Vehicle control system

Abstract

A vehicle control system that performs lane change control for changing a lane of a vehicle from a traveling lane to an adjacent lane, cancels the lane change control according to at least one of an operation of a driver of the vehicle, surrounding environment of the vehicle, and traveling state of the vehicle during the lane change control, and switches the vehicle to a mode in which the driver drives the vehicle manually, the system comprising: a turn signal control unit configured to switch a turn signal of the vehicle between an OFF state and an ON state according to the lane change control, characterized in that the turn signal control unit maintains the turn signal in the ON state until predetermined release conditions are met when the lane change control in progress is canceled and the vehicle is switched to the manual driving mode, and in that the turn signal control unit determines that the release conditions are met when the vehicle has moved a predetermined distance in the lateral direction since the lane change control was canceled and the vehicle was switched to the manual driving mode.

Description

Technical FieldThe present invention relates to a vehicle control system that performs lane change control.BackgroundJP 2015-160 554 A has been known as technical literature related to a vehicle control system that performs lane change control. JP 2015-160 554 A discloses a vehicle control system that performs lane change control such that a vehicle automatically switches its lane and automatically turns on and off a turn signal indicating a lane change direction during lane change. DE 103 55 807 A1 and DE 100 12 737 A1 each disclose a vehicle control system according to the preamble of claim 1. Further relevant prior art is found in DE 103 55 807 A1, WO 2010 / 045 908 A1, DE 10 2013 225 138 A1 or DE 10 2006 042 966 A1.SummaryHowever, in general, when a lane change control is canceled, the vehicle is switched to a manual driving mode in which the driver manually drives the vehicle, and the instructions issued from the system to the vehicle during a lane change control are also canceled. Therefore, when the lane change control is canceled, the turn signal indicating the lane change direction is also turned off. However, even when the lane change control is canceled, the driver wants to change lanes manually in some cases. In this case, the driver needs to turn on the turn signal again after the lane change control is canceled. As a result, the driver's operation is complicated, which is inconvenient.In this technical field, it is preferable to provide a vehicle control system that can improve convenience of the driver that manually switches lanes when lane change control is canceled.To solve the above problem, according to one aspect of the invention, there is provided a vehicle control system having the features recited in claim 1.In the vehicle control system according to the aspect of the invention, when the lane change control is canceled during the lane change control by the driver, the vehicle is switched to the manual driving mode and the turn signal is maintained in the ON state. Therefore, according to the vehicle control system, the time and effort required for the driver who manually switches lanes when a lane change control is canceled to turn the turn signal on again are not necessary, compared with the prior art system in which the turn signal is automatically turned off when a lane change control is canceled. As a result, it is possible to improve the convenience of the driver.In the vehicle control system, the feature cluster disclosed in claim 2 may be additionally provided.According to the vehicle control system, when the vehicle enters an adjacent lane from the traveling lane, the turn signal is turned off even if the turn signal is maintained in the ON state. Therefore, according to the vehicle control system, when the driver manually changes lanes and the vehicle enters an adjacent lane from the traveling lane, it is possible to turn off the turn signal without the driver's operation. As a result, it is possible to improve the convenience of the driver.As described above, according to various aspects of the invention, it is possible to improve convenience of the driver that manually switches lanes when lane change control is canceled.Brief Description of the DrawingsFIG. 1 is a block diagram illustrating a vehicle control system according to an embodiment. FIG. 2A is a diagram illustrating the state of a turn signal when lane change control is canceled in a vehicle control system according to the related art. FIG. 2B is a diagram illustrating the state of a turn signal when lane change control is canceled in a vehicle control system according to this embodiment. FIG. 3 is a flowchart illustrating a lane change control start process. FIG. 4 is a flowchart illustrating a lane change control ending process and a lane change control stopping process. FIG. 5 is a flowchart illustrating a process of releasing the turn signal maintained in an ON state.DETAILED DESCRIPTIONHereinafter, an embodiment of the invention will be described with reference to the drawings.FIG. 1 is a block diagram illustrating a vehicle control system according to this embodiment. A vehicle control system 100 according to this embodiment illustrated in FIG. 1 is provided in a vehicle such as a car, and controls traveling of the vehicle. The vehicle control system 100 is configured such that the vehicle can be driven automatically. Automated driving is a vehicle control technique that drives the vehicle to