Map Generator

Abstract

To easily generate a map defining a traveling lane crossing an intersection.SOLUTION: A map generation apparatus 20 includes: a trace detection section 21 that detects a travel trace of a subject vehicle; a lane association section 23 that associates a front lane before entering an intersection with a rear lane after passing through the intersection on the basis of the travel trace and an external circumstance detected by a camera 1a; and a map generation section 17 that generates a map including position information of a traveling lane from the front lane to the rear lane associated with each other. The lane association section 23 associates a first front lane with a first rear lane on the basis of the travel trace detected by the trace detection section 21, and associates a second front lane with a second rear lane or associates the first front lane with the second rear lane on the basis of the external circumstance detected by the camera 1a.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a map generating device that generates a map including road dividing lines. [Background technology]

[0002] One known example of this type of device is one that uses images captured by a camera mounted on a vehicle to recognize lane markings (white lines) and uses the lane marking recognition results for vehicle driving control (see, for example, Patent Document 1). The device described in Patent Document 1 extracts edge points where the change in brightness of the captured image is equal to or greater than a threshold, and recognizes lane markings based on the edge points. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-104853 Summary of the Invention [Problem to be solved by the invention]

[0004] Since the lane markings are discontinued within an intersection, it is preferable to connect the lane markings before and after the intersection in order to identify the driving lane that passes through the intersection. However, it may be difficult to smoothly connect the lane markings before and after the intersection, for example, when the lanes at the entrance and exit of the intersection are offset in the width direction. In such cases, it is difficult to generate a map that identifies the driving lane. [Means for solving the problem]

[0005] A map generating device according to one aspect of the present invention includes an external environment detection unit that detects an external environment surrounding a vehicle, a trajectory detection unit that detects a travel trajectory of the vehicle, a lane association unit that associates an entry lane, which is a travel lane before entering an intersection, with a passing lane, which is a travel lane after passing through the intersection, based on the external environment detected by the external environment detection unit and the travel trajectory detected by the trajectory detection unit, and a map generating unit that generates a map including position information of the travel lanes from the entry lane to the passing lane associated by the lane association unit. The travel lanes from the entry lane to the passing lane include a first travel lane on which the vehicle has traveled and a second travel lane adjacent to the first travel lane or branching off from the first travel lane. The vehicle travel direction on the first travel lane and the vehicle travel direction on the second travel lane are the same, and the entry lane is The vehicle was traveling First approach lane and , adjacent to the first approach lane The second approach lane includes the lane before the crossing, and the lane after the crossing is The vehicle was traveling 1st passing lane and , adjacent to the first after-traffic lane The lane association unit determines, based on the traveling trajectory detected by the trajectory detection unit, The vehicle was traveling The first approaching lane and the first passing lane are associated with each other, and based on the external situation detected by the external detection unit, Based on the determination result of whether or not the number of lanes among the pre-entry lanes that have the same traveling direction as the first pre-entry lane is the same as the number of lanes among the post-passage lanes that have the same traveling direction as the first post-passage lane, , and associate the second approaching lane with the second passing lane. mosquito Match the first approach lane with the second exit lane Determine whether . [Effects of the Invention]

[0006] According to the present invention, a map that defines driving lanes that cross an intersection can be easily generated. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a block diagram showing an outline of the overall configuration of a vehicle control system having a map generating device according to an embodiment of the present invention; [Figure 2] 1 is a diagram showing an example of a driving scene to which a map generating device according to an embodiment of the present invention is applied; [Figure 3A] FIG. 1 is a diagram showing an example of a problem related to map generation by a map generation device. [Figure 3B] FIG. 10 is a diagram showing another example of a problem relating to map generation by a map generation device. [Figure 4] 1 is a block diagram showing the configuration of a main part of a map generating device according to an embodiment of the present invention. [Figure 5A] FIG. 4 is a diagram showing an example of an operation of the map generating device according to the embodiment of the present invention. [Figure 5B] FIG. 10 is a diagram showing another example of the operation of the map generating device according to the embodiment of the present invention. [Figure 6] 5 is a flowchart showing an example of processing executed by the controller of FIG. 4; DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, an embodiment of the present invention will be described with reference to Figures 1 to 6. A map generating device according to an embodiment of the present invention is configured to generate a map (an environmental map to be described later) used when a vehicle having an automatic driving function (an automatic driving vehicle) is traveling, for example. Note that the vehicle on which the map generating device according to the present embodiment is installed may be referred to as the host vehicle to distinguish it from other vehicles.

[0009] The map generation device generates a map when a driver manually drives the vehicle. Therefore, the map generation device can be installed in a vehicle that does not have an automatic driving function (a manually driven vehicle). Note that the map generation device can be installed not only in manually driven vehicles, but also in automatically driven vehicles that can switch from an automatic driving mode that does not require driver operation to a manual driving mode that does require driver operation. The following description of the map generation device will be given assuming that the map generation device is installed in an automatically driven vehicle.

[0010] First, the configuration of an autonomous vehicle will be described. The vehicle may be an engine vehicle having an internal combustion engine (engine) as a driving source, an electric vehicle having a traction motor as a driving source, or a hybrid vehicle having an engine and a traction motor as driving sources. Fig. 1 is a block diagram showing the overall configuration of a vehicle control system 100 having a map generation device according to an embodiment of the present invention.

[0011] As shown in FIG. 1, the vehicle control system 100 mainly includes a controller 10, a group of external sensors 1 each communicatively connected to the controller 10 via a CAN communication line or the like, a group of internal sensors 2, an input / output device 3, a positioning unit 4, a map database 5, a navigation device 6, a communication unit 7, and a driving actuator AC.

