Driving assistance method and driving assistance device

Abstract

In the present application, in a case where autonomous lane change control that performs a lane change from a lane in which a host vehicle is traveling to an adjacent lane in a direction corresponding to an operation of a direction indicator lever of a direction indicator of the vehicle (V) performed by a driver of the vehicle (V) is executed, when it is determined that there is no adjacent lane in the direction corresponding to the operation performed by the driver, the driver is not notified that the lane change based on the autonomous lane change control cannot be performed.

Description

Technical Field

[0001] This invention relates to driving assistance methods and driving assistance devices. Background Technology

[0002] An autonomous driving device is known to automatically change lanes when instructed to do so and when lane change permission conditions are met (Patent Document 1). In this autonomous driving device, it determines whether the road area serving as the target lane is a shoulder area. If it determines that the road area serving as the target lane is a shoulder area, it prohibits lane change and issues a message or alarm expressing this meaning.

[0003] Existing technical documents Patent documents

[0004] Patent Document 1: Japanese Patent Application Publication No. 2018-140750 Summary of the Invention

[0005] The technical problem that the invention aims to solve

[0006] For example, a vehicle is traveling in the left lane of a two-lane road with left-hand traffic. This left lane branches into a main lane to the right of the direction of travel and a branch lane to the left of the direction of travel. When the vehicle enters the branch lane, the driver operates the turn signal stalk, causing the left-side turn signal indicator to flash from near the branch location, indicating the vehicle's intention to enter the branch lane to other vehicles. If the aforementioned prior art is applied to this driving scenario, the operation of the turn signal stalk is interpreted as an instruction to change lanes to the adjacent lane. Since there is no lane for vehicles traveling to the left of the direction of travel, the driver is notified that a lane change to the left of the direction of travel is not possible.

[0007] However, in the above driving scenario, there is a problem: the driver is aware that it is not possible to change lanes to the left in the direction of travel when the driver is close to the branch position, and operates the directional indicator to express the intention to enter the branch lane from the main lane to other vehicles around, but still informs the driver that it is not possible to change lanes to the adjacent lane, which is unnecessary information.

[0008] The technical problem to be solved by the present invention is to provide a driving assistance method and driving assistance device that can suppress the notification of unnecessary information to the driver.

[0009] Technical solutions for solving technical problems

[0010] The present invention solves the above-mentioned technical problem by means of the following solution: when autonomous lane change control is performed to change lanes from the current lane of the vehicle to the adjacent lane in the direction corresponding to the driver's operation based on the driver's operation of the direction indicator lever of the vehicle's direction indicator, if it is determined that there is no adjacent lane in the direction corresponding to the driver's operation, the driver is not notified that lane change based on autonomous lane change control cannot be performed.

[0011] The effects of the invention

[0012] According to the present invention, it is possible to suppress the notification of unnecessary information to the driver. Attached Figure Description

[0013] Figure 1 This is a block diagram illustrating an example of an embodiment of the driving assistance system of the present invention.

[0014] Figure 2 It means Figure 1 A front view of a portion of the input device.

[0015] Figure 3 It means by Figure 1 A top view of an example of autonomous lane change control performed by a driver assistance system.

[0016] Figure 4 It means Figure 1 A block diagram illustrating the state transitions of a driver assistance device.

[0017] Figure 5 It means through Figure 1 A top-down view of an example of a driving scenario where a driver assistance system performs autonomous driving control.

[0018] Figure 6 It means Figure 1 A flowchart illustrating an example of the processing steps in a driver assistance system. Detailed Implementation

[0019] Hereinafter, embodiments of the present invention will be described based on the accompanying drawings. It should be noted that the following description assumes that vehicles travel on the left in countries with left-hand traffic regulations. In countries with right-hand traffic regulations, vehicles travel on the right; therefore, the terms "right" and "left" in the following description will be interchanged symmetrically.

[0020] [Composition of Driver Assistance Systems] Figure 1This is a block diagram illustrating an example of an embodiment of the driving assistance system of the present invention. The driving assistance system enables the vehicle to travel from its current location to a destination set by the vehicle's occupants through autonomous driving control. Autonomous driving control refers to the autonomous control of the vehicle's driving actions, including all driving actions such as acceleration, deceleration, starting, stopping, and steering. Furthermore, the driving assistance system provides the vehicle's occupants with information related to autonomous driving control.

[0021] like Figure 1 As shown, the driving assistance system 10 of this embodiment includes a camera device 11, a ranging device 12, an onboard sensor 13, a map database 14, a vehicle position detection device 15, a navigation device 16, an input device 17, an actuator 18, a display device 19, and a driving assistance device 20. The devices constituting the driving assistance system 10 are connected in a communicable manner via CAN (Controller Area Network) and other onboard LANs, and send and receive information to each other.

[0022] The camera device 11 is a camera equipped with imaging elements such as a CCD, which captures images of objects around the vehicle and generates images containing those objects. The camera device 11 can also be an infrared camera, a stereo camera, or the like. In addition, to suppress blind spots where objects cannot be captured, multiple camera devices 11 are installed in the vehicle's front grille, exterior rearview mirrors, rear bumper, and other areas.

[0023] The ranging device 12 detects the relative distance and relative speed between the vehicle and the object. The ranging device 12 includes lidar, millimeter-wave radar, LiDAR (light detection and ranging) units, etc. To suppress blind spots where objects cannot be detected, multiple ranging devices 12 are installed in one vehicle.

