Vehicle control methods and vehicle control devices

Abstract

The controller (20) performs the following processing: Before the vehicle (1) starts changing lanes to the adjacent lane based on autonomous driving, it obtains the lane dividing line information and lane width information in front of the vehicle from the camera, i.e., the first lane width information, and controls the yaw angle of the vehicle based on the lane dividing line information and the first lane width information so that the vehicle can drive in the lane; when the lane change starts, it obtains the second lane width information as lane width information from the map information (13), and controls the yaw angle based on the second lane width information to perform the lane change; after the lane change is completed, it controls the yaw angle based on the lane dividing line information and the first lane width information so that the vehicle can drive in the lane after the lane change.

Description

Technical Field

[0001] This invention relates to vehicle control methods and vehicle control devices. Background Technology

[0002] Patent Document 1 describes a vehicle control system that controls lane changes based on the position of lane markings identified from images captured by a camera.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2019-43378 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] However, there are instances where lane markings are misidentified in camera images. If this misidentification occurs during lane changes in autonomous driving, it can make it difficult to control appropriate lane changes. For example, it could lead to unexpected vehicle behavior for passengers.

[0008] The purpose of this invention is to reduce the impact of camera misidentification of lane markings on lane changes in autonomous driving systems.

[0009] Technical solutions for solving the problem

[0010] In a vehicle control method according to an embodiment of the present invention, a computer performs the following processes: before the vehicle begins to change lanes to an adjacent lane based on autonomous driving, it acquires lane dividing line information and lane width information (i.e., first lane width information) from a camera; it controls the yaw angle of the vehicle based on the lane dividing line information and the first lane width information to make the vehicle travel within the lane; when the lane change begins, it acquires second lane width information (which serves as lane width information) from map information, and controls the yaw angle based on the second lane width information to perform the lane change; after the lane change is completed, it controls the yaw angle based on the lane dividing line information and the first lane width information to make the vehicle travel within the lane after the lane change.

[0011] Invention Effects

[0012] According to the present invention, the impact of the camera's misidentification of lane markings on lane changes based on autonomous driving can be reduced.

[0013] The objects and advantages of this invention are embodied using the elements and combinations thereof shown in the claims. The foregoing general description and the following detailed description are merely illustrative and should not be construed as limiting the invention as described in the claims. Attached Figure Description

[0014] Figure 1 This is a diagram illustrating a schematic example of the configuration of a vehicle equipped with a driving assistance device according to an embodiment.

[0015] Figure 2 It means Figure 1 A diagram of a portion of the input device.

[0016] Figure 3 This is a block diagram illustrating an example of the functions of lane keeping control and lane change control implemented in a controller.

[0017] Figure 4 This is a schematic diagram illustrating an example of how the vehicle's position is calculated during lane changes.

[0018] Figure 5 This is a schematic diagram illustrating an example of the calculation method for the target driving trajectory in lane changing.

[0019] Figure 6 This is a schematic diagram illustrating an example of the calculation method for the target driving trajectory in lane changing.

[0020] Figure 7 (a) to (d) are schematic diagrams showing the switching indicator of lane width information during lane change, the lateral movement of the vehicle, the vehicle position, and the time change of the output of lane width information from the lane information setting unit.

[0021] Figure 8 This is a flowchart illustrating an example of controller operation during lane changing. Detailed Implementation

[0022] (constitute)

[0023] Figure 1 This diagram illustrates an example of the general configuration of a vehicle equipped with the driving assistance device according to the embodiments. The driving assistance device 10 mounted on this 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 for transmitting and receiving information, for example, via an in-vehicle LAN such as CAN (Controller Area Network). It should be noted that the driving assistance device 10 is an example of the "vehicle control device" described in the claims.

[0024] Sensor 11 detects the driving status of vehicle 1. For example, sensor 11 may include a front camera that captures images of the front of vehicle 1, a rear camera that captures images of the rear of vehicle 1, and side cameras that capture images of the left and right sides of vehicle 1. Additionally, sensor 11 may include radars such as a front radar that detects obstacles in front of vehicle 1, a rear radar that detects obstacles behind vehicle 1, and side radars that detect obstacles on the left and right sides of vehicle 1. Furthermore, sensor 11 may include a vehicle speed sensor that detects the speed of vehicle 1.

[0025] The positioning device 12 includes a GPS unit, a gyroscope sensor, and a vehicle speed sensor. The positioning device 12 periodically acquires the location information of the vehicle 1 by detecting radio waves transmitted from multiple satellite communications via the GPS unit. Furthermore, the positioning device 12 detects the current position of the vehicle 1 based on the acquired location information, the angle change information acquired from the gyroscope sensor, and the vehicle speed acquired from the vehicle speed sensor.

[0026] Map database 13 is a memory that stores high-precision 3D map information containing location information of various facilities and specific locations, and is accessible from controller 20. The high-precision 3D map information includes lane unit information, which is more detailed than road unit information. For example, the high-precision 3D map information includes information on lane nodes representing reference points on lane baselines (e.g., lane center lines), and information on lane links representing the section shape of lanes between lane nodes, as lane unit information. Lane node information includes the location coordinates of the lane node, the number of lane links it connects to, and information about the connected lane links. Lane link information includes the lane width, the type of lane boundary lines, the shape of the lane, the shape of the lane dividing lines, and the shape of the lane baseline.