[0012] The external sensor group 1 is a collective term for a plurality of sensors (external sensors) that detect the external situation, which is information about the surroundings of the vehicle. For example, the external sensor group 1 includes a lidar that detects the position (distance and direction from the vehicle) of objects around the vehicle by emitting laser light and detecting reflected light, a radar that detects the position of objects around the vehicle by emitting electromagnetic waves and detecting reflected waves, and a camera that has an imaging element such as a CCD or CMOS and captures images of the surroundings (front, rear, and sides) of the vehicle.

[0013] The internal sensor group 2 is a collective term for a plurality of sensors (internal sensors) that detect the driving state of the host vehicle. For example, the internal sensor group 2 includes a vehicle speed sensor that detects the vehicle speed of the host vehicle, an acceleration sensor that detects the acceleration in the forward / backward and left / right directions of the host vehicle, a rotation speed sensor that detects the rotation speed of the driving source, etc. The internal sensor group 2 also includes sensors that detect the driving operations of the driver in manual driving mode, such as operation of the accelerator pedal, operation of the brake pedal, operation of the steering wheel, etc.

[0014] The input / output device 3 is a general term for devices that input commands from the driver and output information to the driver. For example, the input / output device 3 includes various switches through which the driver inputs various commands by operating operating members, a microphone through which the driver inputs commands by voice, a display that provides information to the driver via displayed images, and a speaker that provides information to the driver by voice.

[0015] The positioning unit (GNSS unit) 4 has a positioning sensor that receives positioning signals transmitted from positioning satellites. The positioning sensor can also be included in the internal sensor group 2. The positioning satellite is an artificial satellite such as a GPS satellite or a quasi-zenith satellite. The positioning unit 4 measures the current position (latitude, longitude, altitude) of the vehicle using the positioning information received by the positioning sensor.

[0016] The map database 5 is a device that stores general map information used in the navigation device 6, and is configured with, for example, a hard disk or semiconductor elements. The map information includes road position information, road shape information (curvature, etc.), and position information of intersections and branch points. Note that the map information stored in the map database 5 is different from the highly accurate map information stored in the memory unit 12 of the controller 10.

[0017] The navigation device 6 is a device that searches for a target route on roads to a destination input by the driver and provides guidance along the target route. The input of the destination and guidance along the target route are performed via the input / output device 3. The target route is calculated based on the current position of the vehicle measured by the positioning unit 4 and map information stored in the map database 5. The current position of the vehicle can also be measured using detection values ​​from the external sensor group 1, and the target route can be calculated based on this current position and high-precision map information stored in the memory unit 12.

[0018] The communication unit 7 communicates with various servers (not shown) via networks including wireless communication networks such as the Internet and mobile phone networks, and acquires map information, driving history information, traffic information, and the like from the servers periodically or at any timing. Networks include not only public wireless communication networks but also closed communication networks established for each predetermined management area, such as wireless LAN, Wi-Fi (registered trademark), Bluetooth (registered trademark), and the like. The acquired map information is output to the map database 5 and the storage unit 12, where the map information is updated. Communication with other vehicles is also possible via the communication unit 7.

[0019] Actuators AC are driving actuators for controlling the driving of the host vehicle. When the driving source is an engine, actuators AC include a throttle actuator that adjusts the opening of the engine's throttle valve (throttle opening). When the driving source is a driving motor, actuators AC include the driving motor. Actuators AC also include a brake actuator that operates the host vehicle's braking device and a steering actuator that drives the steering device.

[0020] The controller 10 is composed of an electronic control unit (ECU). More specifically, the controller 10 includes a computer having an arithmetic unit 11 such as a CPU (microprocessor), a storage unit 12 such as a ROM and RAM, and other peripheral circuits (not shown) such as an I / O interface. Note that although multiple ECUs with different functions, such as an engine control ECU, a traction motor control ECU, and a braking device ECU, can be provided separately, for convenience, the controller 10 is shown in FIG. 1 as a collection of these ECUs.

[0021] High-precision road map information is stored in the memory unit 12. This road map information includes road position information, road shape information (such as curvature), road gradient information, intersection and branch point position information, number of lanes information, lane width and lane position information (information on lane center positions and lane boundary lines), position information of landmarks (traffic lights, signs, buildings, etc.) as map markers, and road surface profile information such as road surface irregularities. The map information stored in the memory unit 12 includes map information acquired from outside the vehicle via the communication unit 7 and map information created by the vehicle itself using detection values ​​from the external sensor group 1 or detection values ​​from the external sensor group 1 and the internal sensor group 2. The memory unit 12 also stores driving history information consisting of detection values ​​from the external sensor group 1 and the internal sensor group 2 in association with the map information.

[0022] The calculation unit 11 has, as functional components, a vehicle position recognition unit 13, an external environment recognition unit 14, a behavior plan generation unit 15, a driving control unit 16, and a map generation unit 17.

[0023] The vehicle position recognition unit 13 recognizes the position of the vehicle on the map (own vehicle position) based on the vehicle position information obtained by the positioning unit 4 and the map information in the map database 5. The vehicle position may be recognized using the map information stored in the storage unit 12 and information about the surroundings of the vehicle detected by the external sensor group 1, thereby enabling the vehicle position to be recognized with high accuracy. Note that when the vehicle position can be measured by an external sensor installed on or beside the road, the vehicle position can also be recognized by communicating with the sensor via the communication unit 7.