the destination without the driver's operation. Any known structure may be used for the automated driving. The vehicle control system 100 may perform switching between automated driving and manual driving in which the driver manually drives the vehicle.The vehicle control system 100 performs lane change control for the vehicle. The lane change control is a vehicle control that changes the lane of the vehicle from a traveling lane in which the vehicle travels to a lane adjacent to the traveling lane. The lane change control of the vehicle control system 100 is performed as a portion of the automated driving or is performed to assist the driver during manual driving. When the lane change control is performed, a turn signal of the vehicle that is close to an adjacent lane (lane change direction) is turned on. The turn signal may be automatically turned on by the vehicle control system 100 or may be manually turned on by the driver.During the lane change control, the vehicle control system 100 cancels the lane change control according to at least one of the driver's operation, surrounding environment of the vehicle, or traveling state of the vehicle during the lane change control, and switches to the manual driving mode in which the driver manually drives the vehicle. Even if the lane change control is canceled, the vehicle control system 100 maintains the turn signal in an ON state until release conditions are satisfied. The lane change control suspension and release conditions will be described in detail below.Structure of Vehicle Control SystemAs illustrated in FIG. 1, the vehicle control system 100 includes a global positioning system (GPS) receiving unit 1, an exterior sensor 2, an interior sensor 3, a map database 4, an operation detecting unit 5, an actuator 6, a turn signal driving unit 7, a human machine interface (HMI) 8, and an electronic control unit (ECU) 10.The GPS receiving unit 1 receives signals from three or more GPS satellites and measures the position of the vehicle (e.g., the latitude and longitude of the vehicle). The GPS receiving unit 1 transmits the measured position information of the vehicle to the ECU 10.The external sensor 2 is a detector that detects the surrounding environment of the vehicle. The external sensor 2 includes a camera, a radar, or a laser imaging detecting and ranging (LIDAR) device. The camera is provided on the rear side of the front glass of the vehicle, for example, and captures a view in the foreground of the vehicle. The cameras may be provided on the rear surface and the side surface of the vehicle. The camera transmits information on the captured image of the surroundings of the vehicle to the ECU 10. The stereo camera includes two imaging units provided to reproduce binocular parallax.The radar detects obstacles around the vehicle using radio waves (e.g., millimeter waves). The radar transmits radio waves around the vehicle, receives radio waves reflected from obstacles, and detects the obstacles. The radar transmits the detected obstacle information to the ECU 10. The LIDAR transmits the detected obstacle information to the ECU 10.The internal sensor 3 is a detector that detects the traveling state of the vehicle. The inside sensor 3 includes a vehicle speed sensor, an acceleration sensor, and a yaw rate sensor 17. For example, a wheel speed sensor provided in a wheel of the vehicle or a drive shaft rotated integrally with the wheel and detecting the rotation speed of the wheel is used as the vehicle speed sensor. The vehicle speed sensor transmits the detected vehicle speed information (wheel speed information) to the ECU 10.The acceleration sensor is a detector that detects the acceleration of the vehicle. The acceleration sensor includes, for example, a longitudinal acceleration sensor that detects the longitudinal acceleration of the vehicle and a lateral acceleration sensor that detects the lateral acceleration of the vehicle. The acceleration sensor transmits, for example, vehicle acceleration information to the ECU 10. The yaw rate sensor is a detector that detects the yaw rate (angular velocity) of the vehicle about the vertical axis passing through the center of gravity. For example, a yaw sensor may be used as the yaw rate sensor. The yaw rate sensor transmits the detected vehicle yaw rate information to the ECU 10.The map database 4 is a database that stores map information. The map database is formed in, for example, a hard disk drive (HDD) provided in the vehicle. The map information includes, for example, the position information of the roads, information on the shape of the roads (e.g., a curve, the type of a straight portion, and the curvature of the curve), and the position information of intersection points and branch points.The operation detection unit 5 is a device that detects an operation of the driver of the vehicle for the vehicle. When a lane change control start button is provided in the vehicle, the operation detection unit 5 detects an operation of turning on the lane change control start button and an operation of turning off the lane change control start button. Similarly, when a lane change control cancel button is provided, the operation detection unit 5 detects an operation of turning on the lane change control cancel button and an operation of turning off the lane change control cancel button. The buttons are not necessarily provided. For example, levers may be provided.The operation detection unit 5 includes a turn signal detection unit. The turn signal detection unit is provided in a turn signal operation lever of the vehicle, and detects the