[0027] The vehicle-mounted equipment 14 refers to various devices installed on the vehicle 1 that are operated by the occupants. Such vehicle-mounted equipment may include a steering wheel, accelerator pedal, brake pedal, direction indicator, windshield wipers, lights, horn, and other specific switches.

[0028] The navigation system 15 obtains the current location information of the vehicle 1 from the positioning device 12, and displays the location of the vehicle 1 on a display screen or the like by overlaying it with map information for navigation. In addition, the navigation system 15 has a navigation function that, when a destination is set, sets a route to that destination and guides the occupants along the set route.

[0029] Display device 16 includes, for example, the display of the navigation system 15, a display installed in the rearview mirror inside the vehicle, a display installed in the instrument panel, a head-up display projected onto the windshield, and other various displays. Display device 16 notifies the occupants of various prompts and information under the control of controller 20.

[0030] The sound output device 17 is a device that outputs auditory information, such as a speaker, audio device speaker, or buzzer, provided by the navigation system 15. The sound output device 17 notifies the occupants of various prompts and information according to the control of the controller 20.

[0031] The input device 18 may be a push-button switch that can be manually operated by the occupant, a touch panel on the display screen, or a microphone that can be used for voice input by the occupant. By operating the input device 18, the occupant can input setting information for the prompts displayed by the display device 16 or the sound output device 17.

[0032] Figure 2 This diagram shows a portion of the input device 18 according to this embodiment. The input device 18 may be a group of push-button switches disposed, for example, on the spokes of a steering wheel. The input device 18 is used to activate / deactivate autonomous driving control functions provided by the setting controller 20. The input device 18 includes a main switch 181, a resume / accelerate switch 182, a set / slide switch 183, a cancel switch 184, a vehicle spacing adjustment switch 185, and a lane change assist switch 186.

[0033] The main switch 181 is used to turn the autonomous driving control function of the controller 20 on / off. The resume / accelerate switch 182 is used to restart the autonomous driving control function at the set speed before disconnection, or to increase the set speed, after the autonomous driving control function has been disconnected. The set / coast switch 183 is used to start the autonomous driving control function. To start the autonomous driving control function, after the autonomous driving control function is turned on via the main switch 181, press the set / coast switch 183. Additionally, the set / coast switch 183 is used to decrease the set speed. The cancel switch 184 is used to deactivate the autonomous driving control function. The vehicle spacing adjustment switch 185 is used to set the distance between the vehicle and the preceding vehicle. The lane change assist switch 186 is used to indicate (allow) the start of a lane change when the controller 20 has confirmed the start of a lane change to the occupants.

[0034] It should be noted that, in addition to Figure 2In addition to the button switch group shown, the direction indicator stalk of the direction indicator or the switch of other vehicle equipment 14 can also be used as the input device 18. For example, when the controller 20 asks whether to automatically change lanes, when the occupant operates the direction indicator stalk, the lane change is not in the requested lane, but in the direction in which the direction indicator stalk was operated.

[0035] The vehicle behavior control device 19 controls the vehicle behavior of the vehicle 1. For example, when the vehicle 1 is traveling at a set speed using the autonomous driving control function, the vehicle behavior control device 19 controls the operation of the drive mechanism and braking action used to achieve acceleration, deceleration, and travel speed, so that the vehicle 1 reaches the set speed. Similarly, when the vehicle 1 is following a preceding vehicle using the autonomous driving control function, the vehicle behavior control device 19 also controls the operation of the drive mechanism and brakes. It should be noted that the control of the drive mechanism's operation includes the operation of the internal combustion engine in engine-powered vehicles, and always includes the operation of the drive motor in electric vehicles. Furthermore, hybrid vehicles include the torque distribution between the internal combustion engine and the drive motor.

[0036] Furthermore, when the vehicle behavior control device 19 performs lane keeping control, lane change assist, or overtaking assist functions (described later) through the autonomous driving control function, it performs steering control of the vehicle 1 by controlling the movement of the steering actuator in addition to controlling the movement of the drive mechanism and brakes, thereby controlling the orientation (i.e., posture, yaw angle) of the vehicle body. It should be noted that, instead of steering control that controls the orientation of the vehicle body and moves its lateral position by controlling a set target steering angle, or by controlling the difference between the wheel speeds of the right and left wheels of the vehicle 1 to control the orientation (i.e., posture, yaw angle) of the vehicle body to move its lateral position, it may also be used to control the orientation (i.e., posture, yaw angle) of the vehicle body.

[0037] The controller 20 is one or more electronic control units used to control the movement of the vehicle 1, and includes peripheral components such as a processor 21 and a storage device 22. The processor 21 may be, for example, a CPU or an MPU. The storage device 22 may include semiconductor storage devices, magnetic storage devices, optical storage devices, etc. The storage device 22 may include registers, cache memory, ROM and RAM used as main storage, etc. The functions of the controller 20 described below are implemented, for example, by the processor 21 executing a computer program stored in the storage device 22.

[0038] It should be noted that the controller 20 may also be formed by dedicated hardware for performing the various information processing described below. For example, the controller 20 may also have functional logic circuits set in general-purpose semiconductor integrated circuits. For example, the controller 20 may also have programmable logic devices such as field-programmable gate arrays.

[0039] The controller 20 performs driving information acquisition functions to obtain information related to the driving state of the vehicle 1, and autonomous driving control functions to autonomously control the driving speed and / or steering of the vehicle 1. The driving information acquisition function of the controller 20 is to acquire driving information related to the driving state of the vehicle 1. For example, the controller 20 can acquire image information of the vehicle's exterior captured by the front, rear, and side cameras of the sensor 11 as driving information. Additionally, the controller 20 acquires the detection results of the front, rear, and side radars as driving information. Furthermore, the controller 20 also acquires the vehicle speed information detected by the vehicle speed sensor of the sensor 11 and image information of the occupants' faces captured by the in-vehicle camera as driving information.