[0024] The camera device 11 and the ranging device 12 detect objects existing in and around the road, including lane boundary lines, center lines, road markings, central dividers, guardrails, curbs, traffic lights, pedestrian crossings, etc. Additionally, the objects also include other vehicles, motorcycles, bicycles, pedestrians, and other obstacles that may affect the vehicle's movement. It should be noted that the vehicle (this vehicle) is not specifically limited.

[0025] The driver assistance device 20 acquires image information from the camera device 11 and position information of objects from the ranging device 12 to identify objects and the driving environment around the vehicle. The information acquisition by the driver assistance device 20 is performed at predetermined time intervals (e.g., every 0.1 milliseconds to 1 millisecond). It should be noted that the driver assistance device 20 can also integrate or synthesize the information acquired from the camera device 11 and the ranging device 12 to identify the driving environment.

[0026] The vehicle-mounted sensors 13 detect the vehicle's driving status. These sensors include a vehicle speed sensor, an acceleration sensor, a yaw rate sensor, and a steering angle sensor. Furthermore, the vehicle-mounted sensors 13 include a touch sensor (electrostatic capacitive sensor) that detects the driver's holding of the steering wheel. Known sensors can be used without particular limitation, and their configuration and number can be appropriately set within a range that allows for adequate detection of the vehicle's driving status. The driver assistance device 20 acquires the detection results from each sensor at predetermined time intervals (e.g., every 0.1 milliseconds to 1 millisecond).

[0027] Map database 14 is a storage medium containing map information, located either inside or outside the vehicle. The driving assistance device 20 retrieves map information from map database 14 as needed. The map information includes nodes corresponding to specific locations (intersections, etc.) on roads where the vehicle's direction of travel changes, and information about road segments connecting these nodes. Node information includes location information, information related to entering and exiting intersections, etc., while road segment information includes road width, road curvature radius, shoulder structures, and traffic regulations. Furthermore, the map information can also be high-precision map information capable of tracking the movement trajectory of each lane.

[0028] The vehicle position detection device 15 is a positioning system that detects the current position of the vehicle, for example, by calculating the current position of the vehicle based on radio waves received from satellites used by GPS (Global Positioning System). Furthermore, the vehicle position detection device 15 can also estimate the current position of the vehicle based on vehicle speed and acceleration information obtained from the onboard sensor 13, and calculate the current position of the vehicle by comparing the estimated current position with map information.

[0029] The navigation device 16, referring to map information, calculates the driving route from the vehicle's current position detected by the vehicle position detection device 15 to the destination set by the occupants. The driving route includes at least information about the road, lane, and direction of travel, for example, displayed as a line. The calculated driving route is obtained by the driver assistance device 20.

[0030] The input device 17 is a device for passengers to input instructions to the driver assistance device 20, including a button switch that the driver can manually operate to input, a touch panel disposed on the display device 19, and a microphone that the driver can use for voice input. Figure 2 This is a front view showing a portion of the input device 17, showing a part of the push-button switch assembly provided on the spokes of the steering wheel, etc. Figure 2 The input device 17 shown is used to set the autonomous driving control (especially autonomous speed control and autonomous steering control) of the driving assistance device 20 to be turned on or off.

[0031] like Figure 2 As shown, the input device 17 includes a main switch 171, a resume / accelerate switch 172, a set / decelerate switch 173, a cancel switch 174, a distance adjustment switch 175, and a lane change assist switch 176.

[0032] The main switch 171 is used to turn the power to / from the system that enables autonomous driving control of the driving assistance device 20. The resume / accelerate switch 172 is used to restart autonomous speed control at the set speed before stopping or to increase the set speed after stopping (disabling) autonomous speed control. The set / decelerate switch 173 is used to start autonomous speed control at the current driving speed or to decrease the set speed. The cancel switch 174 is used to stop (disable) autonomous speed control. The distance adjustment switch 175 is used to set the distance to the vehicle ahead. The lane change assist switch 176 is used to indicate (agree to) lane change when the driving assistance device 20 confirms to the driver that a lane change has begun.

[0033] It should be noted that, in addition to Figure 2 In addition to the button switch group shown, the direction indicator stalk of the direction indicator or other in-vehicle equipment switches can also be used as input device 17. For example, when the driver assistance device 20 provides a suggestion on whether to automatically change lanes, when the driver operates the direction indicator stalk, instead of performing the suggested lane change, the driver changes lanes in the direction in which the direction indicator stalk is operated. The setting information input to input device 17 is obtained by the driver assistance device 20.

[0034] return Figure 1 The actuator 18 is a device that converts the electrical control signals input from the driving assistance device 20 into mechanical work, including servo motors, hydraulic motors, hydraulic cylinders, etc. The actuator 18 causes the vehicle's drive and steering systems to operate.

[0035] Display device 19 provides information to the occupants of the vehicle. Display device 19 may be a projector such as an LCD display or head-up display installed on the dashboard, and may also include an input device for the occupants to input instructions to the driver assistance device 20 and a speaker as an output device.