operation of the driver for a turn signal operation lever. The turn signal detection unit transmits the detected operation for the turn signal operation lever to the ECU 10.The operation detection unit 5 includes a steering sensor, an accelerator sensor, and a brake pedal sensor. The steering sensor includes, for example, a steering torque sensor and a steering touch sensor. The steering torque sensor is provided in a steering shaft of the vehicle and detects a steering torque applied to the steering wheel by the driver. The steering touch sensor is provided in the steering wheel of the vehicle, and detects the driver's touch with the steering wheel and a pressure applied to the steering wheel by the driver. The accelerator sensor is provided in a shaft portion of an accelerator pedal, and detects a force applied to the accelerator pedal by the driver or the amount of depression (the position of the accelerator pedal) of the accelerator pedal by the driver. The brake pedal sensor is provided in a shaft portion of a brake pedal and detects a force applied to the brake pedal by the driver or the amount of depression (the position of the brake pedal) of the brake pedal by the user.The actuator 6 is a device that performs traveling control for the vehicle. The actuator 6 includes at least a throttle actuator, a brake actuator, and a steering actuator. The throttle actuator controls the amount of air supplied to the motor (throttle position) and controls the driving force of the vehicle in response to a control signal from the ECU 10. When the vehicle is a hybrid vehicle, a control signal from the ECU 10 is supplied to a motor as a drive source to control the driving force in addition to the amount of air supplied to the motor. When the vehicle is an electric vehicle, a control signal is supplied from the ECU 10 to a motor as a drive source to control the drive force. In these cases, the motor as the drive source constitutes the actuator 6.The brake actuator controls a brake system and controls a braking force applied to the wheels of the vehicle in response to a control signal from the ECU 10. For example, a hydraulic brake system may be used as the brake system. The steering actuator controls driving of an assist motor that controls a steering torque in an electric power steering system in response to a control signal from the ECU 10. Therefore, the steering actuator controls the steering torque of the vehicle.The turn signal driving unit 7 is a device that switches the turn signals of the vehicle between an ON state and an OFF state. The turn signal driving unit 7 may be, for example, an electronic control unit including a driving circuit including a microprocessor, a transistor, and a relay, and a communication device. The turn signal driving unit 7 switches the turn signals between the ON state and the OFF state based on a control signal from the ECU 10.The turn signals are, for example, lamps that emit light having a specific color, and are provided at the left and right positions of the front portion of the vehicle and the left and right positions of a rear portion of the vehicle. When the turn signals are lamps, the ON state is, for example, a blinking state or a lighting state. The aspect of the turn signal varies depending on the area in which the vehicle is used and the type of a vehicle. When the turn signal is not a lamp and is a plate member that emits light, the ON state is, for example, a state in which the plate member that emits light protrudes from the side surface of the vehicle in the traveling direction of the vehicle (a state in which the plate member that emits light and is provided with an emission surface upward is lowered toward the traveling direction of the vehicle).The HMI 8 is an interface that supplies and outputs information between the vehicle control system 100 and the driver. The HMI 8 includes, for example, a display and a speaker. The HMI 8 outputs an image to the display and outputs a sound from the speaker in response to a control signal from the ECU 10.The ECU 10 is an electronic control unit including, for example, a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), and a controller area network communication circuit (CAN). In the ECU 10, for example, a program stored in the ROM by the CAN communication circuit is loaded into the RAM, and the CPU executes the program loaded into the RAM to implement each function. The ECU may include a plurality of electronic control units. In addition, the ECU 10 has a function of performing automated vehicle driving. The ECU 10 generates a vehicle travel plan in advance to perform automated driving using a known method. The travel plan is data in which the position of the vehicle on the map is related to a control target value (a target vehicle speed or a target steering angle) of the vehicle. The ECU 10 performs the automated driving of the vehicle according to the travel plan.Next, the functional structure of the ECU 10 will be described. The ECU 10 includes a vehicle position recognition unit 11, an surrounding environment recognition unit 12, a traveling state recognition unit 13, a lane change control unit 14, and a turn signal control unit 15.The vehicle position recognition unit 11 recognizes the position of the vehicle on the map based on the position information from the GPS receiving unit 1 and the map information in the map database 4. The vehicle position recognition unit 11 can recognize the position of the vehicle using a simultaneous localization and mapping technique (SLAM technique) based on the position information of fixed obstacles such as