JP2018144577A - Drive assisting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately exert traffic lane change assistance control.SOLUTION: In a case where a specific condition in which a difference between a lateral deviation and a previous lateral deviation is larger than a predetermined threshold is satisfied during traffic lane change assistance control, a drive assistance ECU 10 calculates a lateral deviation difference after a corrected previous filter process, in which a lateral deviation after the previous filter process is corrected according to the direction of a traffic lane change by an amount corresponding to a distance between a reference position of a traffic lane in which the own vehicle was traveling before the traffic lane change and a reference position of a traffic lane in which the own vehicle travels after the traffic lane change. The driving assistance ECU calculates for performing a noise removal filter process, using the lateral deviation after the corrected previous filter process instead of the lateral deviation after the previous filter process.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a driving support device having a function of supporting traveling for changing lanes from an own lane that is a lane in which the host vehicle is traveling to an adjacent target lane that is adjacent to the lane.

  Conventionally, when the driver changes the lane of the host vehicle, a control that automatically changes the turning angle of the steered wheels so as to support the driver's steering operation (ie, lane change support control) is executed. Support devices (hereinafter, sometimes referred to as “conventional devices”) have been proposed (see, for example, Patent Document 1).

  In the conventional apparatus, the “white line and the white line on both sides of the adjacent target lane (that is, the lane to which the lane is changed) adjacent to the lane in which the host vehicle is traveling (hereinafter may be referred to as“ own lane ”). A pair of lane markings such as “yellow line etc.” (hereinafter may be simply referred to as “white line”) is detected. Further, the conventional apparatus recognizes the center position of the adjacent target lane as the reference position, and may be referred to as a lateral displacement (hereinafter referred to as “lateral deviation”) that is a deviation amount in the lane width direction from the reference position. ) Is detected. The conventional device controls the snake angle of the steered wheel using the detected lateral deviation or the like. The conventional apparatus performs noise removal filter processing (for example, low-pass filter processing such as a first-order lag filter) on the detected lateral deviation, and uses the lateral deviation after removing the noise component for the control.

JP-A-10-297516

  In the conventional apparatus, since the angle of view (viewing angle) of the camera used for white line recognition (white line detection) is limited, it is difficult to accurately detect the white line on the lane change direction side of the adjacent target lane. Furthermore, the presence of a vehicle in the adjacent target lane may not detect the white line on the lane change direction side of the adjacent target lane. For these reasons, there is a possibility that a pair of white lines in the adjacent target lane cannot be detected stably and accurately. In this case, the reference position of the adjacent target lane cannot be specified with high accuracy.

  Therefore, it has been studied to perform lane change support control without using the lateral deviation of the adjacent target lane. That is, before the vehicle changes lanes, lane change support control is performed using the lateral deviation based on the reference position determined from the left and right white lines of the lane before the lane change, and the vehicle has changed lanes. Later, it is considered to perform lane change support control using a lateral deviation based on a reference position determined from the white line at the left end and the right end of the own lane after the lane change.

  In this case, for example, the center of the own lane is set as a lateral deviation reference position, the left direction with respect to the reference position is set as a positive direction, and the right direction with respect to the reference position is set as a negative direction. Then, obtaining a positive value or a negative value representing a deviation amount in the road width direction with respect to the reference position as a lateral deviation has been studied.

  However, in this case, the following problem may occur. For example, it is assumed that the conventional apparatus performs lane change support control for the vehicle to change lanes from the left lane to the right lane.

  In this case, when the host vehicle is traveling in the left lane, the position of the boundary line (white line (broken line)) between the left lane and the right lane is the lane from the center position of the left lane, which is the reference position of the lateral deviation. Since the distance L / 2 is half the lane width L in the right direction (negative direction) in the width direction, the lateral deviation of the boundary line is −L / 2. On the other hand, when the host vehicle's lane shifts to the right lane and the host vehicle is traveling in the right lane, the position of the boundary line is changed from the center position of the right lane, which is the reference position for lateral deviation, to the left in the road width direction. Since the distance (L / 2) is half of the lane width L in the direction (positive direction), the lateral deviation of the boundary line is + L / 2.

  Therefore, when the lane change support control is performed, as shown in FIG. 3, when the own vehicle is gradually moving in the left lane from the reference position toward the right (negative direction), the movement Accordingly, the lateral deviation gradually decreases from 0 toward -L / 2.

  Then, after the host vehicle reaches the boundary line between the left lane and the right lane and moves from the left lane to the right lane across the boundary line, the host lane changes from the left lane to the right lane.

  Then, the lateral deviation reference position changes from the center position of the left lane to the center position of the right lane when the host vehicle crosses the boundary, so the lateral deviation at this point (lateral deviation of the boundary position) Changes from -L / 2 to + L / 2. When the host vehicle changes lanes from the right lane to the left lane, the lateral deviation reference position changes from the center position of the right lane to the center position of the left lane when the host vehicle crosses the boundary line. At this time, the lateral deviation (lateral deviation of the boundary line position) changes from + L / 2 to -L / 2.

  As described above, when the lane change support control is performed, when the own vehicle changes lanes from the own lane to the adjacent target lane, the reference position of the lateral deviation is changed, so that the position of the own vehicle is the same position. In the lateral deviation, a difference (difference) corresponding to the lane width L inevitably occurs.

  On the other hand, the filter processing for removing noise with respect to the lateral deviation generally includes the filtered lateral deviation obtained after a predetermined time from the current time (lateral deviation after the previous filtering), and the lateral deviation obtained at the current time (current lateral deviation) , Using. Therefore, when the filter process is performed immediately after the own lane is changed from the left lane to the right lane (the timing when the host vehicle crosses the boundary), the current lateral deviation used for the filter process is the reference position of the right lane. The lateral deviation after the previous filtering process used for the filtering process is a lateral deviation obtained by filtering the lateral deviation calculated based on the reference position of the left lane. Therefore, the lateral deviation after filtering, which is calculated immediately after the own lane is changed from the left lane to the right lane, greatly deviates from the true lateral deviation from the reference position of the right lane. As a result, there is a problem that the lane change support control cannot be performed with high accuracy.

  The present invention has been made to address the above-described problems. That is, one of the objects of the present invention is to reduce the possibility that the accuracy of the lateral deviation after the filter processing is deteriorated when the driving support device is executing the lane change support control. Thus, an object of the present invention is to provide a driving support device (hereinafter also referred to as “the device of the present invention”) that can reduce the possibility that the lane change support control cannot be performed with high accuracy.