[0036] The driver assistance device 20 controls the devices constituting the driver assistance system 10 and coordinates them to perform autonomous driving control of the vehicle. The driver assistance device 20 uses devices mounted on the vehicle to perform autonomous control of driving actions, controlling the driving actions within a predetermined range. For driving actions not controlled by the driver assistance device 20, the driver performs manual operation. Furthermore, when the driver manually drives the vehicle, the driver assistance device 20 does not perform autonomous control of driving actions; the driver controls the vehicle's driving actions.

[0037] The driving assistance device 20 is, for example, a computer, which includes a CPU (Central Processing Unit) as a processor, a ROM (Read Only Memory) storing programs, and RAM (Random Access Memory) functioning as an accessible storage device. The CPU is an operating circuit used to execute the programs stored in the ROM and implement the functions of the driving assistance device 20.

[0038] [Functions of driver assistance devices] The ROM of the driving assistance device 20 stores a program for autonomous driving control of the vehicle, and the CPU of the driving assistance device 20 executes this program to perform autonomous driving control. Figure 1 In this context, for the sake of convenience, the functional modules used to perform autonomous driving control are extracted and represented as decision unit 21 and auxiliary unit 22.

[0039] The determination unit 21 reads various information, including image information captured by the camera device 11, position information of objects determined by the ranging device 12, detection information detected by the vehicle-mounted sensor 13, map information stored in the map database 14, current position information detected by the vehicle position detection device 15, and information on the driving route set by the navigation device 16. Based on this information, it identifies the current state of the driving environment surrounding the vehicle. Furthermore, based on the identified current state of the driving environment, the determination unit 21 performs various determinations required by the auxiliary unit 22 to execute autonomous driving control.

[0040] Based on the determination result of the determination unit 21, the auxiliary unit 22 drives the vehicle through autonomous driving control and provides the necessary information to the vehicle occupants. For example, based on image information obtained by the camera device 11 and the position information of objects obtained by the ranging device 12, the auxiliary unit 22 generates a driving trajectory for driving the vehicle along the driving path and generates a control signal for actuating the actuator 18 to drive the vehicle along the driving trajectory. In addition, the auxiliary unit 22 generates notification information about autonomous driving control to the vehicle occupants and outputs it to the display device 19.

[0041] As part of autonomous driving control, the auxiliary unit 22 performs autonomous speed control, which autonomously controls the vehicle's speed, and autonomous steering control, which autonomously controls the vehicle's steering. Autonomous speed control includes distance control and constant speed driving. Specifically, when a vehicle ahead is detected by the distance measuring device 12 or similar device, the auxiliary unit 22 performs distance control, maintaining a distance between the vehicle and the vehicle at a speed set by the driver, up to a maximum speed. Conversely, when no vehicle ahead is detected by the distance measuring device 12 or similar device, the vehicle maintains a constant speed set by the driver.

[0042] When autonomous speed control is in effect, the driver operates... Figure 2 The desired driving speed is input via the recovery / acceleration switch 172 or the setting / deceleration switch 173. Furthermore, the driver's desired inter-vehicle distance is determined by operating... Figure 2 Use the distance adjustment switch 175 shown to set the distance.

[0043] In distance control, the detection result of the distance measuring device 12 is fed back, and the actuator 18 controls the operation of the drive devices such as the engine and brakes at a set driving speed as the upper limit, thereby maintaining the set inter-vehicle distance. On the other hand, in speed control, the detection result of the vehicle speed sensor is fed back, and the actuator 18 controls the operation of the drive devices such as the engine and brakes, thereby maintaining the set driving speed.

[0044] In autonomous steering control, when the conditions specified in the execution of autonomous speed control are met, the actuator 18 controls the movement of the steering device. The auxiliary unit 22 performs lane keeping control and autonomous lane changing control as part of the autonomous steering control.

[0045] Lane keeping control is a control mechanism that maintains the vehicle's movement within its lane. In lane keeping control, the actuator 18 controls the steering mechanism to keep the vehicle near the center of the lane, thereby assisting the driver's steering operations.

[0046] Autonomous lane change control refers to the control that allows a vehicle to change lanes from its current lane to an adjacent lane in the direction corresponding to the driver's input, through autonomous driving control. In autonomous lane change control, if the driver operates the direction indicator stalk, the direction indicator flashes. If the preset lane change initiation conditions are met, a series of processes for automatic lane change (hereinafter also referred to as LCP) begins. The direction indicator stalk is a rod-shaped operating component mounted on the side of the steering column, which can be operated in the direction of rotation of the steering wheel (direction indication) and in the near and inside directions (high beam / low beam).

[0047] If the turn signal stalk is turned clockwise in the direction of rotation, the turn signal indicator on the right side of the vehicle's direction of travel will flash. If the turn signal stalk is turned counterclockwise, the turn signal indicator on the left side of the vehicle's direction of travel will flash. To change lanes to the adjacent lane to the left of the direction of travel using the autonomous lane change control, the driver should not turn the steering wheel but should turn the turn signal stalk in the direction corresponding to the left turn signal indicator (counterclockwise). To change lanes to the adjacent lane to the right of the direction of travel using the autonomous lane change control, the driver should turn the turn signal stalk in the direction corresponding to the right turn signal indicator (clockwise).

