JP6946754B2 - Lane change support device - Google Patents

Description

The present invention relates to a lane change support device capable of executing lane change support control that supports a steering operation for changing lanes.

Patent Document 1 discloses a lane change support device capable of executing lane change support control that assists a steering operation of a steering steering wheel when a vehicle changes lanes.

This lane change support device makes a vehicle equipped with the lane change support device (hereinafter referred to as "own vehicle") adjacent to the original lane from the lane in which the own vehicle is currently traveling (hereinafter referred to as the original lane). It is possible to calculate a target trajectory function that defines a target track for changing lanes to the target lane, which is the lane in which the driver of the own vehicle desires to move. The direction of the target lane when viewed from the original lane can be set by the operating means provided in the own vehicle. In other words, the lane movement direction of the own vehicle by the lane change support control can be set by the operating means.

This type of target track function is, for example, a function for calculating the target lateral position of the own vehicle corresponding to time with reference to the lane center line extending in parallel with the original lane at the center of the original lane in the lane width direction. That is, in order to calculate the target trajectory function, the lane change support device needs to recognize the position of the lane center line of the original lane.
Therefore, the lane change support device recognizes a pair of lane markings (white lines) that define the left and right side edges of the original lane, for example, by using shooting data acquired by the camera. Further, the lane change support device recognizes that the center position in the lane width direction between the left and right lane markings is the position through which the lane center line of the original lane passes.

Further, the lane change support device controls the steering angle of the steering wheel of the own vehicle so that the own vehicle travels along the target trajectory defined by the calculated target trajectory function.
The lane change support device executes lane change support control in this way.

Japanese Unexamined Patent Publication No. 2016-126360 Japanese Unexamined Patent Publication No. 2002-163642

The camera mounted on the own vehicle cannot always recognize the pair of lane markings in the original lane. That is, the camera may temporarily recognize only one lane marking and not the other lane marking.
However, the lane change support device may already recognize the lane width of the original lane by the time the camera does not recognize the other lane marking. Further, for example, the lane change support device may be able to recognize the lane width of the original lane from the information of the map data of the car navigation system mounted on the own vehicle.
Even if the camera recognizes only one lane, if the lane change support device recognizes the lane width of the original lane, the original lane is based on the position and lane width of one lane of the original lane. It is possible to recognize (calculate) the position of the center line of the lane.
Therefore, the lane change support device can execute the lane change support control even when the camera recognizes only one of the pair of lanes of the original lane.

However, when the lane change support device executes such lane change support control, the following problems may occur.

The road shown in FIG. 6 has three lanes (lane 1, lane 2, and lane 3). The vehicle travels on this road in the direction of arrow A.
Further, the lane 1 is curved and merges with the lane 2 in front of the own vehicle located at the position X1 on the lane 1. In other words, the number of lanes on the road has decreased from "3" to "2" in front of the own vehicle located at position X1.
Further, at the confluence (curved portion) of the lane 1 with the lane 2, the lane marking on the left side of the lane 1 is drawn by a solid line. On the other hand, on this road, a lane marking line defining the right edge of the confluence of lane 1 with lane 2 is not drawn.

Here, it is assumed that the own vehicle located at the position X1 is executing the lane change support control.

The direction of the target lane when viewed from the original lane is set to the right by the operation means. That is, the driver of the own vehicle located at the position X1 expects that the own vehicle will change lanes from lane 1 to lane 2 by the lane change support control. In other words, the driver expects his vehicle to change lanes from lane 1 to lane 2 on the right side by lane change support control.
However, when the camera of the own vehicle that has moved to the position X2 on the confluence of lane 1 recognizes the lane marking on the left side of the confluence, the lane change support control has already acquired the lane width information and lane of lane 1. Based on the position information of the lane marking on the left side of the merging portion of 1, there is a risk of erroneously recognizing that there is a lane center line PCL of lane 1 at the merging portion. In other words, the lane change support control may erroneously recognize that the lane 1 is a lane extending to a position ahead of the merging portion.

Therefore, if the lane change support control of the own vehicle C located at the position X2 is erroneously recognized in this way, the own vehicle C located at the position X2 may change lanes to the lane 3 along the target trajectory indicated by the arrow M. be. That is, although the driver of the own vehicle expected that the own vehicle would change lanes from lane 1 to lane 2 by the lane change support control, the own vehicle changed lanes from lane 1 to lane 3 at once. There is a risk that it will end up. In this case, the driver of the own vehicle may feel uncomfortable.

The present invention has been made to address the above problems. That is, one of the objects of the present invention is that the vehicle can execute the lane change support control when the lane recognition means recognizes only one of the pair of lane markings that define the lane in which the vehicle is traveling. It is an object of the present invention to provide a lane change support device capable of preventing a sudden lane change from a running lane to a lane adjacent to this lane when passing through a portion of the road where the number of lanes decreases. ..

In order to achieve the above object, the features of the lane change support device disclosed in this specification are:
When the own vehicle (C) can recognize a pair of lane markings (WL) defining the left and right side edges of the original lane, which is the lane in which the vehicle is traveling, and recognizes at least one of the lane markings, the said A lane recognition means (12) capable of recognizing a relative position of the own vehicle in the lane width direction with respect to the original lane, and
The own vehicle traveling in the original lane is adjacent to the original lane from either the left side or the right side so that the relative position recognized by the lane recognition means changes along a predetermined target track. Lane change support control means (10, 20) capable of executing lane change support control for changing lanes to the target lane, and
With
The lane change support control means
When the lane recognition means does not recognize the lane marking on one side of the original lane and recognizes the lane marking on the other side, the own vehicle traveling in the original lane moves from the one side to the original lane. It is configured so that it is prohibited to execute the lane change support control so as to change lanes to the target lane adjacent to the lane.