[0040] Furthermore, the controller 20 obtains the current location information of the vehicle 1 from the positioning device 12 as driving information. Additionally, the controller 20 obtains the set destination and the route to the destination from the navigation system 15 as driving information. Furthermore, the controller 20 obtains three-dimensional high-precision map information from the map database 13 as driving information. Moreover, the controller 20 obtains the occupant's operation information on the in-vehicle device 14 as driving information.

[0041] The autonomous driving control function of the controller 20 is a function that autonomously controls the driving of the vehicle 1 without relying on the operation of the occupants. The autonomous driving control function of the controller 20 includes an autonomous speed control function that autonomously controls the driving speed of the vehicle 1 and an autonomous steering control function that autonomously controls the steering of the vehicle 1. Hereinafter, the autonomous speed control function and the autonomous steering control function of this embodiment will be described.

[0042] Autonomous speed control function

[0043] The autonomous speed control function, when a preceding vehicle is detected, maintains a distance between vehicles while simultaneously controlling the following distance, using a speed set by the occupants as the upper limit. Conversely, when no preceding vehicle is detected, the autonomous speed control function maintains a constant speed set by the occupants. The former is called distance control, and the latter is called constant speed control.

[0044] Cruise control is activated when the forward radar or other sensors (such as sensor 11) detect that there are no vehicles ahead in the lane. During cruise control, the vehicle speed data from the speed sensor is fed back, and the vehicle behavior control device 19 controls the operation of the drive mechanisms such as the engine and brakes to maintain the set driving speed.

[0045] Vehicle spacing control is performed when a vehicle ahead is detected in the lane by the forward radar or other sensors 11. In vehicle spacing control, the set driving speed is used as the upper limit. While feeding back the vehicle distance data detected by the forward radar, the vehicle behavior control device 19 controls the operation of the drive mechanism such as the engine and brakes to maintain the set vehicle distance.

[0046] Autonomous Steering Control Function

[0047] The autonomous steering control function is a function that performs steering control of the vehicle 1 by controlling the action of the steering actuator.

[0048] Autonomous steering control functions include, for example, lane keeping assist, lane change assist, and overtaking assist.

[0049] Lane keeping function is a function that, for example, controls the steering actuator (i.e., performs steering control of the vehicle 1) to assist the occupant's steering wheel operation in a manner that allows the vehicle to travel in a predetermined lateral position within its lane (e.g., near the center of the lane). Hereinafter, the control of the lateral position of the vehicle 1 based on the lane keeping function will sometimes be referred to as "lane keeping control".

[0050] After the autonomous driving control function is activated via the main switch 181, if the setting / sliding switch 183 is pressed, the controller 20 determines whether the prescribed autonomous driving control start conditions are met. If the autonomous driving control start conditions are met, the controller 20 executes the lane keeping function of the autonomous steering control function.

[0051] Alternatively, after the autonomous driving control function is activated via the main switch 181, if the autonomous driving control start condition is met, the controller 20 waits for the set / coast switch 183 to be pressed. When the set / coast switch 183 is pressed, the controller 20 begins autonomous driving control, executing the lane keeping function of the autonomous steering control function.

[0052] Lane change assist function

[0053] The lane change assist function illuminates the direction indicator when the occupant operates the direction indicator stalk. If the prescribed lane change initiation conditions are met, it initiates a series of processes for lane change control. The lane change assist function determines whether the prescribed lane change initiation conditions are met based on various driving information obtained through the driving information acquisition function.

[0054] The lane change assist function initiates lane change control when the lane change start conditions are met. During lane change control, the vehicle 1 moves laterally into the adjacent lane. After the movement into the adjacent lane is completed, the direction indicator is turned off, and the lane keeping function in the adjacent lane is activated.

[0055] Overtaking Assist Function

[0056] When there is a slower vehicle ahead of vehicle 1 in the current lane and the prescribed overtaking proposal conditions are met, the overtaking assist function prompts the occupants with overtaking information via display device 16. Here, the overtaking information is used to propose to the occupants that the vehicle ahead should overtake. For the overtaking assist function, if the occupants allow the lane change assist switch 186 on the overtaking information prompt input device 18, and the preset overtaking initiation conditions are met, the direction indicator is illuminated, and lane change control begins. The overtaking assist function determines whether the overtaking proposal conditions and overtaking initiation conditions are met based on various driving information obtained through the driving information acquisition function.

[0057] In lane change control, the vehicle 1 is moved laterally to the adjacent lane. After the movement to the adjacent lane is completed, the direction indicator is turned off, and the lane keeping function in the adjacent lane is started.

[0058] Furthermore, if the overtaking assist function, after overtaking by a preceding vehicle, meets the overtaking proposal conditions again, it proposes to the driver via display device 16 that the vehicle return to its original lane. Upon the driver's permission via the lane change assist switch 186 on input device 18, and if the overtaking initiation conditions are met, the overtaking assist function initiates lane change control to return the vehicle to its original lane. After completing the return to the original lane, the direction indicator is turned off, and the lane keeping function in the original lane is activated.