[0048] The determination unit 21 determines whether the lane change initiation condition is met based on the current state of the identified driving environment. There are no particular limitations on the lane change initiation condition, but examples include being in lane keeping mode with the driver holding the steering wheel, the driver holding (touching) the steering wheel for a specified time (e.g., 5 to 20 seconds) or more, the vehicle speed being a specified speed (e.g., 50 to 80 km / h) or more, the existence of a lane in the direction of lane change, the existence of space for lane change in the lane that is the target lane, the lane boundary line being of a type that allows lane change, the radius of curvature of the road on which the vehicle is traveling being a specified radius (e.g., 200 to 300 m) or more (i.e., not a sharp turn), and less than 1 second from when the driver operates the direction indicator stick, etc.

[0049] In addition, the lane keeping mode in hand-held mode refers to the state where autonomous speed control and lane keeping control are in operation and the driver's holding of the steering wheel is detected, which will be explained in detail later.

[0050] Furthermore, in autonomous lane change control, the direction indicator can flash when the driver operates a switch different from the direction indicator stalk (hereinafter also referred to as the lane change switch), and LCP can be initiated when the preset lane change start conditions are met. That is, in this embodiment, the driver's operation of the direction indicator stalk or the lane change switch outputs an execution instruction for autonomous lane change control to the driver assistance device 20.

[0051] Lane change switches are, for example, push-button switches mounted on the steering wheel; specifically, they are... Figure 2 The lane change assist switch 176 is shown. If the lane change assist switch 176 is operated when the driver assistance device 20 confirms to the driver that a lane change has begun, an instruction to agree to begin the lane change is output to the driver assistance device 20 (determination unit 21), and the determination unit 21 determines whether the conditions for starting the lane change are met.

[0052] Hereinafter, the operation of the turn signal stalk will be referred to as the first operation, and the operation of the lane change switch will be referred to as the second operation. Furthermore, the direction corresponding to the driver's operation will be referred to as the corresponding direction. For example, if the driver operates the turn signal stalk in the direction corresponding to the left turn signal (counterclockwise), the leftward direction of the travel direction will be referred to as the corresponding direction. Additionally, the direction corresponding to the driver's first operation will be referred to as the first direction, and the direction corresponding to the driver's second operation will be referred to as the second direction.

[0053] It should be noted that autonomous lane change control can be initiated not only through driver operation, but also by suggesting autonomous lane change control to the driver via the driver assistance device 20, and initiating the control upon the driver's consent. For example, consent to autonomous lane change control can be input via the direction indicator stick.

[0054] Figure 3 It means by Figure 1 A top view of an example of autonomous lane change control performed by the driver assistance system 10. Figure 3 In the driving scenario shown, a road with two lanes on one side, lanes L1 and L2, extends in the left-right direction as shown in the attached diagram. Lane L1 branches at point Z into lane L1 as the main lane and lane L3 as a branch lane. Figure 3 In the road shown, vehicles are traveling from left to right in the attached diagram.

[0055] exist Figure 3 In the driving scenario shown, vehicle V is traveling at position P1 in lane L1, heading towards destination X1, which is located ahead of lane L2. Additionally, in Figure 3 In the driving scenario shown, the power supply of the system that realizes autonomous driving control is on. Since the conditions described later are met, autonomous lane change control can be performed. After vehicle V travels along the driving trajectory T1 from position P1 to position P2, at position P2, the driver of vehicle V operates the direction indicator of vehicle V, causing the direction indicator on the right side of vehicle V to flash.

[0056] In this case, the determination unit 21 detects the space of lane L2 (adjacent lane) in the corresponding direction relative to lane L1 (this lane) based on the image information captured by the camera device 11 and the position information of the object measured by the ranging device 12. Figure 3 In the driving scenario shown, there are no other vehicles traveling in lane L2, therefore, space for vehicle V to enter is detected in lane L2. Therefore, if the autonomous driving control mode is the handheld lane keeping mode, the handheld detection is in progress, the vehicle speed is above the specified speed, the lane boundary line between lanes L1 and L2 is of a type that allows lane changing, the road curvature radius is above the specified radius, and the driver operates the steering wheel within 1 second, then the lane changing initiation condition is met.

[0057] When the lane change initiation conditions are met, the auxiliary unit 22 initiates lane change control (LCP) via autonomous lane change control. This LCP includes the lateral movement of the vehicle V towards the adjacent lane (i.e., lane L2) and the lane change maneuver (hereinafter, LCM) involving actual movement across the lane boundary line towards lane L2. Specifically, the auxiliary unit 22 generates... Figure 3 The driving trajectory T2 is shown, and a control signal is generated to make the actuator 18 move so that the vehicle V moves from position P2 along the driving trajectory T2 to position P6.

[0058] The assist unit 22 begins lateral movement towards lane L2 at position P3 and initiates lane keeping control (LCM) at position P4. During the journey from position P3 to position P4, the steering wheel of vehicle V is rotated clockwise to the right of the direction of travel via actuator 18. After crossing the lane boundary line, during the journey to position P5, the steering wheel of vehicle V is rotated counterclockwise to the left of the direction of travel via actuator 18. At position P5, the steering wheel returns to the neutral position, and the direction indicator is extinguished. The driver assistance device 20 completes LCM at position P5, completes LCP at position P6, and restarts lane keeping control. Thus, lane change control from lane L1 to lane L2 is completed. During the execution of autonomous lane change control, the assist unit 22 notifies the driver of the lane change being performed using the display device 19.

