Vehicle control method and vehicle control device

Abstract

Before a vehicle (1) starts to change lanes to an adjacent lane using automatic driving, a controller (16) therein executes a process which involves obtaining first lane width information which is information about lane width and lane marking information to the front of said vehicle from a camera (11), and on the basis of the lane marking information and the first lane width information, controlling the yaw angle of said vehicle in a manner such that said vehicle travels within its lane. When starting to change lanes, said controller (16) executes a process which involves obtaining second lane width information which is information about lane width from map information (13), and controlling the yaw angle so as to perform the lane change on the basis of the second lane width information. After the lane change has been completed, the controller (16) executes a process for controlling the yaw angle in a manner such that said vehicle travels within its lane after changing lanes on the basis of the lane marking information and the first lane width information.

Description

[Technical field]

[0001] The present invention relates to a vehicle control method and a vehicle control device. [Background technology]

[0002] The following Patent Document 1 describes a vehicle control system that controls lane changing of a vehicle based on the positions of lane markings recognized from an image captured by a camera. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-43378 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, lane markings may be misrecognized on the images captured by the camera. If a lane marking is misrecognized during lane change by autonomous driving, it may be difficult to control the lane change appropriately. For example, the vehicle may behave in a way that is not intended by the occupants. The present invention aims to reduce the impact of erroneous recognition of lane markings by a camera on lane changes during automated driving. [Means for solving the problem]

[0005] In one embodiment of the vehicle control method of the present invention, a controller is caused to execute the following processes before starting a lane change of the host vehicle to an adjacent lane by autonomous driving: acquiring first lane width information, which is information on lane markings and lane width ahead of the host vehicle, from a camera, and controlling a yaw angle of the host vehicle so that the host vehicle travels within the host vehicle's lane based on the lane marking information and the first lane width information; acquiring second lane width information, which is information on the lane width, from map information when the lane change is started, and controlling the yaw angle so that the host vehicle travels within the host vehicle's lane based on the second lane width information; and after the lane change is completed, controlling the yaw angle based on the lane marking information and the first lane width information so that the host vehicle travels in the host vehicle's lane after the lane change. Effect of the Invention

[0006] According to the present invention, it is possible to reduce the impact of erroneous recognition of lane markings by a camera on lane changes during automated driving. The objects and advantages of the invention will be realized and attained by means of the elements and combinations recited in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as claimed. [Brief description of the drawings]

[0007] [Figure 1] 1 is a diagram showing an example of a schematic configuration of a vehicle equipped with a driving assistance device according to an embodiment; [Diagram 2] FIG. 2 is a diagram showing a part of the input device of FIG. [Diagram 3] FIG. 2 is a block diagram of an example of a functional configuration of a controller for executing lane keeping control and lane change control. [Figure 4] FIG. 13 is a schematic diagram of an example of a method for calculating the vehicle position during a lane change; [Diagram 5] 10 is a schematic diagram of an example of a method for calculating a target driving trajectory during a lane change; [Figure 6] 10 is a schematic diagram of an example of a method for calculating a target driving trajectory during a lane change; [Figure 7]5(a) to 5(d) are schematic diagrams showing time changes in lane width information switching flags during lane change, the lateral movement amount of the host vehicle, the host vehicle position, and the output of lane width information from the lane information setting unit. [Figure 8] 11 is a flowchart of an example of control of a controller during a lane change. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] (composition) 1 is a diagram showing an example of a schematic configuration of a vehicle equipped with a driving support device according to an embodiment. The driving support device 10 equipped in the vehicle 1 includes a sensor 11, a positioning device 12, a map database (map DB) 13, an in-vehicle device 14, a navigation system 15, a display device 16, a voice output device 17, an input device 18, a vehicle behavior control device 19, and a controller 20. These devices are connected to each other by, for example, a CAN (Controller Area Network) or other in-vehicle LAN in order to transmit and receive information to and from each other. The driving support device 10 is an example of a "vehicle control device" as described in the claims.

[0009] The sensor 11 detects the traveling state of the host vehicle 1. For example, the sensor 11 includes cameras such as a front camera that captures an image in front of the host vehicle 1, a rear camera that captures an image behind the host vehicle 1, and a side camera that captures an image on the left and right sides of the host vehicle 1. The sensor 11 also includes radars such as a front radar that detects obstacles in front of the host vehicle 1, a rear radar that detects obstacles behind the host vehicle 1, and a side radar that detects obstacles present on the left and right sides of the host vehicle 1. The sensor 11 also includes a vehicle speed sensor that detects the vehicle speed of the host vehicle 1.

[0010] The positioning device 12 includes a GPS unit, a gyro sensor, a vehicle speed sensor, etc. The positioning device 12 detects radio waves transmitted from a plurality of satellite communications by the GPS unit, and periodically acquires position information of the vehicle 1. The positioning device 12 also detects the current position of the vehicle 1 based on the acquired position information of the vehicle 1, angle change information acquired from the gyro sensor, and vehicle speed acquired from the vehicle speed sensor.

[0011] The map database 13 is a memory that stores three-dimensional high-precision map information including position information of various facilities and specific points, and is accessible from the controller 20. The three-dimensional high-precision map information includes lane-by-lane information that is more detailed than road-by-road information. For example, the three-dimensional high-precision map information includes lane node information indicating reference points on lane reference lines (e.g., lane center lines) as lane-by-lane information, and lane link information indicating the section state of the lane between the lane nodes. The lane node information includes the position coordinates of the lane node, the number of connected lane links, and the connected lane links. The lane link information includes the lane width (width) of the lane, the type of lane boundary line, the shape of the lane, the shape of the lane dividing line, and the shape of the lane reference line.