The apparatus of the present invention includes a lane marking recognition unit (16b) that recognizes a pair of left and right lane markings that divide the lane that is the lane in which the host vehicle (C) is traveling,
A calculation unit that calculates a lateral deviation, which is a displacement amount of the vehicle in the width direction from a reference position in the width direction of the vehicle lane determined based on the recognized pair of lane markings, every time a predetermined time elapses. (10) and
A filter unit (10) that performs an operation for performing a noise removal filter process every time the predetermined time elapses with respect to the calculated lateral deviation (Dy (n));
Control for executing lane change support control for controlling the steering angle of the host vehicle so as to support the travel for the host vehicle to change lanes using the lateral deviation (Dfy (n)) subjected to the filter processing. Part (10);
With
When the lateral deviation is newly calculated, the filter unit calculates the newly calculated lateral deviation (Dy (n)) and the lateral width after the filter processing calculated at the time point before the predetermined time. The lateral deviation (Dfy (n)) after the current filtering is calculated by performing the computation for performing the noise removal filtering using the lateral deviation (Dfy (n-1)) after the previous filtering that is the deviation. Configured to
The control unit executes the lane change support control using the target lateral position (y (t)) determined with respect to the reference position of the own lane and the lateral deviation after the current filter processing (FIG. 4). Step 440)
In the driving support device,
The filter unit is
It is determined whether or not a specific condition that the magnitude of the difference between the newly calculated lateral deviation and the lateral deviation calculated at a time point before the predetermined time is larger than a predetermined threshold is satisfied (FIG. 4). Step 415),
When it is determined that the specific condition is satisfied (determined as “Yes” in step 415 in FIG. 4), the lateral deviation after the previous filtering process is determined based on the lane in which the host vehicle was traveling before the lane change. Calculates the lateral deviation after the previous filter process after correction, which is corrected according to the direction of the lane change, by an amount (L) corresponding to the distance between the reference position and the reference position of the lane in which the host vehicle travels after the lane change. (Step 425 or 430 in FIG. 4), an operation for performing the noise removal filter processing is performed using the corrected lateral deviation after the previous filtering instead of the lateral deviation after the previous filtering (Step 435). It is configured.

  According to the apparatus of the present invention, when the host vehicle is executing the lane change assist control, immediately after the host vehicle changes the lane, the host vehicle travels the lateral deviation after the previous filtering process before the lane change. The corrected lateral deviation after the previous filter processing is calculated by the amount corresponding to the distance between the lane reference position and the reference position of the lane where the vehicle travels after the lane change. An operation for performing the noise removal filter process is performed using the lateral deviation after the previous correction after the correction instead of the lateral deviation after the filter process.

  Thus, after the vehicle changes lanes, the lateral deviation after filtering does not greatly deviate from the true lateral deviation, so that the host vehicle can travel along the target track with high accuracy. That is, lane change support can be performed appropriately.

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

FIG. 1 is a schematic configuration diagram of a driving support apparatus according to an embodiment of the present invention. FIG. 2 is a plan view of the host vehicle and the road for explaining the lane change support control. FIG. 3 is a graph showing the relationship between time and lateral deviation when the lane change assist control is being executed. FIG. 4 is a flowchart showing a routine executed by the CPU of the driving assistance ECU shown in FIG.

  Hereinafter, a driving support apparatus according to an embodiment of the present invention (hereinafter, also referred to as “present implementation apparatus”) will be described with reference to the drawings. This implementation apparatus is also a vehicle travel control apparatus and a driving assistance control apparatus.

(Constitution)
As shown in FIG. 1, the present embodiment is applied to a vehicle (hereinafter referred to as “own vehicle” in order to be distinguished from other vehicles), and includes a driving assistance ECU 10, an engine ECU 30, and a brake ECU 40. , A steering ECU 50, a meter ECU 60, and a display ECU 70 are provided.

  These ECUs are electric control units (Electric Control Units) each including a microcomputer as a main part, and are connected to each other so as to be able to transmit and receive information via a CAN (Controller Area Network) (not shown). In this specification, the microcomputer includes a CPU, a ROM, a RAM, a nonvolatile memory, an interface I / F, and the like. The CPU implements various functions by executing instructions (programs, routines) stored in the ROM. Some or all of these ECUs may be integrated into one ECU.

  The driving assistance ECU 10 is connected to sensors (including switches) listed below, and receives detection signals or output signals from these sensors. Each sensor may be connected to an ECU other than the driving support ECU 10. In that case, the driving assistance ECU 10 receives a detection signal or an output signal of the sensor via the CAN from the ECU to which the sensor is connected.

  The accelerator pedal operation amount sensor 11 detects an operation amount (accelerator opening) of the accelerator pedal 11a of the host vehicle and outputs a signal representing the accelerator pedal operation amount AP. The brake pedal operation amount sensor 12 detects the operation amount of the brake pedal 12a of the host vehicle and outputs a signal representing the brake pedal operation amount BP.

The steering angle sensor 13 detects the steering angle of the host vehicle and outputs a signal representing the steering angle θ.
The steering torque sensor 14 detects the steering torque applied to the steering shaft US of the host vehicle by operating the steering handle SW, and outputs a signal representing the steering torque Tra.
The vehicle speed sensor 15 detects the traveling speed (vehicle speed) of the host vehicle and outputs a signal representing the vehicle speed Vsx. That is, the vehicle speed Vsx is a speed (that is, a vertical speed) in the front-rear direction of the vehicle (the direction along the central axis extending in the front-rear direction of the host vehicle).

  The peripheral sensor 16 includes a peripheral radar sensor 16a and a camera sensor 16b. The surrounding sensor 16 is configured to acquire information relating to a three-dimensional object existing at least on a road ahead of the host vehicle and on a road around the host vehicle.

  The peripheral radar sensor 16a includes a radar transmission / reception unit and a signal processing unit (not shown). The radar transmission / reception unit radiates millimeter wave radio waves (hereinafter referred to as “millimeter waves”), and further, a three-dimensional object (for example, another vehicle, a pedestrian, a bicycle, a building, etc.) existing within the radiation range. ) To receive the millimeter wave (ie, the reflected wave). The signal processing unit is based on the phase difference between the transmitted millimeter wave and the received reflected wave, the frequency difference between them, the attenuation level of the reflected wave, the time from transmitting the millimeter wave to receiving the reflected wave, etc. Peripheral information representing the distance between the host vehicle and the three-dimensional object, the relative speed between the host vehicle and the three-dimensional object, and the orientation of the three-dimensional object with respect to the host vehicle is acquired and supplied to the driving support ECU 10 every predetermined time. .

  The driving assistance ECU 10 specifies the position of the three-dimensional object relative to the host vehicle from the distance between the host vehicle and the three-dimensional object and the orientation of the three-dimensional object relative to the host vehicle. Further, the driving support ECU 10 uses the peripheral information to determine the longitudinal component (vertical distance) and lateral component (lateral distance) in the distance between the host vehicle and the three-dimensional object, and the front and rear in the relative speed between the host vehicle and the three-dimensional object. A direction component (vertical relative velocity) and a horizontal component (lateral relative velocity) can be detected. When simply referred to as relative speed, the relative speed means a longitudinal relative speed.

  For example, the peripheral radar sensor 16a detects a three-dimensional object that falls within a range of about 100 meters from the host vehicle. Hereinafter, the three-dimensional object detected by the peripheral radar sensor 16a may be referred to as a “target”. Furthermore, information representing the “position (ie, relative position) and speed (ie, relative speed) of the target vehicle” of the target detected by the peripheral radar sensor 16a is also referred to as “target information”. The peripheral radar sensor 16a may be a radar sensor that uses radio waves in a frequency band other than the millimeter wave band.

