JP6881190B2 - Driving support device - Google Patents

Description

In the present invention, the traveling locus of a preceding vehicle traveling in the front region of a vehicle (own vehicle) and a lane adjacent to the traveling lane in which the own vehicle is traveling (hereinafter, referred to as "adjacent lane") are defined. Steering that changes the steering angle of the own vehicle so that the own vehicle travels according to the traveling locus of another traveling vehicle (hereinafter referred to as "adjacent vehicle") and the target traveling line determined based on the traveling locus. The present invention relates to a driving support device that executes follow-up control.

One of the conventionally known driving support devices sets a target driving line by utilizing the traveling locus of the preceding vehicle (hereinafter referred to as "preceding vehicle locus"), and follows the set target traveling line. Steering follow-up control, which is steering control of the own vehicle, is executed so that the own vehicle travels (see, for example, Patent Document 1).

Japanese Patent Publication No. 2011-514580

By the way, the inventor of the present application applies not only to the locus of the preceding vehicle but also to the locus of the adjacent vehicle (hereinafter, referred to as "adjacent vehicle locus") in order to allow the own vehicle to travel more stably along the traveling lane. Based on this, we are studying a driving support device that sets a target driving line and executes steering follow-up control for that target driving line. It has been found that such a driving support device may cause the following problems.

For example, when an adjacent vehicle overtakes its own vehicle while traveling in the overtaking lane, the time from when the adjacent vehicle is newly detected (for the first time) to when the adjacent vehicle trajectory of the adjacent vehicle is created for the first time is short. Therefore, the amount of position information of the adjacent vehicle that can be acquired by the time of the first creation of the adjacent vehicle locus may be small. In this case, the accuracy of the created adjacent vehicle trajectory may not be good. On the other hand, if the adjacent vehicle trajectory is not created until the position information of the adjacent vehicle is sufficiently accumulated, or if the adjacent vehicle trajectory is not used to determine the target driving line, the next adjacent vehicle may be detected at that time. In the end, the trajectory of the adjacent vehicle cannot be used to determine the target driving line. Such a problem also occurs when the own vehicle is traveling in the overtaking lane and overtaking another vehicle traveling in the normal lane.

The present invention has been made to solve the above problems. That is, one of the objects of the present invention is to suppress a decrease in the accuracy of the adjacent vehicle locus to be created even when the amount of position information of the adjacent vehicle is small at the time of first creating the adjacent vehicle locus, and as a result, a highly accurate target. The purpose of the present invention is to provide a driving support device capable of driving the own vehicle along the traveling line.

The driving support device of the present invention (hereinafter, may be referred to as "the device of the present invention") is
A preceding vehicle that is in front of the own vehicle and traveling in an area in the traveling direction of the own vehicle and an area that is in front of the own vehicle and deviates from the traveling direction of the own vehicle in the road width direction. The adjacent vehicle that is traveling is detected, and each time a predetermined time elapses, the preceding vehicle position information that specifies the position of the preceding vehicle with respect to the own vehicle and the position of the adjacent vehicle with respect to the own vehicle are specified. Detection means (10, 16) for acquiring adjacent vehicle position information,
Creating a traveling locus, which is a traveling locus of the preceding vehicle, is created based on the preceding vehicle position information, and an adjacent vehicle locus, which is a traveling locus of the adjacent vehicle, is created based on the adjacent vehicle position information. Means (10, 10b) and
Control means (10, 10d,) that executes steering follow-up control for changing the steering angle of the own vehicle so that the own vehicle travels according to the target traveling line determined based on the preceding vehicle locus and the adjacent vehicle locus. 40) and
It has.
Further, the traveling locus creating means
At the time of the first creation of the adjacent vehicle trajectory of the newly detected adjacent vehicle after the adjacent vehicle is newly detected by the detection means (step 825: Yes, step 830 and step 835: Yes), the new Based on not only the adjacent vehicle position information about the adjacent vehicle detected in the above, but also the preceding vehicle locus or the preceding vehicle position information, the adjacent vehicle locus of the newly detected adjacent vehicle is created (step 850). It is configured as follows.