The lane marking is, for example, a white line.
However, the lane marking line may include a line different from the white line.

The lane recognition means disclosed in the present specification can recognize a pair of lane markings that define the left and right side edges of the original lane, which is the lane in which the own vehicle is traveling. Further, the lane recognition means can recognize the relative position of the own vehicle in the lane width direction with respect to the original lane when recognizing at least one lane marking.
Further, the lane change support control means moves the own vehicle traveling in the original lane from one side of the left side and the right side to the original lane so that the relative position recognized by the lane recognition means changes along a predetermined target trajectory. It is possible to execute lane change support control for changing lanes to the adjacent target lane.
That is, when the lane recognition means recognizes only one lane of the lane in which the vehicle is traveling, the lane change support control means can execute the lane change support control.

However, in the lane change support control means, when the lane recognition means does not recognize the lane marking on one side of the original lane and recognizes the lane marking on the other side, the own vehicle traveling in the original lane is on the one side. It is prohibited to execute the lane change support control so as to change the lane to the target lane adjacent to the original lane.
For example, if the lane recognition means recognizes only the lane marking on the left side of the original lane, the lane change support control means moves the own vehicle traveling in the original lane to the target lane to the right of the original lane. It is prohibited to change it.

Therefore, for example, the own vehicle located at the position X2 of the lane 1 in FIG. 6 is prohibited from changing lanes from the lane 1 (the confluence of the original lanes) to the lane 3 by the lane change support control. That is, there is no possibility that the own vehicle will be changed from lane 1 to lane 3 at once by the lane change support control.

In the above description, in order to help the understanding of the present invention, the names and / or symbols used in the embodiments are added in parentheses to the configurations of the invention corresponding to the embodiments described later. However, each component of the present invention is not limited to the embodiment defined by the reference numerals. Other objects, other features and accompanying advantages of the invention will be readily understood from the description of embodiments of the invention described with reference to the drawings below.

It is a schematic block diagram of the lane change support device which concerns on embodiment of this invention. It is a figure for demonstrating operation of a turn signal lever. It is a flowchart which shows the steering support control routine which concerns on embodiment. It is a figure which shows the target trajectory of own vehicle. It is a figure which shows the state in which the own vehicle travels in a part where the number of lanes of a road decreases while executing lane keeping support control and lane change support control. It is a figure which shows the state that the own vehicle of the comparative example travels in the part where the number of lanes of a road decreases while executing the lane change support control.

Hereinafter, the steering support device according to the embodiment of the present invention will be described with reference to the drawings.

The steering support device according to the embodiment of the present invention is applied to a vehicle C (hereinafter, may be referred to as "own vehicle C" to distinguish it from other vehicles). As shown in FIG. 1, the own vehicle C includes a driving support ECU 10, an electric power steering ECU 20, a meter ECU 30, a steering ECU 40, an engine ECU 50, a brake ECU 60, and a navigation ECU 70.

These ECUs are electric control units (Electric Control Units) including a microcomputer as a main part, and are connected to each other via CAN (Controller Area Network) 100 so that information can be transmitted and received. As used herein, a microprocessor includes a CPU, ROM, RAM, non-volatile memory, interface I / F, and the like. The CPU realizes various functions by executing instructions (programs, routines) stored in ROM. Some or all of these ECUs may be integrated into one ECU.

Further, a plurality of types of vehicle state sensors 80 for detecting the vehicle state and a plurality of types of driving operation state sensors 90 for detecting the driving operation state are connected to the CAN 100. The vehicle condition sensor 80 includes, for example, a vehicle speed sensor that detects the traveling speed of the vehicle, a front-rear G sensor that detects the acceleration in the front-rear direction of the vehicle, a lateral G sensor that detects the lateral acceleration of the vehicle, and a yaw rate of the vehicle. It is a yaw rate sensor to detect.

The operation operation state sensor 90 detects an accelerator operation amount sensor that detects the operation amount of the accelerator pedal, a brake operation amount sensor that detects the operation amount of the brake pedal, a brake switch that detects the presence or absence of operation of the brake pedal, and a steering angle. These include a steering angle sensor, a steering torque sensor that detects steering torque, and a shift position sensor that detects the shift position of a transmission.

The information (referred to as sensor information) detected by the vehicle state sensor 80 and the driving operation state sensor 90 is transmitted to the CAN 100. In each ECU, the sensor information transmitted to the CAN 100 can be appropriately used.

The driving support ECU 10 is a central control device that assists the driver in driving, and performs lane change support control, lane keeping support control, and follow-up inter-vehicle distance control. As shown in FIG. 1, a peripheral sensor 11 is connected to the driving support ECU 10.