  The camera sensor 16b includes a camera unit that is a stereo camera, and a lane recognition unit that analyzes the image data obtained by photographing with the camera unit and recognizes a white line on the road. The camera sensor 16b (camera unit) captures a landscape in front of the host vehicle. The camera sensor 16b (lane recognition unit) analyzes image data of an image processing area having a predetermined angle range (a range extending in front of the host vehicle), and forms a white line (partition line) formed on the road ahead of the host vehicle. Is recognized (detected). The camera sensor 16b transmits information regarding the recognized white line to the driving assistance ECU 10.

  The driving assistance ECU 10 is based on the information supplied from the camera sensor 16b and, as shown in FIG. 2, the left and right sides of the lane in which the host vehicle C is traveling (hereinafter also referred to as “own lane”). The lane center line that is the center position in the width direction of the white line WL is specified. In FIG. 2, when the own lane is the left lane, the driving assistance ECU 10 specifies the lane center line CL1 that is the center position in the width direction of the left and right white lines WL of the left lane. When the own lane is the right lane, the driving assistance ECU 10 specifies the lane center line CL2 that is the center position in the width direction of the left and right white lines WL of the right lane. The lane center line CL1 or the lane center line CL2 is used as a target travel line in lane keeping control described later. Hereinafter, when it is not necessary to distinguish the lane center line CL1 or the lane center line CL2, it is referred to as a lane center line CL. Further, the driving assistance ECU 10 calculates the curvature Cu of the curve of the lane center line CL of the own lane.

  In addition, the driving assistance ECU 10 calculates the position and orientation of the host vehicle C in the lane divided by the left white line and the right white line for each predetermined calculation cycle. For example, the driving assistance ECU 10 calculates the distance Dy in the road width direction between the reference point P (for example, the center of gravity position) of the host vehicle C and the lane center line CL of the host lane at every predetermined calculation cycle. The distance Dy is a length indicating the amount by which the own vehicle C is shifted in the road width direction with respect to the lane center line CL of the own lane. This distance Dy is also referred to as “lateral deviation Dy” below. Further, the driving assistance ECU 10 performs a filtering process on the calculated lateral deviation Dy at every predetermined calculation cycle. Details of the filtering process will be described later. Furthermore, the driving assistance ECU 10 calculates the lane width L in which the host vehicle C is traveling based on the information supplied from the camera sensor 16b.

  The driving assistance ECU 10 calculates an angle θy formed by the direction of the lane center line CL of the own lane and the direction of the own vehicle C. This angle θy is also referred to as “yaw angle θy” below. Hereinafter, information (Cu, Dy, θy) representing the curvature Cu, the lateral deviation Dy, and the yaw angle θy may be referred to as “lane related vehicle information”.

  The camera sensor 16b supplies the driving support ECU 10 with information on the type of the left and right white lines (for example, whether it is a solid line or a broken line) and the shape of the white line. Further, the camera sensor 16b also supplies the driving support ECU 10 with respect to the types of the left and right white lines and the shape of the white lines in the lane adjacent to the own lane. That is, the camera sensor 16b also supplies “information regarding the white line” to the driving support ECU 10. When the white line is a solid line, the vehicle is prohibited from changing lanes across the white line. On the other hand, when the white line is a broken line (a white line formed intermittently at regular intervals), the vehicle is permitted to change lanes across the white line. The lane related vehicle information (Cu, Dy, θy) and the information regarding the white line may be referred to as “lane information”.

  In this embodiment, the driving assistance ECU 10 calculates the lane related vehicle information (Cu, Dy, θy), but instead, the camera sensor 16b calculates the lane related vehicle information (Cu, Dy, θy). Then, the calculation result may be supplied to the driving support ECU 10.

  Referring to FIG. 1 again, the operation switch 17 is used to select whether or not to execute each of “lane change assist control, lane keeping control, and following inter-vehicle distance control” to be described later. It is an operating device operated by. Therefore, the operation switch 17 outputs a signal indicating whether or not the execution of each control described above has been selected in accordance with the driver's operation. In addition, the operation switch 17 has a function of allowing the driver to input or select a parameter (for example, an inter-vehicle time to be described later) for reflecting the driver's preference when executing each of the above-described controls.

  The driving assistance ECU 10 determines whether or not the execution of the following inter-vehicle distance control is selected based on the signal supplied from the operation switch 17, and when the execution of the following inter-vehicle distance control is not selected, the lane change assist control In addition, the lane keeping control is not executed. Further, the driving assistance ECU 10 determines whether or not execution of the lane keeping control is selected based on a signal supplied from the operation switch 17, and when the execution of the lane keeping control is not selected, the lane change assistance control Do not run.

The yaw rate sensor 18 detects the yaw rate YRt of the host vehicle C and outputs the actual yaw rate YRt. The actual yaw rate YRt is a positive value when the host vehicle C is turning left while moving forward, and is a negative value when the host vehicle C is turning right while moving forward.
The longitudinal acceleration sensor 19 detects the longitudinal acceleration Gx of the host vehicle C and outputs the actual longitudinal acceleration Gx. Note that the actual longitudinal acceleration Gx is a positive value when the host vehicle C is accelerating forward, and is a negative value when the host vehicle C is decelerating.
The lateral acceleration sensor 20 detects an acceleration Gy in the lateral (vehicle width) direction of the host vehicle C (a direction orthogonal to the central axis of the host vehicle C) and outputs an actual lateral acceleration Gy. The actual lateral acceleration Gy is a positive value when the host vehicle C is turning left while moving forward (that is, with respect to the acceleration in the right direction of the vehicle), and the host vehicle C is turning right while moving forward. In some cases (ie, with respect to acceleration in the left direction of the vehicle).

  As described above, the driving assistance ECU 10 can execute the following inter-vehicle distance control, the lane keeping control, and the lane change assistance control.

  The engine ECU 30 is connected to the engine actuator 31. The engine actuator 31 is an actuator for changing the operating state of the internal combustion engine 32. In this example, the internal combustion engine 32 is a gasoline fuel injection / spark ignition / multi-cylinder engine, and includes a throttle valve for adjusting the intake air amount. The engine actuator 31 includes at least a throttle valve actuator that changes the opening of the throttle valve. The engine ECU 30 can change the torque generated by the internal combustion engine 32 by driving the engine actuator 31. Torque generated by the internal combustion engine 32 is transmitted to drive wheels (not shown) via a transmission (not shown). Therefore, the engine ECU 30 can control the driving force of the host vehicle C and change the acceleration state (acceleration) by controlling the engine actuator 31.