[0024] The external environment recognition unit 14 recognizes the external situation around the vehicle based on signals from the external sensor group 1, such as a lidar, radar, and camera. For example, it recognizes the positions, speeds, and accelerations of surrounding vehicles (vehicles ahead and vehicles behind) traveling around the vehicle, the positions of surrounding vehicles stopped or parked around the vehicle, and the positions and states of other objects. Examples of other objects include signs, traffic lights, markings such as road dividing lines and stop lines, buildings, guardrails, utility poles, signs, pedestrians, bicycles, etc. Examples of the states of other objects include the color of traffic lights (red, green, yellow), the moving speed and direction of pedestrians and bicycles, etc.

[0025] The behavior plan generation unit 15 generates a driving trajectory (target trajectory) of the host vehicle from the current time to a predetermined time ahead based on, for example, a target route calculated by the navigation device 6, map information stored in the memory unit 12, the host vehicle position recognized by the host vehicle position recognition unit 13, and external conditions recognized by the external environment recognition unit 14. When there are multiple trajectories that are candidates for the target trajectory on the target route, the behavior plan generation unit 15 selects an optimal trajectory from among them that satisfies criteria such as compliance with laws and regulations and efficient and safe driving, and sets the selected trajectory as the target trajectory. The behavior plan generation unit 15 then generates a behavior plan according to the generated target trajectory. The behavior plan generation unit 15 generates various behavior plans corresponding to overtaking driving to overtake a preceding vehicle, lane-changing driving to change lanes, following driving to follow a preceding vehicle, lane-keeping driving to maintain the vehicle in its lane without deviating from the lane, decelerating driving, accelerating driving, etc. When generating the target trajectory, the behavior plan generation unit 15 first determines a driving mode and generates the target trajectory based on the driving mode.

[0026] In the autonomous driving mode, the driving control unit 16 controls each actuator AC so that the host vehicle travels along the target trajectory generated by the behavior plan generation unit 15. More specifically, in the autonomous driving mode, the driving control unit 16 calculates a required driving force for achieving the target acceleration per unit time calculated by the behavior plan generation unit 15, taking into account the driving resistance determined by the road gradient, etc. Then, for example, the driving control unit 16 feedback-controls the actuators AC so that the actual acceleration detected by the internal sensor group 2 becomes the target acceleration. In other words, the driving control unit 16 controls the actuators AC so that the host vehicle travels at the target vehicle speed and target acceleration. Note that when the driving mode is the manual driving mode, the driving control unit 16 controls each actuator AC in accordance with a driving command (such as a steering operation) from the driver acquired by the internal sensor group 2.

[0027] While driving in manual driving mode, the map generation unit 17 generates an environmental map consisting of three-dimensional point cloud data using detection values ​​detected by the external sensor group 1. Specifically, edges indicating the contours of objects are extracted from camera images acquired by a camera based on brightness and color information for each pixel, and feature points are extracted using the edge information. Feature points are, for example, points on edges or intersections of edges, and correspond to road markings on the road surface, corners of buildings, corners of road signs, etc. The map generation unit 17 calculates the distance to the extracted feature points and sequentially plots the feature points on the environmental map, thereby generating an environmental map of the area around the road on which the vehicle has traveled. Instead of using a camera, data acquired by radar or lidar may be used to extract feature points of objects around the vehicle and generate an environmental map.

[0028] The vehicle position recognition unit 13 performs a process of estimating the position of the vehicle in parallel with the map generation process by the map generation unit 17. That is, the vehicle position is estimated based on changes in the positions of feature points over time. The map generation process and the position estimation process are performed simultaneously according to a SLAM (Simultaneous Localization and Mapping) algorithm using signals from a camera or a lidar, for example. The map generation unit 17 can generate an environmental map not only when driving in manual driving mode, but also when driving in automatic driving mode. If an environmental map has already been generated and stored in the memory unit 12, the map generation unit 17 may update the environmental map with newly obtained feature points.

[0029] Next, a map generating device according to this embodiment, that is, the configuration of the vehicle control system 100 as a map generating device, will be described. FIG. 2 is a diagram showing an example of a road 200 to which the map generating device according to this embodiment is applied. FIG. 2 shows an intersection 203 (dotted line area) where a first road 201 and a second road 202 intersect at right angles. The first road 201 includes multiple lanes. Note that the lanes of the second road 202 are not shown.

[0030] The first road 201 includes multiple driving lanes LN1 in which the host vehicle 101 is located and multiple oncoming lanes LN2 that face the driving lane LN1. The driving lane LN1 and the oncoming lane LN2 are separated by a center line L0, and the vehicle travel direction along the driving lane LN1 is opposite to the vehicle travel direction along the oncoming lane LN2. The driving lane LN1 and the oncoming lane LN2 are defined by left and right dividing lines, except for the intersection 203. Hereinafter, for convenience, the driving lane LN1 ahead of the intersection 203 (the near side of the intersection 203) will be referred to as the leading lane, and the driving lane LN1 behind the intersection 203 (the side beyond the intersection 203) will be referred to as the trailing lane.

[0031] The front lanes consist of three lanes LN11 to L13, and the rear lanes consist of two lanes L14 and L15. The front lanes LN11 to LN13 determine the direction of vehicle travel at the intersection 203. That is, lane LN11 is a lane for going straight and turning left, lane LN12 is a lane for going straight, and lane LN13 is a lane for turning right. As shown in FIG. 2, road markings 150 are painted on the road surface of the front lanes LN11 to LN13, using arrows to indicate the directions in which vehicles can travel.