[0059] Next, lane keeping control and lane change control based on autonomous steering control will be explained. It should be noted that this manual illustrates, in the explanation of lane change control, the scenario where vehicle 1 changes lanes from the first lane Le to the adjacent lane, the second lane Ln (see reference). Figure 4 ). Figure 3 This is a block diagram illustrating an example of the lane keeping control and lane change control functions performed in the controller 20. The controller 20 includes a lane change status calculation unit 30, a lane information setting unit 31, a vehicle position calculation unit 32, a target trajectory calculation unit 33, and a yaw angle control unit 34.

[0060] The lane change state calculation unit 30 determines whether to initiate a lane change for the vehicle 1. For example, the lane change state calculation unit 30 determines whether the conditions for initiating lane change control are met in autonomous steering control functions such as lane change assist function and overtaking assist function. For example, the lane change state calculation unit 30 determines whether the lane change initiation condition is met in the lane change assist function. Additionally, for example, the lane change state calculation unit 30 determines whether the overtaking initiation condition is met in the overtaking assist function. If these conditions are met, the lane change state calculation unit 30 initiates a lane change.

[0061] It should be noted that in this specification, "start of lane change" is used as a statement indicating the start of lane change control. From the start of lane change control until the vehicle 1 performs a lane change, there is a delay due to various calculations or actuator actions.

[0062] When lane changing begins for vehicle 1, the lane change state calculation unit 30 switches the switching flag from off to on in order to switch the lane width information used in calculating the lateral position (i.e., lateral position or lane width direction position) of vehicle 1 or the target driving trajectory during lane changing. When the switching flag is off, the lateral position or target driving trajectory is calculated based on an image captured by the camera of sensor 11 of the front of vehicle 1. When the switching flag is on, the lateral position or target driving trajectory is calculated based on second lane width information obtained from the three-dimensional high-precision map information of map database 13.

[0063] Furthermore, when the lane change of vehicle 1 is completed, the lane change status calculation unit 30 sets the switching flag from on to off. The lane change status calculation unit 30 outputs the switching flag to the lane information setting unit 31.

[0064] In addition, during lane change, the lane change status calculation unit 30 determines whether the vehicle 1 has crossed (crossed) the lane dividing line (hereinafter sometimes referred to as "boundary lane dividing line") between the first lane Le and the second lane Ln, and outputs the determination result to the lane information setting unit 31.

[0065] For example, the lane change status calculation unit 30 can determine that the vehicle 1 has crossed the boundary lane dividing line based on the switching of the symbol of the lateral position of the boundary lane dividing line with the vehicle 1 as a reference. As for the lateral position of the boundary lane dividing line, for example, the lane dividing line can be identified based on the captured image obtained by the camera of the front of the vehicle 1, and the calculation is performed based on the position of the lane dividing line on the captured image and the optical conditions of the camera.

[0066] The lane information setting unit 31 identifies the lane dividing lines on both sides of the lane based on the image captured by the camera of the sensor 11 in front of the vehicle 1, and calculates the lateral position of the lane dividing lines with respect to the vehicle 1. That is, when the vehicle 1 is traveling in the first lane Le, the lateral position of the lane dividing lines of the first lane Le is calculated, and when the vehicle 1 is traveling in the second lane Ln, the lateral position of the lane dividing lines of the second lane Ln is calculated.

[0067] The lane information setting unit 31 calculates the lateral position of the lane dividing lines based, for example, on the position of the lane dividing lines in the captured image and the optical conditions of the camera. The lane information setting unit 31 outputs information related to the identified lane dividing lines, i.e., lane dividing line information, to the vehicle position calculation unit 32 and the target trajectory calculation unit 33.

[0068] The lane marking information includes at least the calculated lateral position of the lane markings. In the following description, the lateral position of the lane marking on the left side of vehicle 1, relative to vehicle 1, is referred to as "lateral position yL", and the lateral position of the lane marking on the right side of vehicle 1 is referred to as "lateral position yR".

[0069] Furthermore, the lane information setting unit 31 obtains the lane width information, i.e., the first lane width information wc, from the image captured by the camera of sensor 11 in front of the vehicle 1. That is, when the vehicle 1 is traveling in the first lane Le, the lane width information of the first lane Le is obtained as the first lane width information wc, and when traveling in the second lane Ln, the lane width information of the second lane Ln is obtained as the first lane width information wc.

[0070] For example, the lane information setting unit 31 can directly calculate the first lane width information wc based on the position of the lane dividing lines on the left and right sides of the lane in the captured image and the optical conditions of the camera, or it can directly calculate the first lane width information wc from the lateral positions yL and yR of the lane dividing lines on the left and right sides of the lane as calculated above.

[0071] Furthermore, when the lane change of vehicle 1 begins, the lane information setting unit 31, based on the current position of vehicle 1 detected by the positioning device 12, obtains (reads out) the lane width information wme of the first lane Le that vehicle 1 is currently traveling in, and the lane width information wmn of the second lane Ln that the lane change target is in, from the three-dimensional high-precision map information of the map database 13. For example, the lane information setting unit 31 obtains the second lane width information wme and wmn from the three-dimensional high-precision map information based on the current position of vehicle 1 in the extension direction of the first lane Le or the second lane Ln.

[0072] In the following description, the second lane width information wme and wmn may be collectively referred to as "second lane width information wm".

[0073] Before or after a lane change is initiated by the vehicle 1, the lane information setting unit 31 outputs the first lane width information wc acquired from the camera to the 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 vehicle position calculation unit 32 and the target trajectory calculation unit 33 is referred to as "lane width output wo".

