V1 will stop at intersection C4 to avoid contact with the detected obstacle. In the driving scene shown in FIG. 4 , since no obstacle is detected at intersection C4, the driving assistance device 19 predicts that the host vehicle V1 will not stop at intersection C4 and continues traveling along the driving route R1. The driving assistance device 19 generates a driving trajectory T3 that travels from position P3 on lane L3 to position P4 on lane L4 and then changes lanes. In the driving scene shown in FIG. 4, no obstacles are detected in the lanes L3 and L4, so the host vehicle V1 follows the driving trajectory T3 and drives to a position P4.

[0084] Next, the driving assistance device 19 generates a traveling trajectory T4 that travels from position P4 on lane L4, turns right at intersection C4, and travels to position P5 on lane L5. In the traveling scene shown in Fig. 4, since no obstacle is detected at intersection C4, the host vehicle V1 follows the traveling trajectory T4, turns right at intersection C2, and travels to position P5.

[0085] Then, the driving assistance device 19 generates a driving trajectory T5 that travels straight from the position P5 and reaches a position Px in front of the destination X. In the driving scene shown in FIG. 4, since no obstacle is detected in the lane L5, the host vehicle V1 travels by following the driving trajectory T5 and reaches the destination X.

[0086] Next, Figures 5A to 5B will be described. Figures 5A to 5B are plan views showing a driving scene in which the host vehicle V1 is driving along driving route R1 and detour route R2. The driving scene shown in Figures 5A to 5B is similar to the driving scene shown in Figure 4, but differs from the driving scene shown in Figure 4 in that other vehicles V2 to V4 form a queue of vehicles stuck in lane L5, other vehicle V5 turns left at intersection C4, and other vehicles V6 to V8 are stopped waiting to turn left. Note that the driving from position P1 to position P2 is the same as the driving scene shown in Figure 4, so a description thereof will be omitted.

[0087] The driving assistance device 19 generates a driving trajectory T2 that travels from position P2 on lane L2, turns left at intersection C2, and travels to position P3 on lane L3. In the driving scene shown in Fig. 5A, no obstacle is detected at intersection C2, so the host vehicle V1 follows driving trajectory T2, turns left at intersection C2, and travels to position P3. In addition, in the driving scene shown in Fig. 5A, while the host vehicle V1 travels from position P2 to position P3, the driving assistance device 19 detects other vehicles V2 to V4 traveling on lane L5, other vehicle V5 turning left at intersection C4, and other vehicles V6 to V8 waiting to turn left, from image information from a fixed camera installed at intersection C4.

[0088] Next, the driving assistance device 19 predicts whether the host vehicle V1 will stop at the intersection C4. In the driving scene shown in FIG. 5A , the host vehicle V1 detects another vehicle V5 turning left at the intersection C4 before reaching position P3, which is the lane change start position. Therefore, the driving assistance device 19 predicts that the host vehicle V1 will stop at the intersection C4 when turning right at the intersection C4. Therefore, the driving assistance device 19 switches from traveling along the travel route R1 to traveling along the detour route R2 before the host vehicle V1 reaches position P3. This switching may be performed at a position before position P3, taking into account the time required for the driving assistance device 19 to switch the autonomous driving control. Alternatively, the driving assistance device 19 may switch to autonomous driving control for traveling along the detour route R2 before the host vehicle V1 reaches a position where the turn signal starts flashing to change lanes from lane L3 to lane L4.

[0089] After switching to autonomous driving control for driving along detour route R2, driving assistance device 19 generates a driving trajectory for driving along detour route R2 in the driving lanes that were set when detour route R2 was generated. For detour route R2, for example, as shown in FIG. 5A , lanes L3 and L7 of road B2, lane L8 of road A3, lane L9 of road B1, and lanes L10 and L5 of road A2 are set as driving lanes. Using a driving control device in control unit 25, driving assistance device 19 generates a driving trajectory for driving along the set driving lanes.

[0090] First, a travel trajectory T6 is generated, which travels from position P3 on lane L3, passes through intersection C4, and travels to position P6 on lane L7. In the travel scene shown in Fig. 5A, no obstacles are detected on lanes L3 and L7, and no obstacles that would obstruct straight travel through intersection C4 are detected, so the host vehicle V1 travels to position P7 by following travel trajectory T6.

