Vehicle control method and vehicle control device

Abstract

The vehicle control device of the present invention includes: a steering angle calculation unit (103) that calculates a target steering angle of the steering wheel of the vehicle so that the vehicle travels on a travel trajectory for lane change; a steering angle correction unit (104) that corrects the target steering angle based on a lane slope representing the slope of the road surface in the width direction of the lane on which the vehicle travels and an adjacent lane slope representing the slope of the road surface in the width direction of the adjacent lane that is the target of the vehicle's lane change; and a steering control unit (105) that performs steering control so that the steering angle of the steering wheel follows the corrected target steering angle.

Description

Technical Field

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

[0002] The following technique is known: a feedforward control term, a feedback control term, and an integral control term are added together, and an operation is performed on a target steering angle for the present vehicle to travel along a target travel line, and a steering assist control for applying a steering torque to a steering mechanism is performed in such a manner that the steering angle of the present vehicle follows the target steering angle (Patent Document 1).

[0003] The technique of Patent Document 1 determines whether the traveling road surface of the present vehicle has switched from a non-inclined road surface that is not laterally inclined to an inclined road surface that is laterally inclined based on a change amount per unit time of an inclination index value representing the lateral inclination degree of the traveling road surface of the present vehicle, and when it is determined that the switch has occurred, the control gain of the integral control term is set to a value higher than a normal value.

[0004] Prior Art Documents

[0005] Patent Document

[0006] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2020-040524

[0007] In the technique of Patent Document 1, after it is determined based on the inclination index value of the road surface on which the present vehicle actually travels that the traveling road surface of the present vehicle has switched to an inclined road surface, a steering assist control corresponding to a change in the slope in the width direction of the traveling road surface is performed. Therefore, in the technique of Patent Document 1, when changing lanes from the present lane to an adjacent lane having a different slope in the width direction from the present lane, there is a problem of a delay in the steering assist control corresponding to the change in the slope in the width direction from the present lane to the adjacent lane, and a lateral deviation of the present vehicle with respect to the target travel trajectory occurring based on the change in the slope between the lanes. Summary of the Invention

[0008] The problem to be solved by the present invention is to provide a vehicle control method and a vehicle control device that can suppress a lateral deviation of the present vehicle with respect to a target travel trajectory that occurs based on a change in the slope between lanes even when the slopes in the width direction are different between the present lane and an adjacent lane as a lane change target.

[0009] The present invention solves the above problems through the following processing: calculating the target steering angle of the steering wheel of the vehicle in such a way that the vehicle travels on a target travel trajectory for lane change, correcting the target steering angle based on the slope of the road surface in the width direction of the lane on which the vehicle is traveling (hereinafter referred to as the "own lane slope") and the slope of the road surface in the width direction of the adjacent lane that is the target of the lane change of the vehicle (hereinafter referred to as the "adjacent lane slope"), and performing steering control in such a way that the steering angle of the steering wheel follows the corrected target steering angle.

[0010] Advantages of the Invention.

[0011] According to the present invention, even if there is a difference in the slope in the width direction between the own lane and the adjacent lane that is the target of the lane change, it is possible to suppress the lateral deviation of the vehicle from the target travel trajectory that occurs due to the change in the slope between the lanes during the lane change. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a block diagram showing an embodiment of a vehicle control device of the vehicle of the present invention.

[0013] Figure 2 It is a diagram showing a situation of performing a lane change between lanes with different slopes in the width direction of the road surface.

[0014] Figure 3 It is a flowchart showing the sequence of vehicle control of the present embodiment.

[0015] Figure 4 It is shown Figure 3 A diagram of a subroutine of step 6 shown. DETAILED DESCRIPTION OF THE EMBODIMENT

[0016] Figure 1 It is a block diagram showing the structure of a vehicle control device 1 of the vehicle of the present embodiment (hereinafter also referred to as the "own vehicle"). The vehicle control device 1 of the present embodiment is an embodiment of implementing the vehicle control method of the present invention. As Figure 1 shown, the vehicle control device 1 of the present embodiment includes: a sensor 11, a vehicle position detection device 12, a map database 13, in-vehicle equipment 14, a navigation device 15, a notification device 16, an input device 17, a drive control device 18, and a control device 19. These devices are connected via an in-vehicle LAN such as CAN in order to receive and transmit information to each other. In addition, in the present embodiment, as long as the vehicle control device 1 includes at least the control device 19, the other structures are not limited to the above structure. For example, the map database 13 is not limited to being stored in the vehicle control device 1, and may be a database external to the vehicle control device 1.

[0017] The sensor 11 detects the environment around the vehicle. For example, the sensor 11 includes cameras such as a front camera that captures the front of the vehicle, a rear camera that captures the rear of the vehicle, and side cameras that capture the left and right sides of the vehicle. In this embodiment, the sensor 11 identifies lane boundary lines and the like through image recognition based on the images captured by the cameras. The lane boundary lines include white lines, yellow lines, dashed lines, double lines, and the like. In addition, the sensor 11 includes radars such as a front radar that detects obstacles in front of the vehicle, a rear radar that detects obstacles behind the vehicle, and side radars that detect obstacles present on the left and right sides of the vehicle. The sensor 11 outputs the detection results regarding the surrounding environment of the vehicle as surrounding environment information to the control device 19 at a prescribed cycle.

[0018] Furthermore, the sensor 11 detects the driving state of the vehicle. For example, the sensor 11 includes a vehicle speed sensor that detects the vehicle speed of the vehicle. The sensor 11 includes a steering angle sensor that detects the steering angle of the steering gear. In this embodiment, the steering angle sensor takes the neutral position of the steering wheel as a reference, outputs the steering angle when steering to the right with respect to the traveling direction of the vehicle as a positive value, and outputs the steering angle when steering to the left with respect to the traveling direction of the vehicle as a negative value. The neutral position is the reference position where the steering angle is zero and is the position of the steering wheel when the vehicle is traveling straight. In addition, the output of the steering angle sensor is not limited to this, and it may also output the steering angle when steering to the right with respect to the traveling direction of the vehicle as a negative value and the steering angle when steering to the left with respect to the traveling direction of the vehicle as a positive value.