electric poles included in the map information of the map database 4 and the detection result from the external sensor 2.The vehicle position recognition unit 11 recognizes the lateral position of the vehicle using a known image processing method, based on an image (an image of white lines) in front of the vehicle captured by an in-vehicle camera. The mounting position of the in-vehicle camera in the vehicle is determined, and the imaging range of the camera is determined by the mounting position. In addition, the relationship between the mounting position of the camera and the position of the center of the vehicle (positional relationship in a plan view) is determined. Therefore, the vehicle position recognition unit 11 can calculate the position of the center of the vehicle (the lateral position of the vehicle) in a lane width direction from the position of two left and right white lines on the image captured by the camera. The white lines may be detected by the radar or LIDAR instead of the camera.The surrounding environment recognition unit 12 recognizes the surrounding environment of the vehicle on the basis of the detection result from the external sensor 2. the surrounding environment includes, for example, the position of an obstacle with respect to the vehicle, the speed of an obstacle with respect to the vehicle, and the moving direction of an obstacle with respect to the vehicle. The surrounding environment recognition unit 12 recognizes the surrounding environment of the vehicle using a known method based on the image captured by the camera, obstacle information from the radar, or obstacle information from the LIDAR.The traveling state recognition unit 13 recognizes the traveling state of the vehicle. The traveling state of the vehicle includes, for example, the speed of the vehicle, the acceleration of the vehicle, and the steering angle of the vehicle. The traveling state recognition unit 13 recognizes the traveling state of the vehicle on the basis of the detection result from the internal sensor 3. The failure state of the vehicle control system 100 includes, for example, a failure of the transmitters (for example, the GPS receiving unit 1, the external transmitter 2, and the internal transmitter 3) of the vehicle, a failure of the actuator 6 such as the steering actuator, a failure of the communication device, a failure of a power supply device, a failure of the electronic control unit, a failure of the turn signals, and a failure of the HMI 8. The vehicle control system 100 determines a failure of each device using a known method. The traveling state recognition unit 13 recognizes the traveling state of the vehicle on the basis of the detection result from the internal sensor 3 and the failure determination information from the vehicle control system 100.The lane change control unit 14 performs lane change control that changes the lane of the vehicle from the traveling lane to an adjacent lane. The lane change control unit 14 transmits a control signal to the actuator 6 to perform the lane change control.While the vehicle is automatically driven, the lane change control unit 14 starts the lane change control based on the position of the vehicle on the map recognized by the vehicle position recognition unit 11. The lane change control unit 14 starts the lane change control according to the travel plan set for automated driving.While the vehicle is being driven manually, the lane change control unit 14 starts the lane change control based on the detection result of the operation detection unit 5. The lane change control start operation of the user is not limited to the operation of turning on the start button. The lane change control start operation may be the operation of the driver to switch the turn signal near an adjacent lane of the vehicle from an OFF state to an ON state, or the operation of the driver to turn the steering wheel to the adjacent lane at a steering torque equal to or greater than a predetermined value.When the lane change control is started, the lane change control unit 14 may notify the driver of the start of the lane change control through the HMI 8. The lane change control unit 14 outputs a sound from the speaker or displays an image on the display to notify the driver of the start of the lane change control.When the lane change control starts, the lane change control unit 14 sets a target traveling line of the vehicle by the lane change control. The target moving line means a target moving line of the vehicle by which the lane is changed from the moving lane to an adjacent lane by the lane change control. The lane change control unit 14 sets the target moving line on the basis of the lateral position of the vehicle recognized by the vehicle position recognition unit 11, the surrounding environment of the vehicle recognized by the surrounding environment recognition unit 12, and the traveling state of the vehicle recognized by the traveling state recognition unit 13. In addition, the lane change control unit 14 sets a target vehicle speed pattern (for example, time-series data of a vehicle speed control target value) in the lane change control. The lane change control unit 14 sets the target vehicle speed pattern in which the lateral acceleration of the vehicle is equal to or less than a predetermined value so that the driver does not feel uncomfortable, based on the current speed of the vehicle. The lane change control unit 14 may use any one of a plurality of combinations of the target moving lines and the target vehicle speed patterns stored in advance.The lane change control unit 14 performs