  The brake ECU 40 is connected to the brake actuator 41. The brake actuator 41 is provided in a hydraulic circuit between a master cylinder (not shown) that pressurizes hydraulic oil by the depression force of the brake pedal and a friction brake mechanism 42 provided on the left and right front and rear wheels. The friction brake mechanism 42 includes a brake disc 42a fixed to the wheel and a brake caliper 42b fixed to the vehicle body. The brake actuator 41 adjusts the hydraulic pressure supplied to the wheel cylinder built in the brake caliper 42b in accordance with an instruction from the brake ECU 40, and operates the wheel cylinder by the hydraulic pressure to press the brake pad against the brake disc 42a and perform friction. Generate braking force. Therefore, the brake ECU 40 can control the braking force of the host vehicle C by controlling the brake actuator 41.

  The steering ECU 50 is a known control device for an electric power steering system, and is connected to a motor driver 51. The motor driver 51 is connected to the steering motor 52. The steering motor 52 is incorporated in a “steering mechanism including a steering handle, a steering shaft coupled to the steering handle, a steering gear mechanism, and the like” of the vehicle. The steering motor 52 generates torque by the electric power supplied from the motor driver 51, and can apply steering assist torque or steer the left and right steering wheels by this torque. That is, the steering motor 52 can change the steering angle of the host vehicle C (the turning angle of the steered wheels).

  The steering ECU 50 is connected to a winker lever switch 53. The winker lever switch 53 is a detection switch that detects an operation position of a winker lever operated by a driver to operate (flash) a turn signal lamp 61 described later.

  The blinker lever is provided on the steering column. The winker lever is a first stage position rotated by a predetermined angle in the clockwise operation direction from the initial position and a second stage position rotated in the clockwise operation direction by a predetermined rotation angle further than the first stage position. It can be operated in one position. The winker lever maintains its position as long as it is maintained by the driver at the first stage position in the clockwise direction. However, when the driver releases the winker lever, the winker lever automatically returns to the initial position. Yes. The winker lever switch 53 outputs to the steering ECU 50 a signal indicating that the winker lever is maintained at the first stage position in the clockwise operation direction when the winker lever is in the first stage position in the clockwise operation direction.

  Similarly, the winker lever has a first stage position rotated by a predetermined angle in the counterclockwise operation direction from the initial position, and a second stage position rotated in the counterclockwise operation direction by a predetermined rotation angle further than the first stage position. The two positions can be operated. The winker lever maintains its position as long as it is maintained by the driver at the first stage position in the counterclockwise operation direction. However, when the driver releases the winker lever, the winker lever automatically returns to the initial position. Yes. The winker lever switch 53 outputs to the steering ECU 50 a signal indicating that the winker lever is maintained at the first stage position in the counterclockwise operation direction when the winker lever is in the first stage position in the counterclockwise operation direction. Such a blinker lever is disclosed in, for example, Japanese Patent Application Laid-Open No. 2005-138647.

  Based on the signal from the winker lever switch 53, the driving assistance ECU 10 measures the duration time during which the winker lever is held at the first stage position in the clockwise operation direction. Further, when the driving assistance ECU 10 determines that the measured duration is equal to or longer than a predetermined assistance request confirmation time (for example, 0.8 seconds), the lane for the driver to change the lane to the right lane It is determined that a request to receive change support (hereinafter also referred to as “lane change support request”) is issued.

  Further, the driving assistance ECU 10 measures the duration time that the winker lever is held at the first stage position in the counterclockwise operation direction based on the signal from the winker lever switch 53. Furthermore, when the driving assistance ECU 10 determines that the measured duration is equal to or longer than a predetermined assistance request confirmation time, the driver issues a lane change assistance request to change the lane to the left lane. It comes to judge.

  The meter ECU 60 is connected to left and right turn signal lamps 61 (blinker lamps) and an information display 62.

  The meter ECU 60 blinks the left or right turn signal lamp 61 in accordance with a signal from the winker lever switch 53 and an instruction from the driving support ECU 10 via a winker drive circuit (not shown). For example, the meter ECU 60 causes the left turn signal lamp 61 to blink when the winker lever switch 53 outputs a signal indicating that the winker lever is maintained at the first step position in the counterclockwise operation direction. Further, the meter ECU 60 causes the right turn signal lamp 61 to blink when the winker lever switch 53 outputs a signal indicating that the winker lever is maintained at the first stage position in the clockwise operation direction.

  The information display 62 is a multi-information display provided in front of the driver's seat. The information display 62 displays various information in addition to the measured values such as the vehicle speed and the engine rotation speed. For example, when the meter ECU 60 receives a display command corresponding to the driving support state from the driving support ECU 10, the meter ECU 60 causes the information display 62 to display a screen specified by the display command.

  The display ECU 70 is connected to the buzzer 71 and the display device 72. The display ECU 70 can alert the driver by sounding the buzzer 71 in response to an instruction from the driving support ECU 10. Furthermore, the display ECU 70 turns on a warning mark (for example, a warning lamp) on the display 72, displays an alarm image, displays a warning message, displays a warning message, etc. in accordance with an instruction from the driving support ECU 10. The operating status of the assist control can be displayed. The display device 72 is a head-up display, but may be another type of display.

(Overview of basic driving support control)
As described above, the driving assistance ECU 10 can execute the following inter-vehicle distance control, the lane keeping control, and the lane change assistance control. Hereinafter, an outline of each control will be described.

  The driving assistance ECU 10 defines XY coordinates in order to execute these controls (see FIG. 2). The X axis is a coordinate axis that extends along the front-rear direction of the host vehicle C so as to pass through the center position in the width direction of the front end portion of the host vehicle C, and has a forward value as a positive value. The Y axis is a coordinate axis that is orthogonal to the X axis and has the left direction of the host vehicle C as a positive value. The origin of the X axis and the origin of the Y axis are the center positions in the width direction of the front end of the host vehicle C.

  Further, the driving assistance ECU 10 determines the inter-vehicle distance Dfx (n), the relative speed Vfx (n), the direction H (n), and the like for each detected target (n) from the peripheral sensor 16 every predetermined time. get.

The inter-vehicle distance Dfx (n) is a distance along the X-axis direction between the host vehicle C and the target (n) (for example, a preceding vehicle), and is also referred to as a vertical distance.
The relative speed Vfx (n) is a difference (= Vt−Vsx) between the speed Vtx of the target (n) (for example, the preceding vehicle) and the speed Vsx of the host vehicle C. The speed Vtx of the target (n) is the speed of the target (n) along the X-axis direction.
The direction H (n) is an angle formed by a straight line connecting the target (n) and the center position in the width direction of the front end of the host vehicle C and the center axis of the host vehicle C. The direction H (n) is a positive value when the target (n) is on the left side of the central axis of the host vehicle C, and is a negative value when the target (n) is on the right side of the central axis of the host vehicle C. It is determined to be.

<Following inter-vehicle distance control (ACC)>
The following inter-vehicle distance control follows the own vehicle C to the preceding vehicle while maintaining the predetermined distance between the preceding vehicle and the own vehicle C traveling immediately before the own vehicle C based on the target information. Control. The following inter-vehicle distance control itself is well known (see, 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). Accordingly, a brief description will be given below. Note that the following inter-vehicle distance control is sometimes referred to as adaptive cruise control.