[0091] Next, the driving assistance device 19 generates a traveling trajectory T7 that travels from position P6 on lane L7, turns left at intersections C7 and C6 in that order, and travels to position P7 on lane L9. In the traveling scene shown in Fig. 5A, since no obstacles are detected at the intersections C7 and C6 and lane L8, the host vehicle V1 travels by following the traveling trajectory T7 to position P7.

[0092] 5B, the driving assistance device 19 generates a traveling trajectory T8 that travels from position P7 on lane L9, turns left at intersection C3, and travels to position P8 on lane L10. In the traveling scene shown in FIG. 5B, since no obstacles are detected on lane L9 or intersection C3, the host vehicle V1 travels by following the traveling trajectory T8 to position P8.

[0093] In the driving scene shown in Figure 5B, when the host vehicle V1 reaches position P8, vehicles traveling on road A2 are able to enter intersection C4, but vehicles traveling on road B2 are unable to enter intersection C4. In other words, other vehicles V6-V8 traveling on lane L6 are unable to enter intersection C4 and are stopped just before intersection C4. In contrast, other vehicles V2-V4, which turned left and passed intersection C4, travel straight on lane L5 and pass intersection C5. Also, other vehicle V5 is following other vehicle V4 and passing intersection C4.

[0094] In this case, the driving assistance device 19 generates a traveling trajectory T9 that travels straight from the position P8 and reaches a position Px in front of the destination X. In the traveling scene shown in FIG. 5B, since no obstacles are detected in the lanes L10 and L5 and the intersection C4, the host vehicle V1 travels following the traveling trajectory T9 and reaches the destination X.

[0095] [Processing in driving assistance systems] The procedure for information processing by the driving assistance device 19 will be described with reference to Fig. 6. Fig. 6 is 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 following description is based on the premise that the host vehicle V1 is traveling on a road where people keep to the left.

[0096] First, in step S1, the route generation function generates a driving route R1 to travel to the destination X set by the occupant of the vehicle V1, using road network data acquired from the map information 14 and information on the current position acquired from the vehicle position detection device 15. In the following step S2, the extraction function extracts intersections (non-priority intersections) at which the vehicle V1 will turn right from the driving route R1 acquired from the navigation device 16.

[0097] In step S3, it is determined whether or not a detour route R2 can be generated for the extracted intersection using the detour function. If it is determined that a detour route cannot be generated for the extracted intersection, the process proceeds to step S5, where the probability of a traffic jam occurring at a non-priority intersection due to oncoming vehicles waiting to turn left is calculated. In the following step S6, it is determined whether or not this probability is equal to or less than a predetermined value. If this probability is equal to or less than the predetermined value, the process proceeds to step S8. On the other hand, if this probability exceeds the predetermined value, the process proceeds to step S7, where the time required to pass through the intersection where the host vehicle V1 turns right and for which a detour route cannot be generated is increased. Then, the process proceeds to step S1, where the driving route R1 is generated again.

[0098] On the other hand, if it is determined in step S3 that a detour route can be generated for the extracted intersection, the process proceeds to step S4. In step S4, a detour route R2 is generated by the detour function. In the following step S8, the driving control function causes the host vehicle V1 to travel so as to follow the travel route R1. In the following step S9, it is determined whether or not there is an intersection at which the host vehicle V1 can turn right within a predetermined distance ahead of the host vehicle V1. If it is determined that there is no intersection at which the host vehicle V1 can turn right within a predetermined distance ahead of the host vehicle V1, the process proceeds to step S10. In step S10, the host vehicle V1 continues traveling so as to follow the travel route R1, and in the following step S11, it is determined whether or not the host vehicle V1 has reached the destination X. If it is determined that the host vehicle V1 has reached the destination X, the process terminates the execution of the routine, and the driver is prompted to drive manually via the display device 18. On the other hand, if it is determined that the host vehicle V1 has not reached the destination X, the process proceeds to step S8.