the lane change control based on the target moving line and the target vehicle speed pattern. The lane change control unit 14 performs the lane change control such that the vehicle enters an adjacent lane based on the lateral position of the vehicle recognized by the vehicle position recognition unit 11, the surrounding environment recognized by the surrounding environment recognition unit 12, and the traveling state of the vehicle recognized by the traveling state recognition unit 13.The lane change control unit 14 determines whether the lane change of the vehicle has been completed based on the lateral position of the vehicle recognized by the vehicle position recognition unit 11. For example, when the lateral position of the vehicle reaches the center of an adjacent lane (the center of the adjacent lane in the lane width direction), the lane change control unit 14 determines that the lane change of the vehicle has been completed. When the lane change of the vehicle has been completed, the lane change control unit 14 terminates the lane change control.During the lane change control, the lane change control unit 14 cancels the lane change control based on at least one of the driver's operation, surrounding environment of the vehicle, and traveling state of the vehicle. The suspension of the lane change control means the suspension (handover) of the lane change control before a lane change is completed. When predetermined canceling conditions are satisfied, the lane change control unit 14 cancels the lane change control. The termination conditions are conditions for determining whether the termination of the lane change control is necessary.When the driver's operation that cancels the lane change control is detected based on the detection result of the operation detection unit 5, the lane change control unit 14 determines that the cancellation conditions have been satisfied. Examples of the driver's operation that cancels the lane change control include the operation of the driver applying a steering torque equal to or greater than a predetermined value to the steering wheel of the vehicle, the operation of the driver applying a force equal to or greater than a predetermined value to the brake pedal or the accelerator pedal, the operation of the driver depressing the brake pedal or the accelerator pedal with pressure equal to or greater than a predetermined value, and the operation of the driver turning on the button for canceling the lane change control (or the system).When the driver continuously operates at least one of the steering wheel, brake pedal, and accelerator pedal for a predetermined period of time or longer, the lane change control unit 14 may determine that the cancellation conditions have been satisfied. When the time integration of the steering torque of the steering wheel by the driver is equal to or greater than a predetermined value, the lane change control unit 14 may determine that the cancellation conditions have been satisfied. Similarly, when the time integration of force applied to the brake pedal or the accelerator pedal (or the amount of depression of the brake pedal or the accelerator pedal) is equal to or greater than a predetermined value, the lane change control unit 14 may determine that the cancellation conditions have been satisfied.When another vehicle approaching the vehicle is detected in a predetermined distance range on the basis of the surrounding environment recognized by the surrounding environment recognition unit 12, the lane change control unit 14 determines that the cancellation conditions have been satisfied. When the failure state of the vehicle control system 100 is detected based on the traveling state of the vehicle recognized by the traveling state recognition unit 13, the lane change control unit 14 determines that the cancellation conditions have been satisfied. That is, even if the driver does not perform any operation, the lane change control unit 14 automatically cancels the lane change control based on the surrounding environment or the traveling state. When the lane change control is canceled, the lane change controller 14 switches the vehicle to the manual driving mode.The turn signal control unit 15 switches the turn signals of the vehicle between an OFF state and an ON state. The turn signal control unit 15 transmits a control signal to the turn signal driving unit 7 to control the state of the turn signals. When the vehicle that is automatically driven starts the lane change control, the turn signal control unit 15 automatically switches the turn signal near an adjacent lane (lane change direction) from the OFF state to the ON state.When the vehicle that is manually driven starts the lane change control and the turn signal that is close to an adjacent lane is in an OFF state, the turn signal control unit 15 automatically turns on the turn signal. In addition, the driver can manually turn on the turn signal. In either case, the turn signal that is close to an adjacent lane is turned on when the lane change control starts.When the lane change control ends, the turn signal control unit 15 switches the turn signal from the ON state to the OFF state. When the vehicle enters an adjacent lane, the turn signal control unit 15 may turn off the turn signal.When the lane change control is canceled and the vehicle is switched to the manual driving mode, the turn signal control unit 15 maintains the turn signal, which is near an adjacent lane, in the ON state until predetermined release conditions are satisfied. These release conditions are conditions for determining whether to