  The driving support ECU 10 executes the following inter-vehicle distance control when the execution of the following inter-vehicle distance control is selected by the operation of the operation switch 17.

  More specifically, the driving assistance ECU 10 determines that the execution of the following inter-vehicle distance control is selected (in fact, the vehicle speed Vsx of the host vehicle C is a vehicle speed within a predetermined range in that case) A tracking target vehicle is selected based on the target information acquired by the sensor 16. For example, the driving assistance ECU 10 determines that the relative position of the target (n) specified from the detected direction H (n) of the target (n) and the inter-vehicle distance Dfx (n) is longer than the inter-vehicle distance Dfx (n). It is determined whether or not the vehicle exists within a predetermined tracking target vehicle area so that the absolute value of the azimuth H (n) becomes smaller. Then, when the relative position of the target exists in the tracking target vehicle area for a predetermined time or more, the target (n) is selected as the tracking target vehicle. In addition, when there are a plurality of targets existing in the tracking target vehicle area for a predetermined time or more, the target closest to the own vehicle C (the target with the smallest inter-vehicle distance Dfx (n)) is selected as the tracking target vehicle. Is done.

  Further, the driving assistance ECU 10 calculates the target acceleration Gtgt according to either of the following formulas (1) and (2). In the equations (1) and (2), Vfx (a) is the relative speed of the vehicle to be followed (a), k1 and k2 are predetermined positive gains (coefficients), and ΔD1 is “the vehicle to be followed ( The inter-vehicle deviation (= Dfx (a) −Dtgt) obtained by subtracting the target inter-vehicle distance Dtgt from the inter-vehicle distance Dfx (a) in a). The target inter-vehicle distance Dtgt is calculated by multiplying the target inter-vehicle time Ttgt set by the driver using the operation switch 17 by the vehicle speed Vsx of the host vehicle C (that is, Dtgt = Ttgt · Vsx).

When the value (k1 · ΔD1 + k2 · Vfx (a)) is positive or “0”, the driving assistance ECU 10 determines the target acceleration Gtgt using the following equation (1). ka1 is a positive gain (coefficient) for acceleration, and is set to a value of “1” or less.
When the value (k1 · ΔD1 + k2 · Vfx (a)) is negative, the driving assistance ECU 10 determines the target acceleration Gtgt using the following equation (2). kd1 is a positive gain (coefficient) for deceleration, and is set to “1” in this example.

Gtgt (for acceleration) = ka1 · (k1 · ΔD1 + k2 · Vfx (a)) (1)
Gtgt (for deceleration) = kd1 · (k1 · ΔD1 + k2 · Vfx (a)) (2)

  When the target does not exist in the tracking target vehicle area, the driving assistance ECU 10 determines that the target speed and the vehicle speed are such that the vehicle speed Vsx of the host vehicle C matches the “target speed set according to the target inter-vehicle time Ttgt”. A target acceleration Gtgt is determined based on Vsx.

  The driving assistance ECU 10 controls the engine actuator 31 using the engine ECU 30 and controls the brake actuator 41 using the brake ECU 40 as necessary so that the actual longitudinal acceleration Gx matches the target acceleration Gtgt.

<Lane maintenance control (LKA or LTC)>
Lane maintenance control applies steering torque to the steering mechanism so that the position of the host vehicle C is maintained near the target travel line in the host lane (that is, the lane (lane) in which the host vehicle C is traveling). Thus, the steering angle of the host vehicle C is changed, and thus the control is performed to assist the driver's steering operation. The lane keeping control itself is well known (see, 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). Accordingly, a brief description will be given below. The lane keeping control may be referred to as lane keeping assist (LKA) or lane trace control (LTC).

  The driving assistance ECU 10 executes the lane keeping control when the execution of the lane keeping control is selected by the operation of the operation switch 17 during the execution of the following inter-vehicle distance control. More specifically, the driving assistance ECU 10 determines the lane center line CL of the own lane as the target travel line Ld. In addition, the driving assistance ECU 10 obtains the curvature Cu, the lateral deviation Dy, and the yaw angle θy of the target travel line Ld (that is, the lane center line CL) by calculation.

Based on the lateral deviation Dy, the yaw angle θy, and the curvature Cu of the target travel line Ld, the driving assistance ECU 10 calculates the target yaw rate YRc * at a predetermined calculation cycle by the following equation (3). In the equation (3), K1, K2, and K3 are control gains. The target yaw rate YRc * is a yaw rate set so that the host vehicle C can travel along the target travel line Ld.

YRc * = K1 × Dy + K2 × θy + K3 × Cu (3)

  The driving assistance ECU 10 calculates a target steering torque Tr * for obtaining the target yaw rate YRc * at a predetermined calculation cycle based on the target yaw rate YRc * and the actual yaw rate YRt. More specifically, the driving support ECU 10 stores in advance a look-up table that defines the relationship between the deviation between the target yaw rate YRc * and the actual yaw rate YRt and the target steering torque Tr *, and the target yaw rate is stored in this table. The target steering torque Tr * is calculated by applying a deviation between YRc * and the actual yaw rate YRt. Then, the driving assistance ECU 10 controls the steering motor 52 using the steering ECU 50 so that the actual steering torque Tra matches the target steering torque Tr *.

  In this way, the driving support ECU 10 executes lane keeping control for controlling the steering angle (steering angle, steering angle) of the host vehicle C so that the host vehicle C travels along the target travel line Ld. The driving assistance ECU 10 directly calculates the target steering angle necessary for the host vehicle C to travel along the target travel line Ld based on the lane-related vehicle information (Cu, Dy, θy) and the target travel line Ld. The steering motor 52 may be controlled so that the actual steering angle θ matches the target steering angle.

<Lane change support control (LCS)>
The lane change support control is performed by applying steering torque to the steering mechanism so that the own vehicle C moves from the own lane (ie, the original lane) to the adjacent lane desired by the driver (ie, the adjacent target lane). In this control, the steering angle of the vehicle C is changed to assist the driver's steering operation (steering operation for changing lanes). The lane change support control may be referred to as “LCS (lane change support)”.

  The lane change support control is control for adjusting the lateral position (position in the width direction of the road) of the host vehicle C with respect to the lane as in the lane keeping control. The lane change support control is executed instead of the lane maintenance control when a “lane change support request” is received during the execution of the following inter-vehicle distance control and the lane maintenance control.

  When the driving support ECU 10 receives the lane change support request, the driving support ECU 10 informs the driver that the lane change support request has been received by ringing the buzzer 71 for a short time. At this time, the driving assistance ECU 10 continues the blinking of the turn signal lamp 61 started by the operation of the winker lever.