[0019] In addition, the sensor 11 includes a distance sensor that obtains the distance to an object. The distance sensor includes a laser sensor and a depth camera, etc. The sensor 11 includes a yaw rate sensor that obtains the yaw rate of the vehicle about the center of gravity axis. The yaw rate sensor obtains the yaw rate generated when the vehicle turns. The sensor 11 includes a lateral acceleration sensor that detects the lateral acceleration of the vehicle. In this embodiment, the sensor 11 identifies the lane boundary line based on the image outside the vehicle captured by the side camera or the like, and measures the object distance that is the distance between the vehicle and the lane boundary line. The sensor 11 outputs the detection results related to the driving state of the vehicle as driving information to the control device 19 at a prescribed cycle. In addition, as the sensor 11, it may be a structure that uses one of the above-mentioned multiple sensors, or a structure that combines and uses two or more sensors.

[0020] The vehicle position detection device 12 includes a GPS unit, a gyro sensor, a vehicle speed sensor, etc. The vehicle position detection device 12 detects the radio waves transmitted from multiple communication satellites through the GPS unit, and periodically obtains the position information of the target vehicle (this vehicle). In addition, the vehicle position detection device 12 detects the current position of the target vehicle based on the obtained position information of the target vehicle, the angle change information obtained from the gyro sensor, and the vehicle speed obtained from the vehicle speed sensor. The vehicle position detection device 12 outputs the detected position information of the target vehicle to the control device 19 at a prescribed cycle.

[0021] The map database 13 is a database that stores map information including road information. The map database 13 is stored in a memory accessible from the control device 19. In the road information, each location on the map such as intersections and branch points is stored as a node, and the road section between nodes is stored as a road link. The road information includes road link information for each road link. A road link is composed of one or more lanes, and the traffic direction is specified for each lane. The road link information includes information such as the road type, width, number of lanes, curved road and the size of its curve (such as curvature or radius of curvature) of the road link. In addition, the road link information includes slope information. The slope information at least includes information related to the slope of the road surface in the width direction of the lane. Specifically, it is information indicating the size and orientation of the slope of the road surface in the width direction of the lane. The size of the slope is, for example, a value obtained by dividing the height difference between the left end and the right end of the lane in the width direction of the lane by the length of the width of the lane. The size of the slope is expressed in %. The orientation of the slope, for example, indicates a slope facing left when the right end of the lane is higher than the left end of the lane in the width direction of the lane, and indicates a slope facing right when the left end of the lane is higher than the right end of the lane in the width direction of the lane. For example, the slope information can use the average slope in the width direction of the lane. When the number of lanes of a road link is 2 or more, the slope information included in the road link includes information related to the slope of the road surface in the width direction of each lane. The slope of the road surface in the width direction of the lane includes, for example, the inclination provided on a curved road.

[0022] The in-vehicle device 14 is various devices mounted on the vehicle and operates through the driver's operation. Examples of such in-vehicle devices include a steering wheel, an accelerator pedal, a brake pedal, a direction indicator, a wiper, a lamp, a horn, and other specific switches. When the driver operates the in-vehicle device 14, its operation information is output to the control device 19.

[0023] The navigation device 15 acquires the current position information of the host vehicle from the host vehicle position detection device 12, overlaps the position of the host vehicle in the map information for navigation, and displays it on a display or the like. In addition, the navigation device 15 has a navigation function that, when a destination is set, sets a route to the destination and guides the set route to the driver. This navigation function displays the route on the map of the display and notifies the driver of the route by sound or the like.

[0024] The prompting device 16 includes, for example, various displays such as the display included in the navigation device 15, the display integrated in the interior rearview mirror, the display integrated in the instrument panel, and the head-up display projected on the windshield. In addition, the prompting device 16 includes devices other than the display, such as the speaker of the audio device and the seat device in which a vibrating body is embedded. The prompting device 16 notifies the driver of various prompting information according to the control of the control device 19.

[0025] The input device 17 is, for example, a button switch that can be input by the driver's manual operation, a touchpad arranged on the display screen, or a microphone that can be input by the driver's voice. In the present embodiment, by the driver operating the input device 17, setting information for the prompting information prompted by the prompting device 16 can be input. The input device 17 has switches used when the driver sets the ON / OFF of the autonomous speed control function and the autonomous steering control function included in the control device 19. For example, the switch for the autonomous steering control function includes a lane change switch for executing the lane change control function. The lane change switch is a button switch for instructing (consenting) the driver to start a lane change when the control device 19 confirms the start of the lane change to the driver. In addition, after the driver consents to start the lane change, the driver can cancel the consent of the control device 19 for the lane change proposal by operating the lane change switch for a longer time than a specified time.

[0026] In addition, the direction indicator lever or the switch of other in-vehicle devices 14 can also be used as the input device 17. For example, when the control device 19 proposes whether to automatically perform a lane change to the driver, if the driver operates the direction indicator lever, the host vehicle performs a lane change in the direction of the operated direction indicator lever. The input device 17 outputs the input setting information to the control device 19. In addition, in the present embodiment, the direction in which the host vehicle performs a lane change is not particularly limited, and the host vehicle can change lanes to an adjacent lane on the right side with respect to the traveling direction or an adjacent lane on the left side with respect to the traveling direction.