The device of the present invention creates an adjacent vehicle locus by utilizing the position information of the preceding vehicle or the preceding vehicle with high accuracy of the traveling locus even when the amount of the position information of the adjacent vehicle is small at the time of the first creation of the adjacent vehicle locus. be able to. Therefore, the accuracy of the adjacent vehicle locus created for the first time can be improved. As a result, the accuracy of the target traveling line is improved, so that the own vehicle can travel more stably along the traveling line.

One aspect of the device of the present invention includes determination means (10, 10e) for determining whether or not the preceding vehicle is traveling along the traveling lane. In this embodiment, the traveling locus creating means is such that the preceding vehicle is the first to create the adjacent vehicle locus of the newly detected adjacent vehicle after the adjacent vehicle is newly detected by the detecting means. When it is determined that the vehicle is traveling along the traveling lane (step 845: Yes), not only the adjacent vehicle position information for the newly detected adjacent vehicle but also the preceding vehicle locus or the preceding vehicle position information The adjacent vehicle trajectory of the newly detected adjacent vehicle is created based on the above. According to this, only when the preceding vehicle is traveling along the traveling lane (that is, when the preceding vehicle trajectory is likely to be along the traveling lane), the preceding vehicle trajectory or the preceding vehicle position information is available. It will be reflected in the adjacent vehicle track created for the first time. Therefore, the accuracy of the adjacent vehicle locus can be further improved.

In the above description, the name and / or reference numeral used in the embodiment is added in parentheses to the configuration of the invention corresponding to the embodiment described later. However, each component of the present invention is not limited to the embodiment defined by the above name and / or reference numeral.

It is a schematic block diagram of the operation support device which concerns on this Embodiment of this invention. It is a top view for demonstrating the lane keeping control based on the target traveling line set by using the preceding vehicle locus. (A) is a plan view for explaining the lane keeping control of FIG. 2 in more detail, and (B) is for explaining the relationship between the coefficient of the cubic function of the preceding vehicle locus and the curvature, the radius of curvature, and the like. It is a mathematical formula, and (C) is a mathematical formula for explaining the relationship between the coefficient of the cubic function of the preceding vehicle locus, the curvature, the yaw angle, and the like. It is a top view for demonstrating the lane keeping control based on the target driving line set by using the central line of a driving lane. It is a figure for demonstrating the process which corrects the preceding vehicle locus of the preceding vehicle based on the center line of a traveling lane. It is a top view for demonstrating the process of creating the adjacent vehicle locus based on the preceding vehicle locus and the position information of the adjacent vehicle which concerns on this embodiment. It is a top view for demonstrating the process of creating an adjacent vehicle locus based on the position information of a preceding vehicle and the position information of an adjacent vehicle, which is related to a modified example. It is a flowchart which showed the routine which the operation support ECU which concerns on this Embodiment of this invention executes.

Hereinafter, the driving support device according to the embodiment of the present invention (hereinafter, may be referred to as “the present embodiment”) will be described with reference to the accompanying drawings.

<Structure>
This implementation device is applied to a vehicle (automobile). As shown in FIG. 1, the present implementation device includes a driving support ECU 10, an engine ECU 20, a brake ECU 30, a steering ECU 40, and a navigation ECU 50.

These ECUs are electric control units (Electric Control Units) 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 the present specification, the microcomputer includes a CPU, RAM, ROM, an interface (I / F), and the like. For example, the driving support ECU 10 includes a microcomputer including a CPU 10v, a RAM 10w, a ROM 10x, an interface (I / F) 10y, and the like. The CPU 10v realizes various functions by executing instructions (programs, routines) stored in the ROM 10x.

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

The accelerator pedal operation amount sensor 11 detects the operation amount (accelerator opening degree) of the accelerator pedal 11a of the own 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 own vehicle and outputs a signal indicating the brake pedal operation amount BP.