1. Calculation of target trajectory When the driving assistance ECU 10 executes lane change assistance control, the current lane information supplied from the camera sensor 16b, the current vehicle state of the host vehicle C (for example, the lateral deviation Dy and the vehicle speed Vsx, etc.) ) To calculate a target track for changing the lane of the host vehicle C. Based on the target lane change time, the target track takes the target lane change time, and changes the vehicle C from the current lane (that is, the original lane) that is currently traveling to the lane change support request adjacent to the original lane. The track is moved to the center position in the width direction of the lane in the designated direction (that is, the adjacent target lane). The center position in the width direction of the target lane is also referred to as “final target lateral position”. The target track is represented by the target lateral position y (t) of the host vehicle C with respect to the elapsed time t from the start time of the lane change support control with reference to the lane center line CL1 (see FIG. 2) of the original lane.

  The target lane change time described above is set to be proportional to the distance (hereinafter referred to as “necessary lateral distance”) by which the host vehicle C is moved laterally to the final target lateral position. For example, when the lane width is generally 3.5 m, the target lane change time is set to 8.0 seconds, and when the lane width is 4.0 m, the target lane change time is 9.1 seconds ( = 8.0 × 4.0 / 3.5).

  Note that the target lane change time is the amount of displacement (lateral deviation) when the lateral position of the host vehicle C at the start of the lane change assist control is shifted to the adjacent target lane side from the lane center line CL1 of the original lane. It is set so that it decreases as the size of Dy increases. Conversely, when the lateral position of the host vehicle C at the start of the lane change support control is shifted to the side opposite to the adjacent target lane from the lane center line CL1 of the original lane, the target lane change time is the amount of displacement It is set to increase as (the size of the lateral deviation Dy) increases. The driving assistance ECU 10 corrects a reference lane change time (for example, 8.0 seconds), which is a reference value of the target lane change time, according to the lane width, the displacement amount of the original lane from the lane center line CL1, and the like. Thus, the target lane change time is determined.

The driving assistance ECU 10 represents the target lateral position y by a target lateral position function y (t) shown in the following equation (4). This lateral position function y (t) is a quintic function using the elapsed time t.

y (t) = a · t ⁵ + b · t ⁴ + c · t ³ + d · t ² + e · t + f (4)

  The “constants a, b, c, d, e, and f” in the equation (4) are determined based on the traveling state of the host vehicle C, the lane information, the target lane change time, etc. at the time of calculating the target track. The The driving support ECU 10 inputs the travel state of the host vehicle C, the lane information, and the target lane change time into the vehicle model stored in advance in the ROM so that a smooth target trajectory can be obtained. , B, c, d, e and f are calculated. By substituting the calculated “coefficients a, b, c, d, e, and f” and the elapsed time t from the disclosure time of the lane change support control into the target lateral position function y (t), the target at the time t A lateral position is required. Note that the value f in the above equation (4) is set to a value equal to the lateral deviation Dy in order to represent the lateral position of the host vehicle C at t = 0 (that is, when the lane change assist control starts).

  The target lateral position y is not limited to the above method, and can be set by any method. For example, the target lateral position y does not need to be calculated using a quintic function such as the above equation (4), and can be obtained using an arbitrarily set function.

2. Steering angle control The driving assistance ECU 10 executes lane keeping control until lane change assistance control is started. In the lane keeping control, the target steering torque Tr * (or target rudder angle) is calculated as described above, and the steering motor 52 is controlled so as to obtain the target steering torque Tr * (or target rudder angle). The The driving assistance ECU 10 performs the same control as the lane keeping control also in the lane change assistance control.

That is, the driving assistance ECU 10 represents the target travel line Ld that has been set to coincide with the lane center line CL1 of the original lane in the lane keeping control by the target lateral position function y (t) of the above equation (4). Lane change support control is performed by changing to a line to be performed. The driving assistance ECU 10 may obtain the target rudder angle according to the following equation (5) and drive the steering motor 52 so as to obtain the target rudder angle.

θlcs * = Klcs1 · Cu * + Klcs2 · (θy * −θy) + Klcs3 · (Dy * −Dy)
... (5)

  In equation (5), θy and Dy are values represented by lane-related vehicle information (Cu, Dy, θy) at the present time (at the time of calculation) t. Klcs1, Klcs2, and Klcs3 are control gains. Cu * is the curvature of the target track at the current time t, θy * is the yaw angle of the target track with respect to the lane center line CL of the own lane at the current time t, and Dy * is the lateral deviation of the target track at the current time t ( Dy * = y (t)).

  Dy * is y (t) before the lane change (before the own vehicle C crosses the boundary line between the own lane and the adjacent target lane). On the other hand, after the lane change (after the host vehicle C straddles the boundary line (white line (dashed line) WL) between the original lane and the adjacent target lane), Dy * is the own lane (adjacent target lane after the lane change). ) As the lateral deviation of the “target track represented by y (t)” with respect to the lane center line. More specifically, Dy * after the lane change is calculated as a value (y (t) + L) obtained by adding the lane width L to y (t) when the lane change direction is the right direction, and the lane change direction Is the left direction, the lane width L is subtracted from y (t) (y (t) -L).

<Overview of operation>
Next, an outline of the operation of the driving support ECU 10 of the present embodiment will be described. The driving assistance ECU 10 is based on the white line recognition result for each predetermined calculation period during the period from the time t1 to the time t3 when the traveling state of the host vehicle C is executing the lane change assistance control shown in FIG. Then, the lateral deviation Dy (n) of the host vehicle C is calculated. Further, the driving assistance ECU 10 performs a filtering process on the lateral deviation Dy (n) at every predetermined calculation cycle, and uses the lateral deviation Dfy (n) after the filtering process (that is, Dfy (n)). (Used as Dy in equation (5)) to perform lane change assist control.

  Specifically, the driving assistance ECU 10 performs a filtering process according to the following equation (6) in order to remove noise components included in the calculated lateral deviation Dy (n).

Dfy (n) = αDfy (n−1) + (1−α) Dy (n)
... (6)

  In equation (6), Dy (n) is the lateral deviation Dy calculated by the driving support ECU 10 at the time of the current calculation. Dfy (n) is a lateral deviation after the driving support ECU 10 performs the filtering process on the lateral deviation Dy (n) at the time of the current calculation. Dfy (n−1) is a lateral deviation (“previous filter process” after the driving assistance ECU 10 performs a filtering process on the previous lateral deviation Dy (Dy (n−1)) calculated one calculation period before. It may be referred to as “later lateral deviation”). α is a coefficient larger than 0 and smaller than 1. As α becomes smaller, more noise components can be removed. Therefore, typically, the lateral deviation Dfy (n−1) after the previous filtering process of the first term of the right equation is more current than the lateral deviation Dy (n) of the second term of the right equation. A coefficient α (for example, 0.8) is set so as to be reflected in the processed lateral deviation Dfy (n).

  As shown in FIG. 2, when the host vehicle C is traveling in the left lane during the period from time t0 to time t1, the driving assistance ECU 10 travels the reference position of the lateral deviation Dy and the host vehicle C travels. It is set to the lane center line CL1, which is a position near the center of the own lane.

  The lateral deviation Dy is a positive displacement direction (displacement amount) in the road width direction from the reference position, with the left direction as the positive direction relative to the reference position and the right direction as the negative direction relative to the reference position. It is expressed by the value of or a negative value. Therefore, the lateral deviation Dy (t0-t1) during the period from time t0 to time t1 changes as shown by the line a1 in FIG.