The peripheral sensor 11 includes a radar transmission / reception unit and a signal processing unit (not shown), and the radar transmission / reception unit emits radio waves in the millimeter wave band (hereinafter, referred to as “millimeter wave”) and has a radiation range. Receives millimeter waves (ie, reflected waves) reflected by a three-dimensional object (eg, another vehicle, pedestrian, bicycle, building, etc.) existing within. The signal processing unit is stereoscopic with the own vehicle C based on the phase difference between the transmitted millimeter wave and the received reflected wave, the attenuation level of the reflected wave, the time from the transmission of the millimeter wave to the reception of the reflected wave, and the like. Information (hereinafter referred to as peripheral information) indicating the distance to the object, the relative speed between the own vehicle C and the three-dimensional object, the relative position (direction) of the three-dimensional object with respect to the own vehicle C, etc. is acquired every time a predetermined time elapses. It is supplied to the operation support ECU 10. From this peripheral information, it is possible to detect the front-rear direction component and the lateral direction component in the distance between the own vehicle C and the three-dimensional object, and the front-rear direction component and the lateral direction component in the relative speed between the own vehicle C and the three-dimensional object. ..

The peripheral sensor 11 is a radar sensor in the present embodiment, but other sensors such as a clearance sonar and a rider sensor can be adopted instead.

Further, a camera sensor 12 is connected to the driving support ECU 10. The camera sensor 12 includes a camera unit and a lane recognition unit that analyzes image data obtained by taking a picture by the camera unit and recognizes a white line WL, which is a kind of road marking line. The camera sensor 12 (camera unit) captures the scenery in front of the own vehicle C. The camera sensor 12 (lane recognition unit) repeatedly supplies the recognized white line WL information to the operation support ECU 10 at a predetermined calculation cycle.

The camera sensor 12 recognizes a lane (see FIG. 5) representing an area partitioned by a pair of white lines WL, and is relative to the lane of the own vehicle C based on the positional relationship between the white line WL and the own vehicle C. The positional relationship can be detected. Here, the position of the own vehicle C is the position of the center of gravity of the own vehicle C. Further, the lateral position of the own vehicle C represents the position of the center of gravity of the own vehicle C in the lane width direction, and the lateral speed of the own vehicle C represents the speed of the center of gravity of the own vehicle C in the lane width direction. The lateral acceleration of the vehicle C represents the acceleration of the position of the center of gravity of the own vehicle C in the lane width direction. These are obtained by the relative positional relationship between the white line WL detected by the camera sensor 12 and the own vehicle C.

As shown in FIG. 5, the camera sensor 12 sets a lane center line CL (dashed line) which is a center position in the width direction of the left and right white lines WL in the lane in which the own vehicle C is traveling. This lane center line CL is used as a target traveling line in lane keeping support control described later. Further, the camera sensor 12 calculates the curvature Cu of the curve of the lane center line CL.

When the camera sensor 12 recognizes (simultaneously) a pair of white line WLs that define the left and right side edges of the lane in which the own vehicle C is traveling, the camera sensor 12 recognizes both (simultaneously) the pair of white lines WL in the lane width direction between the recognized pair of white lines WL. The center position is recognized as the position through which the lane center line CL of this lane passes.

Further, the camera sensor 12 cannot always recognize the pair of white line WLs in the lane in which the own vehicle C is traveling. That is, the camera sensor 12 may temporarily recognize only one white line WL and not the other white line WL.
However, as will be described later, the map information stored in the map database 72 connected to the navigation ECU 70 includes information on the lane width of the road (each lane). Therefore, even in such a situation, the camera sensor 12 can recognize the lane width of this lane based on the information in the map database 72. If the camera sensor 12 has already recognized the pair of white line WLs in this lane at the same time at least once before such a situation occurs, the camera sensor 12 is based on the acquired position information of the pair of white line WLs. Can recognize the lane width of this lane.
Then, the camera sensor 12 can recognize (calculate) the position of the lane center line CL of this lane based on the information regarding the lane width of this lane and the information regarding the position of one white line WL.
The road shown in FIG. 5 has a plurality of lanes 1, 2, and 3. In this case, when the camera sensor 12 of the own vehicle C recognizes the lane width of the lane 1 by recognizing the white lines WL on the left and right of the lane 1, the camera sensor 12 also recognizes the lane width of the lane 2 and the lane 3 of the lane 1. Recognize that it is the same as the lane width. However, if the information stored in the map database 72 indicates that the lane width of lane 1 and the lane widths of lanes 2 and 3 are different, the camera sensor 12 determines that the lane widths of lanes 2 and 3 are the map database 72. Recognizes that it is the lane width indicated by the information stored in.

Further, the camera sensor 12 includes not only the lane in which the own vehicle C is traveling but also the lane adjacent to this lane, the type of the detected white line WL (solid line, broken line), and the distance between the adjacent left and right white line WLs. Information about the white line WL, such as (lane width) and the shape of the white line WL, is also supplied to the driving support ECU 10 at a predetermined calculation cycle. When the white line WL is a solid line, it is prohibited for the vehicle to change lanes across the white line WL. On the other hand, when the white line WL is a broken line (white line formed intermittently at regular intervals), the vehicle is allowed to change lanes across the white line WL.

The driving support ECU 10 includes peripheral information supplied from the peripheral sensor 11, information on the lane obtained based on white line recognition of the camera sensor 12, vehicle status detected by the vehicle status sensor 80, and driving operation status sensor 90. Based on the driving operation state and the like detected in the above, lane change support control, lane keeping support control, and follow-up vehicle-to-vehicle distance control are performed.