[0099] On the other hand, if it is determined in step S9 that an intersection where the host vehicle V1 will turn right is present within a predetermined distance ahead of the host vehicle V1, the process proceeds to step S12. In step S12, obstacles present at the intersection are detected using the environment recognition function. At this time, other vehicles traveling before the intersection and other vehicles about to enter the intersection are also detected. For the detection, in addition to the detection results of the imaging device 11 and the distance measuring device 12, image information from fixed cameras installed at traffic lights and information obtained through vehicle-to-vehicle communication with other vehicles traveling around the host vehicle V1 are used. In the following step S13, it is determined whether or not congestion has occurred in the lane in which the host vehicle V1 will travel after the right turn. If it is determined that no congestion has occurred in the lane in which the host vehicle V1 will travel after the right turn, the process proceeds to step S10. On the other hand, if it is determined that congestion has occurred in the lane in which the host vehicle V1 will travel after the right turn, the process proceeds to step S14.

[0100] In step S14, the driving control function sets a congestion detection range Z in the oncoming left-turn lane at the intersection. In the following step S15, it is determined whether a line of vehicles longer than the congestion detection range Z has been detected in the oncoming left-turn lane. If a line of vehicles longer than the congestion detection range Z has not been detected in the oncoming left-turn lane, the process proceeds to step S10. On the other hand, if a line of vehicles longer than the congestion detection range Z has been detected in the oncoming left-turn lane, the process proceeds to step S16, where the driving of the host vehicle V1 is autonomously controlled so as to follow the detour route R2. Then, the process proceeds to step S11.

[0101] [Embodiments of the present invention] As described above, according to this embodiment, a route generation method is provided in which a processor generates a driving route R1 along which the host vehicle V1 will travel by autonomous driving control, extracts from among intersections on the driving route R1 a non-priority intersection at which the other vehicle has priority when the traveling direction of the host vehicle V1 traveling along the driving route R1 intersects with the traveling direction of the other vehicle, determines whether a detour route R2 can be generated for the non-priority intersection, and if it is determined that the detour route R2 can be generated, generates the detour route R2 for the non-priority intersection, and the detour route R2 is a route that exits the non-priority intersection in a traveling direction in which the host vehicle V1 has priority when the traveling direction of the other vehicle intersects, continues to travel in a lane in which the host vehicle V1 has priority when the traveling direction of the host vehicle V1 intersects with the traveling direction of the other vehicle, and enters the same lane as the lane that the host vehicle V1 will enter when the non-priority intersection is passed along the driving route R1. This can prevent the host vehicle V1 from being unable to pass through the intersection and coming to a stop in the intersection.

[0102] Furthermore, according to the vehicle driving assistance method of this embodiment, when the processor determines that the detour route R2 cannot be generated for the non-priority intersection, it changes the setting conditions for route generation so that the non-priority intersection for which the detour route R2 cannot be generated is more difficult to pass through than when the driving route R1 is generated, and generates a new driving route for the host vehicle V1 to travel by the autonomous driving control based on the changed setting conditions. This makes it possible to prevent the non-priority intersection for which the detour route R2 cannot be generated from being included in the driving route R1.

[0103] Furthermore, according to the vehicle driving assistance method of this embodiment, the processor calculates the probability of a traffic jam occurring at the non-priority intersection where the detour route R2 cannot be generated, where oncoming vehicles are waiting to turn, from information accumulated during past travel, and does not generate the new driving route if the probability is equal to or less than a predetermined value. This makes it possible to prevent the generation of an unnecessary detour route R2 when the probability of stopping at the intersection is low.

[0104] According to the vehicle driving assistance method of the present embodiment, the processor generates the detour route R2 whose travel distance is longer by a predetermined distance or less than that in the case where the vehicle passes through the non-priority intersection without traveling on the detour route R2. This makes it possible to prevent the generation of detour routes R2 whose travel distance is long and which cause discomfort to the occupants.

[0105] Furthermore, according to the vehicle driving assistance method of this embodiment, the processor sets the route generation setting conditions so that the non-priority intersections for which the detour route R2 can be generated are easier to pass through than the non-priority intersections for which the detour route R2 cannot be generated, thereby suppressing an increase in the number of times the driving route R1 is generated again.