[0032] Because the dividing lines defining the driving lanes end at the intersection 203, it is necessary to associate the front and rear lanes to form driving lanes across the intersection 203. In the example of FIG. 2, lanes LN11 and LN14 are associated with each other, and lanes LN12 and LN15 are associated with each other. Therefore, lanes LN11 and LN14, and lanes LN12 and LN15 are connected via virtual dividing lines within the intersection, forming adjacent driving lanes. Position information of the driving lanes formed in this manner is stored in the memory unit 12 as part of the map information. As a result, when the host vehicle 101 travels in autonomous driving mode, a target trajectory for passing through the intersection 203 can be generated based on the stored map information.

[0033] To define the driving lanes, the controller 10 must associate the lanes before and after the intersection 203. For example, as shown in FIG. 2, if the widthwise centers of lanes LN14 and LN15 are located on extensions of the widthwise centers of lanes LN11 and LN12, respectively, the controller 10 can easily associate the lanes LN11 and LN12 with the lanes LN14 and LN15. In contrast, as shown in FIG. 3A, in the case of a staggered intersection where the widthwise centers of lanes LN14 and LN15 are offset in the left-right direction from the extensions of the widthwise centers of lanes LN11 and LN12, association is difficult. As a result, as shown by the connecting line La, there is a risk that the leading lane (lane LN12) and the trailing lane (lane LN14) may be erroneously associated.

[0034] Furthermore, other vehicles or the like around the host vehicle 101 may become obstacles, and the external sensor group 1 may not recognize the lanes (demarcation lines) around the host vehicle 101. For example, as shown in FIG. 3B, the lanes in the hatched area may not be recognized. In this case, too, as shown by the connecting line Lb, the front lane (lane LN12) and the rear lane (lane LN14) may be erroneously associated. Therefore, in this embodiment, the map generating device is configured as follows so that lanes across the intersection 203 can be accurately associated.

[0035] Fig. 4 is a block diagram showing the configuration of the main parts of a map generating device 20 according to this embodiment. The map generating device 20 is included in the vehicle control system 100 of Fig. 1. As shown in Fig. 4, the map generating device 20 has a camera 1a, a sensor 2a, and a controller 10.

[0036] Camera 1a is a monocular camera having an imaging element (image sensor) such as a CCD or CMOS, and constitutes part of the external sensor group 1 in FIG. 1. Camera 1a may be a stereo camera. Camera 1a is attached to a predetermined position in front of vehicle 101 as shown in FIG. 2, and continuously captures images of the space ahead of vehicle 101 to obtain images of objects (camera images). Objects include lane markings L1 to L3 and center line L0 on the road, and markings on the road surface. Note that instead of or in addition to camera 1a, objects may be detected by a lidar or the like.

[0037] The sensor 2a is a detector used to calculate the amount of movement and the direction of movement of the host vehicle 101. The sensor 2a is part of the internal sensor group 2 and is configured by, for example, a vehicle speed sensor and a yaw rate sensor. That is, the controller 10 (host vehicle position recognition unit 13) calculates the amount of movement of the host vehicle 101 by integrating the vehicle speed detected by the vehicle speed sensor, and calculates the yaw angle by integrating the yaw rate detected by the yaw rate sensor, and estimates the position of the host vehicle 101 by odometry when creating a map. Note that the configuration of the sensor 2a is not limited to this, and the host vehicle position may be estimated using information from other sensors.

[0038] 4 has a trajectory detection unit 21, a marking recognition unit 22, and a lane association unit 23 in addition to the memory unit 12 and the map generation unit 17 as functional components carried out by the calculation unit 11 (FIG. 1). Note that the trajectory detection unit 21, the marking recognition unit 22, and the lane association unit 23 also have a map generation function, and therefore these can also be included in the map generation unit 17.

[0039] The memory unit 12 stores map information. The stored map information includes map information acquired from outside the vehicle 101 via the communication unit 7 (referred to as external map information) and map information created by the vehicle itself (referred to as internal map information). The external map information is, for example, information on a map acquired via a cloud server (referred to as a cloud map), and the internal map information is, for example, information on a map (referred to as an environmental map) made up of point cloud data generated by mapping using a technology such as SLAM. The external map information is shared between the vehicle 101 and other vehicles, whereas the internal map information is map information unique to the vehicle 101 (for example, map information that is solely owned by the vehicle). The memory unit 12 also stores information on various control programs, thresholds used in the programs, and the like.

[0040] The trajectory detection unit 21 detects the travel trajectory of the host vehicle 101 at the time of map generation based on signals from the camera 1a and the sensor 2a. When the map information includes multiple travel lanes, the travel trajectory includes position information of the travel lanes on which the host vehicle 101 has traveled. The trajectory detection unit 21 may detect the travel trajectory based on signals from the positioning unit 4. The detected travel trajectory is stored in the memory unit 12.

[0041] The marking recognition unit 22 recognizes the lane markings L1 to L3 and the center line L0 based on the image (camera image) acquired by the camera 1a, and also recognizes road markings 150 painted on the lane ahead. As shown in FIG. 2, the road markings 150 include arrows indicating going straight, turning left, and turning right. The marking recognition unit 22 recognizes the lane markings and road markings 150 not only in the lane in which the vehicle 101 is traveling, but also in adjacent lanes adjacent to the lane and lanes outside the adjacent lanes (for example, the oncoming lane LN2).

[0042] The lane association unit 23 associates the leading lane before entering the intersection 203 with the trailing lane after passing through the intersection 203. This defines the driving lane from the leading lane to the trailing lane after passing through the intersection 203. A specific example of lane association will be described.

[0043] 5A is a diagram showing an example of association of lanes before and after an intersection 203 when the vehicle is traveling straight ahead. As shown in FIG. 5A, the lane association unit 23 first associates the front lane LN12 and the rear lane LN15 on which the vehicle 101 has traveled based on the travel trajectory of the vehicle 101 detected by the trajectory detection unit 21. This defines a travel lane A1 indicated by an arrow extending from the front lane LN12 to the rear lane LN15. Note that the lanes LN12 and LN15 are lanes on which the vehicle 101 has traveled and are included in the vehicle's lane (travel lane A1).