  When it is detected that the host vehicle C straddles the white line WL (broken line) that is the boundary between the original lane and the adjacent target lane at a time between time t1 and time t2, the driving assistance ECU 10 determines that the lateral deviation Dy is The reference position is set to the lane center line CL2 which is the center position of the current own lane (that is, the right lane in FIG. 2). Therefore, at time t2 immediately after the host vehicle C crosses the white line WL (broken line), the reference position of the lateral deviation Dy is changed from the lane center line CL1 to the lane center line CL2. As a result, the lateral deviation Dy (t2) at time t2 immediately after the host vehicle C straddles the white line changes abruptly from the lateral deviation Dy (t1) at time t1 immediately before the host vehicle C straddles the white line. A difference corresponding to the lane width L is generated in the deviation Dy (t2) and the lateral deviation Dy (t1).

  More specifically, as shown in FIG. 3, at time t1 immediately before the host vehicle C crosses the white line, the host vehicle C has a lane width in the right direction (negative direction) in the road width direction from the reference position. It is at a position half the distance of L (= L / 2). Accordingly, the lateral deviation Dy (t1) at time t1 is “−L / 2”.

  At a time point between time t1 and time t2 when the host vehicle C straddles the white line, the reference position of the lateral deviation Dy is changed from the lane center line CL1 to the lane center line CL2. At time t2 immediately after the host vehicle C straddles the white line, the host vehicle C moves from the changed reference position (lane center line CL2) to the lane width L in the left direction (positive direction) in the road width direction. It is at a position that is half the distance (= L / 2) apart. Accordingly, the lateral deviation D (t2) at time t2 becomes “+ L / 2” which has changed rapidly from the lateral deviation Dy (t1) (= “− L / 2”) at time t1, and the lateral deviation Dy (t2 ) And lateral deviation Dy (t1) are different by a lane width L. Note that the lateral deviation Dy (t2-t3) in the period from immediately after time t2 to time t3 changes as shown by the line a2 in FIG.

  As described above, when the lane change assist control is executed, the lateral deviation Dy is determined by changing the reference position of the lateral deviation Dy when the host vehicle C straddles the white line, thereby causing the lateral deviation Dy (t2) and the lateral deviation. A difference corresponding to the lane width L occurs in Dy (t1). The lateral deviation D (t1) represents an accurate deviation amount from the reference position, whereas after the reference position has changed, it represents an accurate deviation amount from the changed reference position. Absent.

  Therefore, the lateral deviation Dfy (t1) = Dfy (n−1) after the filtering process, which was calculated before the own vehicle C crossed the white line that separates the own lane and the adjacent target lane, and the own vehicle C When the horizontal deviation Dfy (t2) immediately after crossing is applied to the expression (6) as it is and the filter process is performed, the horizontal deviation Dfy (n) after the filter process increases from the correct value as described below. Deviation.

  That is, when the lateral deviation Dfy (t2) after filtering the lateral deviation Dy (t2) at time t2 is calculated according to the equation (6), the reference position is the Dfy (n−1) in the first term on the right side. A value after filtering of the lateral deviation Dy (t1) different from Dy (t2) is used.

  As a result, the lateral deviation Dfy (t2) after the filtering process becomes the lateral deviation Dy (b1) indicated by the point b1, and the actual lateral deviation Dy (t2) (lateral deviation Dy (t2) at time t2 is obtained. ) Is far from the accurate deviation amount from the reference position).

  Further, the lateral deviation Dfy after the subsequent filter processing is also greatly deviated from the actual lateral deviation after changing the lane indicated by the line a2 (after straddling the white line) for a while as indicated by the broken line b. Resulting in. In this case, appropriate steering control for following the target trajectory cannot be performed until the filtered lateral deviation Dfy (n) becomes a value close to the actual lateral deviation.

  Therefore, the driving assistance ECU 10 of the present embodiment determines whether or not the own vehicle C has moved from the own lane to the adjacent target lane. Further, the driving support ECU 10 indicates that the current time is immediately after the own vehicle C moves from the own lane to the adjacent target lane (the time immediately after the own vehicle C straddles the white line between the own lane and the adjacent target lane). In some cases, filter processing according to the equation (6) is performed as follows.

  That is, the driving assistance ECU 10 is when the host vehicle C is about to move to the adjacent target lane on the right side of the host lane (that is, when the lane change direction is the right direction), and the host vehicle C is adjacent to the host lane. At the time immediately after straddling the white line with the target lane, the lane width L is set to the lateral deviation Dfy (n−1) after the previous filtering process in Dfy (n) of the first term on the right side of the above equation (6). The added first correction deviation (= Dfy (n−1) + L) ”is substituted, and the current lateral deviation Dy (n) is substituted for Dy (n) in the second term on the right side of equation (6).

  On the other hand, the driving support ECU 10 is when the host vehicle C is about to move to the adjacent target lane on the left side of the host lane (that is, when the lane change direction is the left direction), and the host vehicle C is the host lane. At the time immediately after straddling the white line between the target lane and the adjacent target lane, the lane width from the lateral deviation Dfy (n−1) after the previous filtering is added to Dfy (n) in the first term on the right side of the above equation (6). Substitute L for the second corrected deviation (= Dfy (n−1) −L) ”, and substitute the current lateral deviation Dy (n) for Dy (n) in the second term on the right side of equation (6). .

  Thus, after the host vehicle C changes the lane, the lateral deviation Dfy (n) after the filtering process is a value obtained by filtering the “lateral deviation with the lane center line of the adjacent target lane as the reference position”. . As a result, after the own vehicle C changes lanes, the filtered lateral deviation Dfy (n) does not greatly deviate from the true lateral deviation, so the vehicle C travels along the target track with high accuracy. Can be made. That is, lane change support can be performed appropriately.

<Specific operation>
Next, a specific operation of the embodiment apparatus will be described. When the CPU of the driving assistance ECU 10 (hereinafter simply referred to as “CPU”) receives the above-described lane change assistance request, the CPU executes the routine shown in FIG. 4 every time a predetermined time (predetermined calculation cycle) elapses. It is like that.

  Therefore, the CPU starts the process from step 400 of FIG. 4 at a predetermined timing, proceeds to step 410, and calculates the current lateral deviation Dy (n) of the host vehicle C based on the white line recognition result. The lateral deviation Dy (n) is calculated using the lane center line of the own lane identified based on white line recognition as the reference position of the lateral deviation Dy (n).

  Therefore, in the example shown in FIG. 2, before the own vehicle C crosses the white line (broken line) between the own lane before the lane change (left lane) and the adjacent target lane (right lane), the own lane ( The lateral deviation Dy (n) is calculated using the lane center line C1 of the own lane before the lane change) as the reference position. After the host vehicle C straddles the white line (broken line) between the host lane before the change and the adjacent target lane, the lateral deviation Dy with the lane center line C2 of the adjacent target lane (the host lane after the lane change) as the reference position (N) is calculated.