[0012] The in-vehicle devices 14 are various devices mounted on the vehicle 1 and are operated by the driver of the vehicle. Examples of such in-vehicle devices include a steering wheel, an accelerator pedal, a brake pedal, a turn signal, wipers, lights, a horn, and other specific switches. The navigation system 15 acquires current position information of the vehicle 1 from the positioning device 12, and displays the position of the vehicle 1 on a display or the like by superimposing it on map information for navigation. In addition, the navigation system 15 has a navigation function that, when a destination is set, sets a route to the destination and guides the occupant along the set route.

[0013] The display device 16 includes various displays, such as a display provided in the navigation system 15, a display built into a rearview mirror, a display built into a meter section, a head-up display projected on the windshield, etc. The display device 16 notifies the occupant of various pieces of presented information under the control of the controller 20. The audio output device 17 is a device that outputs auditory information such as a speaker provided in the navigation system 15, a speaker of an audio device, a buzzer, etc. Under the control of the controller 20, the audio output device 17 notifies the occupant of various pieces of presentation information.

[0014] The input device 18 is, for example, a button switch that allows the occupant to manually input information, a touch panel arranged on a display screen, or a microphone that allows the occupant to input information by voice. By operating the input device 18, the occupant can input setting information for the presentation information presented by the display device 16 and the audio output device 17. 2 is a diagram showing a part of the input device 18 of this embodiment. The input device 18 may be, for example, a group of button switches arranged on the spokes of a steering wheel. The input device 18 is used when setting the on / off of an autonomous driving control function provided in the controller 20. The input device 18 includes a main switch 181, a resume / accelerate switch 182, a set / coast switch 183, a cancel switch 184, a vehicle distance adjustment switch 185, and a lane change assist switch 186.

[0015] The main switch 181 is a switch for turning on / off the autonomous driving control function of the controller 20. The resume / accelerate switch 182 is a switch for setting the autonomous driving control function to resume at the set speed before the autonomous driving control function was turned off after it was turned off, or for increasing the set speed. The set / coast switch 183 is a switch for starting the autonomous driving control function. To start the autonomous driving control function, the set / coast switch 183 is pressed after the autonomous driving control function is turned on by the main switch 181. The set / coast switch 183 is also a switch for lowering the set speed. The cancel switch 184 is a switch for canceling the autonomous driving control function. The vehicle distance adjustment switch 185 is a switch for setting the vehicle distance from the preceding vehicle. The lane change assistance switch 186 is a switch for instructing (agreeing to) start lane change when the controller 20 has confirmed with the occupant that the lane change should be started. 2, a turn signal lever of a turn signal or other switches of the in-vehicle device 14 can be used as the input device 18. For example, when the controller 20 suggests whether or not to automatically change lanes, if the occupant operates the turn signal lever, the vehicle will change lanes in the direction in which the turn signal lever was operated, rather than the suggested lane change.

[0016] The vehicle behavior control device 19 controls the vehicle behavior of the host vehicle 1. For example, when the host vehicle 1 travels at a constant speed at a set speed due to the autonomous driving control function, the vehicle behavior control device 19 controls the operation of the drive mechanism and the brake operation to realize the acceleration / deceleration and traveling speed so that the host vehicle 1 reaches the set speed. In addition, the vehicle behavior control device 19 also controls the operation of the drive mechanism and the brake in the same manner when the host vehicle 1 travels following a preceding vehicle due to the autonomous driving control function. Note that the operation control of the drive mechanism includes the operation of the internal combustion engine in an engine vehicle and the operation of the driving motor in an electric vehicle system. In addition, in a hybrid vehicle, it includes the torque distribution between the internal combustion engine and the driving motor. Furthermore, when the vehicle behavior control device 19 executes lane keeping control, lane change assist function, or overtaking assist function described later using the autonomous driving control function, in addition to controlling the operation of the drive mechanism and the brakes, it controls the operation of the steering actuator to execute steering control of the host vehicle 1 and controls the orientation (i.e., attitude, yaw angle) of the body of the host vehicle 1. Note that instead of or in addition to the steering control that controls the orientation of the body by controlling it to a set target steering angle and moves the lateral position, the orientation (i.e., attitude, yaw angle) of the body of the host vehicle 1 may be controlled by controlling the difference between the wheel speeds of the right and left wheels of the host vehicle 1 to move the lateral position.

[0017] The controller 20 is one or more electronic control units for controlling the traveling of the host vehicle 1, and includes a processor 21 and peripheral components such as a memory device 22. The processor 21 may be, for example, a CPU or an MPU. The memory device 22 may include a semiconductor memory device, a magnetic memory device, an optical memory device, etc. The memory device 22 may include memories such as a register, a cache memory, and a ROM and a RAM used as a main memory device. The functions of the controller 20 described below are realized, for example, by the processor 21 executing a computer program stored in the memory device 22. The controller 20 may be formed of dedicated hardware for executing each information processing described below. For example, the controller 20 may include a functional logic circuit set in a general-purpose semiconductor integrated circuit. For example, the controller 20 may include a programmable logic device such as a field programmable gate array.

[0018] The controller 20 realizes a driving information acquisition function for acquiring information about the driving state of the host vehicle 1, and an autonomous driving control function for autonomously controlling the driving speed and / or steering of the host vehicle 1. The driving information acquisition function of the controller 20 is a function for acquiring driving information about the driving state of the host vehicle 1. For example, the controller 20 may acquire image information of the outside of the vehicle captured by the front camera, rear camera, and side camera of the sensor 11 as the driving information. The controller 20 also acquires detection results by the front radar, rear radar, and side radar as the driving information. Furthermore, the controller 20 also acquires vehicle speed information of the host vehicle 1 detected by the vehicle speed sensor of the sensor 11 and image information of the face of the occupant captured by the in-vehicle camera as the driving information.