A setting operator 14 operated by a driver is connected to the driving support ECU 10. The setting operation device 14 is an operation device for setting whether or not to implement each of the lane change support control, the lane keeping support control, and the following inter-vehicle distance control. The operation support ECU 10 inputs the setting signal of the setting operation device 14 to determine whether or not each control is executed. In this case, if the implementation of the following inter-vehicle distance control is not selected, the lane change support control and the lane keeping support control are automatically set so as not to be implemented. If the implementation of lane keeping support control is not selected, the lane change support control is automatically set so as not to be implemented.

Further, the setting operation device 14 also has a function of inputting a parameter or the like indicating a driver's preference when performing the above control.

The electric power steering ECU 20 is a control device for the electric power steering device. Hereinafter, the electric power steering ECU 20 will be referred to as an EPS / ECU (Electric Power Steering ECU) 20. The EPS / ECU 20 is connected to the motor driver 21. The motor driver 21 is connected to the steering motor 22. The steering motor 22 is incorporated in a "steering mechanism including a steering wheel, a steering shaft connected to the steering handle, a steering gear mechanism, and the like" of a vehicle (not shown). The EPS / ECU 20 detects the steering torque input by the driver to the steering handle (not shown) by the steering torque sensor provided on the steering shaft, and controls the energization of the motor driver 21 based on the steering torque. It drives the steering motor 22. Steering torque is applied to the steering mechanism by driving the assist motor to assist the driver's steering operation.

Further, when the EPS / ECU 20 receives a steering command from the driving support ECU 10 via the CAN 100, the EPS / ECU 20 drives the steering motor 22 with a control amount specified by the steering command to generate steering torque. This steering torque is different from the steering assist torque given to lighten the steering operation (steering wheel operation) of the driver described above, and the steering mechanism is given by a steering command from the driving support ECU 10 without requiring the steering operation of the driver. Represents the torque applied to.

Even when the EPS / ECU 20 receives a steering command from the driving support ECU 10, if the steering torque due to the steering wheel operation of the driver is detected, the steering torque is larger than the threshold value. Gives priority to the steering wheel steering of the driver and generates a steering assist torque that lightens the steering wheel operation.

The meter ECU 30 is connected to a display 31 and left and right turn signal 32s (meaning turn signal lamps, sometimes called turn lamps). The display 31 is, for example, a multi-information display provided in front of the driver's seat, and displays various information in addition to displaying measured values of meters such as vehicle speed. For example, when the meter ECU 30 receives a display command according to the driving support state from the driving support ECU 10, the meter ECU 30 causes the display 31 to display the screen specified by the display command. As the display unit 31, a head-up display (not shown) may be used instead of or in addition to the multi-information display. When a head-up display is adopted, it is preferable to provide a dedicated ECU for controlling the display of the head-up display.

Further, the meter ECU 30 is provided with a turn signal drive circuit (not shown), and when a turn signal blinking command is received via the CAN 100, the turn signal 32 in the direction (right, left) specified by the turn signal blinking command is blinked. Let me. Further, the meter ECU 30 transmits the blinker blinking information indicating that the blinker 32 is in the blinking state to the CAN 100 while the blinker 32 is blinking. Therefore, in other ECUs, the blinking state of the blinker 32 can be grasped.

The steering ECU 40 is connected to the turn signal lever 41. The turn signal lever 41 is an operator for operating (blinking) the turn signal 32, and is provided on the steering column. The turn signal lever 41 is provided so as to be swingable around the support shaft O in two steps of operation strokes in each of the clockwise operation direction and the counterclockwise operation direction.

The turn signal lever 41 of the present embodiment is also used as an actuator for which the driver requests lane change support control. As shown in FIG. 2, the turn signal lever 41 has a first stroke which is a position rotated by a first angle θW1 from the neutral position PN in each of the counterclockwise operation direction and the clockwise operation direction about the support shaft O. It is configured to be selectively operable at the position P1L (P1R) and the second stroke position P2L (P2R) which is a position rotated by a second angle θW2 (> θW1) from the neutral position PN. At the first stroke position P1L (P1R), the turn signal lever 41 returns to the neutral position PN when the driver's lever operating force is released, and at the second stroke position P2L (P2R), even if the lever operating force is released, the blinker lever 41 returns to the neutral position PN. The state is held by the lock mechanism. Further, when the turn signal lever 41 is held at the second stroke position P2L (P2R) and the steering handle is rotated in the reverse direction to return to the neutral position, or when the driver moves the turn signal lever 41 toward the neutral position. When the return operation is performed, the lock by the lock mechanism is released and the position is returned to the neutral position PN.

The turn signal lever 41 is turned on only when the first switch 411L (411R) is tilted to the first stroke position P1L (P1R) and when it is tilted to the second stroke position P2L (P2R). It is equipped with a second switch 412L (412R).

The steering ECU 40 detects the operating state of the turn signal lever 41 based on the states of the first switch 411L (411R) and the second switch 412L (412R), and the turn signal lever 41 moves to the first stroke position P1L (P1R). In each of the state of being tilted to the second stroke position P2L (P2R) and the state of being tilted to the second stroke position P2L (P2R), a blinker blinking command including information indicating the operation direction (left and right) is transmitted to the meter ECU 30. ..