[0074] In this specification, "before starting lane change" is used to indicate any time earlier than the start time of lane change control. Similarly, "after completing lane change" is used to indicate any time later than the completion time of lane change control. That is, "before starting lane change" and "after completing lane change" can be any time between the completion time of the last lane change control and the start time of the next lane change control.

[0075] On the other hand, during lane changing, the second lane width information wm is output as lane width output wo to the vehicle position calculation unit 32 and the target trajectory calculation unit 33.

[0076] For example, when initiating a lane change, the lane information setting unit 31 switches the lane width output wo, which is sent 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 can switch the lane width output wo from the first lane width information wc to the second lane width information wm at the moment when the controller 20 starts lane change control, or it can 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.

[0077] Additionally, for example, when the lane information setting unit 31 completes a lane change, it 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 also switch the lane width output wo from the second lane width information wm to the first lane width information wc when the vehicle 1 reaches the target position, i.e., the completion point Pe, within the second lane Ln after the lane change is completed. For example, the completion point Pe may be set in the center of the second lane Ln.

[0078] Alternatively, 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 time before the lane change is completed (e.g., when it reaches the vicinity of the completion location Pe).

[0079] Here, the location near the completion point Pe can be set, for example, at the position where high-precision first lane width information wc is obtained from the camera's captured image. For example, the location near the completion point Pe can be the position where the lane dividing lines on both sides of the second lane Ln are included in the camera's field of view (i.e., the position of the lane dividing lines on both sides can be identified from the captured image).

[0080] Alternatively, for example, the lateral movement from the starting point Ps (where the lane change begins) to the ending point Pe can be defined as the lateral movement amount ytrg, and the location where a certain percentage (e.g., 95%) of the lateral movement ytrg is completed can be defined as the vicinity of the ending point Pe. Alternatively, the vicinity of the ending point Pe can also be a lateral position closer to the ending point Pe by a specified distance.

[0081] The lane information setting unit 31 can also make the lane width output wo gradually change when switching between the second lane width information wm and the first lane width information wc.

[0082] For example, when the lane information setting unit 31 starts changing lanes, it can use a weighting coefficient K1 of 0 to 1 to set the lane width output wo by weighting the following formula (1), and increase K1 from 0 to 1 at a first switching speed.

[0083] wo=K1×wme+(1-K1)×wc…(1)

[0084] For example, when the lane information setting unit 31 completes a lane change, it can use a weighting coefficient K2 of 0 to 1 to set the lane width output wo by weighting the following formula (2), and reduce K2 from 1 to 0 at a second switching speed.

[0085] wo=K2×wmn+(1-K2)×wc…(2)

[0086] It should be noted that the second switching speed can be lower than the first switching speed, or it can be the same as the first switching speed.

[0087] The vehicle position calculation unit 32 calculates the vehicle position by taking the lateral position ycr of the vehicle 1 in the lane as the vehicle position based on the lane division information and lane width output wo from the lane information setting unit 31.

[0088] Before initiating a lane change and after completing a lane change, the vehicle position calculation unit 32 calculates the vehicle position ycr based on the lateral position of any lane dividing line on the left and right sides and the lane width output wo (i.e., the first lane width information wc). For example, in lane keeping control, the vehicle position calculation unit 32 calculates the vehicle position ycr based on the lateral position of any lane dividing line on the left and right sides and the first lane width information wc.

[0089] For example, the vehicle position calculation unit 32 can calculate the vehicle position ycr based on the lateral position of the lane dividing line that is closer to the vehicle 1 among the lane dividing lines on the left and right sides and the first lane width information wc.

[0090] For example, when calculating the vehicle position ycr based on the lane dividing line on the left, the vehicle position calculation unit 32 can calculate the vehicle position ycr based on the center position of the lane with the current position of the vehicle 1 as the reference.

[0091] ycr=0.5×wc+yL…(3)

[0092] In addition, for example, when calculating the vehicle position ycr based on the lane dividing line on the right, the vehicle position calculation unit 32 can calculate the vehicle position ycr based on the following formula (4).

[0093] ycr=-0.5×wc+yR…(4)

[0094] Next, during the 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 outputs wo (i.e., the second lane width information wme, wmn).

[0095] Figure 4 This is a schematic diagram illustrating an example of how the vehicle's position is calculated during lane changes. Referring to the attached diagram, reference numeral 1e indicates vehicle 1 before crossing the lane divider line, and reference numeral 1n indicates vehicle 1 after crossing the lane divider line.

[0096] Specifically, before the vehicle 1 crosses the boundary lane dividing line, 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. After the vehicle 1 crosses the boundary lane dividing line, the vehicle position ycr is calculated based on the lateral position of the boundary lane dividing line and the second lane width information wmn of the second lane Ln.

[0097] For example, such as Figure 4As shown, when the second lane Ln after the lane change is the left lane of the first lane Le, the position ycr of the vehicle is calculated based on the following formula (5) before the vehicle 1 crosses the boundary lane dividing line.

[0098] ycr=0.5×wme+yL…(5)

[0099] After vehicle 1 crosses the boundary lane dividing line, the position ycr of vehicle 1 is calculated based on the following formula (6).

[0100] ycr=-0.5×wmn+yR…(6)

[0101] Additionally, for example, if the second lane Ln after the lane change is the right lane of the first lane Le, the vehicle position ycr is calculated based on the following formula (7) before the vehicle 1 crosses the boundary lane dividing line.