[0019] Furthermore, the controller 20 acquires current position information of the vehicle 1 from the positioning device 12 as the travel information. The controller 20 also acquires a set destination and a route to the destination from the navigation system 15 as the travel information. The controller 20 also acquires three-dimensional high-precision map information from the map database 13 as the travel information. In addition, the controller 20 acquires operation information of the in-vehicle device 14 by the occupant from the in-vehicle device 14 as the travel information.

[0020] The autonomous driving control function of the controller 20 is a function for autonomously controlling the driving of the host vehicle 1 without relying on the operation of the occupant. The autonomous driving control function of the controller 20 includes an autonomous speed control function for autonomously controlling the driving speed of the host vehicle 1, and an autonomous steering control function for autonomously controlling the steering of the host vehicle 1. The autonomous speed control function and the autonomous steering control function of this embodiment will be described below. Autonomous speed control function The autonomous speed control function is a function that, when a preceding vehicle is detected, follows the preceding vehicle while controlling the vehicle distance to maintain a vehicle distance according to the vehicle speed, with the vehicle speed set by the occupant as the upper limit. On the other hand, when a preceding vehicle is not detected, the autonomous speed control function performs constant speed driving at the vehicle speed set by the occupant. The former is also called vehicle distance control, and the latter is called constant speed control.

[0021] The constant speed control is executed when the forward radar of the sensor 11 or the like detects that there is no preceding vehicle ahead in the own lane. In the constant speed control, the vehicle behavior control device 19 controls the operation of the drive mechanisms such as the engine and brakes while feeding back the vehicle speed data from the vehicle speed sensor so as to maintain the set traveling speed. The vehicle distance control is executed when the forward radar of the sensor 11 detects the presence of a preceding vehicle ahead in the own lane. In the vehicle distance control, the vehicle behavior control device 19 controls the operation of the drive mechanisms such as the engine and brakes while feeding back the vehicle distance data detected by the forward radar so as to maintain the set vehicle distance with the set travel speed as the upper limit.

[0022] Autonomous steering control function The autonomous steering control function is a function that executes steering control of the host vehicle 1 by controlling the operation of the steering actuator. The autonomous steering control function includes, for example, a lane keeping function, a lane change assist function, and an overtaking assist function. The lane keeping function is a function that assists the occupant in steering the vehicle so that the vehicle travels in a predetermined lateral position (e.g., near the center of the lane) in the vehicle's lane, for example, by controlling the steering actuator (i.e., by executing steering control of the vehicle 1). Hereinafter, the control of the lateral position of the vehicle 1 by the lane keeping function may be referred to as "lane keeping control."

[0023] When the set / coast switch 183 is pressed after the autonomous driving control function is turned on by the main switch 181, the controller 20 judges whether or not a predetermined autonomous driving control start condition is satisfied. If it is judged that the autonomous driving control start condition is satisfied, the controller 20 executes the lane keeping function of the autonomous steering control function. Alternatively, when an autonomous driving control start condition is satisfied after the autonomous driving control function is turned on by the main switch 181, the controller 20 waits for the set / coast switch 183 to be pressed. When the set / coast switch 183 is pressed, the controller 20 starts the autonomous driving control and executes the lane keeping function of the autonomous steering control function.

[0024] Lane change assistance function The lane change assist function turns on the turn signal when the driver operates the turn signal lever, and starts lane change control, which is a series of processes for changing lanes when a predetermined lane change start condition is met. The lane change assist function determines whether the predetermined lane change start condition is met based on various driving information acquired by the driving information acquisition function. The lane change assist function starts lane change control when the lane change start condition is satisfied. In the lane change control, the host vehicle 1 is moved laterally to the adjacent lane, and when the movement to the adjacent lane is completed, the turn signal is turned off and the lane keeping function in the adjacent lane is started.

[0025] Overtaking Assistance Function The overtaking support function presents overtaking information to the occupant via the display device 16 when there is a preceding vehicle slower than the vehicle 1 ahead in the vehicle lane and when a predetermined overtaking suggestion condition is satisfied. Here, the overtaking information is information for suggesting to the occupant to overtake the preceding vehicle. When the occupant accepts the overtaking information presented by operating the lane change support switch 186 of the input device 18 and a preset overtaking start condition is satisfied, the overtaking support function turns on the turn signal and starts lane change control. The overtaking support function judges whether the overtaking suggestion condition and the overtaking start condition are satisfied based on various driving information acquired by the driving information acquisition function. In lane change control, the host vehicle 1 is moved laterally to the adjacent lane, and when the movement to the adjacent lane is completed, the turn signal is turned off and the lane keeping function in the adjacent lane is started.

[0026] Furthermore, the overtaking support function suggests to the driver via the display device 16 that the vehicle should return to the original lane if the overtaking suggestion conditions are met again after the vehicle has overtaken the preceding vehicle. If the driver accepts this suggestion by operating the lane change support switch 186 of the input device 18 and if the overtaking start conditions are met, the overtaking support function starts lane change control to return the vehicle to the original lane. When the vehicle has completed moving to the original lane, the turn signal is turned off and the lane keeping function starts to be executed in the original lane.

[0027] Next, lane keeping control and lane change control by the autonomous steering control function will be described. In this specification, in explaining the lane change control, a case where the host vehicle 1 changes lanes from the first lane Le to the second lane Ln, which is an adjacent lane to the first lane Le, will be exemplified (see FIG. 4). FIG. 3 is a block diagram of an example of a functional configuration for executing the lane keeping control and lane change control in the controller 20. The controller 20 includes a lane change state calculation unit 30, a lane information setting unit 31, a host vehicle position calculation unit 32, a target trajectory calculation unit 33, and a yaw angle control unit 34.