Further, the steering ECU 40 has detected that the turn signal lever 41 is continuously held at the first stroke position P1L (P1R) for a preset time (lane change request confirmation time: for example, 1 second) or longer. In this case, a lane change support request signal including information indicating the operation direction (left and right) is output to the driving support ECU 10. Therefore, if the driver wants to receive lane change support during driving, the driver may tilt the turn signal lever 41 to the first stroke position P1L (P1R) in the lane change direction and hold the turn signal lever 41 for a set time or longer. Such an operation is called a lane change support request operation.

In the present embodiment, the turn signal lever 41 is also used as an operating device for the driver to request lane change support, but instead, a dedicated lane change support request operating device may be provided on the steering wheel or the like. ..

The engine ECU 50 is connected to the engine actuator 51. The engine actuator 51 is an actuator for changing the operating state of the internal combustion engine 52. In the present embodiment, the internal combustion engine 52 is a gasoline fuel injection / spark ignition type / multi-cylinder engine, and includes a throttle valve for adjusting the intake air amount. The engine actuator 51 includes at least a throttle valve actuator that changes the opening degree of the throttle valve. The engine ECU 50 can change the torque generated by the internal combustion engine 52 by driving the engine actuator 51. The torque generated by the internal combustion engine 52 is transmitted to drive wheels (not shown) via a transmission (not shown). Therefore, the engine ECU 50 can control the driving force of the own vehicle C and change the acceleration state (acceleration) by controlling the engine actuator 51.

The brake ECU 60 is connected to the brake actuator 61. The brake actuator 61 is provided in a hydraulic circuit between a master cylinder (not shown) that pressurizes hydraulic oil by the pedaling force of a brake pedal and a friction brake mechanism 62 provided on the left, right, front, and rear wheels. The friction brake mechanism 62 includes a brake disc 62a fixed to the wheel and a brake caliper 62b fixed to the vehicle body. The brake actuator 61 adjusts the hydraulic pressure supplied to the wheel cylinder built in the brake caliper 62b in response to an instruction from the brake ECU 60, and operates the wheel cylinder by the hydraulic pressure to press the brake pad against the brake disc 62a to cause friction. Generates braking force. Therefore, the brake ECU 60 can control the braking force of the own vehicle C by controlling the brake actuator 61.

The navigation ECU 70 is connected to a GPS receiver 71 that receives a GPS signal for detecting the current position of the own vehicle C, a map database 72 that stores map information, and a touch panel (touch panel display) 73. .. The navigation ECU 70 identifies the current position of the own vehicle C based on the GPS signal, and performs various arithmetic processes based on the position of the own vehicle C and the map information stored in the map database 72, and performs various arithmetic processes, and the touch panel 73. Use to guide the route.

The map information stored in the map database 72 includes road information. The road information includes parameters indicating the position and shape of the road (for example, the radius or curvature of the road, the width of the lane of the road, the number of lanes, the position of the center line of each lane, and the like). In addition, the road information includes road type information and the like that can distinguish whether or not the road is a motorway.

<Control processing performed by the driving support ECU 10>
Next, the control process performed by the driving support ECU 10 will be described. The driving support ECU 10 executes lane change support control when a lane change support request is received in a situation where both lane keeping support control and follow-up inter-vehicle distance control are performed. Therefore, first, lane keeping support control and follow-up inter-vehicle distance control will be briefly described.

<Lane maintenance support control (LTA)>
In the lane keeping support control, the steering torque is applied to the steering mechanism so that the position of the own vehicle C is maintained near the target driving line in the "lane in which the own vehicle C is traveling", and the driver's steering operation is performed. It is a control that supports. In the present embodiment, the target traveling line is the lane center line CL, but a line offset from the lane center line CL by a predetermined distance in the lane width direction can also be adopted.
Hereinafter, lane keeping support control will be referred to as LTA (lane tracing assist). LTA is well known, and its control contents are disclosed in, for example, Japanese Patent Application Laid-Open No. 2008-195402, Japanese Patent Application Laid-Open No. 2009-190464, Japanese Patent Application Laid-Open No. 2010-6279, and Japanese Patent No. 4349210. There is.
The operation support ECU 10 executes the LTA when the LTA is requested by the operation of the setting operation device 14 and the predetermined LTA start condition is satisfied. In order for the driving support ECU 10 to execute the LTA, the camera sensor 12 needs to recognize the lane center line CL of the lane. Therefore, in the LTA start condition, at least, "the camera sensor 12 (lane recognition unit) recognizes only one of the pair of white line WLs and the lane width that define the left and right side edges of the lane, respectively, or a pair. The requirement that the camera sensor 12 recognizes both of the white line WLs at the same time is included.

<Following inter-vehicle distance control (ACC)>
When it is determined that there is a preceding vehicle traveling in front of the own vehicle C based on the surrounding information, the following inter-vehicle distance control maintains the inter-vehicle distance between the preceding vehicle and the own vehicle C at a predetermined distance. However, the control is such that the own vehicle C follows the preceding vehicle, and when the preceding vehicle does not exist, the own vehicle C is driven at a constant speed at the set vehicle speed. This control is executed by the driving support ECU 10 controlling the engine actuator 51 and / and the brake actuator 61 via the engine ECU 50 and / and the brake ECU 60. Hereinafter, the following vehicle-to-vehicle distance control is referred to as ACC (adaptive cruise control). ACC is well known, and its control contents are disclosed in, for example, Japanese Patent Application Laid-Open No. 2014-148293, Japanese Patent Application Laid-Open No. 2006-315491, Japanese Patent No. 4172434, and Japanese Patent No. 4929777.
The operation support ECU 10 executes the ACC when the ACC is requested by the operation of the setting operation device 14.