[0102] ycr=-0.5×wme+yR…(7)

[0103] After vehicle 1 crosses the boundary lane dividing line, the position ycr of vehicle 1 is calculated based on the following formula (8).

[0104] ycr=0.5×wmn+yL…(8)

[0105] The vehicle position calculation unit 32 outputs the calculated vehicle position ycr to the yaw angle control unit 34.

[0106] The target trajectory calculation unit 33 calculates the target trajectory of the vehicle 1, i.e., the target trajectory.

[0107] For example, when lane keeping control is executed, a trajectory that maintains a predetermined lateral position within the lane is generated as the target driving trajectory. For example, a target driving trajectory that maintains the center position within the lane can be calculated.

[0108] For example, before starting a lane change, a target driving trajectory that maintains the center position Ce of the first lane Le can be calculated, and after the lane change is completed, a target driving trajectory that maintains the center position Cn of the second lane Ln can be calculated.

[0109] On the other hand, for example, when calculating the target driving trajectory in lane change control, the target trajectory calculation unit 33 sets the lateral movement amount ytrg from the start point Ps of the lane change to the completion point Pe based on the lane width output wo and the vehicle position ycr.

[0110] Figure 5 and Figure 6 This is a schematic diagram illustrating an example of the calculation method for the target driving trajectory in lane changing.

[0111] When lane change begins, the target trajectory calculation unit 33 sets the lateral movement amount ytrg according to the following formula (9) based on the lane width output wo (i.e., the second lane width information wme).

[0112] ytrg=wo…(9)

[0113] It should be noted that, when the lane width output wo is gradually changed, the lane width output wo can also be calculated based on the above formula (1), so that the lateral movement amount ytrg is gradually changed.

[0114] Furthermore, the target trajectory calculation unit 33 sets the longitudinal movement amount xtrg from the starting point Ps to the ending point Pe based on the lateral movement amount ytrg and the vehicle speed V of the vehicle 1. For example, the larger the lateral movement amount ytrg, the larger the longitudinal movement amount xtrg can be set; the higher the vehicle speed V, the larger the longitudinal movement amount xtrg can be set. It should be noted that in Figure 5 and Figure 6 In the attached figure, reference numeral 1s indicates the vehicle 1 located at the starting point Ps.

[0115] The target trajectory calculation unit 33 calculates the completion location Pe based on the set lateral movement amount ytrg, longitudinal movement amount xtrg, and the starting location Ps of the lane change.

[0116] The target trajectory calculation unit 33 sets the curve connecting the start point Ps and the finish point Pe as the target driving trajectory T1. For example, the target trajectory calculation unit 33 can set the spiral curve connecting the start point Ps and the finish point Pe as the target driving trajectory T1. For example, the target trajectory calculation unit 33 can define the target driving trajectory T1 as the curve of the lateral movement of the lane relative to the movement in the extension direction.

[0117] During lateral movement in lane changes, the target trajectory calculation unit 33 can also update the target trajectory T1 based on the actual driving position of the vehicle 1. For example, the remaining lateral movement yrem is calculated by subtracting the difference in lateral position from the starting point Ps to the current position of the vehicle 1 from the lateral movement ytrg. Based on the remaining lateral movement yrem and the vehicle speed V, the remaining longitudinal movement xrem is calculated. Then, the completion point Pe is updated based on the lateral movement ytrg and the remaining longitudinal movement xrem, and the curve connecting the current position of the vehicle 1 and the updated completion point Pe is used as the updated target trajectory T1 for calculation.

[0118] Next, when the vehicle 1 crosses the boundary lane dividing line during lane change, the target trajectory calculation unit 33 updates the lateral movement amount ytrg to the value obtained by the following formula (10).

[0119] ytrg=ycr[k-1]-ycr[k]=0.5×(wme+wmn)+(yL[k-1]-yR[k])…(10)

[0120] Here, ycr[k-1] and yL[k-1] are as follows: Figure 5 As shown, the vehicle's position and the lateral position of the boundary lane dividing line are calculated in the control loop when vehicle 1 is about to cross the boundary lane dividing line. ycr[k] and yR[k] are as follows: Figure 6 The diagram shows the vehicle's position and the lateral position of the boundary lane divider calculated in the control loop when vehicle 1 has just crossed the boundary lane divider. Referring to the attached diagram, reference numerals 1[k-1] and 1[k] represent vehicle 1 about to cross the boundary lane divider and vehicle 1 that has just crossed the boundary lane divider. According to equation (10), the lateral movement ytrg is calculated as the difference between the vehicle's position cr when it is about to cross the boundary lane divider and when it has just crossed the boundary lane divider.

[0121] The target trajectory calculation unit 33 subtracts the difference in lateral position from the starting point Ps to the current position of the vehicle 1 from the updated lateral movement amount ytrg, calculates the remaining lateral movement amount yrem, and calculates the remaining longitudinal movement amount xrem based on the remaining lateral movement amount yrem and the vehicle speed V. Furthermore, the completion point Pe is updated based on the updated lateral movement amount ytrg and the remaining longitudinal movement amount xrem, and the curve (e.g., a spiral curve) connecting the current position and the updated completion point Pe is set as the target driving trajectory T2.

[0122] The target trajectory calculation unit 33 can also update the target driving trajectory T2 based on the actual driving position of the vehicle 1 during lateral movement from crossing the boundary lane dividing line to before the lane change is completed.