[0028] The lane change state calculation unit 30 judges whether or not to start a lane change of the vehicle 1. For example, the lane change state calculation unit 30 judges whether or not a condition for starting lane change control is satisfied in an autonomous steering control function such as a lane change assist function or an overtaking assist function. For example, the lane change state calculation unit 30 judges whether or not a lane change start condition is satisfied in the lane change assist function. Also, for example, the lane change state calculation unit 30 judges whether or not an overtaking start condition is satisfied in the overtaking assist function. When these conditions are satisfied, the lane change state calculation unit 30 starts a lane change. In this specification, the start of lane change is used as a term meaning the start of lane change control. There is a delay time due to various calculations and actuator operations between the start of lane change control and the occurrence of the vehicle behavior in which the host vehicle 1 changes lanes.

[0029] When the host vehicle 1 starts changing lanes, the lane change state calculation unit 30 sets a switching flag from off to on in order to switch the lane width information used for calculating the lateral position (i.e., lateral position or lane width direction position) of the host vehicle 1 during the lane change and for calculating the target driving trajectory. When the switching flag is off, the lateral position and the target driving trajectory are calculated based on a captured image of the area ahead of the host vehicle 1 captured by the camera of the sensor 11. When the switching flag is on, the lateral position and the target driving trajectory are calculated based on second lane width information acquired from the three-dimensional high-precision map information of the map database 13. When the host vehicle 1 completes the lane change, the lane change state calculation unit 30 sets the switching flag from on to off. The lane change state calculation unit 30 outputs the switching flag to the lane information setting unit 31.

[0030] In addition, during a lane change, the lane change state calculation unit 30 determines whether the vehicle 1 has crossed (crossed) a lane marking at the boundary between the first lane Le and the second lane Ln (hereinafter sometimes referred to as a “boundary lane marking”), and outputs the determination result to the lane information setting unit 31. For example, the lane change state calculation unit 30 can determine that the host vehicle 1 has crossed a boundary lane marking based on a change in the sign of the lateral position of the boundary lane marking relative to the host vehicle 1. The lateral position of the boundary lane marking can be calculated, for example, by recognizing the lane marking from a captured image of the area ahead of the host vehicle 1 captured by a camera, and based on the position of the lane marking in the captured image and the optical conditions of the camera.

[0031] The lane information setting unit 31 recognizes lane markings on both sides of the host vehicle lane from an image captured by the camera of the sensor 11 of the area ahead of the host vehicle 1, and calculates the lateral positions of the lane markings based on the host vehicle 1. That is, when the host vehicle 1 is traveling in the first lane Le, the lane information setting unit 31 calculates the lateral positions of the lane markings of the first lane Le, and when the host vehicle 1 is traveling in the second lane Ln, the lane information setting unit 31 calculates the lateral positions of the lane markings of the second lane Ln. The lane information setting unit 31 calculates the lateral position of the lane markings based on, for example, the positions of the lane markings on the captured image and the optical conditions of the camera. The lane information setting unit 31 outputs lane marking information, which is information about the recognized lane markings, to the vehicle position calculation unit 32 and the target trajectory calculation unit 33. The lane marking information includes at least information on the lateral position of the calculated lane marking. In the following description, the lateral position of the lane marking on the left side of the vehicle 1 relative to the vehicle 1 is referred to as "lateral position yL," and the lateral position of the lane marking on the right side of the vehicle 1 is referred to as "lateral position yR."

[0032] Furthermore, the lane information setting unit 31 acquires first lane width information wc, which is information on the width of the host vehicle 1, from a captured image of the area ahead of the host vehicle 1 captured by the camera of the sensor 11. That is, when the host vehicle 1 is traveling on the first lane Le, information on the lane width of the first lane Le is acquired as the first lane width information wc, and when the host vehicle 1 is traveling on the second lane Ln, information on the lane width of the second lane Ln is acquired as the first lane width information wc. For example, the lane information setting unit 31 may directly calculate the first lane width information wc based on the positions of the lane markings on the left and right sides of the own lane in the captured image and the optical conditions of the camera, or may directly calculate the first lane width information wc from the lateral positions yL and yR of the lane markings on the left and right sides of the own lane calculated as described above.

[0033] Furthermore, when the host vehicle 1 starts changing lanes, the lane information setting unit 31 acquires (reads) second lane width information wme, which is information on the lane width of the first lane Le on which the host vehicle 1 is currently traveling, and second lane width information wmn, which is information on the lane width of the second lane Ln, which is the target of the lane change, from the three-dimensional high-precision map information in the map database 13, based on the current position of the host vehicle 1 detected by the positioning device 12. For example, the lane information setting unit 31 acquires the second lane width information wme, wmn from the three-dimensional high-precision map information based on the current position of the host vehicle 1 in the extension direction of the first lane Le and the second lane Ln. In the following description, the second lane width information wme, wmn may be collectively referred to as "second lane width information wm."

[0034] Before the host vehicle 1 starts to change lanes or after the host vehicle 1 has completed changing lanes, the lane information setting unit 31 outputs the first lane width information wc acquired from the camera to the host vehicle position calculation unit 32 and the target trajectory calculation unit 33. The lane width information output from the lane information setting unit 31 to the host vehicle position calculation unit 32 and the target trajectory calculation unit 33 is denoted as "lane width output wo." In this specification, "before starting a lane change" is used as a term meaning any time point before the start of lane change control. Also, in this specification, "after completing a lane change" is used as a term meaning any time point after the completion of lane change control. In other words, "before starting a lane change" and "after completing a lane change" may be any time point in the period from the completion of the previous lane change control to the start of the next lane change control.