[0106] Furthermore, according to the vehicle driving assistance method of this embodiment, when the processor detects an obstacle present at the non-priority intersection and predicts that the host vehicle V1 will stop at the non-priority intersection to avoid contact with the obstacle when the host vehicle V1 changes lanes before the non-priority intersection at which the detour route R2 can be generated in order to travel along the travel route R1, the processor switches to the autonomous travel control to travel along the detour route R2 by the time the host vehicle V1 reaches a position from which to start the lane change. This makes it possible to avoid a situation in which the host vehicle V1 is unable to enter a lane for travel along the detour route R2 and is therefore unable to travel along the detour route R2.

[0107] Furthermore, according to the vehicle driving assistance method of this embodiment, when the processor predicts that the host vehicle V1 will stop at the non-priority intersection, the processor switches to the autonomous driving control for traveling along the detour route R2 by the time the host vehicle V1 reaches a position a distance before the position where the host vehicle V1 starts changing lanes that corresponds to the time for switching from the autonomous driving control for traveling along the traveling route R1 to the autonomous driving control for traveling along the detour route R2. This makes it possible to cancel the lane change midway and prevent significant changes in vehicle behavior.

[0108] Furthermore, according to the vehicle driving assistance method of this embodiment, when the processor predicts that the host vehicle V1 will stop at the non-priority intersection, the processor switches to the autonomous driving control in which the host vehicle V1 travels along the detour route R2 by the time the host vehicle V1 reaches a position where the turn signal starts flashing for the lane change. This makes it possible to avoid canceling the lane change after flashing the turn signal.

[0109] Furthermore, according to the vehicle driving assistance method of this embodiment, when the processor detects that congestion has occurred in a lane that the host vehicle V1 will enter after passing through the non-priority intersection along the travel route R1, the processor predicts that the host vehicle V1 will stop in the intersection. This makes it possible to predict whether the host vehicle V1 will stop in the intersection, taking into account the traffic conditions of the lane that the host vehicle V1 will enter after passing through the intersection.

[0110] Furthermore, according to the vehicle driving assistance method of this embodiment, the processor sets a congestion detection range Z having a predetermined length D in the lane of the oncoming lane of the lane in which the host vehicle V1 is traveling at the non-priority intersection, where the host vehicle V1 turns in the same direction as when exiting the non-priority intersection along the travel route R1, and if a line of vehicles longer than the congestion detection range Z is detected in the lane where the host vehicle V1 turns in the same direction as when exiting the non-priority intersection along the travel route R1, the processor predicts that the host vehicle V1 will stop at the non-priority intersection. This makes it possible to predict whether the host vehicle V1 will stop at the intersection, taking into account vehicles waiting to turn left at the intersection (vehicles waiting to turn right in the case of right-hand traffic).

[0111] Furthermore, according to the vehicle driving assistance method of this embodiment, the processor sets the predetermined length D according to the distance between the non-priority intersection and another intersection that exists ahead of the lane that the host vehicle V1 will enter after passing through the non-priority intersection along the travel route R1. This makes it possible to predict whether the host vehicle V1 will stop at the intersection, taking into account the distance between the intersections of the lane that the host vehicle V1 will enter after passing through the intersection.

[0112] Furthermore, according to the vehicle driving assistance method of this embodiment, when the processor detects that congestion has occurred in the lane that the host vehicle V1 will enter after passing through the non-priority intersection, the processor sets the predetermined length D to be shorter than the predetermined length D in a case where the host vehicle V1 does not enter the intersection, in accordance with the length of the queue of vehicles in the congestion. This makes it possible to predict whether the host vehicle V1 will stop in the intersection, taking into account the traffic conditions of the lane that the host vehicle V1 will enter after passing through the intersection.

[0113] Furthermore, according to the vehicle driving assistance method of this embodiment, when there are multiple oncoming lanes, the processor detects congestion occurring in a lane among the multiple oncoming lanes that turns in the same direction as the direction in which the host vehicle V1 will exit the non-priority intersection along the travel route R1, thereby making it possible to more accurately predict whether the host vehicle V1 will stop in the intersection.