[0027] The drive control device 18 controls the running of the vehicle based on the target speed and the target steering angle output from the control device 19. The control contents executed by the drive control device 18 include autonomous speed control and autonomous steering control. In addition, the autonomous steering control includes lane keeping control, lane change control, and overtaking control. For example, when the drive control device 18 makes the vehicle travel at a constant speed at the target speed through autonomous speed control, in order to accelerate and decelerate, or maintain the running speed so that the vehicle becomes the target speed, it controls the actions of the drive mechanism and the brake. In addition, when the drive control device 18 makes the vehicle follow the preceding vehicle through autonomous speed control, it also controls the actions of the drive mechanism and the brake in the same way. In addition, the action control of the drive mechanism includes the action of the internal combustion engine in a gasoline vehicle, and includes the action of the drive motor for running in an electric vehicle system. In addition, in a hybrid vehicle, it includes the torque distribution between the internal combustion engine and the drive motor for running.

[0028] In addition, through autonomous steering control, the drive control device 18, in addition to the above-mentioned action control of the drive mechanism and the brake, also executes the steering control of the vehicle by controlling the action of the steering actuator so that the steering angle of the steering wheel of the vehicle follows the target steering angle. For example, when the drive control device 18 executes lane keeping control through autonomous steering control, it executes steering control so that the vehicle travels on the target travel trajectory along the lane, and controls the running position (lateral position) of the vehicle in the width direction. The lateral position of the vehicle is the position of the vehicle in the width direction of the lane (the width direction of the vehicle). In the present embodiment, the lateral position of the vehicle includes the lateral position of the vehicle relative to the lane boundary line and the lateral position of the vehicle relative to the target travel trajectory. The lateral position of the vehicle can be any position of the vehicle, for example, it is the center of gravity position of the vehicle in the width direction of the lane. In addition, when the drive control device 18 executes a lane change through autonomous steering control, it executes steering control so that the vehicle travels on the target travel trajectory for lane change, and controls the lateral position of the vehicle. In addition, as a vehicle control method of the drive control device 18, other known methods can also be adopted.

[0029] The control device 19 includes: a ROM that stores a program for controlling the running of the vehicle, a CPU that executes the program stored in the ROM, and a RAM that functions as an accessible storage device, etc. Additionally, as an operation circuit, an MPU, DSP, ASIC, FPGA, etc. can be used instead of or together with the CPU. The control device 19 controls the running of the vehicle through an autonomous speed control function and an autonomous steering control function. The autonomous steering control function includes, for example, a lane keeping function, a lane change function, and an overtaking function. The control device 19 executes each function through the cooperation of software and hardware for realizing the above-mentioned various functions or executing each process. The control device 19 generates a target running trajectory for the vehicle to run, calculates a target speed and a target steering angle so that the vehicle runs along the target running trajectory, and outputs the calculated target speed and target steering angle to the drive control device 18. In the present embodiment, the control device 19 executes the autonomous driving or driving assistance of the vehicle.

[0030] In the present embodiment, the control device 19 executes a steering angle correction control for correcting the target steering angle through the autonomous steering control function. The control device 19 is configured to include, as functional blocks: a slope information acquisition unit 100, a determination unit 101, a running trajectory generation unit 102, a steering angle calculation unit 103, a steering angle correction unit 104, and a steering control unit 105. First, the control device 19 acquires a lane slope indicating the slope of the road surface in the width direction of the lane on which the vehicle is running, and an adjacent lane slope indicating the slope of the road surface in the width direction of an adjacent lane adjacent to the lane. Next, the control device 19 determines whether the lane change start condition is satisfied. When it is determined that the lane change start condition is satisfied, a target running trajectory for lane change is generated, and a target steering angle is calculated so that the vehicle runs on the target running trajectory. The control device 19 corrects the target steering angle based on the lane slope and the adjacent lane slope. Then, the control device 19 performs a steering control so that the steering angle of the steering wheel follows the corrected target steering angle. Additionally, in the present embodiment, on the basis of dividing the functions of the control device 19 into 6 blocks, the functions of each functional block are described. However, the functions of the control device 19 do not necessarily need to be divided into 6 blocks, and can also be divided into 5 or fewer functional blocks or 7 or more functional blocks.

[0031] The slope information acquisition unit 100 acquires slope information of the lane where the vehicle is currently located and the slope information of the adjacent lane. The slope information acquisition unit 100 refers to the map database 13 to acquire the slope of the lane where the vehicle is currently located and the slope of the adjacent lane within a specified distance (for example, 2 km) along the traveling direction from the current position of the vehicle. For example, the slope information acquisition unit 100 acquires the slope of the lane where the vehicle is currently located and the slope of the adjacent lane at a specified cycle during driving. In addition, before the start of lane change, the slope information acquisition unit 100 regards the lane in which the vehicle is traveling as the lane where the vehicle is currently located to acquire the slope of the lane where the vehicle is currently located. During the period from the start of lane change to the end of lane change, the slope information acquisition unit 100 regards the lane in which the vehicle is traveling at the start of lane change as the lane where the vehicle is currently located to acquire the slope of the lane where the vehicle is currently located, and regards the lane to which the lane change is targeted as the adjacent lane to acquire the slope of the adjacent lane. For example, as an example of the scenario during the period from the start of lane change to the end of lane change, a scenario can be cited in which, during lane change, the vehicle end of the vehicle on the adjacent lane side of the lane change target exceeds the lane boundary line, a part of the vehicle is located on the adjacent lane, and the other part of the vehicle is located on the lane where the vehicle is currently located. In such a scenario, the slope information acquisition unit 100 regards the lane in which the vehicle is traveling at the start of lane change as the lane where the vehicle is currently located to acquire the slope of the lane where the vehicle is currently located, and regards the lane to which the lane change is targeted as the adjacent lane to acquire the slope of the adjacent lane. Then, when the lane change ends, the slope information acquisition unit 100 regards the adjacent lane of the lane change target, that is, the lane regarded as the adjacent lane before the lane change, as the lane where the vehicle is currently located to acquire the slope of the lane where the vehicle is currently located.