<Lane change support control (LCA)>
The lane change support control monitors the surroundings of the own vehicle C by using the peripheral information acquired by the peripheral sensor 11, and after it is determined that the lane can be changed safely, the surroundings of the own vehicle C are monitored. At the same time, the control applies steering torque to the steering mechanism so that the own vehicle C moves from the lane in which the vehicle is currently traveling to an adjacent lane to support the driver's steering operation (lane change operation). Therefore, according to the lane change support control, it is possible to change the lane in which the own vehicle C travels without requiring the driver's steering operation (steering wheel operation). Hereinafter, lane change support control will be referred to as LCA (lane change assist).

Like the LTA, the LCA is a control of the lateral position of the own vehicle C with respect to the lane, and is implemented in place of the LTA when a lane change support request is received during the implementation of the LTA and the ACC. Hereinafter, LTA and LCA are collectively referred to as steering support control, and the state of steering support control is referred to as steering support control state.

Since the steering support device supports the steering operation of the driver, when performing steering support control (LTA, LCA), a steering force for control is generated so that the steering wheel operation of the driver is prioritized. Let me. Therefore, the driver can advance the own vehicle C in the intended direction by operating his / her own steering wheel even during the steering support control.

FIG. 3 shows a steering support control routine executed by the driving support ECU 10. The steering support control routine is executed when the conditions for permitting the execution of LTA are satisfied. The LTA execution permission conditions include that the implementation of the LTA is selected by the setting actuator 14, that the ACC is executed, that the LTA start condition is satisfied, and the like.

When the driving support ECU 10 starts the steering support control routine, the driving support ECU 10 sets the steering support control state to the LTA / ON state in step S11. The LTA / ON state represents a control state in which LTA is executed.

Subsequently, the driving support ECU 10 determines in step S12 whether or not the LCA start condition is satisfied.

The LCA start condition is satisfied, for example, when all of the following conditions are satisfied.
1. 1. The lane change support request operation is detected.
2. Implementation of LCA is selected by the setting actuator 14.
3. 3. The white line WL in the turn signal operation direction (the white line WL that is the boundary between the original lane, which is the lane in which the own vehicle C is currently traveling, and the target lane) is a broken line.
4. The result of determining whether or not LCA can be performed for peripheral monitoring is possible (the peripheral information obtained by the peripheral sensor 11 does not detect obstacles (other vehicles, etc.) that hinder the lane change, and the lane can be changed safely. It is judged that).
5. The road is a motorway (the road type information acquired from the navigation ECU 70 represents a motorway).
6. The vehicle speed of own vehicle C is within the LCA permitted vehicle speed range permitted by LCA.
7. The camera sensor 12 (lane recognition unit) recognizes only one white line WL on the left side and the right side of the pair of white line WLs that define the left and right side edges of the original lane, respectively, and the driving support ECU 10 provides information on the lane width of the original lane. When the acquisition is made, the lane change direction of the own vehicle C by the lane change support request operation and the direction of the one white line WL seen from the own vehicle C are the same as each other, or both of the pair of white line WLs. The camera sensor 12 recognizes at the same time. For example, when the map information of the map database 72 includes information on the lane width of the road (each lane), or the information on the lane width of the road is a fixed value (for example, in the memory (ROM) of the driving support ECU 10). When recorded as 3.5 m), the driving support ECU 10 can acquire information on the lane width of the original lane even when the camera sensor 12 recognizes only one white line WL.
For example, the condition "4." is satisfied when it is estimated that the distance between the two vehicles after the lane change is appropriately secured based on the relative speed between the own vehicle C and another vehicle traveling in the target lane. ..
The LCA start condition is not limited to these conditions as long as the condition "7." is included, and can be set arbitrarily.

If the LCA start condition is not satisfied, the operation support ECU 10 returns the process to step S11 to continue the execution of the LTA.

If the LCA start condition is satisfied while the LTA is being implemented (step S12: Yes), the operation support ECU 10 implements the LCA instead of the LTA in step S13. Then, the driving support ECU 10 transmits an LCA execution display command to the meter ECU 30.
For example, the camera sensor 12 (lane recognition unit) of the own vehicle C that satisfies the conditions "1." to "6." and is traveling in the lane 3 of FIG. 5 recognizes the white line WL on the right side of the lane 3. If only the white line WL on the left side is recognized and the lane width of lane 3 is recognized and the lane change direction of the own vehicle C by the lane change support request operation is on the left side, the driving support ECU 10 yes in step S12. Is determined.

The driving support ECU 10 calculates a target trajectory function representing the target trajectory of the own vehicle C by a well-known method in step S13. This target track function is a function that calculates the target lateral position (position in the lane width direction) of the own vehicle C with respect to the lane center line CL of the original lane based on time.