[0044] Furthermore, the lane association unit 23 determines whether or not the lanes LN11 and LN13 adjacent to the current vehicle lane A1 contain road markings 150 that define the same traveling direction as the current vehicle lane A1, based on the road markings 150 of the lanes LN11 to LN13 ahead recognized by the marking recognition unit 22. Of the lanes LN11 and LN13, the road markings of the lane LN11 include road markings in the straight-ahead direction, just like the current vehicle lane A1. In this case, if there are road markings that define the same traveling direction as the current vehicle lane A1, the lane association unit 23 associates the lanes LN11 and LN14, which are adjacent to the current vehicle lane A1 and are on the same left-right side as the current vehicle lane A1. This defines a traveling lane A2, indicated by an arrow, that runs from the current vehicle lane LN11 to the current vehicle lane LN14. The traveling lane A2 is an adjacent lane adjacent to the current vehicle lane A1.

[0045] 5A shows an example in which the number of lanes in the forward direction is multiple (two lanes), and the number of lanes in the forward lane is the same as the number of lanes in the rear lane. In this case, as described above, the lane association unit 23 associates lanes LN12 and LN15 based on the travel history of the vehicle 101, and also associates lanes LN11 and LN14 adjacent to the lanes LN12 and LN15. In other words, the lane association unit 23 associates multiple lanes across an intersection with each other.

[0046] When the host vehicle 101 turns left at the intersection 203 and enters the second road 202 from the first road 201, the leading lane is a lane on the first road 201, and the trailing lane is a lane on the second road 202. In this case, if the leading lane has multiple lanes (for example, two lanes) in the left-turn direction and the number of lanes is the same as the number of lanes in the trailing lane, the leading lane and the trailing lane are associated with each other in the same manner as described above. That is, the lane association unit 23 associates the leading lane on the first road 201 with the trailing lane on the second road 202 based on the driving history, and also associates other lanes adjacent to the associated lanes with each other. When the host vehicle 101 turns right at the intersection 203 and enters the second road 202 from the first road 201, the lane association unit 23 similarly associates multiple leading lanes with multiple trailing lanes.

[0047] FIG. 5B shows an example in which the vehicle 101 turns left at an intersection and moves from lane LN11 to lane LN16. The lane LN16 is adjacent to lane LN17, which runs in the same direction as lane LN16. After turning left, the vehicle 101 moves from lane LN11 to lane LN16. 16 In this way, when the number of rear lanes is greater than the number of front lanes, the lane association unit 23 associates the front lanes LN11 and rear lanes LN16 on which the host vehicle 101 has traveled with the front lanes LN11 and rear lanes LN16 based on the travel history of the host vehicle. This defines a travel lane A3 (host lane) indicated by an arrow from the front lane LN11 to the rear lane LN16.

[0048] Furthermore, based on the road markings 150 of the lanes LN11 to LN13 ahead recognized by the marking recognition unit 22, the lane association unit 23 determines whether the lane LN12 adjacent to the current lane A3 has a road marking 150 that defines the same traveling direction as the current lane A3. The lane LN12 does not have a road marking that defines the same traveling direction (left turn). Therefore, the lane association unit 23 determines whether the rear lane has another lane that extends in the same traveling direction as the current lane A3. Since another lane LN17 exists in FIG. 5B, the lane association unit 23 associates not only lane LN16 but also lane LN17 with lane LN11. This defines a traveling lane A4, indicated by an arrow, that runs from the current lane LN11 to the rear lane LN117. The traveling lane A4 is a branch lane that branches off from the current lane A3.

[0049] In this way, when the number of lanes in the rear lanes is greater than the number of lanes in the front lanes, in addition to the driving lane A3 based on the driving history, a driving lane A4 branching off from the driving lane A3 is defined by the lane association unit 23 associating the front lanes with the rear lanes. Similarly, not only when the host vehicle 101 turns left, but also when the host vehicle 101 goes straight or turns right, the lane association unit 23 associates the front lanes with the rear lanes to define the driving lane based on the driving history (the host vehicle's lane) and a driving lane branching off from the driving lane (branching lane).

[0050] Based on signals from camera 1a and sensor 2a, map generation unit 17 generates a map including position information of driving lanes from the front lane to the rear lane associated by lane association unit 23. For example, as shown in FIG. 5A, a map for straight driving including position information of current lane A1 based on the driving history of host vehicle 101 and a map for straight driving including position information of adjacent lane A2 adjacent to current lane A1 are generated. Alternatively, as shown in FIG. 5B, a map for left turns including position information of current lane A3 based on the driving history and a map for left turns including position information of branch lane A4 branching off from current lane A3 are generated. The maps generated by map generation unit 17 are stored in memory unit 12.

[0051] Fig. 6 is a flowchart showing an example of processing executed by the controller 10 of Fig. 4 in accordance with a predetermined program. The processing shown in this flowchart is started when the host vehicle 101 traveling in manual driving mode enters an intersection 203, for example, in order to generate an environmental map, and is repeated at a predetermined interval until the host vehicle 101 passes through the intersection 203.