[0032] The determination unit 101 determines whether the lane change start condition is satisfied. For example, the determination unit 101 determines whether the lane change start condition is satisfied based on the surrounding environment information of the vehicle acquired by the sensor 11 and the position information of the vehicle acquired by the vehicle position detection device 12. Specifically, the determination unit 101 determines that the lane change start condition is satisfied when there is a space available for lane change on the adjacent lane based on the detection result of the obstacle on the adjacent lane to which the lane change is targeted detected by the sensor 11. In addition, the determination unit 101 determines that the lane change start condition is satisfied when the position of the vehicle reaches the lane change start position set on the route based on the position information of the vehicle detected by the vehicle position detection device 12. In addition, the determination unit 101 may also determine that the lane change start condition is satisfied when an instruction input for starting lane change is acquired from the driver via the input device 17. And the determination unit 101 may also determine that the lane change start condition is satisfied when operation information is acquired by the driver operating the turn signal lever.

[0033] In addition, the determination unit 101 determines whether the host vehicle has started a lane change. When the host vehicle has started a lateral movement for a lane change, that is, when the lateral position of the host vehicle has started to move along the target travel trajectory for the lane change, the determination unit 101 determines that the host vehicle has started a lane change. For example, when the lateral position of the host vehicle has moved a specified distance or more within a specified time from a specified determination start time, the determination unit 101 determines that the host vehicle has started a lane change. The specified determination start time is, for example, when it is determined that the lane change start condition is satisfied, or when the target speed and target steering angle for the lane change are output to the drive control device 18.

[0034] In addition, the determination unit 101 determines whether the vehicle end of the host vehicle has reached the lane boundary line between the host lane and the adjacent lane. For example, the determination unit 101 identifies the position of the lane boundary line through a side camera of the sensor 11 or the like, and determines that the vehicle end of the host vehicle has reached the lane boundary line when the side of the host vehicle on the adjacent lane side of the lane change target has reached the lane boundary line.

[0035] In addition, the determination unit 101 determines whether the lane change of the host vehicle has ended. When the lateral position of the host vehicle has reached the center line in the width direction of the adjacent lane of the lane change target, the determination unit 101 determines that the lane change of the host vehicle to the adjacent lane has ended. In addition, the determination unit 101 may also determine that the lane change to the adjacent lane has ended when the side of the host vehicle on the side opposite to the adjacent lane side of the lane change target has reached the lane boundary line between the host lane and the adjacent lane.

[0036] The travel trajectory generation unit 102 generates a target travel trajectory for the host vehicle to travel based on the position information of the host vehicle, the map information, the surrounding environment information of the host vehicle, and the travel information of the host vehicle. For example, when the drive control device 18 executes lane keeping control, the travel trajectory generation unit 102 generates a target travel trajectory for the host vehicle to travel on the center line of the host lane. In addition, when the drive control device 18 executes lane change control, the travel trajectory generation unit 102 generates a target travel trajectory for the lane change. Specifically, when it is determined by the determination unit 101 that the lane change start condition is satisfied, the travel trajectory generation unit 102 generates a target travel trajectory for the host vehicle to travel from the current position of the host vehicle to the center line of the adjacent lane. In addition, when it is determined by the determination unit 101 that the lane change has ended, the travel trajectory generation unit 102 regards the adjacent lane of the lane change target, that is, the lane regarded as the adjacent lane before the lane change, as the host lane, and generates a target travel trajectory for traveling on the center line of the host lane.

[0037] The rudder angle calculation unit 103 calculates the target rudder angle of the steering wheel of the vehicle so that the vehicle travels along the target travel trajectory. For example, the rudder angle calculation unit 103 calculates the target rudder angle based on the target travel trajectory and the current position of the vehicle (the lateral position of the vehicle).

[0038] The rudder angle correction unit 104 corrects the target rudder angle calculated by the rudder angle calculation unit 103. During the period when the vehicle travels along the own lane, the rudder angle correction unit 104 calculates a rudder angle correction amount based on the slope of the own lane through the lane keeping function, and corrects the target rudder angle based on the calculated rudder angle correction amount. For example, the greater the slope of the road surface in the width direction of the lane, the greater the horizontal component of gravity acts on the vehicle on the inclined road surface, and the greater the lateral deviation of the vehicle's lateral position relative to the target travel trajectory will be. The lateral deviation is the deviation amount between the lateral position of the vehicle and the target travel trajectory. The rudder angle correction amount is a correction amount for reducing the lateral deviation caused by the slope of the road surface in the width direction of the lane. In addition, the lateral deviation caused by the slope of the road surface in the width direction of the lane determines in which left or right direction the lateral deviation occurs relative to the target travel trajectory according to the orientation of the slope. For example, when the orientation of the slope in the width direction of the lane is to the left, the lateral position of the vehicle has a lateral deviation to the left relative to the target travel trajectory. In addition, when the orientation of the slope in the width direction of the lane is to the right, the lateral position of the vehicle has a lateral deviation to the right relative to the target travel trajectory.

[0039] For example, the rudder angle correction amount corresponding to the slope of the road surface in the width direction of the lane is set in the map in advance. The map represents the relationship between the magnitude and direction of the slope of the road surface in the width direction of the lane and the rudder angle correction amount. In this map, the magnitude (absolute value) of the rudder angle correction amount is set according to the magnitude of the slope of the road surface in the width direction of the lane, and whether the rudder angle correction amount is positive or negative is set according to the orientation of the slope of the road surface in the width direction of the lane. When the orientation of the slope in the width direction of the lane is to the left, the rudder angle correction amount is set to be positive, and when the orientation of the slope in the width direction of the lane is to the right, the rudder angle correction amount is set to be negative. In addition, in this map, when the magnitude of the slope of the road surface in the width direction of the lane is zero, the rudder angle correction amount is set to zero. The rudder angle correction unit 104 refers to this map and calculates the rudder angle correction amount based on the slope of the own lane (the magnitude and orientation of the slope of the own lane). Moreover, the rudder angle correction unit 104 corrects the target rudder angle by adding the calculated rudder angle correction amount to the target rudder angle. In addition, the relationship between the orientation of the slope and the positive or negative of the rudder angle correction amount is only an example, and the relationship between the orientation of the slope and the positive or negative of the rudder angle correction amount is not limited. For example, contrary to this embodiment, the rudder angle correction amount may be set to be negative when the orientation of the slope is to the left, and the rudder angle correction amount may be set to be positive when the orientation of the slope is to the right.