maintain the turn signal in the ON state.FIG. 2A is a diagram illustrating the state of the turn signal when lane change control is canceled in the vehicle control system according to the related art. As illustrated in FIG. 2A, in the vehicle control system according to the related art, at a time tc when lane change control is canceled, the turn signal that is in an ON state is automatically turned off. FIG. 2B is a diagram illustrating the state of the turn signal when lane change control is canceled in the vehicle control system 100 according to this embodiment. As illustrated in FIG. 2B, according to the vehicle control system 100, at a time tc when lane change control is canceled, the turn signal control unit 15 maintains the turn signal in an ON state. Therefore, it is possible to avoid the time and trouble required for the driver who wants to manually change lanes to manually turn on the turn signal which has been automatically switched to the OFF state.Even when the lane change control is canceled and the vehicle is switched to the manual driving mode, the turn signal control unit 15 does not turn on the turn signal that is in the OFF state. That is, when the turn signal near an adjacent lane has already been turned off, for example, when the vehicle has entered the adjacent lane, the turn signal control unit 15 does not switch the turn signal from the OFF state to the ON state even if the lane change control is canceled.When the vehicle is switched to the manual driving mode and enters an adjacent lane from the driving lane, the turn signal control unit 15 determines that the release conditions have been satisfied. The turn signal control unit 15 detects the entry of the vehicle from the traveling lane to an adjacent lane on the basis of the white lines and the lateral position of the vehicle recognized by the vehicle position recognition unit 11. It is determined that the vehicle enters an adjacent lane from the traveling lane when the center line of the vehicle (a virtual line passing through the center of the vehicle and extending in the front-rear direction) crosses a white line that is a boundary line between the traveling lane and the adjacent lane. It may be determined that the vehicle enters an adjacent lane from the traveling lane when the front wheel of the vehicle that is near the adjacent lane crosses the white line. When the driver operates the turn signal operation lever, the turn signal control unit 15 determines that the release conditions have been satisfied.When a predetermined period of time has elapsed since the lane change control was canceled and the vehicle was switched to the manual driving mode, the turn signal control unit 15 determines that the release conditions have been satisfied. In addition, when the vehicle has traveled a predetermined distance since the lane change control was canceled and the vehicle was switched to the manual driving mode, the turn signal control unit 15 may determine that the release conditions have been satisfied. For example, the turn signal control unit 15 calculates the distance travelled from the vehicle speed and the elapsed time.When the vehicle has moved a predetermined distance in the lateral direction since the lane change control was canceled and the vehicle was switched to the manual driving mode, the turn signal control unit 15 may determine that the release conditions have been satisfied. The turn signal control unit 15 calculates the moving distance of the vehicle in the lateral direction based on the lateral position of the vehicle recognized by the vehicle position recognition unit 11.When it is determined that the release conditions have been satisfied, the turn signal control unit 15 releases the maintenance of the ON state of the turn signal to turn off the turn signal. When the releasing conditions are satisfied and the turn signal is turned off, the turn signal control unit 15 may notify the driver that the turn signal has been turned off through the HMI 8. When the maintenance of the ON state of the turn signal is released, the turn signal control unit 15 does not necessarily turn off the turn signal.Lane Change Control Start Process in Vehicle Control SystemNext, the lane change control start process in the vehicle control system 100 according to this embodiment will be described. FIG. 3 is a flowchart illustrating the lane change control start process. The process in the flowchart illustrated in FIG. 3 is performed when the lane change control is determined to be started by automatic driving or when the driver performs a lane change control start operation.As illustrated in FIG. 3, in S 10, the ECU 10 of the vehicle control system 100 notifies the driver of the start of the lane change control by the HMI 8. The HMI 8 outputs a sound or displays an image to notify the driver of the start of the lane change control in response to a control signal transmitted from the lane change controller 14. Then, the ECU 10 proceeds to S 12.In S 12, the lane change control unit 14 of the ECU 10 starts the lane change control. The lane change control unit 14 transmits a control signal to the actuator 6 to perform the lane change control that changes the lane of the vehicle from the traveling lane to an adjacent lane. In S 12, when the turn signal near the adjacent lane is in an OFF state, the turn signal control unit 15 automatically turns on the turn signal. The turn signal control unit 15 transmits a control signal to the turn signal driving unit 7 to turn on the turn signal.Lane Change Control Ending Process and Lane Change Control Stopping Process in the Vehicle