[0123] Alternatively, the target trajectory calculation unit 33 may calculate the target driving trajectory T1 by setting the lateral movement amount ytrg based on the following formula (11) when the lane change begins, and not update the lateral movement amount ytrg when crossing the boundary lane dividing line.

[0124] ytrg=0.5×(wme+wmn)…(11)

[0125] In the following description, target driving trajectories T1 and T2 are sometimes referred to collectively as "target driving trajectory T".

[0126] The target trajectory calculation unit 33 calculates the amount of movement of the vehicle 1 in the direction of extension 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 moment based on the amount of movement of the vehicle 1 in the direction of extension and the target driving trajectory T.

[0127] The target trajectory calculation unit 33 outputs the calculated target lateral position to the yaw angle control unit 34. In lane keeping control, the predetermined lateral position within the current lane is output as the target lateral position.

[0128] The yaw angle control unit 34 calculates the deviation of the vehicle position ycr calculated by the 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, thereby controlling the yaw angle of the vehicle 1 so that the vehicle 1 follows the target driving trajectory T. For example, the yaw angle control unit 34 can control the steering of the vehicle 1 by outputting a steering command to the vehicle behavior control device 19, thereby controlling the yaw angle of the vehicle 1. Alternatively, for example, the yaw angle control unit 34 can control the yaw angle of the vehicle 1 by controlling the operation of the drive mechanism and braking action by the vehicle behavior control device 19 to generate wheel speed between the right and left wheels.

[0129] (action)

[0130] Figure 7 (a)~ Figure 7 (d) are schematic diagrams representing the switching flag for lane width information during lane change, the lateral movement of the vehicle, the vehicle position cr, and the time change of lane width output wo.

[0131] At time t1, the lane change state calculation unit 30 initiates a lane change for vehicle 1. Prior to time t1, lane keeping control is executed, and the lane change state calculation unit 30 sets the switching flag to off. Figure 7 (a)). The lane information setting unit 31 outputs the first lane width information wc as the lane width output wo( Figure 7 (d)).

[0132] When a lane change begins at time t1, the lane change state calculation unit 30 changes the switching flag from off to on. Subsequently, the lane information setting unit 31 causes the lane width output w0 to gradually change at a first switching speed, from time t1 to time t2, from the first lane width information wc to the second lane width information wme. The interval between time t1 and time t2 can be, for example, 1 second.

[0133] Additionally, at time t1, the target trajectory calculation unit 33 calculates the lateral movement amount ytrg for 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 vehicle 1 so that the vehicle 1 follows the target driving trajectory T1. The result is as follows: Figure 7(b) As shown by the solid line, the lateral movement Δy[k] of vehicle 1 increases. The vertical axis ytrg1 is the lateral movement calculated based on the above equation (9), and the dotted line Δy1 represents the change in the lateral movement of the target trajectory T1. From time t1 to time t3, the lateral movement Δy[k] of vehicle 1 increases in line with the lateral movement Δy1 of the target trajectory T1.

[0134] When vehicle 1 crosses the lane divider at time t3, it switches its lane from lane 1 (Le) to lane 2 (Ln), as follows: Figure 7 As shown in (c), the position ycr of this vehicle changes significantly.

[0135] 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 vehicle 1 so that the vehicle 1 follows the target driving trajectory T2.

[0136] Figure 7 (b) The vertical axis ytrg2 is the lateral movement calculated based on the above formula (10), and the dashed line Δy2 represents the change in the lateral movement of the target driving trajectory T2. From time t3 to time t6, the lateral movement Δy[k] of this vehicle 1 increases in line with the lateral movement Δy2 of the target driving trajectory T2.

[0137] At time t4, vehicle 1 arrives near the completion point Pe, such as Figure 7 As shown in (b), when the lateral movement Δy[k] of vehicle 1 reaches the threshold yth, the lane change state calculation unit 30 sets the switching flag from on to off. Figure 7 (a)). Subsequently, the lane information setting unit 31 causes the lane width output wo to gradually change at a second switching speed, from time t4 to time t5, changing from the second lane width information wmn to the first lane width information wc. Figure 7 (d) The interval between time t4 and time t5 can be, for example, 1.5 seconds.

[0138] When the lateral movement Δy[k] of vehicle 1 reaches the lateral movement ytrg2 at time t6, the lane change process is completed. Lane keeping control is then executed.

[0139] Figure 8 This is a flowchart illustrating an example of the control of controller 20 during lane changing. In lane changing, controller 20 executes repeatedly with a constant control cycle. Figure 8 The processing shown.

[0140] In step S1, the controller 20 acquires the image captured by the camera as data from the sensor 11.

[0141] In step S2, the controller 20 determines whether lane change control has just started. If lane change control has just started (step S2: Y), the process proceeds to step S3. If lane change control has not just started (step S2: N), the process proceeds to step S5.

[0142] In step S3, the controller 20 obtains the second lane width information wm from the three-dimensional high-precision map information. In step S4, the controller 20 changes the switching flag from off to on.

[0143] 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., lateral movement amount ytrg) and the lateral position of the vehicle (i.e., the vehicle position cr) based on the lane width calculated according to the above formula (1).

[0144] In step S7, the controller 20 determines whether the vehicle 1 has reached the vicinity of the completion location Pe. If the vehicle 1 has reached the vicinity of the completion location Pe (step S7: Y), the process proceeds to step S8. If the vehicle 1 has not reached the vicinity of the completion location Pe (step S7: N), the process ends.

[0145] In step S8, the controller 20 changes the switching flag from off to on. Afterward, the process ends.