[0040] In addition, after the vehicle has started a lane change, the rudder angle correction unit 104 corrects the target rudder angle based on the slope of the current lane and the slope of the adjacent lane until the vehicle end of the vehicle reaches the lane boundary line. First, starting from when the vehicle starts a lane change, the rudder angle correction unit 104 calculates the target distance between the lane boundary line between the current lane and the adjacent lane and the vehicle at a prescribed cycle. Specifically, starting from when the vehicle starts lateral movement for a lane change, the rudder angle correction unit 104 calculates the target distance at a prescribed cycle based on the external image of the vehicle captured by the side camera of the sensor 11. The target distance is, for example, the distance between the lane boundary line and the side surface of the vehicle on the adjacent lane side of the lane change target. The target distance can also be the distance between the lane boundary line and the center of gravity of the vehicle.

[0041] Next, the rudder angle correction unit 104 determines the weighting for the slope of the current lane and the weighting for the slope of the adjacent lane respectively according to the calculated target distance. For example, the rudder angle correction unit 104 determines the weighting for the slope of the current lane as α (0 < α < 1), and determines the weighting for the slope of the adjacent lane as 1 - α. The value of α is a value determined according to the target distance, and the shorter the target distance, the smaller the value set. That is, the closer the vehicle is to the lane boundary line, the smaller the weighting for the slope of the current lane set by the rudder angle correction unit 104, and the larger the weighting for the slope of the adjacent lane set. In the present embodiment, each time the rudder angle correction unit 104 calculates the target distance, it sets the respective weightings for the slope of the current lane and the slope of the adjacent lane according to the target distance. Therefore, as the vehicle approaches the lane boundary line and the target distance becomes shorter, the weighting for the slope of the current lane is set smaller, and the weighting for the slope of the adjacent lane is set larger. The rudder angle correction unit 104 weights the obtained slope of the current lane (X a ) and the slope of the adjacent lane (X b ) respectively, and calculates the weighted slope (X c ). That is, the weighted slope (X c ) is obtained as shown in the following formula (1).

[0042] Formula (1)

[0043] X c = αX a + (1 - α)X b ……(1)

[0044] Then, the rudder angle correction unit 104 calculates the rudder angle correction amount based on the weighted gradient. The rudder angle correction amount based on the weighted gradient is calculated by the same method as the above-described calculation method of the rudder angle correction amount. At this time, the orientation of the weighted gradient is set according to the target distance. When the vehicle is at a distance greater than or equal to the specified distance from the lane boundary line, the steering control corresponding to the gradient of the own lane is prioritized, and the orientation of the weighted gradient is set to the orientation of the gradient of the own lane. In addition, when the vehicle is approaching the lane boundary line and the distance is less than the specified distance, the operation control corresponding to the gradient of the adjacent lane is prioritized, and the orientation of the weighted gradient is set to the orientation of the gradient of the adjacent lane. For example, when the value of α determined according to the target distance is less than 0.5, the orientation of the weighted gradient is set to the same orientation as the gradient of the adjacent lane, and when the value of α is 0.5 or more, the orientation of the weighted gradient is set to the same orientation as the gradient of the own lane.

[0045] For example, when the orientation of the gradient of the own lane is to the right and the orientation of the gradient of the adjacent lane is to the left, before the value of α becomes less than 0.5 due to the shortening of the target distance, the rudder angle correction unit 104 sets the orientation of the weighted gradient to the orientation of the gradient of the own lane (to the right) and sets the rudder angle correction amount to a negative value. Then, when the value of α becomes less than 0.5, the rudder angle correction unit 104 sets the orientation of the weighted gradient to the orientation of the gradient of the adjacent lane (to the left) and sets the rudder angle correction amount to a positive value. When the rudder angle correction amount based on the weighted gradient is calculated, the rudder angle correction unit 104 corrects the target rudder angle by adding the calculated rudder angle correction amount to the target rudder angle. In the present embodiment, during the period when the vehicle is traveling in the own lane, that is, before the vehicle enters the adjacent lane, in addition to the gradient of the own lane, the target rudder angle is calculated using the gradient of the adjacent lane and the steering control is performed. In particular, as the vehicle approaches the adjacent lane, the rudder angle correction amount can be made closer to the rudder angle correction amount for reducing the lateral deviation caused by the gradient of the adjacent lane through the weighting process. Thus, even if the gradients of the road surfaces in the width direction of the own lane and the adjacent lane are different, the steering control corresponding to the gradient of the adjacent lane can be performed.

[0046] In addition, in the present embodiment, not limited to weighting the gradient of the road surface in the width direction of the lane, after calculating the rudder angle correction amount based on the gradient of the road surface in the width direction of the lane, the rudder angle correction amount may be weighted. The rudder angle correction unit 104 first calculates the rudder angle correction amount based on the gradient of the own lane and the rudder angle correction amount based on the gradient of the adjacent lane. Next, the rudder angle correction unit 104 performs a weighting process of weighting the rudder angle correction amount based on the gradient of the own lane and the rudder angle correction amount based on the gradient of the adjacent lane according to the target distance, respectively. Then, the rudder angle correction unit 104 corrects the target rudder angle by adding the weighted rudder angle correction amount based on the gradient of the own lane and the weighted rudder angle correction amount based on the gradient of the adjacent lane to the target rudder angle.