[0059] Furthermore, the LCP based on the aforementioned autonomous lane change control performs the same actions for both the first and second operations. However, in the case of the second operation, the flashing of the direction indicator is controlled by the driver assistance device 20. That is, the driver assistance device 20 keeps the direction indicator flashing continuously during the journey from position P3 to position P5, and turns it off at position P5.

[0060] Figure 4 It is a block diagram representing the state transitions of various functions established in the driving assistance device 20. Figure 4The system shown refers to the autonomous driving control system implemented by the driving assistance device 20.

[0061] First, if from Figure 4 The system is shown as being in a closed state. Turning on the main switch puts the system into a standby state. The main switch is a switch that turns the power to the system that enables autonomous speed control and autonomous steering control of the driver assistance device 20 on / off; for example, it is located on the steering wheel.

[0062] Autonomous speed control is initiated by turning on the set / deceleration switch 173 or the resume / acceleration switch 172 from the standby state. Thus, the aforementioned constant speed control or distance control begins, allowing the driver to move the vehicle V without pressing the accelerator pedal or brake simply by operating the steering wheel.

[0063] During the execution of autonomous speed control, when Figure 4 When condition (1) is met, the lane keeping mode is entered into autonomous steering control / hand grip mode. As for condition (1), examples include the driver holding the steering wheel when the lane boundary lines on both sides of the vehicle V are detected, the vehicle V is driving near the center of the lane, the steering indicator is not activated, and the wipers are not activated at high speed (HI).

[0064] The hands-on mode refers to a mode where the autonomous steering control does not engage if the driver does not hold the steering wheel, while the hands-free mode refers to a mode where the autonomous steering control engages even if the driver removes their hands from the steering wheel. The driver's holding of the steering wheel is detected by touch sensors on the steering wheel.

[0065] During the execution of lane keeping mode in autonomous steering control / hand grip mode, when Figure 4 When condition (2) is met, the lane keeping mode of autonomous steering control / hands-free mode is entered. As for condition (2), it can be assumed that the current position of the vehicle can be detected by the vehicle position detection device 15 using high-precision map information of the road in motion, and there are no intersections, merging points, tunnels or sharp turns with a radius of curvature of less than 100Rm within a specified distance (e.g., 500 to 800m) in front of the vehicle.

[0066] Conversely, during lane keeping mode when executing autonomous steering control / hands-free mode, when Figure 4 When condition (3) is met, the lane keeping mode of autonomous steering control / hand grip mode is entered. As this condition (3), examples include the vehicle V driving on a road other than a dedicated motor vehicle lane, the vehicle V driving at a speed exceeding the speed limit, and the driver holding the steering wheel and pressing the accelerator pedal.

[0067] During the lane keeping mode of autonomous steering control / hands-free mode, when Figure 4When condition (4) is met, autonomous steering control is suspended and autonomous speed control is initiated. As a condition (4), it is possible to enable the driver to perform steering wheel operations, etc.

[0068] Furthermore, during lane keeping mode operation in autonomous steering control / hands-free mode, when Figure 4 When condition (5) is met, autonomous steering control and autonomous speed control are suspended, and the system enters a standby state. Condition (5) can be cited as an example of the driver operating the brakes, the driver... Figure 2 The cancel switch 174 was operated, etc.

[0069] During the execution of autonomous steering control / hands-on mode, when Figure 4 When condition (6) is met, autonomous steering control is terminated and autonomous speed control is entered. As a condition (6), examples include the driver operating the steering wheel or steering indicator, and the failure to detect at least one lane boundary line of vehicle V.

[0070] Additionally, during the execution of autonomous steering control / hands-on mode, when Figure 4 When condition (7) is met, autonomous steering control and autonomous speed control are suspended, and the system enters a standby state. Condition (7) can be cited as an example of the driver operating the brakes, the driver... Figure 2 The cancel switch 174 was operated, etc.

[0071] During the execution of autonomous speed control, when Figure 4 When condition (8) is met, the system enters standby mode. Examples of conditions (8) include the driver operating the brake or the driver operating the cancel switch that turns off autonomous speed control.

[0072] During the lane keeping mode of autonomous steering control / hands-free mode, when Figure 4 When condition (9) is met, the lane change mode is entered into autonomous steering control / hand grip mode. As a condition (9), for example, a lane change suggestion for the driver assistance system 10 can be given, the driver operates the lane change assist switch 176, or the driver operates the direction indicator stick to perform autonomous lane change control, etc.

[0073] During lane change operations in autonomous steering control / hand grip mode, when Figure 4 When condition (10) is met, the lane keeping mode of autonomous steering control / hand grip mode is entered. As for condition (10), examples include driving at a speed exceeding the speed limit before the start of LCP.

[0074] If the main switch is turned off in any of the following states: autonomous steering control / hands-free mode, autonomous steering control / hands-free mode, autonomous speed control, or standby mode, the system will shut down.

[0075] The auxiliary unit 22, in principle, notifies the occupants whether a lane change based on autonomous lane change control can be performed, as notification information related to autonomous driving control. Figure 3 In the driving scenario shown, if no space is detected in lane L2 for vehicle V to enter, the display device 19 notifies the occupants that a lane change cannot be performed. However, this principle-based notification can sometimes provide occupants with unnecessary information.