[0035] On the other hand, during a lane change, the second lane width information wm is output to the vehicle position calculation unit 32 and the target trajectory calculation unit 33 as a lane width output wo. For example, when starting a lane change, the lane information setting unit 31 switches the lane width output wo output to the vehicle position calculation unit 32 and the target trajectory calculation unit 33 from the first lane width information wc to the second lane width information wm. For example, the lane information setting unit 31 may switch the lane width output wo from the first lane width information wc to the second lane width information wm at the time when the controller 20 starts lane change control, or may switch the lane width output wo from the first lane width information wc to the second lane width information wm after the controller 20 starts lane change control and before the vehicle position calculation unit 32 and the target trajectory calculation unit 33 calculate the vehicle position and the target trajectory.

[0036] Also, for example, when completing a lane change, the lane information setting unit 31 switches the lane width output wo from the second lane width information wm to the first lane width information wc. For example, the lane information setting unit 31 may switch the lane width output wo from the second lane width information wm to the first lane width information wc when the host vehicle 1 reaches a completion point Pe, which is a target position in the second lane Ln of the host vehicle 1 after the lane change is completed. For example, the completion point Pe may be set to the center of the second lane Ln.

[0037] Also, for example, the lane information setting unit 31 may switch the lane width output wo from the second lane width information wm to the first lane width information wc at a point before the lane change is completed (for example, at the point of reaching the vicinity of the completion point Pe). Here, the vicinity of the completion point Pe may be set to a position where the first lane width information wc with high accuracy can be obtained from the captured image of the camera. For example, the vicinity of the completion point Pe may be a position where the lane markings on both sides of the second lane Ln are within the angle of view of the camera (i.e., a position where the lane markings on both sides can be recognized from the captured image). For example, the amount of lateral movement from the start point Ps, which is the point where the lane change is started, to the completion point Pe may be defined as a lateral movement amount ytrg, and the position where a certain percentage (e.g., 95%) of the lateral movement amount ytrg is completed may be defined as the vicinity of the completion point Pe. For example, the vicinity of the completion point Pe may be a lateral position a predetermined distance before the completion point Pe.

[0038] The lane information setting unit 31 may gradually change the lane width output wo when switching between the second lane width information wm and the first lane width information wc. For example, when starting a lane change, the lane information setting unit 31 may set the lane width output wo by a weighted sum of the following equation (1) using a weighting coefficient K1 between 0 and 1, and may increase K1 from 0 to 1 at a first switching speed. wo = K1 × wme + (1 - K1) × wc … (1) For example, when completing a lane change, the lane information setting unit 31 may set the lane width output wo by the weighted sum of the following equation (2) using a weighting coefficient K2 between 0 and 1, and may reduce K2 from 1 to 0 at the second switching speed. wo = K2 × wmn + (1 - K2) × wc … (2) The second switching speed may be lower than the first switching speed or may be the same as the first switching speed.

[0039] The vehicle position calculation unit 32 calculates the lateral position ycr of the vehicle 1 in the own lane as the vehicle position, based on the lane dividing line information output from the lane information setting unit 31 and the lane width output wo. The vehicle position calculation unit 32 calculates the vehicle position ycr based on the lateral position of either the left or right lane marking and the lane width output wo (i.e., first lane width information wc) before starting a lane change and after completing the lane change. For example, in lane keeping control, the vehicle position calculation unit 32 calculates the vehicle position ycr based on the lateral position of either the left or right lane marking and the first lane width information wc. For example, the vehicle position calculation unit 32 may calculate the vehicle position ycr based on the lateral position of the lane marking that is closer to the vehicle 1 out of the left and right lane markings and the first lane width information wc.

[0040] For example, when calculating the vehicle position ycr based on the lane markings on the left side, the vehicle position calculation unit 32 may calculate the center position of the vehicle lane based on the current position of the vehicle 1 as the vehicle position ycr based on the following equation (3). ycr = 0.5 × wc + yL … (3) Further, for example, when calculating the vehicle position ycr based on the lane markings on the right side, the vehicle position calculation unit 32 may calculate the vehicle position ycr based on the following equation (4). ycr = -0.5 × wc + yR … (4)

[0041] Next, while executing a lane change, the vehicle position calculation unit 32 calculates the vehicle position ycr based on the lateral position of the boundary lane dividing line between the first lane Le and the second lane Ln and the lane width output wo (i.e., the second lane width information wme, wmn). 4 is a schematic diagram of an example of a method for calculating the vehicle position during a lane change. Reference symbol 1e indicates the vehicle 1 before crossing the boundary lane marking, and reference symbol 1n indicates the vehicle 1 after crossing the boundary lane marking. Specifically, the vehicle position calculation unit 32 calculates the vehicle position ycr based on the lateral position of the boundary lane dividing line and the second lane width information wme of the first lane Le before the vehicle 1 crosses the boundary lane dividing line, and based on the lateral position of the boundary lane dividing line and the second lane width information wmn of the second lane Ln after the vehicle 1 crosses the boundary lane dividing line.

[0042] For example, when the second lane Ln after the lane change is the left lane of the first lane Le as shown in FIG. 4, the host vehicle position ycr is calculated based on the following equation (5) before the host vehicle 1 crosses the boundary lane dividing line. ycr = 0.5 × wme + yL … (5) After the vehicle 1 crosses the boundary lane marking, the vehicle position ycr is calculated based on the following equation (6). ycr = -0.5 × wmn + yR … (6)

[0043] Furthermore, for example, when the second lane Ln after the lane change is the lane to the right of the first lane Le, the host vehicle position ycr is calculated based on the following equation (7) before the host vehicle 1 crosses the boundary lane dividing line. ycr = -0.5 × wme + yR … (7) After the vehicle 1 crosses the boundary lane marking, the vehicle position ycr is calculated based on the following equation (8). ycr=0.5×wmn+yL …(8) The vehicle position calculation unit 32 outputs the calculated vehicle position ycr to the yaw angle control unit .