  The CPU determines whether the reference point P of the host vehicle C exists in the original lane or the adjacent target lane. If the reference point P exists in the original lane, the lane center of the original lane The line is set to the reference position of the lateral deviation Dy (n), and if the reference point P is in the adjacent target lane, the lane center line of the adjacent target lane is set to the reference position of the lateral deviation Dy (n). .

  Thereafter, the CPU proceeds to step 415 to determine whether or not the own vehicle C has changed lanes. This determination is based on the magnitude Ddiff (= | Dy (n) −Dy () of the difference between the current lateral deviation Dy (n) and the previous lateral deviation Dy (n−1) (the lateral deviation calculated one calculation period before). n-1) is performed by determining whether or not |) is larger than a predetermined threshold value Dyth. The predetermined threshold Dyth is set to an arbitrary value appropriate for the determination (for example, a value slightly smaller than the lane width L).

  When the reference position of the lateral deviation Dy changes when the host vehicle C straddles the white line, the lateral deviation Dy corresponding to the lane width L changes due to the change of the lateral deviation reference position. The magnitude of the change amount of the lateral deviation Dy is a larger value (change greater than the threshold value Dyth) than the magnitude of the change amount of the lateral deviation Dy before the reference position is changed.

  Therefore, when the difference magnitude Ddiff is equal to or less than the predetermined threshold value Dyth, the lane change is not performed (the reference position of the lateral deviation Dy is not changed). In this case, the CPU makes a “No” determination at step 415 to directly proceed to step 435 to filter the lateral deviation Dy (n) and “previous lateral deviation Dy (n−1) acquired at step 410. Using the lateral deviation Dfy (n−1) ”after that, the filter processing according to the equation (6) is performed. Next, the CPU proceeds to step 440, obtains the target rudder angle by applying the lateral deviation Dfy (n-1) to the equation (5), and drives the steering motor 52 so as to obtain the target rudder angle. Thus, lane change support control is executed. Thereafter, the CPU proceeds to step 495 to end the present routine tentatively.

  On the other hand, when the magnitude Ddiff of the difference is larger than the predetermined threshold value Dyth, it is after the lane change (after the reference position of the lateral deviation Dy is changed). In this case, the CPU makes a “Yes” determination at step 415 to proceed to step 420 to determine whether or not the lane change direction is the right direction.

  If the lane change direction (the direction from the own lane before the lane change to the adjacent target lane) is the right direction, the CPU makes a “Yes” determination at step 420 to proceed to step 425, where After calculating the first corrected lateral deviation Dfy1 (n-1) by adding the lane width L to the deviation Dfy (n-1), the process proceeds to step 435.

  On the other hand, when the lane change direction is not the right direction (that is, when the lane change direction is the left direction), the CPU makes a “No” determination at step 420 to proceed to step 430, where the previous filter After calculating the second corrected lateral deviation Dfy2 (n−1) by subtracting the lane width L from the processed lateral deviation Dfy (n−1), the process proceeds to step 435.

  When the CPU proceeds to step 435, the first corrected lateral deviation Dfy1 calculated in step 425 or step 430 is used instead of the current lateral deviation Dy (n) and the lateral deviation Dfy (n-1) after the previous filtering process. Using (n−1) or the second corrected lateral deviation Dfy2 (n−1), the filter processing according to the equation (6) is performed. Thereafter, the CPU executes lane assistance control in step 440, proceeds to step 495, and once ends this routine.

  According to the present embodiment described above, the following effects are obtained. In this embodiment, the host vehicle is executing the lane change support control, and immediately after the host vehicle C changes the lane, the lateral deviation Dfy (n−1) after the previous filter processing is the lane change before the lane change. Is corrected by an amount corresponding to the distance between the reference position of the lane in which the host vehicle was traveling and the reference position of the lane in which the host vehicle is traveling after the lane change. Then, instead of the lateral deviation Dfy (n−1) after the previous filtering process, the corrected lateral deviation after the previous filtering process (the first corrected lateral deviation Dfy1 (n−1) or the second corrected lateral deviation Dfy2 (n−)). 1)) is used to perform an operation for applying a noise removal filter process.

  Thus, after the host vehicle C changes the lane, the lateral deviation Dfy (n) after the filtering process is a value obtained by filtering the “lateral deviation with the lane center line of the adjacent target lane as the reference position”. . As a result, after the own vehicle C changes lanes, the filtered lateral deviation Dfy (n) does not greatly deviate from the true lateral deviation, so the vehicle C travels along the target track with high accuracy. Can be made. That is, lane change support can be performed appropriately.

<Modification>
As mentioned above, although embodiment of this invention was described concretely, this invention is not limited to the above-mentioned embodiment, Various modifications based on the technical idea of this invention can be employ | adopted.

  For example, in the above-described embodiment, the execution of the following inter-vehicle distance control and the lane keeping control is a premise for executing the lane change support control, but such a premise is not necessarily required. do not do.

  DESCRIPTION OF SYMBOLS 10 ... Driving assistance ECU, 15 ... Vehicle speed sensor, 16 ... Perimeter sensor, 16a ... Perimeter radar sensor, 16b ... Camera sensor, 17 ... Operation switch, 52 ... Steering motor, 53 ... Blinker lever switch

Claims (1)

A lane marking recognition unit that recognizes a pair of left and right lane markings that divide the lane that is the lane in which the host vehicle is traveling;
A calculation unit that calculates a lateral deviation, which is a displacement amount of the vehicle in the width direction from a reference position in the width direction of the vehicle lane determined based on the recognized pair of lane markings, every time a predetermined time elapses. When,
A filter unit that performs a calculation for performing a noise removal filter process every time the predetermined time elapses with respect to the calculated lateral deviation;
A control unit that executes lane change support control for controlling the steering angle of the host vehicle so as to support traveling for the host vehicle to change lanes;
With
When the lateral deviation is newly calculated, the filter unit includes the newly calculated lateral deviation, and the previous filtering process that is the lateral deviation after the filtering that is calculated at the time point before the predetermined time. A lateral deviation, and a calculation for performing the noise removal filter processing using
The control unit is configured to execute the lane change support control using a target lateral position determined with respect to a reference position of the own lane and the lateral deviation after the current filter processing,
In the driving support device,
The filter unit is
Determining whether a specific condition that the magnitude of the difference between the newly calculated lateral deviation and the lateral deviation calculated at a time point before the predetermined time is larger than a predetermined threshold is satisfied,
When it is determined that the specific condition is satisfied, the lateral deviation after the previous filtering process is determined based on the reference position of the lane in which the host vehicle was traveling before the lane change and the lane in which the host vehicle is traveling after the lane change. Calculates the corrected lateral deviation after the previous filtering after correction according to the direction of the lane change by an amount corresponding to the distance from the reference position, and after the corrected previous filtering after replacing the lateral deviation after the previous filtering. Configured to perform an operation for performing the noise removal filter processing using a lateral deviation,
Driving assistance device.

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