[0047] In addition, when the determination unit 101 determines that the vehicle end of the host vehicle has reached the lane boundary line, the rudder angle correction unit 104 corrects the target rudder angle based on the adjacent lane gradient. The rudder angle correction amount based on the adjacent lane gradient is calculated by the same method as the above-described calculation method of the rudder angle correction amount. The rudder angle correction unit 104 corrects the target rudder angle by adding the calculated rudder angle correction amount to the target rudder angle. In addition, the method for correcting the target rudder angle is not limited to the above method. For example, from the time when it is determined that the vehicle end of the host vehicle has reached the lane boundary line until it is determined that the lane change of the host vehicle has ended, the rudder angle correction unit 104 may correct the target rudder angle based on the gradient of the host lane and the adjacent lane gradient. That is, as in the above method, the gradient information used to correct the target rudder angle is not changed according to the position of the host vehicle.

[0048] In addition, when the determination unit 101 determines that the lane change of the host vehicle has ended, the rudder angle correction unit 104 regards the lane that was regarded as the adjacent lane before the lane change, that is, the lane in which the host vehicle travels after the lane change, as the host lane to obtain the host lane gradient, and corrects the target rudder angle based on the obtained host lane gradient. In the present embodiment, when it is determined that the lane change has ended, the lane that was regarded as the adjacent lane before the lane change is regarded as the host lane. Accordingly, the rudder angle correction unit 104 obtains the gradient information obtained as the adjacent lane gradient as the host lane gradient, and calculates the rudder angle correction amount based on the host lane gradient. Then, the rudder angle correction unit 104 corrects the target rudder angle by adding the calculated rudder angle correction amount to the target rudder angle. In addition, the rudder angle correction unit 104 is not limited to the case where it is determined that the lane change of the host vehicle has ended, and may also use the host lane gradient when the lane that was regarded as the adjacent lane before the lane change is regarded as the host lane.

[0049] The steering control unit 105 performs steering control in such a manner that the rudder angle of the steering wheel of the host vehicle follows the target rudder angle calculated by the rudder angle calculation unit 103. In addition, when the target rudder angle is corrected by the rudder angle correction unit 104, the steering control unit 105 performs steering control in such a manner that the rudder angle of the steering wheel of the host vehicle follows the corrected target rudder angle. Specifically, the steering control unit 105 outputs a steering control instruction for causing the rudder angle of the steering wheel of the host vehicle to follow the target rudder angle to the drive control device 18.

[0050] In addition, in the present embodiment, the steering control unit 105 may perform driving control based on the target steering angle corrected by the steering angle correction unit 104 as feedforward control, and perform feedback control with respect to the lateral deviation of the vehicle from the target travel trajectory caused by the difference between the slope of the road surface in the width direction of the lane obtained from the map database 13 and the slope of the road surface in the width direction of the actual lane. In the feedforward control of the present embodiment, the steering angle correction amount is calculated based on the slope information obtained from the map database 13, and the calculated steering angle correction amount is used to correct the target steering angle. Therefore, when there is a difference between the slope information obtained from the map database 13 and the slope information of the road surface in the width direction of the actual lane, after the feedforward control, there may sometimes remain a lateral deviation of the vehicle from the target travel trajectory caused by this difference. The steering control unit 105 corrects this lateral deviation by feedback control.

[0051] Figure 2 It is a diagram showing a scenario of changing lanes between lanes with different slopes. Use Figure 2 to illustrate an application example of the vehicle control method of the present embodiment. Figure 2 It shows a scenario where the vehicle V changes lanes from the current lane L1 to the adjacent lane L2. In Figure 2 , the depth direction of the drawing is the traveling direction of the vehicle V, and the vehicle V starts changing lanes to the left with respect to the traveling direction from the vehicle position P1 on the current lane L1. When starting to change lanes, the lateral position of the vehicle V moves upward in the slope direction with respect to the current lane, and at the vehicle position P2, the vehicle end of the vehicle V reaches the lane boundary line B. Furthermore, the lateral position of the vehicle V moves downward in the slope direction with respect to the adjacent lane, and moves to the vehicle position P3. When the vehicle V moves to the vehicle position P3, the lane change ends. In a lane change scenario as Figure 2 shown, when the vehicle end (for example, the wheel on the adjacent lane side) of the vehicle V transfers from the current lane to the adjacent lane, the slope of the road surface in the width direction of the lane in which the vehicle V travels changes.

[0052] In the vehicle control method of the present embodiment, when the vehicle V is traveling on the present lane L1, the target steering angle is corrected using the slope information of the adjacent lane L2 which is the target for lane change. That is, according to the vehicle control method of the present embodiment, since the target steering angle is corrected using the slope of the present lane before the change and the slope of the adjacent lane after the change before the slope of the lane changes, even if the slope of the road surface in the width direction of the lane changes during the lane change, it is possible to perform the steering control corresponding to the slope of the adjacent lane L2 after the change. Thus, in the present embodiment, compared with the case of performing the steering control corresponding to the slope of the road surface in the width direction of the present lane, it is possible to suppress the lateral deviation of the present vehicle with respect to the target travel trajectory caused by the change in the slope between the lanes. Therefore, the vehicle control device of the present embodiment can stably execute the steering control of the present vehicle and improve the riding comfort of the present vehicle.

[0053] Next, the sequence of performing the vehicle control of the present embodiment will be described using Figure 3 the flowchart. Figure 3 FIG. is a flowchart showing the sequence of the vehicle control of the present embodiment. In the present embodiment, when the present vehicle starts to travel, the control device 19 starts the process from step S1. For example, it is assumed that a target travel trajectory for the travel of the present vehicle and a target steering angle for traveling along the target travel trajectory are set, and the present vehicle starts to travel along the target travel trajectory. In step S1, the control device 19 acquires slope information related to the slope of the present lane on which the present vehicle is traveling and the slope of the adjacent lane adjacent to the present lane during travel. For example, the control device 19 acquires each slope information using the map information stored in the map database 13. In step S2, the control device 19 determines whether the lane change start condition is satisfied. For example, the control device 19 determines whether the lane change start condition is satisfied based on the detection result of an obstacle on the adjacent lane which is the target for lane change detected by the sensor 11 and based on whether there is a space available for lane change on the adjacent lane.