[0044] The target trajectory calculation unit 33 calculates a target running trajectory, which is a target running trajectory along which the host vehicle 1 is to run. For example, when lane keeping control is being performed, a trajectory for maintaining a predetermined lateral position within the own lane is generated as the target driving trajectory. For example, the target driving trajectory for maintaining the center position of the own lane may be calculated. For example, before starting a lane change, a target driving trajectory that maintains the center position Ce of the first lane Le may be calculated, and after the lane change is completed, a target driving trajectory that maintains the center position Cn of the second lane Ln may be calculated.

[0045] On the other hand, for example, when calculating a target driving trajectory in lane change control, the target trajectory calculation unit 33 sets a lateral movement amount ytrg from the start point Ps to the completion point Pe of the lane change based on the lane width output wo and the vehicle position ycr. 5 and 6 are schematic diagrams showing an example of a method for calculating a target driving trajectory during a lane change. The target trajectory calculation unit 33 sets a lateral movement amount ytrg of the following equation (9) based on the lane width output wo (i.e., the second lane width information wme) at the start of a lane change. ytrg=wo …(9) In addition, when the lane width output wo is gradually changed, the lane width output wo may be calculated based on the above formula (1) to gradually change the lateral movement amount ytrg.

[0046] Furthermore, the target trajectory calculation unit 33 sets a longitudinal movement amount xtrg from the start point Ps to the completion point Pe based on the lateral movement amount ytrg and the vehicle speed V of the host vehicle 1. For example, the greater the lateral movement amount ytrg, the greater the longitudinal movement amount xtrg may be set, and the higher the vehicle speed V, the greater the longitudinal movement amount xtrg may be set. Note that in Fig. 5 and Fig. 6, reference symbol 1s indicates the host vehicle 1 located at the start point Ps. The target trajectory calculation unit 33 calculates a completion point Pe based on the set lateral movement amount ytrg and longitudinal movement amount xtrg and the lane change start point Ps. The target trajectory calculation unit 33 sets a curve connecting the start point Ps and the completion point Pe as the target driving trajectory T1. For example, the target trajectory calculation unit 33 may set a clothoid curve connecting the start point Ps and the completion point Pe as the target driving trajectory T1. For example, the target trajectory calculation unit 33 may define the target driving trajectory T1 as a profile of the lateral movement amount relative to the movement amount in the extension direction of the lane.

[0047] During lateral movement in lane change, the target trajectory calculation unit 33 may update the target driving trajectory T1 in accordance with the actual driving position of the vehicle 1. For example, the remaining lateral movement amount yrem is calculated by subtracting the difference in lateral position from the start point Ps to the current position of the vehicle 1 from the lateral movement amount ytrg, and the remaining longitudinal movement amount xrem is calculated based on the remaining lateral movement amount yrem and the vehicle speed V. Then, the completion point Pe is updated based on the lateral movement amount ytrg and the remaining longitudinal movement amount xrem, and a curve connecting the current position of the vehicle 1 and the updated completion point Pe is calculated as the updated target driving trajectory T1.

[0048] Next, the target trajectory calculation unit 33 updates the lateral movement amount ytrg to a value obtained by the following equation (10) at the timing when the host vehicle 1 crosses a boundary lane marking during a lane change. ytrg = ycr[k-1] - ycr[k] =0.5×(wme+wmn)+(yL[k-1]-yR[k]) …(10) Here, ycr[k-1] and yL[k-1] are the vehicle position and the lateral position of the boundary lane marking calculated in the control cycle immediately before the host vehicle 1 crosses the boundary lane marking as shown in Fig. 5, and ycr[k] and yR[k] are the vehicle position and the lateral position of the boundary lane marking calculated in the control cycle immediately after the host vehicle 1 crosses the boundary lane marking as shown in Fig. 6. Reference symbols 1[k-1] and 1[k] indicate the host vehicle 1 immediately before crossing the boundary lane marking and the host vehicle 1 immediately after crossing it. As can be seen from equation (10), the lateral movement amount ytrg is calculated as the difference between the host vehicle position cr immediately before and immediately after the host vehicle 1 crosses the boundary lane marking.

[0049] The target trajectory calculation unit 33 calculates the remaining lateral movement amount yrem by subtracting the difference in lateral position from the start point Ps to the current position of the vehicle 1 from the updated lateral movement amount ytrg, and calculates the remaining longitudinal movement amount xrem based on the remaining lateral movement amount yrem and the vehicle speed V. Then, the target trajectory calculation unit 33 updates the completion point Pe based on the updated lateral movement amount ytrg and the remaining longitudinal movement amount xrem, and sets a curve (e.g., a clothoid curve) connecting the current position and the updated completion point Pe as the target driving trajectory T2. The target trajectory calculation unit 33 may update the target driving trajectory T2 in accordance with the actual driving position of the host vehicle 1 even during lateral movement after crossing a boundary lane marking and before completing a lane change.

[0050] Alternatively, the target trajectory calculation unit 33 may set the lateral movement amount ytrg based on the following equation (11) at the start of a lane change to calculate the target driving trajectory T1, and may not need to update the lateral movement amount ytrg when crossing a boundary lane marking. ytrg=0.5×(wme+wmn) …(11) In the following description, the target driving trajectories T1 and T2 may be collectively referred to as "target driving trajectory T." The target trajectory calculation unit 33 calculates the amount of movement of the vehicle 1 in the extension direction of the lane based on the vehicle speed V of the vehicle 1, and calculates the target lateral position of the vehicle 1 at the current time based on the amount of movement of the vehicle 1 in the extension direction and the target driving trajectory T. The target trajectory calculation unit 33 outputs the calculated target lateral position to the yaw angle control unit 34. During lane keeping control, a predetermined lateral position within the own lane is output as the target lateral position.