[0052] Before the host vehicle 101 enters the intersection 203, the camera 1a detects left and right dividing lines that define the host vehicle's lane. Furthermore, as the host vehicle 101 approaches the intersection 203, the camera 1a detects road markings 150 that define the traveling direction of the host vehicle 101. Therefore, when the road markings 150 are detected on the road surface of the lane ahead and the left and right dividing lines are no longer detected, it is determined that the host vehicle 101 has entered the intersection. Note that the camera 1a can also detect traffic lights, stop lines, crosswalks, and the like to determine whether the host vehicle 101 has entered the intersection 203. Until the host vehicle 101 enters the intersection 203, the driving lane is defined by the left and right dividing lines, and a map including position information of the driving lane is generated based on signals from the camera 1a and the sensor 2a. In this case, the driving lanes include not only the host vehicle's lane but also adjacent lanes and oncoming lanes.

[0053] As shown in FIG. 6, first, in step S1, it is determined based on a camera image whether the host vehicle 101 has passed through the intersection 203. For example, when a rear lane marking is detected in the camera image and the host vehicle 101 reaches the rear lane marking, it is determined that the host vehicle 101 has passed through the intersection. If the result in step S1 is affirmative, the process proceeds to step S2, and if the result is negative, the process proceeds to step S5. In step S5, a map is generated based on signals from the camera 1a and the sensor 2a. However, if the result in step S1 is negative, a map of the driving lanes within the intersection has not yet been generated.

[0054] In step S2, the travel path of the host vehicle 101 is detected based on signals from the camera 1a and the sensor 2a, and the road markings 150 of the front lane on which the host vehicle 101 traveled are recognized, and the front lane on which the host vehicle 101 traveled is associated with the rear lane on which the host vehicle 101 traveled. Next, in step S3, based on the camera images, it is determined whether the number of lanes extending in the same direction as the traveling direction of the host vehicle 101 is the same before and after passing through the intersection 203. That is, the number of lanes extending in the same direction as the traveling direction of the host vehicle 101 is recognized based on the road markings 150 of the front lane, and it is further determined whether this number of lanes is the same as the number of lanes in the rear lane recognized when passing through the intersection. This determination is made to determine whether there is an adjacent lane (e.g., A2 in FIG. 5A) extending in the same direction as the host vehicle's lane (e.g., A1 in FIG. 5A) on which the host vehicle 101 traveled, regardless of whether the vehicle was traveling straight, turning left, or turning right. If the answer is YES in step S3, the process proceeds to step S4, and if it is NO, the process proceeds to step S6.

[0055] In step S4, a front lane adjacent to the front lane on which the host vehicle 101 is traveling (referred to as an adjacent front lane) is associated with a rear lane adjacent to the rear lane on which the host vehicle 101 is traveling (referred to as an adjacent rear lane). In other words, an association is made so that the lanes are adjacent to the host lane. The associated adjacent front lane and adjacent rear lane are lanes located on the same left-right side of the host lane. Next, in step S5, a map is generated that includes position information of the traveling lanes from the adjacent front lane to the adjacent rear lane.

[0056] In step S6, it is determined whether the number of lanes extending in the same direction as the traveling direction of the host vehicle 101 before passing through the intersection is less than the number of lanes extending in the same direction as the traveling direction of the host vehicle 101 after passing through the intersection. For example, if there are no other lanes ahead extending in the same direction as the traveling direction of the host vehicle 101 (no adjacent lanes ahead), and there are other lanes behind extending in the same direction as the traveling direction of the host vehicle 101 (when there are adjacent lanes behind), the result in step S6 is affirmative and the process proceeds to step S7. On the other hand, if the result in step S6 is negative, the process proceeds to step S7. and Proceed to step S5.

[0057] In step S7, the front lane on which the host vehicle 101 traveled is associated with the rear lane (adjacent rear lane) adjacent to the rear lane on which the host vehicle 101 traveled. That is, the association is made so that the lane becomes a branch lane (e.g., A4 in FIG. 5B) branching off from the host vehicle lane (e.g., A3 in FIG. 5B). Note that when there are multiple front lanes (e.g., two lanes) extending in the same direction as the traveling direction of the host vehicle 101 and more rear lanes (e.g., three lanes) extending in the same direction as the traveling direction of the host vehicle 101, the front lane on which the host vehicle 101 traveled is associated with a rear lane that may or may not be adjacent to the rear lane on which the host vehicle 101 traveled. That is, the front lane on which the host vehicle 101 traveled is associated with a rear lane on which the host vehicle 101 is not traveling but on which the host vehicle 101 can travel. At this time, the preceding adjacent lane adjacent to the own lane is also associated with a plurality of subsequent lanes. Next, in step S5, a map including position information of the travel lanes from the preceding lane to the subsequent lane is generated.

[0058] The operation of the map generating device 20 according to this embodiment will be described in more detail. While the host vehicle 101 is being driven in manual driving mode, an environmental map of the surroundings of the host vehicle 101 is generated based on signals from the camera 1a and the sensor 2a. At this time, for example, after traveling along the front lane LN12 of the first road 201 shown in FIG. 5A, when the host vehicle 101 passes through the intersection 203 and reaches the rear lane LN15, the front lane LN12 and the rear lane LN15 are associated with each other based on the travel trajectory of the host vehicle 101 (step S2). As a result, an environmental map is generated that includes map information of the travel lane A1 during straight-ahead travel, connecting the front lane LN12 and the rear lane LN15 (step S5).

[0059] At this time, when the host vehicle 101 travels in the front lane LN12, the camera image recognizes the front lane LN11, which has a road marking 150 in the same straight-ahead direction as the front lane LN12. As a result, the front lane LN11 adjacent to the host vehicle lane A1 and the rear lane LN14 are associated with each other, and an environmental map is generated that includes map information for the traveling lane A2 adjacent to the host vehicle lane A1, which connects the front lane LN11 and the rear lane LN14 (steps S4 and S5). This makes it possible to generate an environmental map for the intersection 203 where the lane markings are discontinued, based on the travel trajectory of the host vehicle 101 and the camera image. The generated map is stored in the memory unit 12 and is used when traveling in the autonomous driving mode.