[0054] In the case where the control device 19 determines that the lane change start condition is satisfied, the control device 19 proceeds to step S3. In the case where the control device 19 does not determine that the lane change start condition is satisfied, the control device 19 proceeds to step S14. In the present embodiment, when the present vehicle does not perform a lane change, the control device 19 corrects the target steering angle using the slope of the present lane instead of the slope of the adjacent lane. In step S3, the control device 19 generates a target travel trajectory for lane change. In step S4, the control device 19 calculates a target control amount including the target steering angle in such a manner that the present vehicle travels in the target travel trajectory generated in step S3. When the target control amount including the target steering angle is calculated, the control device 19 outputs the target control amount including the target steering angle to the drive control device 18.

[0055] In step S5, the control device 19 determines whether the host vehicle has started a lane change. For example, the control device 19 determines whether the host vehicle has started a lateral movement for a lane change, that is, whether the lateral position of the host vehicle has started to move along the target travel trajectory for the lane change, to determine whether the host vehicle has started a lane change. When it is determined by the control device 19 that the host vehicle has started a lane change, the process proceeds to step S6. When it is not determined by the control device 19 that the lane change has started, the process proceeds to step S14. In step S6, the control device 19 performs rudder angle correction control to correct the target rudder angle. The specific steps of the rudder angle correction control will be described later using Figure 4 In step S7, the control device 19 performs steering control of the host vehicle. Specifically, the control device 19 outputs a steering control instruction to the drive control device 18 in such a manner that the rudder angle of the steering wheel of the host vehicle follows the target rudder angle corrected in step S6. The drive control device 18 controls the operation of the steering actuator based on the steering control instruction.

[0056] In step S8, the control device 19 determines whether the vehicle terminal of the host vehicle has reached the lane boundary line. When it is determined by the control device 19 that the vehicle terminal of the host vehicle has reached the lane boundary line, the process proceeds to step S9. When it is not determined by the control device 19 that the vehicle end of the host vehicle has reached the lane boundary line, the process returns to step S6, and the control device 19 repeats the processes of steps S6 to S8 until an affirmative determination is made in step S8. In step S9, the control device 19 corrects the target rudder angle based on the slope of the adjacent lane. In step S10, the control device 19 performs steering control in such a manner that the rudder angle of the steering wheel of the host vehicle follows the target rudder angle corrected in step S9.

[0057] In step S11, the control device 19 determines whether the lane change has ended. For example, the control device 19 determines whether the lane change of the host vehicle to the adjacent lane has ended based on whether the lateral position of the host vehicle has reached the center line in the width direction in the adjacent lane that is the target of the lane change. When the control device 19 determines that the lane change has ended, it proceeds to step S12. When the control device 19 does not determine that the lane change has ended, it returns to step S9, and the control device 19 repeats the processes of step S9 to step S11 until a positive determination is made in step S11. In step S12, since the control device 19 determines that the lane change has ended, the lane that was regarded as the adjacent lane before the lane change is regarded as the host lane, and a target travel trajectory along the host lane is generated. In the subsequent steps S12 to S15, the control device 19 regards the lane that was regarded as the adjacent lane before the lane change as the host lane. In step S13, the control device 19 calculates a target steering angle in such a way as to travel along the target travel trajectory generated in step S12. In step S14, the control device 19 corrects the target steering angle calculated in step S13 based on the host lane gradient. In step S15, the control device 19 performs steering control in such a way that the steering angle of the steering wheel of the host vehicle follows the target steering angle corrected in step S14.

[0058] Next, the flowchart of Figure 4 is used to illustrate the subroutine of the steering angle correction control of the present embodiment. Figure 4 It is a diagram showing Figure 3 the subroutine of the steering angle correction control in step S6 shown in Figure 3 . When the control device 19 determines in step S5 of Figure 3 that the host vehicle has started a lane change, the control device 19 first enters step S61. In step S61, the control device 19 calculates the object distance between the lane boundary line between the host lane and the adjacent lane and the host vehicle. In step S62, the control device 19 determines the weights for the host lane gradient and the adjacent lane gradient obtained in step S1 of Figure 3 respectively according to the object distance calculated in step S61. For example, the shorter the object distance, that is, the closer to the lane boundary line, the smaller the weight set by the control device 19 for the host lane gradient and the larger the weight for the adjacent lane gradient. In step S63, the control device 19 calculates a steering angle correction amount for correcting the target steering angle calculated in step S4 of Figure 3 . For example, the control device 19 calculates a weighted gradient by weighting the host lane gradient and the adjacent lane gradient, and calculates a steering angle correction amount based on the weighted gradient. In step S64, the control device 19 corrects the target steering angle by adding the steering angle correction amount calculated in step S63 to the target steering angle. After correcting the target steering angle in step S64, it exits Figure 4The shown subroutine enters Figure 3 step S7 of

[0059] As described above, in the present embodiment, the control device 19 calculates the target steering angle of the steering wheel of the vehicle in such a way that the vehicle travels on a target travel trajectory for lane change, and corrects the target steering angle based on the own lane slope indicating the road surface slope in the width direction of the own lane on which the vehicle travels and the adjacent lane slope indicating the road surface slope in the width direction of the adjacent lane that is the target of the vehicle lane change, and performs steering control in such a way that the steering angle of the steering wheel follows the corrected target steering angle. Thus, even if the slopes in the width direction of the own lane and the adjacent lane that is the target of the lane change are different, it is possible to suppress the lateral deviation of the vehicle with respect to the target travel trajectory that occurs based on the slope difference between the lanes during the lane change.