[0051] The yaw angle control unit 34 calculates the deviation of the host vehicle position ycr calculated by the host vehicle position calculation unit 32 from the target lateral position calculated by the target trajectory calculation unit 33, and performs feedback control on the deviation to control the yaw angle of the host vehicle 1 so that the host vehicle 1 travels following the target travel trajectory T. For example, the yaw angle control unit 34 may control the yaw angle of the host vehicle 1 by outputting a steering command to the vehicle behavior control device 19 to perform steering control of the host vehicle 1. Also, for example, the yaw angle control unit 34 may control the yaw angle of the host vehicle 1 by generating a wheel speed between the right wheel and the left wheel by controlling the operation of the drive mechanism and the brake operation by the vehicle behavior control device 19.

[0052] (operation) 7(a) to 7(d) are schematic diagrams showing time changes in the lane width information switching flag during lane change, the lateral movement amount of the host vehicle, the host vehicle position cr, and the lane width output wo, respectively. At time t1, the lane change state calculation unit 30 starts changing lanes of the host vehicle 1. Before time t1, lane keeping control is being executed and the lane change state calculation unit 30 sets the switching flag to OFF (FIG. 7(a)). The lane information setting unit 31 sets the first lane width information as the lane width output wo. w c is output (Figure 7(d)). When a lane change starts at time t1, the lane change state calculation unit 30 sets the switching flag from OFF to ON. Accordingly, the lane information setting unit 31 gradually changes the lane width output wo at a first switching speed, and sets the first lane width information w c to 2nd lane width information w The interval between time t1 and time t2 may be, for example, 1 second.

[0053] Also, at time t1, the target trajectory calculation unit 33 calculates the lateral movement amount ytrg of the lane change based on the above formula (9), and calculates the target driving trajectory T1 based on the lateral movement amount ytrg. The yaw angle control unit 34 controls the yaw angle of the host vehicle 1 so that the host vehicle 1 drives following the target driving trajectory T1. As a result, the lateral movement amount Δy[k] of the host vehicle 1 increases as shown by the solid line in FIG. 7(b). The vertical axis ytrg1 is the lateral movement amount calculated based on the above formula (9), and the dashed line Δy1 indicates the change in the lateral movement amount of the target driving trajectory T1. From time t1 to time t3, the lateral movement amount Δy[k] of the host vehicle 1 increases following the lateral movement amount Δy1 of the target driving trajectory T1.

[0054] When the host vehicle 1 crosses the boundary lane marking at time t3, the host vehicle lane changes from the first lane Le to the second lane Ln, causing the host vehicle position ycr to change significantly, as shown in FIG. 7(c). The target trajectory calculation unit 33 calculates the lateral movement amount ytrg of the lane change based on the above formula (10), and calculates the target driving trajectory T2 based on the lateral movement amount ytrg. The yaw angle control unit 34 controls the yaw angle of the host vehicle 1 so that the host vehicle 1 drives following the target driving trajectory T2. The vertical axis ytrg2 in Fig. 7(b) is the horizontal movement calculated based on the above equation (10), Dashed line Δy2 indicates a change in the lateral movement amount of the target driving trajectory T2. From time t3 to time t6, the lateral movement amount Δy[k] of the host vehicle 1 increases following the lateral movement amount Δy2 of the target driving trajectory T2.

[0055] At time t4, when the host vehicle 1 reaches the vicinity of the completion point Pe and the lateral movement amount Δy[k] of the host vehicle 1 reaches the threshold value yth as shown in FIG. 7(b), the lane change state calculation unit 30 sets the switching flag from ON to OFF (FIG. 7(a)). Accordingly, the lane information setting unit 31 gradually changes the lane width output wo at the second switching speed and sets the second lane width information wo at the second switching speed from time t4 to time t5. w mn to 1st lane width information w The interval between time t4 and time t5 may be, for example, 1.5 seconds. When the lateral movement amount Δy[k] of the host vehicle 1 reaches the lateral movement amount ytrg2 at time t6, the lane change process is completed. After that, the lane keeping control is executed.

[0056] 8 is a flowchart of an example of control by the controller 20 during a lane change. During a lane change, the controller 20 repeatedly executes the process shown in FIG. 8 at a fixed control period. In step S1, the controller 20 acquires an image captured by the camera as data of the sensor 11. In step S2, the controller 20 determines whether or not the lane change control has just started. If the lane change control has just started (step S2: Y), the process proceeds to step S3. If the lane change control has not just started (step S2: N), the process proceeds to step S5. In step S3, the controller 20 acquires the second lane width information wm from the three-dimensional high-precision map information. In step S4, the controller 20 sets the switching flag from OFF to ON.

[0057] In step S5, the controller 20 calculates the lane width according to the above formula (1). In step S6, the controller 20 calculates the target lateral position (i.e., the lateral movement amount ytrg) and the lateral position of the host vehicle (i.e., the host vehicle position cr) based on the lane width calculated according to the above formula (1). In step S7, the controller 20 determines whether the host vehicle 1 has reached the vicinity of the completion point Pe. If the host vehicle 1 has reached the vicinity of the completion point Pe (step S7: Y), the process proceeds to step S8. If the host vehicle 1 has not reached the vicinity of the completion point Pe (step S7: N), the process ends. In step S8, the controller 20 sets the switching flag from OFF to ON, and then the process ends.