Control SystemNext, a lane change control ending process and a lane change control stopping process in the vehicle control system 100 will be described with reference to FIG. 4. FIG. 4 is a flowchart illustrating the lane change control ending process and the lane change control stopping process. The processes in the flowchart illustrated in FIG. 4 are performed when the lane change control starts in S 12 of FIG. 3.As illustrated in FIG. 4, in S 20, the lane change control unit 14 determines from the ECU 10 in the vehicle control system 100 whether a lane change has been completed by the lane change control. The lane change control unit 14 determines whether a lane change has been completed based on the lateral position of the vehicle recognized by the vehicle position recognition unit 11. When it is determined that a lane change has been completed (S 20: YES), the ECU 10 proceeds to S 22. When it is determined that a lane change has not been completed (S 20: NO), the ECU 10 proceeds to S 26.In S 22, the ECU 10 notifies the driver that the lane change control has been completed through the HMI 8. The HMI 8 outputs a sound or displays an image to notify the driver that the lane change control has been completed in response to a control signal transmitted from the lane change control unit 14. Then, the ECU 10 proceeds to S 24.In S 24, the lane change control unit 14 of the ECU 10 terminates the lane change control. When the turn signal is in an ON state, the turn signal control unit 15 switches the turn signal to an OFF state. When the vehicle enters an adjacent lane from the traveling lane during the lane change control, the turn signal control unit 15 may switch the turn signal near the adjacent lane to an OFF state. Then, the ECU 10 ends the present process.In S 26, the lane change control unit 14 of the ECU 10 determines whether the cancellation conditions have been satisfied. For example, when the operation of the driver that cancels the lane change control is detected based on the detection result from the operation detection unit 5, the lane change control unit 14 determines that the cancellation conditions have been satisfied. When another vehicle approaching the vehicle in a predetermined distance range is detected based on the surrounding environment recognized by the surrounding environment recognition unit 12, the lane change control unit 14 determines that the cancellation conditions have been satisfied. When it is determined that the termination conditions have not been satisfied (S 26: NO), the ECU 10 terminates the present process. Then, the ECU 10 repeats the process from S 20 again. When it is determined that the termination conditions have been satisfied (S 26: YES), the ECU 10 proceeds to S 28.In S 28, the ECU 10 notifies the driver that the lane change control has been canceled through the HMI 8. The HMI 8 outputs a sound or displays an image to notify the driver that the lane change control has been canceled in response to a control signal transmitted from the lane change control unit 14. Then, the ECU 10 proceeds to S 30.In S 30, the lane change control unit 14 of the ECU 10 cancels the lane change control. The ECU 10 switches the vehicle for which the lane change control has been canceled to the manual driving mode. In this case, the turn signal unit 15 maintains the turn signal near the adjacent lane in the ON state. Then, the ECU 10 ends the present process.Turn Signal Enabling / Cancelling Process in Vehicle Control SystemNext, a turn signal enabling / cancelling process in the vehicle control system 100 will be described with reference to FIG. 5. FIG. 5 is a flowchart illustrating a process of releasing the turn signal maintained in the ON state. The process in the flowchart illustrated in FIG. 5 is performed when the turn signal is maintained in the ON state in S 30 of FIG. 4.As illustrated in FIG. 5, in S 40, the lane change control unit 14 of the ECU 10 in the vehicle control system 100 determines whether the release conditions have been satisfied. When the vehicle that has been switched to the manual driving mode enters an adjacent lane from the traveling lane, the lane change control unit 14 determines that the release conditions have been satisfied. When a predetermined period of time has elapsed since the lane change control was canceled and the vehicle was switched to the manual driving mode, the lane change control unit 14 determines that the releasing conditions have been satisfied. When it is determined that the releasing conditions have not been satisfied (S 40: NO), the ECU 10 terminates the present process. Then, the ECU 10 repeats the process in S 40 again. When it is determined that the releasing conditions have been satisfied (S 40: YES), the ECU 10 proceeds to S 42.In S 42, the ECU 10 notifies the driver that the turn signal has been turned off through the HMI 8. The HMI 8 outputs a sound or displays an image to notify the driver that the turn signal has been turned off in response to a control signal transmitted from the turn signal control unit 15. Then, the ECU 10 proceeds to S 44.In S 44, the turn signal control unit 15 of the ECU 10 turns off the turn signal. The turn signal control unit 15 releases the maintenance of the ON state of the turn signal and turns off the turn signal. The turn signal control unit 15 transmits a control signal to the turn signal driving unit 7 to turn off the turn signal. Then, the ECU 10 ends the present process.Operation and Effect of Vehicle Control SystemAccording to the above-mentioned vehicle control system 100 according to this embodiment, when the