[0060] 5B, when the host vehicle 101 turns left at the intersection 203 and transitions from the front lane LN11 to the rear lane LN16, the front lane LN11 and the rear lane LN16 are associated with each other based on the travel path of the host vehicle 101, as in the case of traveling straight ahead (step S2). As a result, an environmental map is generated that includes map information of the travel lane A3 when turning left, which connects the front lane LN11 and the rear lane LN16 (step S5).

[0061] At this time, only the own vehicle lane A3 has the road marking 150 for a left turn, but after the left turn, the second road 202 has not only the own vehicle lane LN16 but also the adjacent lane LN17 as a rear lane. Therefore, the front lane LN11 and the rear lane LN17 are associated with each other, and an environmental map is generated that includes map information for the traveling lane A4 that branches off from the own vehicle lane A3 and connects the front lane LN11 and the rear lane LN17 (steps S7 and S5). This makes it possible to generate a good environmental map for the intersection 203 where the dividing lines are discontinued, based on the travel trajectory of the own vehicle 101 and the camera images, even if the number of lanes before and after the intersection 203 is not the same.

[0062] According to this embodiment, the following effects can be achieved. (1) The map generating device 20 includes a camera 1a that detects the external environment surrounding the host vehicle 101, a trajectory detection unit 21 that detects the traveling trajectory of the host vehicle, a lane association unit 23 that associates a front lane, which is the traveling lane before entering an intersection 203, with a rear lane, which is the traveling lane after passing through the intersection 203, based on the external environment detected by the camera 1a and the traveling trajectory detected by the trajectory detection unit 21, and a map generating unit 17 that generates a map including position information of the traveling lanes from the front lane to the rear lane associated by the lane association unit 23 (FIG. 4). The traveling lanes include traveling lanes A1 and A3 (first traveling lanes) on which the host vehicle 101 is traveling and traveling lanes A2 and A4 (second traveling lanes) that are adjacent to traveling lane A1 or branch off from traveling lane A3 (FIGS. 5A and 5B). The direction of vehicle travel on lanes A1 and A3 is the same as the direction of vehicle travel on lanes A2 and A4 (FIGS. 5A and 5B). The leading lanes include adjacent lanes LN11 (first approach leading lane) and LN12 (second approach leading lane), and the trailing lanes include adjacent lanes LN15 or LN16 (first passing lane) and LN14 or LN17 (second passing lane) (FIGS. 5A and 5B). The lane matching unit 23 matches the front lane LN12 or LN11 with the rear lane LN15 or LN16 (driving lanes A1, A3) based on the driving trajectory detected by the trajectory detection unit 21, and also matches the front lane LN11 with the rear lane LN14 (driving lane A2) or the front lane LN11 with the rear lane LN17 (driving lane A4) based on the external conditions detected by the camera 1a.

[0063] As a result, even if the lanes are offset in the width direction at the entrance and exit of the intersection 203 (for example, FIG. 3A), or if the lanes around the vehicle 101 cannot be recognized from the camera image due to the presence of obstacles such as other vehicles around the vehicle 101 (for example, FIG. 3B), it is possible to smoothly connect the lane markings before and after the intersection based on the travel trajectory of the vehicle 101 and the camera image. As a result, it is possible to easily generate a map that defines travel lanes that straddle an intersection.

[0064] (2) The map generating device 20 further includes a marking recognition unit 22 that recognizes road markings 150 indicating the traveling direction on the lane ahead based on the external environment detected by the camera 1a (FIG. 4). When the traveling direction marked on the lane ahead LN12 and the traveling direction marked on the lane ahead LN11 recognized by the marking recognition unit 22 are the same, the lane association unit 23 associates the lane ahead LN11 with the lane ahead LN14 (FIG. 5A). This makes it possible to easily and accurately generate map information not only about the lane A1 on which the host vehicle 101 actually traveled, but also about the lane A2 on which the host vehicle 101 is not traveled.

[0065] (3) The lane association unit 23 associates the front lane LN12 with the rear lane LN15 so that the driving lane A1 extends straight through the intersection 203, or associates the front lane LN11 with the rear lane LN16 so that the driving lane A3 extends and turns left (FIGS. 5A and 5B). Although not shown, the lane association unit 23 also associates the front lane with the rear lane so that the driving lane extends and turns right at the intersection 203. This makes it possible to generate a map that includes driving lanes based on the travel trajectory of the vehicle 101, regardless of the direction in which the vehicle 101 travels in manual driving mode.

[0066] (4) The front lane LN11 and the rear lane LN14 are adjacent to the front lane LN12 and the rear lane LN15, respectively, on the same left-right side as the front lane LN12 and the rear lane LN15 on which the host vehicle 101 is traveling (FIG. 5A). This makes it possible to generate a map of the adjacent lane A2 along the host lane A1 on which the host vehicle 101 is not traveling.

[0067] The above-described embodiment can be modified in various ways. In the above-described embodiment, the external environment surrounding the vehicle 101 is detected by the external sensor group 1, such as the camera 1a. However, the external environment may also be detected using a lidar or the like, and the configuration of the external environment detection unit is not limited to the above. In the above-described embodiment, the trajectory detection unit 21 detects the traveling trajectory of the vehicle 101 based on signals from the camera 1a and the sensor 2a. However, the configuration of the trajectory detection unit is not limited to this. In the above-described embodiment, the map generation unit 17 generates an environmental map while the vehicle is traveling in manual driving mode. However, the environmental map may also be generated while the vehicle is traveling in automatic driving mode. In the above-described embodiment, the environmental map is generated based on camera images. However, instead of the camera 1a, data acquired by radar or lidar may be used to extract feature points of objects around the vehicle 101, and the environmental map may be generated. Therefore, the configuration of the map generation unit is not limited to the above.