[0076] Figure 5 It means by Figure 1 A top-view view of an example of a driving scenario in which the driver assistance system 10 performs autonomous driving control. Figure 5 The driving scenario shown, besides vehicle V heading towards destination X2 located ahead of lane L3, is similar to... Figure 3 The driving scenario shown is the same. Lane L3, which is a branch lane, is not an adjacent lane to lane L1. Therefore, vehicle V enters lane L3 through autonomous driving control other than manual driving by the driver or autonomous lane change control.

[0077] For example, through autonomous driving control, when heading to Figure 5 In the case of destination X2, after alerting surrounding vehicles that vehicle V is entering lane L3 (a branch lane), and with the main switch for autonomous driving control on and capable of autonomous lane change control, after vehicle V autonomously travels along the driving trajectory T1 from position P1 to position P2, the driver of vehicle V operates the turn signal lever at position P2 to flash the turn signal indicator. The driver of vehicle V flashes the turn signal indicator on the left side of vehicle V to alert surrounding vehicles that vehicle V is entering lane L3 (a branch lane). This operation of the turn signal lever puts the autonomous driving control into standby mode.

[0078] Next, with the left-hand turn indicator flashing, the driver of vehicle V drives vehicle V along the driving trajectory T3 to position P7. At position P7, the driver turns the steering wheel to the left (counter-clockwise) in the direction of travel, changing the direction of travel of vehicle V. The driver turns the steering wheel to the left in the direction of travel and enters lane L3 at position P8. Then, after passing position P8, the driver turns the steering wheel to the right (clockwise) in the direction of travel and operates the turn indicator again to turn off the turn indicator. The driver returns the steering wheel to the neutral position at position P9, completing the entry of vehicle V into lane L3 (branch lane).

[0079] exist Figure 5In the driving scenario shown, autonomous lane change control can be performed before the steering wheel is rotated at position P7. Therefore, by operating the driver's direction indicator stick at position P2, the driver assistance device 20 is given an execution instruction to change lanes to the adjacent lane to the left of the direction of travel. Therefore, in Figure 5 In the driving scenario shown, the auxiliary unit 22 notifies the driver of vehicle V that a lane change to the left cannot be performed between position P2 and position P7.

[0080] This notification is unnecessary information for the driver, causing them a sense of unease (or discomfort). This is because the driver manipulated the directional indicator to signal to surrounding vehicles that vehicle V was entering lane L3, clearly knowing that a lane change to the left is not possible at position P2.

[0081] In addition, as another example, in Figure 5 In the driving scenario shown, when vehicle V autonomously drives towards destination X1 (not shown) located ahead of lane L2, the same problem arises when, to avoid traffic congestion ahead, it enters lane L3 (a branch lane) from lane L1 (the main lane) and heads towards destination X2 (different from X1) located ahead of lane L3. That is, the driver of vehicle V... Figure 5 The indicated position P2 operates the direction indicator stalk, causing the direction indicator on the left side of vehicle V to flash, reminding surrounding vehicles that vehicle V is entering lane L3, which is a branch lane. However, in response to this operation, the auxiliary unit 22 notifies the driver of unnecessary information such as that the lane change to the left cannot be performed.

[0082] Therefore, in order to suppress the notification of unnecessary information to the driver, in this invention, unless there is an adjacent lane in the direction corresponding to the driver's first operation, the driver is exceptionally not notified that a lane change based on autonomous lane change control cannot be performed. The processing in the driver assistance device 20 will be specifically described below.

[0083] First, the determination unit 21 determines whether autonomous lane change control can be performed based on the identified driving environment around the vehicle V. If it is determined that autonomous lane change control cannot be performed, the driver assistance device 20 terminates autonomous lane change control and enters autonomous speed control or terminates autonomous driving control. On the other hand, if it is determined that autonomous lane change control can be performed, the determination unit 21 determines whether a first operation on the steering wheel has been detected.

[0084] If it is determined that no first operation on the direction indicator stalk has been detected, the determination unit 21 may repeatedly perform the detection process until the first operation is detected. On the other hand, if it is determined that the first operation on the direction indicator stalk has been detected, such as when a signal output to the driver assistance device 20 is detected during the operation of the direction indicator stalk, the determination unit 21 determines whether there is an adjacent lane in the first direction corresponding to the first operation.

[0085] The determination unit 21 determines whether there is an adjacent lane in the first direction based on image information output from the camera device 11, object location information output from the ranging device 12, and high-precision map information output from the map database 14. For example, it obtains lane-related information about the road that vehicle V is traveling on from the high-precision map information, identifies which lane vehicle V is traveling on based on the image information and object location information, and determines whether there is an adjacent lane in the first direction of the lane that vehicle V is traveling on based on the obtained lane-related information.

[0086] If it is determined that there is an adjacent lane in the first direction, the determination unit 21 determines whether the vehicle V can change lanes to the adjacent lane in the first direction through autonomous lane change control. That is, based on the identified driving environment, the determination unit 21 determines whether space for the vehicle V to enter is detected in the adjacent lane in the first direction.

[0087] If it is determined that vehicle V is capable of changing lanes to an adjacent lane in the first direction, the assistance unit 22 performs a lane change based on autonomous lane change control (hereinafter also referred to as first autonomous lane change control) executed according to the first operation, causing vehicle V to move from its current lane to an adjacent lane in the first direction. On the other hand, if it is determined that vehicle V is unable to change lanes to an adjacent lane in the first direction, the assistance unit 22 uses the display device 19 to notify the driver that a lane change based on first autonomous lane change control cannot be performed.