lane change control is canceled by, for example, an operation of the user during the lane change control and the vehicle is switched to the manual driving mode, the turn signal is maintained in an ON state. Therefore, according to the vehicle control system 100, the time and effort required for the driver to turn the turn signal on again is not necessary, compared with the prior art system in which the turn signal is automatically turned off when the lane change control is cancelled. As a result, according to the vehicle control system 100, it is possible to improve convenience of the driver who manually switches lanes when lane change control is canceled.According to the vehicle control system 100, when the vehicle enters an adjacent lane from the traveling lane, it is determined that the release conditions have been satisfied even if the turn signal is maintained in an ON state. Then, the turn signal is turned off. When the driver manually changes lanes such that the vehicle enters an adjacent lane from the traveling lane, the turn signal may be turned off without being operated by the driver. As a result, it is possible to improve the convenience of the driver. In addition, when the vehicle enters an adjacent lane from the traveling lane, the turn signal is turned off. Therefore, it is possible to prevent drivers of adjacent vehicles from misunderstanding that the vehicle changes its lane to a lane adjacent to the adjacent lane, compared to a case where the turn signal is maintained in an ON state until lane change control ends.The preferred embodiment of the invention has been described above, but the invention is not limited to the embodiment described above. Various modifications and various improved structures of the invention including the above-described embodiment can be made based on the knowledge of those skilled in the art.For example, the vehicle control system 100 does not necessarily need to perform automated driving. In this case, the vehicle control system 100 may perform lane change control as driving support that supports the manual driving of the driver. When the lane change control ends as the driving support, the vehicle control system 100 switches the traveling state of the vehicle to a state in which the driver manually drives the vehicle. After the lane change control ends as the driving support, the vehicle control system 100 may start other types of driving support such as lane keeping support. When the vehicle control system 100 performs lane change control as automated driving, the lane change control is not necessarily performed as the driving support during manual driving. The vehicle control system 100 may perform both lane change control as automated driving and lane change control as driving support.In the above-described embodiment, the vehicle control system 100 includes the GPS receiving unit 1 and the map database 4. In addition, the HMI 8 is not essential. That is, in the above-described embodiment, various notifications are transmitted to the driver through the HMI 8. However, the notification to the driver is not indispensable. In addition, the conditions for releasing the turn signal maintained in an ON state do not necessarily include the entry of the vehicle from the traveling lane to an adjacent lane.List of reference characters1 GPS receiving unit 2 External sensor 3 Internal sensor 4 Map database 5 Operation detecting unit 6 Actuator 7 Turn signal driving unit 11 Vehicle position detecting unit 12 Surrounding environment detecting unit 13 Traveling state detecting unit 14 Lane change control unit 15 Turn signal control unit 100 Vehicle control systemThe vehicle control system includes a turn signal control unit configured to switch a turn signal of the vehicle between an OFF state and an ON state according to the lane change control. The turn signal control unit maintains the turn signal in the ON state until predetermined release conditions are satisfied when the lane change control in processing is canceled and the vehicle is switched to the manual driving mode.

Claims

A vehicle control system that performs lane change control for changing a lane of a vehicle from a traveling lane to an adjacent lane, breaks the lane change control according to at least one of operation of a driver of the vehicle, surrounding environment of the vehicle, and traveling state of the vehicle during the lane change control, and switches the vehicle to a mode in which the driver manually drives the vehicle, the system comprising: a turn signal control unit configured to switch a turn signal of the vehicle between an OFF state and an ON state according to the lane change control, characterized in that the turn signal control unit maintains the turn signal in the ON state until predetermined enabling conditions are satisfied, when the lane change control is canceled in processing and the vehicle is shifted to the manual driving mode, and by the turn signal control unit determining that the enabling conditions are satisfied when the vehicle has moved in the lateral direction by a predetermined distance since the lane change control was canceled and the vehicle is shifted to the manual driving mode.The vehicle control system according to claim 1, wherein when the vehicle enters the adjacent lane from the traveling lane after the lane change control is canceled to be processed and the vehicle is switched to the manual driving mode, the turn signal control unit determines that the release conditions are satisfied and switches the turn signal to the OFF state.

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