When the target trajectory function is calculated, the driving support ECU 10 performs steering control based on the target trajectory function in the following step S14.
That is, the driving support ECU 10 calculates the target steering angle of the steering wheel at the current time by using the value obtained by substituting the current time into the target trajectory function. At this time, the driving support ECU 10 reduces the error between the lateral position of the own vehicle C obtained by substituting the current time into the target trajectory function and the actual lateral position at the current time obtained by the camera sensor 12, for example. Calculate the target steering angle. That is, the calculation formula used by the driving support ECU 10 to obtain the target steering angle includes a feedback term. In addition to the lateral position error, this feedback term may reduce the lateral speed and lateral acceleration errors of the own vehicle.
Then, the driving support ECU 10 transmits information regarding the target steering angle to the EPS / ECU 20. Then, the EPS / ECU 20 drives and controls the steering motor 22 so that the steering wheels rotate at the target steering angle at the current time. As a result, the own vehicle C executes a lane change along the target track.

Further, the operation support ECU 10 that has completed the process of step S14 determines in step S15 whether or not the predetermined LCA interruption condition is satisfied. The LCA interruption condition of the present embodiment is satisfied when the above "7." of the LCA start condition is no longer satisfied. That is, the camera sensor 12 (lane recognition unit) recognizes only one white line WL on the left side and the right side of the pair of white line WLs that define the left and right side edges of the original lane, respectively, and the driving support ECU 10 relates to the lane width of the original lane. When the lane change direction of the own vehicle C by the lane change support request operation and the direction of the one white line WL seen from the vehicle C are different from each other when the information is acquired, or both of the pair of white line WLs are captured by the camera. When the sensors 12 stop recognizing at the same time, the LCA interruption condition is satisfied.

If the driving support ECU 10 determines Yes in step S15, the driving support ECU 10 interrupts the LCA and returns to step S11 to set the steering support control state to the LTA / ON state. That is, the driving support ECU 10 restarts the LTA.

The driving support ECU 10 that determines No in step S15 determines whether or not the LCA completion condition is satisfied in step S16. The LCA completion condition of the present embodiment is that when the lateral position of the own vehicle C matches the final target lateral position represented by the target trajectory (target trajectory function) calculated in step S13 (the lateral speed of the own vehicle C becomes zero). When) holds. If the LCA completion condition is not satisfied, the operation support ECU 10 returns the process to step S14, and repeats the processes of step S14 and step S15 at a predetermined calculation cycle. The final target lateral position represented by the target track is a position on the lane center line CL of the target lane.

On the other hand, when it is determined in step S16 that the LCA completion condition is satisfied, the driving support ECU 10 sets the steering support control state to the LTA / ON state in step S17. That is, the LCA is terminated and the LTA is restarted. As a result, steering control is performed so that the own vehicle C travels along the lane center line CL in the target lane. When the steering support control state is set to the LTA / ON state in step S17, the driving support ECU 10 returns the process to step S11 and continues the above-described steering support control routine as it is.

The driving support ECU 10 transmits a blinking command of the turn signal 32 in the turn signal operation direction to the meter ECU 30 during the period from the start of the LCA to the end of the steering support control routine. Before the LCA is started, the turn signal 32 blinks according to a blinking command transmitted from the steering ECU 40 in response to the operation of the turn signal lever 41 to the first stroke position P1L (P1R). Even if the blinking command transmitted from the steering ECU 40 is stopped, the meter ECU 30 continues blinking of the blinker 32 while the blinking command is transmitted from the driving support ECU 10.

According to the lane change support device of the present embodiment described above, in steps S12 and S15 of the flowchart of FIG. 3, the camera sensor 12 defines the left and right side edges of the original lane, respectively, on the left and right sides of the pair of white lines WL. When only one white line WL is recognized and the lane width of the original lane is recognized, the lane change direction of the own vehicle C by the lane change support request operation and the direction of the one white line WL as seen from the vehicle C. LCA control is not executed (interrupted) when they are different from each other. Therefore, it is possible to exert the effects described below.

The road shown in FIG. 5 has three lanes (lane 1, lane 2, and lane 3). The vehicle travels on this road in the direction of arrow A.
Further, the lane 1 is curved and merges with the lane 2 in front of the own vehicle C located at the position X1 on the lane 1. In other words, the number of lanes on the road is reduced from "3" to "2" in front of the own vehicle C located at the position X1.
Further, at the confluence (curved portion) of the lane 1 with the lane 2, the white line WL on the left side of the lane 1 is drawn as a solid line. On the other hand, a white line WL that defines the right edge of the confluence of lane 1 with lane 2 is not drawn on this road. That is, the camera sensor 12 of the own vehicle C can recognize only the white line WL on the left side at the confluence.

Here, the own vehicle C located at the position X1 is executing LTA and LCA, and the driver continuously holds the turn signal lever 41 at the first stroke position P1R for a set time (lane change request confirmation time) or longer. Imagine a case.
The driver of the own vehicle C located at the position X1 expects that the own vehicle C will change lanes from the original lane 1 to the target lane 2 by the LCA. In other words, the driver expects the vehicle C to change lanes from lane 1 to lane 2 on the right side by LCA.
However, when the camera sensor 12 of the own vehicle C that has moved to the position X2 on the confluence of the lane 1 by LTA recognizes the white line WL on the left side of the confluence, the camera sensor 12 provides the lane width information of the lane 1 and the lane 1 of the lane 1. Based on the position information of the white line WL on the left side of the merging portion, there is a risk of erroneously recognizing that there is a lane center line PCL of lane 1 at the merging portion. In other words, the camera sensor 12 may erroneously recognize that the lane 1 is a lane extending to a position ahead of the merging portion.