[0058] (Effects of the embodiment) (1) Before starting a lane change of the host vehicle 1 to an adjacent lane by automatic driving, the controller 20 executes a process of acquiring lane marking information and first lane width information, which is information on lane width and lane marking information ahead of the host vehicle 1, from a camera, and controlling the yaw angle of the host vehicle 1 so that the host vehicle 1 travels within the host vehicle's lane based on the lane marking information and the first lane width information, a process of acquiring second lane width information, which is information on lane width, from map information when the lane change is started, and controlling the yaw angle so that the host vehicle 1 travels within the host vehicle's lane after the lane change based on the lane marking information and the first lane width information after the lane change is completed. This prevents the host vehicle 1 from misidentifying the lane width before the lane change even if there is an error in the lane width information from the camera, and thus stabilizes the trajectory during the lane change.

[0059] (2) The controller 20 may switch the lane width information used for controlling the yaw angle from the first lane width information to the second lane width information when starting a lane change. This makes it possible to prevent unintended lateral movement even if there is an error in the lane width information acquired from the camera when starting a lane change. (3) Before the lane change is completed, the controller 20 may switch the lane width information used for controlling the yaw angle from the second lane width information to the first lane width information. This allows the first lane width information to be used quickly once it becomes possible to obtain the first lane width information with high accuracy from the image captured by the camera.

[0060] (4) When starting a lane change, the controller 20 may gradually change the lane width information used for controlling the yaw angle from the first lane width information to the second lane width information at a first switching speed, and when completing the lane change, may gradually change the lane width information used for controlling the yaw angle from the second lane width information to the first lane width information at a second switching speed lower than the first switching speed. This makes it possible to suppress fluctuations in vehicle behavior caused by switching of the lane width information just before completing the lane change.

[0061] All examples and conditional terms described herein are intended for educational purposes to help the reader understand the present invention and the concepts provided by the inventor for the advancement of technology, and should be interpreted without being limited to the above specifically described examples and conditions, and the configuration of the examples in this specification with respect to showing the advantages and disadvantages of the present invention. Although the embodiments of the present invention have been described in detail, it should be understood that various changes, substitutions and modifications can be made thereto without departing from the spirit and scope of the present invention. [Explanation of symbols]

[0062] 1... host vehicle, 10... driving assistance device, 11... sensor, 12... positioning device, 13... map DB, 14... in-vehicle equipment, 15... navigation system, 16... display device, 17... audio output device, 18... input device, 19... vehicle behavior control device, 20... controller, 21... processor, 22... storage device

Claims

1. Before starting a lane change of the host vehicle to an adjacent lane by autonomous driving, a process of acquiring lane marking information and first lane width information, which is information on a lane width ahead of the host vehicle, from a camera, and controlling a yaw angle of the host vehicle so that the host vehicle travels within the host lane based on the lane marking information and the first lane width information; When the lane change is started, a process of acquiring second lane width information, which is information on a lane width, from map information and controlling the yaw angle so as to perform the lane change based on the second lane width information; After the lane change is completed, a process of controlling the yaw angle based on the lane dividing line information and the first lane width information so that the host vehicle travels in the host lane after the lane change; A vehicle control method comprising: causing a controller to execute the above steps.

2. 2. The vehicle control method according to claim 1, wherein the controller switches lane width information used for controlling the yaw angle from the first lane width information to the second lane width information at the start of the lane change.

3. 3. The vehicle control method according to claim 1, wherein the controller switches lane width information used for controlling the yaw angle from the second lane width information to the first lane width information before the lane change is completed.

4. The controller: When starting the lane change, lane width information used for controlling the yaw angle is gradually changed from the first lane width information to the second lane width information at a first switching speed, and switched; When completing the lane change, lane width information used for controlling the yaw angle is gradually changed from the second lane width information to the first lane width information at a second switching speed lower than the first switching speed.

4. The vehicle control method according to claim 1, wherein the vehicle is driven in a vehicle-controlled manner.

5. A camera that captures an image in front of the vehicle; A controller for controlling at least a yaw angle of the host vehicle, The controller: Before starting a lane change of the host vehicle to an adjacent lane by autonomous driving, a process of acquiring lane marking information and first lane width information, which is information on a lane width ahead of the host vehicle, from a camera, and controlling a yaw angle of the host vehicle so that the host vehicle travels within the host lane based on the lane marking information and the first lane width information; When the lane change is started, a process of acquiring second lane width information, which is information on a lane width, from map information and controlling the yaw angle so as to perform the lane change based on the second lane width information; After the lane change is completed, a process of controlling the yaw angle based on the lane dividing line information and the first lane width information so that the host vehicle travels in the host lane after the lane change; A vehicle control device comprising:

6. The vehicle control method according to any one of claims 1 to 4, characterized in that the controller controls the yaw angle based on the second lane width information of the first lane on which the host vehicle is traveling before the lane change and the second lane width information of the second lane on which the host vehicle is traveling after the lane change.

7. 7. The vehicle control method according to claim 6, wherein the controller controls the yaw angle based on the second lane width information of the first lane before the host vehicle crosses a lane dividing line between the first lane and the second lane, and controls the yaw angle based on the second lane width information of the second lane after the host vehicle crosses the lane dividing line.

8. The vehicle control method according to any one of claims 1 to 4, 6 and 7, characterized in that the controller sets a lateral movement amount of the host vehicle to a completion point of the lane change based on the second lane width information.

9. The vehicle control method according to any one of claims 1 to 4 and 6 to 8, characterized in that the controller generates a target driving trajectory based on the second lane width information, and performs the lane change based on the target driving trajectory.

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