[0146] (Effects of the implementation method)

[0147] (1) The controller 20 performs the following processing: Before the vehicle 1 begins to change lanes to an adjacent lane based on autonomous driving, it acquires lane dividing line information and lane width information (i.e., first lane width information) from the camera. Based on the lane dividing line information and the first lane width information, it controls the yaw angle of the vehicle 1 to ensure that the vehicle 1 travels within its lane. When the lane change begins, it acquires second lane width information (which serves as lane width information) from the map information. Based on the second lane width information, it controls the yaw angle to perform the lane change. After the lane change is completed, it controls the yaw angle based on the lane dividing line information and the first lane width information to ensure that the vehicle 1 travels within its lane after the lane change. Therefore, even if there is an error in the lane width information acquired from the camera, the lane width before the lane change will not be misidentified, thus ensuring a stable trajectory during lane changes.

[0148] (2) The controller 20 can also switch the lane width information used for yaw angle control from the first lane width information to the second lane width information when a lane change begins. Thus, even if there is an error in the lane width information obtained from the camera when a lane change begins, it can suppress unexpected lateral movement.

[0149] (3) The controller 20 can also switch the lane width information used for yaw angle control from the second lane width information to the first lane width information before the lane change is completed. Thus, the first lane width information can be quickly utilized after obtaining high-precision first lane width information from the camera's captured image.

[0150] (4) Alternatively, when a lane change begins, the controller 20 switches the lane width information used for yaw angle control from first lane width information to second lane width information at a first switching speed. When a lane change is completed, the controller 20 switches the lane width information used for yaw angle control from second lane width information to first lane width information at a second switching speed lower than the first switching speed. This suppresses changes in vehicle behavior that occur when lane width information switches upon completion of a lane change.

[0151] All examples and terms used herein are intended for educational purposes to help the reader understand the invention and the concepts given by the inventors for technological advancements, and should be interpreted as not being limited to the specific examples and conditions described above, as well as the examples in this specification that illustrate the advantages and disadvantages of the invention. While embodiments of the invention have been described in detail, it should be understood that various changes, substitutions, and modifications can be made therein without departing from the spirit and scope of the invention.

[0152] Explanation of reference numerals in the attached figures

[0153] 1…This vehicle, 10…Driver assistance device, 11…Sensor, 12…Positioning device, 13…Map database, 14…In-vehicle equipment, 15…Navigation system, 16…Display device, 17…Sound output device, 18…Input device, 19…Vehicle behavior control device, 20…Controller, 21…Processor, 22…Storage device

Claims

1. A vehicle control method, characterized in that, Cause the controller to perform the following processing: Before the autonomous vehicle begins to change lanes from the first lane to the second lane adjacent to the first lane, the lane dividing line information and lane width information in front of the vehicle are obtained from the camera, i.e., the first lane width information. Based on the lane dividing line information and the first lane width information, the yaw angle of the vehicle is controlled so that the vehicle travels within the lane. When the lane change is initiated, second lane width information, which serves as the lane width of the first lane and the lane width of the second lane, is obtained from the map information. A target driving trajectory is set based on the lane dividing line information and the second lane width information. The yaw angle is controlled based on the target driving trajectory to perform the lane change. After the lane change is completed, the yaw angle is controlled based on the lane dividing line information of the second lane and the first lane width information, so that the vehicle travels within the lane after the lane change. When the lane change is initiated, the controller switches the lane width information used for yaw angle control by gradually changing from the first lane width information to the second lane width information at a first switching speed. When the controller completes the lane change, it switches the lane width information used for controlling the yaw angle by gradually changing from the second lane width information to the first lane width information at a second switching speed that is lower than the first switching speed.

2. The vehicle control method according to claim 1, characterized in that, When the lane change begins, the controller switches the lane width information used for controlling the yaw angle from the first lane width information to the second lane width information.

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

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

5. The vehicle control method according to claim 4, characterized in that, For the controller Before the vehicle crosses the lane dividing line between the first lane and the second lane, the yaw angle is controlled based on the width information of the second lane in the first lane. After the vehicle crosses the lane divider, the yaw angle is controlled based on the second lane width information of the second lane.

6. The vehicle control method according to any one of claims 1 to 5, characterized in that, The controller sets the lateral movement of the vehicle up to the point where the lane change is completed, based on the second lane width information.

7. A vehicle control device, characterized in that, have: A camera that films the front of the vehicle; The controller controls at least the yaw angle of the vehicle. The controller performs the following processing: Before the autonomous vehicle begins to change lanes from the first lane to the second lane adjacent to the first lane, the lane dividing line information and lane width information in front of the vehicle are obtained from the camera, i.e., the first lane width information. Based on the lane dividing line information and the first lane width information, the yaw angle of the vehicle is controlled so that the vehicle travels within the lane. When the lane change begins, the lane width of the first lane and the lane width information of the second lane obtained from the map information are used to set a target driving trajectory based on the lane dividing line information and the second lane width information. The yaw angle is controlled based on the target driving trajectory to perform the lane change. After the lane change is completed, the yaw angle is controlled based on the lane dividing line information of the second lane and the first lane width information, so that the vehicle travels within the lane after the lane change. When the lane change is initiated, the controller switches the lane width information used for yaw angle control by gradually changing from the first lane width information to the second lane width information at a first switching speed. When the controller completes the lane change, it switches the lane width information used for controlling the yaw angle by gradually changing from the second lane width information to the first lane width information at a second switching speed that is lower than the first switching speed.

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