[0088] Conversely, if it is determined that there is no adjacent lane in the first direction, the assistance unit 22 does not notify the driver that a lane change based on the first autonomous lane change control cannot be performed. In this case, the assistance unit 22 may either suspend the first autonomous lane change control or notify the driver to drive manually.

[0089] As an example, in Figure 5 In the driving scenario shown, when the direction indicator is operated at position P2 to make the direction indicator flash, the determination unit 21 determines whether there is an adjacent lane in the direction to the left of the vehicle V's direction of travel (the first direction). Because in Figure 5Since there is no adjacent lane to the left of lane L1, the determination unit 21 outputs a determination result to the auxiliary unit 22 stating that there is no adjacent lane to the left of the vehicle V's direction of travel. Based on the input determination result, the auxiliary unit 22 does not notify the driver that a lane change based on the first autonomous lane change control cannot be performed, and instead terminates the autonomous lane change control.

[0090] The determination unit 21 can also determine, when it determines that autonomous lane change control can be performed based on the identified driving environment around the vehicle V, which of the first and second operations the execution instruction depends on when an execution instruction for autonomous lane change control is input. If it is determined that the execution instruction depends on the first operation, the auxiliary unit 22 performs the above-described processing. On the other hand, if it is determined that the execution instruction depends on the second operation, the determination unit 21 determines whether a lane change to the adjacent lane in the second direction can be performed by autonomous lane change control (hereinafter also referred to as second autonomous lane change control) performed according to the second operation.

[0091] If it is determined that a lane change to an adjacent lane in the second direction can be performed via autonomous lane change control, the assistance unit 22 executes a lane change based on the second autonomous lane change control, causing vehicle V to move from its current lane to an adjacent lane in the second direction. Conversely, if it is determined that a lane change to an adjacent lane in the second direction cannot be performed via autonomous lane change control, the assistance unit 22 notifies the driver that a lane change based on the second autonomous lane change control cannot be performed.

[0092] Furthermore, in the second autonomous lane change control, no instruction is input to change lanes in a direction where no adjacent lanes exist. This is because the second autonomous lane change control is executed only after the driver has agreed to the lane change suggestion provided by the driver assistance system 10 by operating the lane change switch; the driver assistance system 10 does not suggest lane changes in a direction where no adjacent lanes exist. That is, during the phase where the driver assistance system 10 suggests a lane change, it identifies whether there are adjacent lanes in the direction of the lane change.

[0093] [Processing in driver assistance systems] Reference Figure 6 The steps for the driver assistance device 20 to process information are explained. Figure 6 This is a flowchart illustrating an example of the processing steps performed in the driver assistance system 10. The processing described below is performed by the processor (CPU) of the driver assistance device 20 at predetermined time intervals (e.g., every 0.1 milliseconds to 1 millisecond).

[0094] First, in step S1, the driving assistance device 20 determines whether autonomous lane change control can be performed. That is, the driving assistance device 20 determines whether the execution conditions for autonomous lane change control are met based on the driving environment identified by the function of the determination unit 21. If it is determined that autonomous lane change control cannot be performed (step S1: No), the autonomous lane change control ends. Conversely, if it is determined that autonomous lane change control can be performed (step S1: Yes), the process proceeds to step S2.

[0095] In step S2, the driver assistance device 20 determines whether it has detected the driver's operation on the direction indicator stalk. That is, the driver assistance device 20 detects the signal output to the driver assistance device 20 when the direction indicator stalk is operated, using the function of the determination unit 21. If it is determined that no operation on the direction indicator stalk was detected (step S2: No), the autonomous lane change control ends. Conversely, if it is determined that the driver's operation on the direction indicator stalk was detected (step S2: Yes), the process proceeds to step S3.

[0096] In step S3, the driving assistance device 20 determines, based on the driving environment identified by the function of the determination unit 21, whether there is an adjacent lane in the direction corresponding to the operation of the opposite direction indicator. If it is determined that there is an adjacent lane in the direction corresponding to the operation of the opposite direction indicator (step S3: Yes), the process proceeds to step S4.

[0097] In step S4, the driver assistance device 20 determines whether a lane change can be performed in the adjacent lane corresponding to the direction indicated by the directional indicator (corresponding direction). If it is determined that a lane change can be performed in the adjacent lane in the corresponding direction (step S4: Yes), the process proceeds to step S5, where a lane change based on autonomous lane change control is executed. Conversely, if it is determined that a lane change cannot be performed in the adjacent lane in the corresponding direction (step S4: No), the process proceeds to step S6, where the driver is notified that a lane change based on autonomous lane change control cannot be performed.

[0098] On the other hand, if it is determined that there is no adjacent lane in the direction corresponding to the operation of the opposite direction indicator (step S3: No), proceed to step S7. In step S7, the driving assistance device 20, through the function of the assistance unit 22, does not notify the driver that lane change based on autonomous lane change control cannot be performed, and in the following step S8, the autonomous lane change control is aborted, and the driver is notified to drive manually.