[0060] In addition, in the present embodiment, the control device 19 calculates the object distance between the lane boundary line between the own lane and the adjacent lane and the vehicle at a prescribed cycle, and determines the weights for the own lane slope and the adjacent lane slope respectively according to the calculated object distance, and corrects the target steering angle based on the weighted own lane slope and adjacent lane slope. Thus, since the weights of the slope of the own lane and the slope of the adjacent lane change according to the distance to the adjacent lane, even if the slope in the width direction between the lanes changes, it is possible to suppress the lateral deviation of the vehicle with respect to the target travel trajectory that occurs during the change.

[0061] In addition, in the present embodiment, the control device 19 uses the map information to acquire the information on the own lane slope and the adjacent lane slope. Thus, it is possible to acquire not only the slope of the lane on which the vehicle actually travels, but also the slope of the adjacent lane in advance before traveling in the adjacent lane.

[0062] In addition, in the present embodiment, the control device 19 calculates the object distance at a prescribed cycle from when the vehicle starts to move laterally for lane change. Thus, it is possible to perform steering angle control considering the slope of the adjacent lane from when the vehicle starts to move laterally for lane change, so even if the slope of the lane on which the vehicle travels changes, it is possible to suppress the lateral deviation of the vehicle with respect to the target travel trajectory that occurs during the change.

[0063] In addition, in the present embodiment, the control device 19 determines whether the lane change of the vehicle has ended. When it is determined that the lane change of the vehicle has ended, the target steering angle is calculated in such a way that the vehicle travels along the target travel trajectory of the lane that was regarded as the adjacent lane before the lane change, and the target steering angle is corrected based on the slope of the road surface in the width direction of the lane that was regarded as the adjacent lane before the lane change. Thus, after the lane change, it is possible to perform steering angle control corresponding to the slope of the lane in which the vehicle is traveling.

[0064] In addition, the embodiments described above are described for the purpose of facilitating understanding of the present invention and are not described for the purpose of limiting the present invention. Therefore, the gist of each element disclosed in the above embodiments also includes all design changes and equivalents belonging to the technical scope of the present invention.

[0065] For example, in the present embodiment, the correction of the target steering angle using the slope of the own lane and the slope of the adjacent lane during the lane change is described, but it is not limited thereto. Even during the lane change, when there is no slope of the road surface in the width direction in the own lane, that is, when it is zero, the target steering angle may be corrected using only the slope of the adjacent lane without using the slope of the own lane. In this case, the control device 19 determines the weight for the slope of the adjacent lane to be a larger value as the object distance between the vehicle and the lane boundary line is shorter, and calculates the steering angle correction amount based on the weighted slope of the adjacent lane. In addition, in the present embodiment, even during the lane change, when there is no slope of the road surface in the width direction in the adjacent lane, that is, when it is zero, the target steering angle may be corrected using only the slope of the own lane without using the slope of the adjacent lane. In this case, the control device 19 determines the weight for the slope of the own lane to be a smaller value as the object distance between the vehicle and the lane boundary line is shorter, and calculates the steering angle correction amount based on the weighted slope of the own lane.

[0066] Symbol Explanation

[0067] 1: Vehicle control device

[0068] 11: Sensor

[0069] 12: Own vehicle position detection device

[0070] 13: Map database

[0071] 18: Drive control device

[0072] 19: Control device

[0073] 100: Slope information acquisition unit

[0074] 101: Determination unit

[0075] 102: Travel trajectory generation unit

[0076] 103: Rudder Angle Calculation Unit

[0077] 104: Rudder Angle Correction Unit

[0078] 105: Steering Control Unit

Claims

1. A vehicle control method, which is executed by a controller, wherein, the controller performs the following processing: calculating a target steering angle of the steering wheel of the vehicle in such a manner that the vehicle travels on a target travel trajectory for lane change, before the vehicle enters an adjacent lane that is the target of the vehicle's lane change, correcting the target steering angle during the vehicle's travel in the own lane based on the own lane slope representing the slope of the road surface in the width direction of the own lane in which the vehicle travels, using the adjacent lane slope representing the slope of the road surface in the width direction of the adjacent lane, performing steering control in such a manner that the steering angle of the steering wheel follows the corrected target steering angle.

2. The vehicle control method according to claim 1, wherein, the controller performs the following processing: calculating an object distance between the lane boundary line between the own lane and the adjacent lane and the vehicle at a prescribed period, respectively determining the weights for the own lane slope and the adjacent lane slope according to the calculated object distance, correcting the target steering angle based on the weighted own lane slope and adjacent lane slope.

3. The vehicle control method according to claim 1 or 2, wherein, the controller acquires information on the own lane slope and the adjacent lane slope using map information.

4. The vehicle control method according to claim 2, wherein, the controller calculates the object distance at a prescribed period from when the vehicle starts lateral movement for the lane change.

5. The vehicle control method according to any one of claims 1, 2, and 4, wherein, the controller performs the following processing: determining whether the lane change of the vehicle has ended, in the case where it is determined that the lane change of the vehicle has ended, calculating the target steering angle in such a manner that the vehicle travels on the target travel trajectory along the lane that was regarded as the adjacent lane before the lane change, correcting the target steering angle based on the slope of the road surface in the width direction of the lane that was regarded as the adjacent lane before the lane change.

6. A vehicle control device, wherein, it includes: a steering angle calculation unit that calculates a target steering angle of the steering wheel of the vehicle in such a manner that the vehicle travels on a travel trajectory for lane change; a steering angle correction unit that corrects the target steering angle during the vehicle's travel in the own lane based on the own lane slope representing the slope of the road surface in the width direction of the own lane in which the vehicle travels, using the adjacent lane slope representing the slope of the road surface in the width direction of the adjacent lane, before the vehicle enters an adjacent lane that is the target of the vehicle's lane change; a steering control unit that performs steering control in such a manner that the steering angle of the steering wheel follows the corrected target steering angle.

Images