Therefore, if the camera sensor 12 of the own vehicle C located at the position X2 erroneously recognizes the lane 1 in this way and the own vehicle C starts the LCA at the position X2, the own vehicle C located at the position X2 is indicated by an arrow by the LCA. There is a risk of changing lanes to lane 3 along the target track indicated by PM. That is, although the driver of the own vehicle C expected that the LCA would change lanes from lane 1 (former lane) to lane 2 (target lane), the own vehicle C suddenly changed lanes from lane 1 to lane 3. There is a risk of changing. In this case, the driver of the own vehicle C may feel uncomfortable.

However, in this embodiment, in this case, the camera sensor 12 recognizes only the white line WL on the left side of the confluence of the lane 1. On the other hand, the lane change direction from lane 1 of the own vehicle C, which is defined by the rotation direction of the turn signal lever 41, is the "right side". That is, the camera sensor 12 recognizes only one white line WL on the left side and the right side of the pair of white line WLs in the lane 1 which is the original lane (white line WL on the left side), and the camera sensor 12 recognizes lane 1 (and lanes 2, 3). When recognizing the lane width of, the lane change direction (right side) of the own vehicle C by the lane change support request operation and the direction (left side) of the one white line WL seen from the vehicle C are different from each other. Therefore, the driving support ECU 10 determines No in step S12 and / or Yes in step S15.
Therefore, in the present embodiment, the own vehicle C located at the position X2 does not execute the LCA. Therefore, there is no possibility that the own vehicle C changes lanes from lane 1 (position X2) to lane 3 at once along the target track indicated by the arrow PM.

On the other hand, for example, it is assumed that the own vehicle C moves to the position X3 on the lane 2 by the LTA. When the camera sensor 12 of the own vehicle C located at the position X3 recognizes only the white line WL on the right side of the lane 2 and recognizes the lane width of the lane 2, the lane change of the own vehicle C by the lane change support request operation. When the direction is on the right side, the LCA changes the lane of the own vehicle C from the lane 2 (position X3) to the position X4 on the lane 3 along the target track indicated by the arrow M.

Although the lane change support device according to the present embodiment has been described above, the present invention is not limited to the above embodiment, and various changes can be made without departing from the object of the present invention.

For example, in the present embodiment, it steering assist control state is LTA · ON state (LTA being performed) has become a prerequisite for carrying out the LCA, A CC is performed Hisage may be is rather than before that it is state. Further, in the present embodiment, the LCA is carried out on the condition that the road on which the own vehicle C travels is an automobile-only road, but it is not always necessary to provide such a condition.

10 ... Driving support ECU, 11 ... Peripheral sensor, 12 ... Camera sensor, 20 ... EPS / ECU, 21 ... Motor driver, 22 ... Steering motor, 40 ... Steering ECU, 41 ... Turn signal lever, 80 ... Vehicle status sensor, 90 ... Driving operation status sensor, CL ... Lane center line, WL ... White line (partition line).

Claims (1)

A camera sensor that can recognize a pair of lane markings that define the left and right edges of the original lane, which is the lane in which the vehicle is driving.
When both of the pair of lanes in the original lane are recognized, the relative position of the own vehicle in the lane width direction to the original lane and the lane center line of the original lane or the said lane based on the pair of lanes. It recognizes a line offset in the lane width direction by a predetermined distance from the lane center line, recognizes only one of the pair of lanes of the original lane, and recognizes the lane width of the original lane. At that time, based on the recognized one lane marking and the lane width, the relative position of the own vehicle in the lane width direction with respect to the original lane and the predetermined position from the lane center line of the original lane or the lane center line. Recognizing a line offset in the lane width direction by a distance, setting a lane center line or a line offset in the lane width direction by a predetermined distance from the lane center line as a target driving line is set as the target driving line, and the lane of the own vehicle is set. A lane keeping support control means capable of executing lane keeping support control for controlling the own vehicle so that the relative position in the width direction is maintained at the target traveling line, and
When a lane change support request operation is detected during execution of the lane keeping support control, the own vehicle traveling in the original lane is moved from one of the left side and the right side to the target lane adjacent to the original lane. Lane change support that changes the relative position in the lane width direction of the own vehicle along a predetermined target trajectory from the target driving line of the original lane to the final target position of the target lane so as to change the lane. Lane change support control means that can perform control,
With
The lane change support control means
The lane keeping support control means executes the lane keeping support control based on only one of the recognized lanes of the pair of lanes of the original lane and the lane width of the original lane. If so,
The lane change support request for the own vehicle traveling in the original lane to change lanes to the target lane adjacent to the recognized one of the pair of lanes in the original lane. When the operation is detected, the execution of the lane change support control to the target lane adjacent to the one lane marking is permitted.
Change lanes to the target lane in which the vehicle traveling in front Symbol original lane adjacent to the opposite side of the division line and one of the division line said being recognized of the pair of separation lines of the original lane wherein it Ru is prohibited to perform the pre-Symbol lane change assist control to the target lane adjacent to the separation line between the opposite when the lane change assist request operation is detected for,
It was sea urchin configuration,
Lane change support device.

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