[0068] In the above embodiment, the lane association unit 23 associates the front lane (the entrance lane) before entering the intersection 203 with the rear lane (the passing lane) after passing through the intersection 203. More specifically, the lane association unit 23 associates the front lane LN12 or LN11 (the first entrance lane) with the rear lane LN15 or LN16 (the first passing lane) based on the traveling trajectory detected by the trajectory detection unit 21, and associates the front lane LN11 (the second entrance lane) with the rear lane LN14 (the second passing lane) or associates the front lane LN11 (the first entrance lane) with the rear lane LN17 (the second passing lane) based on the external situation detected by the camera 1a. However, the configuration of the lane association unit is not limited to the above. In the above embodiment, the marking recognition unit 22 recognizes the road marking 150 indicating the direction of travel of the lane ahead based on the external environment detected by the camera 1a, but the configuration of the marking recognition unit is not limited to this.

[0069] In the above embodiment, the map generation unit 17 generates an environmental map while the host vehicle 101 is traveling, but data obtained by camera images while the host vehicle 101 is traveling may be stored in the storage unit 12, and the environmental map may be generated using the stored data after the host vehicle 101 has completed traveling. Therefore, it is not necessary to generate a map while traveling.

[0070] In the above embodiment, an example has been described in which the host vehicle 101 having an automatic driving function functions as the map generating device 20. However, the host vehicle 101 without an automatic driving function may function as the map generating device. In this case, map information generated by the map generating device 20 may be shared with other vehicles, and the driving of the other vehicles (e.g., automatic driving vehicles) may be assisted using the map information. In other words, the host vehicle 101 may only have the function of the map generating device 20.

[0071] The above description is merely an example, and the present invention is not limited to the above-described embodiment and modifications as long as the features of the present invention are not impaired. One or more of the above-described embodiment and modifications can be arbitrarily combined, and modifications can also be combined with each other. [Explanation of symbols]

[0072] 1a camera, 2a sensor, 10 controller, 17 map generation unit, 20 map generation device, 21 trajectory detection unit, 22 sign recognition unit, 23 lane association unit, 101 host vehicle, LN11, LN12 lanes (front lanes), LN14, LN15, LN16, LN17 lanes (rear lanes), A1, A2, A3, A4 driving lanes

Claims

1. an external environment detection unit that detects an external environment around the vehicle; a trajectory detection unit that detects a travel trajectory of the host vehicle; a lane association unit that associates an approach lane, which is a lane to be traveled before entering an intersection, with a passing lane, which is a lane to be traveled after passing through the intersection, based on the external environment detected by the external environment detection unit and the travel trajectory detected by the trajectory detection unit; a map generating unit that generates a map including position information of the travel lanes from the preceding lane to the subsequent lane associated by the lane associating unit, The driving lanes from the pre-entry lane to the post-passage lane include a first driving lane in which the host vehicle has traveled and a second driving lane adjacent to the first driving lane or branching off from the first driving lane, a vehicle traveling direction on the first driving lane and a vehicle traveling direction on the second driving lane are the same; the pre-entry lane includes a first pre-entry lane in which the host vehicle has traveled and a second pre-entry lane adjacent to the first pre-entry lane, the after-passing lane includes a first after-passing lane in which the host vehicle has traveled and a second after-passing lane adjacent to the first after-passing lane, The lane matching unit matches the first pre-entry lane on which the vehicle traveled with the first after-passing lane based on the driving trajectory detected by the trajectory detection unit, and determines whether to match the second pre-entry lane with the second after-passing lane or the first pre-entry lane with the second after-passing lane based on a determination result based on the external environment conditions detected by the external environment detection unit as to whether the number of lanes among the pre-entry lanes that have the same direction of travel as the first pre-entry lane is the same as the number of lanes among the after-passing lanes that have the same direction of travel as the first after-passing lane.

2. 2. The map generating device according to claim 1, The vehicle further includes a marking recognition unit that recognizes a road marking indicating a traveling direction on the preceding lane based on the external environment detected by the external environment detection unit, The map generating device is characterized in that the lane correspondence unit determines, based on the road markings recognized by the marking recognition unit, whether the number of lanes among the pre-entry lanes whose direction of travel is the same as that of the first pre-entry lane is the same as the number of lanes among the post-passage lanes whose direction of travel is the same as that of the first post-passage lane.

3. 3. The map generating device according to claim 1, The map generating device is characterized in that the lane correspondence unit corresponds the first approaching lane and the first passing lane so that the first driving lane extends straight, turns left, or turns right at the intersection.

4. The map generating device according to any one of claims 1 to 3, The map generating device is characterized in that the second approaching lane and the second passing lane are adjacent to the first approaching lane and the first passing lane, respectively, on the same side in the left-right direction.

5. In the map generating device according to claim 1, The lane matching unit matches the second pre-entry lane with the second post-passing lane when the number of lanes among the pre-entry lanes that have the same direction of travel as the first pre-entry lane is the same as the number of lanes among the post-passing lanes that have the same direction of travel as the first post-passing lane.

6. In the map generating device according to claim 1, The lane matching unit matches the first pre-entry lane with the second post-passing lane when the number of lanes among the post-passing lanes that have the same direction of travel as the first post-passing lane is greater than the number of lanes among the pre-entry lanes that have the same direction of travel as the first pre-entry lane.

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