[0099] [Embodiments of the Invention] According to this embodiment, a driving assistance method is provided, executed by a driving assistance device 20 of a vehicle V. When the driving assistance device 20 performs a first autonomous lane change control to change lanes from the current lane of the vehicle V to an adjacent lane in a first direction corresponding to the first operation, based on a first operation performed by the driver of the vehicle V on the direction indicator stick of the vehicle V's direction indicator, and determines that there is no adjacent lane in the first direction corresponding to the driver's first operation, it does not notify the driver that the lane change based on the first autonomous lane change control cannot be performed. This suppresses the notification of unnecessary information to the driver.

[0100] In the driving assistance method of this embodiment, when the driving assistance device 20 performs the first autonomous lane change control according to the first operation, if there is no adjacent lane in the first direction corresponding to the first operation performed by the driver, it stops the first autonomous lane change control and notifies the driver to drive manually. Thus, autonomous driving control that conforms to the intention of the driver performing the first operation can be executed.

[0101] In the driving assistance method of this embodiment, when the driving assistance device 20 performs the first autonomous lane change control according to the first operation, if there is an adjacent lane in the first direction corresponding to the first operation performed by the driver, it determines whether the lane change based on the first autonomous lane change control can be performed. If it is determined that the lane change based on the first autonomous lane change control cannot be performed, it notifies the driver that the lane change based on the first autonomous lane change control cannot be performed. Thus, information consistent with the driver's intention of "lane change based on autonomous lane change control" can be communicated.

[0102] In the driving assistance method of this embodiment, when the driving assistance device 20 performs a second autonomous lane change control to change lanes from the current lane to the adjacent lane in the second direction corresponding to the second operation, based on a second operation performed by the driver to a switch different from the direction indicator stalk, it determines whether the lane change based on the second autonomous lane change control can be performed. If it determines that the lane change based on the second autonomous lane change control cannot be performed, it notifies the driver that the lane change based on the second autonomous lane change control cannot be performed. Thus, information consistent with the driver's intention of "lane change based on autonomous lane change control" can be communicated.

[0103] Furthermore, according to this embodiment, a driving assistance device 20 is provided, which includes an assistance unit 22. When the assistance unit 22 performs a first autonomous lane change control to change lanes from the current lane of the vehicle V to an adjacent lane in a first direction corresponding to the first operation, based on a first operation performed by the driver of the vehicle V on the direction indicator stick of the vehicle V's direction indicator, and determines that there is no adjacent lane in the first direction corresponding to the driver's first operation, it does not notify the driver that the lane change based on the first autonomous lane change control cannot be performed. This suppresses the notification of unnecessary information to the driver.

[0104] Explanation of reference numerals in the attached figures

[0105] 10: Driving assistance system; 11: Camera device; 12: Distance measuring device; 13: On-board sensor; 14: Map database; 15: Vehicle position detection device; 16: Navigation device; 17: Input device; 171: Main switch; 172: Resume / Accelerate switch; 173: Set / Decelerate switch; 174: Cancel switch; 175: Distance adjustment switch; 176: Lane change assist switch; 18: Actuator; 19: Display device; 20: Driving assistance device; 21: Decision unit; 22: Assist unit; L1, L2, L3: Lane; P1, P2, P3, P4, P5, P6, P7, P8, P9: Position; T1, T2, T3: Driving trajectory; V: Vehicle; X1, X2: Destination; Z: Branch point.

Claims

1. A driving assistance method, executed by a vehicle's driving assistance device, characterized in that, When the driving assistance device performs a first autonomous lane change control to change lanes from the vehicle's current lane to an adjacent lane in a first direction corresponding to the first operation based on a first operation performed by the driver of the vehicle's direction indicator, if it determines that there is no adjacent lane in the first direction corresponding to the first operation performed by the driver, it does not notify the driver that the lane change based on the first autonomous lane change control cannot be performed.

2. The driving assistance method according to claim 1, characterized in that, When the driving assistance device performs the first autonomous lane change control according to the first operation, if there is no adjacent lane in the first direction corresponding to the first operation performed by the driver, it stops the first autonomous lane change control and notifies the driver to drive manually.

3. The driving assistance method according to claim 1 or 2, characterized in that, When the driving assistance device performs the first autonomous lane change control according to the first operation, if there is an adjacent lane in the first direction corresponding to the first operation performed by the driver, it determines whether the lane change based on the first autonomous lane change control can be performed. If it is determined that the lane change based on the first autonomous lane change control cannot be performed, the driver is notified that the lane change based on the first autonomous lane change control cannot be performed.

4. The driving assistance method according to any one of claims 1 to 3, characterized in that, When the driving assistance device performs a second autonomous lane change control based on a second operation by the driver to a switch different from the direction indicator stalk, and performs a lane change from the current lane to the adjacent lane in the second direction corresponding to the second operation, it determines whether the lane change based on the second autonomous lane change control can be performed. When it is determined that the lane change based on the second autonomous lane change control cannot be performed, the driver is notified that the lane change based on the second autonomous lane change control cannot be performed.

5. A driving assistance device, characterized in that, The system includes an auxiliary unit that, when performing a first autonomous lane change control to change lanes from the vehicle's current lane to an adjacent lane in a first direction corresponding to the first operation based on a first operation performed by the driver of the vehicle's direction indicator, does not notify the driver that the lane change based on the first autonomous lane change control cannot be performed if it determines that there is no adjacent lane in the first direction corresponding to the first operation performed by the driver.

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