[0114] Furthermore, according to the vehicle driving assistance method of this embodiment, when the vehicle V1 can choose between going straight or turning in the same direction as the direction in which the vehicle V1 will exit the non-priority intersection along the travel route R1 in the oncoming lane, the higher the proportion of vehicles traveling in the oncoming lane that will turn, the shorter the predetermined length D is set. This makes it possible to more accurately predict whether the vehicle V1 will stop in the intersection.

[0115] Furthermore, according to this embodiment, there are provided a generating unit 21 that generates a driving route R1 along which the host vehicle V1 will travel by autonomous driving control, an extracting unit 22 that extracts, from among intersections on the driving route R1, a non-priority intersection at which the driving of another vehicle has priority when the traveling direction of the host vehicle V1 traveling along the driving route R1 intersects with the traveling direction of the other vehicle, and a determining unit 23 that determines whether a detour route R2 can be generated for the non-priority intersection, and if it is determined that the detour route R2 can be generated, extracts the detour route R2 for the non-priority intersection. and a detouring unit 23 that generates a detouring route R2, wherein the detouring route R2 is a route that exits the non-priority intersection along a traveling direction that has priority for the host vehicle V1 when it intersects with the traveling direction of the other vehicle, continues traveling in a lane that has priority for the host vehicle V1 when the traveling direction of the host vehicle V1 and the traveling direction of the other vehicle intersect, and enters the same lane as the lane that the host vehicle V1 will enter when it passes the non-priority intersection along the traveling route R1. This makes it possible to prevent the host vehicle V1 from being unable to pass through the intersection and stopping within the intersection. [Explanation of symbols]

[0116] 10...Driver 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...Vehicle speed control device 172...Steering control device 18...Display device 19...Driving assistance device (route generation device) 191...CPU (processor) 192...ROM 193...RAM 20…Support Department 21...Generation part 22...Extraction part 23...Detour section 24...Recognition part 25...Control unit A1, A2, A3, B1, B2, B3… Road C1, C2, C3, C4, C5, C6, C7… Intersection D… Specified length L1, L2, L3, L4, L5, L6, L7, L8, L9, L10… Lane Lr… Right-turn only lane P1, P2, P3, P4, P5, P6, P7, P8, Px… Position R1… Travel route R2… Detour route Rx… Route (comparative example) T1, T2, T3, T4, T5, T6, T7, T8, T9, Tx, Ty, Tz… Travel trajectory V1… Own vehicle V2, V3, V4, V5, V6, V7, V8… Other vehicles X… Destination Y1, Y2, Y3, Y4, Y5, Y6, Y7, Y8, Y9, Y10, Y11, Y12… Other vehicles Z… Traffic jam detection range

Claims

1. The processor: Generate a driving route for the vehicle to travel by autonomous driving control, extracting, from among intersections on the travel route, a non-priority intersection at which priority is given to the travel of another vehicle when the travel direction of the vehicle traveling along the travel route intersects with the travel direction of the other vehicle; determining whether a detour route can be generated for the non-priority intersection; If it is determined that the detour route can be generated, the detour route is generated for the non-priority intersection; The detour route is When the traveling direction of the vehicle crosses the traveling direction of the other vehicle, the vehicle exits the non-priority intersection along a traveling direction in which the traveling direction of the vehicle has priority; When the traveling direction of the host vehicle and the traveling direction of the other vehicle intersect, the host vehicle continues to travel in a lane in which the host vehicle has priority; A route generation method in which the route is one in which the vehicle enters the same lane as the lane into which the vehicle would enter if the vehicle passed through the non-priority intersection along the travel route.

2. The processor: When it is determined that the detour route cannot be generated for the non-priority intersection, changing the setting conditions for route generation so that it is more difficult to pass through the non-priority intersection for which the detour route cannot be generated than when the driving route is generated; The route generation method according to claim 1 , further comprising generating a new driving route along which the host vehicle travels under the autonomous driving control based on the changed setting conditions.

3. The processor: calculating a probability of a traffic jam occurring at the non-priority intersection where the detour route cannot be generated, where oncoming vehicles are waiting to change direction, based on information accumulated when the vehicle has traveled in the past; The route generation method according to claim 2 , wherein the new travel route is not generated if the probability is equal to or less than a predetermined value.

4. The processor: The route generation method according to claim 1 , further comprising generating the detour route such that the travel distance is longer by a predetermined distance or less than that required when the vehicle passes through the non-priority intersection without traveling on the detour route.

5. The processor: The route generation method according to claim 1 , wherein a setting condition for route generation is set so that the non-priority intersections for which the detour route can be generated are easier to pass through than the non-priority intersections for which the detour route cannot be generated.

6. The processor: Detecting an obstacle present at the non-priority intersection; A route generation method according to any one of claims 1 to 5, wherein when the vehicle changes lanes before the non-priority intersection at which the detour route can be generated in order to travel along the travel route, if it is predicted that the vehicle will stop at the non-priority intersection to avoid contact with the obstacle, the method switches to autonomous driving control to travel along the detour route before the vehicle reaches a position from which the lane change will begin.

7. The processor:

7. The route generation method of claim 6, wherein, when it is predicted that the vehicle will stop at the non-priority intersection, the autonomous driving control is switched to driving along the detour route by the time the vehicle reaches a position a distance before the position at which the lane change is started that corresponds to the time for switching from the autonomous driving control that drives along the driving route to the autonomous driving control that drives along the detour route.

8. The processor:

8. The route generation method of claim 7, wherein, when it is predicted that the vehicle will stop at the non-priority intersection, the autonomous driving control is switched to drive along the detour route before the vehicle reaches a position where the turn signal starts flashing for the lane change.

9. The processor:

7. The route generation method according to claim 6, wherein, when it is detected that congestion has occurred in a lane that the vehicle will enter after passing the non-priority intersection along the driving route, it is predicted that the vehicle will stop within the intersection.

10. The processor: a congestion detection range having a predetermined length is set in a lane of an oncoming lane of the non-priority intersection in which the host vehicle is traveling, and in which the host vehicle turns in the same direction as the direction in which the host vehicle will exit the non-priority intersection along the traveling route; 7. The route generation method according to claim 6, wherein, when a line of vehicles longer than the congestion detection range is detected in a lane where the vehicle turns in the same direction as the direction in which the vehicle will exit the non-priority intersection along the driving route, the method predicts that the vehicle will stop at the non-priority intersection.

11. The processor: The route generation method according to claim 10, wherein the predetermined length is set according to the distance between the non-priority intersection and another intersection located ahead of the lane into which the vehicle will enter after passing through the non-priority intersection along the travel route.

12. The processor:

11. The route generation method according to claim 10, wherein, when it is detected that a traffic jam has occurred in the lane into which the vehicle is to enter after passing through the non-priority intersection, the predetermined length is set to be shorter than when no traffic jam has occurred, depending on the length of the line of vehicles in the traffic jam.

13. The processor:

11. The route generation method according to claim 10, wherein, when there are a plurality of oncoming lanes, a congestion occurring in a lane among the plurality of oncoming lanes that turns in the same direction as the direction in which the host vehicle is exiting the non-priority intersection along the travel route is detected.

14. 11. The route generation method of claim 10, wherein, when the vehicle can choose between going straight or turning in the same direction as the vehicle exiting the non-priority intersection along the driving route in the oncoming lane, the higher the proportion of vehicles traveling in the oncoming lane that make the turn, the shorter the specified length is set.

15. a generation unit that generates a driving route along which the host vehicle will travel under autonomous driving control; an extraction unit that extracts, from among intersections on the travel route, a non-priority intersection at which priority is given to the travel of another vehicle when the travel direction of the host vehicle traveling along the travel route intersects with the travel direction of the other vehicle; determining whether a detour route can be generated for the non-priority intersection; a detouring unit that generates the detouring route for the non-priority intersection when it is determined that the detouring route can be generated, The detour route is When the traveling direction of the vehicle crosses the traveling direction of the other vehicle, the vehicle exits the non-priority intersection along a traveling direction in which the traveling direction of the vehicle has priority; When the traveling direction of the host vehicle and the traveling direction of the other vehicle intersect, the host vehicle continues to travel in a lane in which the host vehicle has priority; A route generation device that generates a route that enters the same lane as the lane that the host vehicle will enter if it passes through the non-priority intersection along the travel route.

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