The steering angle sensor 13 detects the steering angle of the own 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 own 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 own vehicle and outputs a signal indicating the vehicle speed SPD.

The surrounding sensor 16 acquires information on at least the road in front of the own vehicle and the three-dimensional object existing on the road. The three-dimensional object represents, for example, a moving object such as a pedestrian, a bicycle and an automobile, and a fixed object such as a utility pole, a tree and a guardrail. Hereinafter, these three-dimensional objects may be referred to as "targets". The surrounding sensor 16 includes a radar sensor 16a and a camera sensor 16b.

The radar sensor 16a radiates, for example, a radio wave in the millimeter wave band (hereinafter, referred to as “millimeter wave”) to a peripheral region of the own vehicle including at least the front region of the own vehicle, and is a target existing within the radiation range. Receives millimeter waves (ie, reflected waves) reflected by. Further, the radar sensor 16a determines whether or not there is a target, and parameters indicating the relative relationship between the own vehicle and the target (that is, the position of the target with respect to the own vehicle, the distance between the own vehicle and the target, and , The relative speed between the own vehicle and the target, etc.) is calculated, and the judgment result and the calculation result are output.

More specifically, the radar sensor 16a includes a millimeter wave transmission / reception unit and a processing unit. The processing unit determines the phase difference between the millimeter wave transmitted from the millimeter wave transmitter / receiver and the reflected wave received by the millimeter wave transmitter / receiver, the attenuation level of the reflected wave, and the time from the transmission of the millimeter wave to the reception of the reflected wave. Based on the above, parameters indicating the relative relationship between the own vehicle and the target are acquired every time a predetermined time elapses. This parameter includes the inter-vehicle distance (longitudinal distance) Dfx (n), the relative speed Vfx (n), the lateral distance Dfy (n), the relative lateral velocity Vfy (n), and the like for each detected target (n).

The inter-vehicle distance Dfx (n) is the distance between the own vehicle and the target (n) (for example, the preceding vehicle) along the central axis of the own vehicle (the central axis extending in the front-rear direction, that is, the x-axis described later). Is.
The relative speed Vfx (n) is the difference (= Vs−Vj) between the speed Vs of the target (n) (for example, the preceding vehicle) and the speed Vj of the own vehicle. The speed Vs of the target (n) is the speed of the target (n) in the traveling direction of the own vehicle (that is, the direction of the x-axis described later).
The lateral distance Dfy (n) is in the direction orthogonal to the central axis of the own vehicle (that is, the y-axis direction described later) of the "center position of the target (n) (for example, the center position of the vehicle width of the preceding vehicle)". It is the distance from the same central axis. The lateral distance Dfy (n) is also referred to as the "lateral position".
The relative lateral velocity Vfy (n) is the velocity of the center position of the target (n) (for example, the center position of the width of the preceding vehicle) in the direction orthogonal to the center axis of the own vehicle (that is, the y-axis direction described later). Is.

The camera sensor 16b includes a stereo camera and an image processing unit, and captures landscapes in the left side region and the right side region in front of the vehicle to acquire a pair of left and right image data. The camera sensor 16b determines the presence or absence of a target based on the pair of left and right image data captured, calculates a parameter indicating the relative relationship between the own vehicle and the target, and calculates the determination result and the calculation result. And output. In this case, the driving support ECU 10 has a parameter indicating the relative relationship between the own vehicle and the target obtained by the radar sensor 16a, a parameter indicating the relative relationship between the own vehicle and the target obtained by the camera sensor 16b, and a parameter indicating the relative relationship between the own vehicle and the target. By synthesizing the above, the parameters indicating the relative relationship between the own vehicle and the target are determined.

Further, the camera sensor 16b recognizes the left and right lane markings of the road (running lane of the own vehicle) based on the pair of left and right image data captured, and recognizes the shape of the road and the road and the vehicle (own vehicle). And other vehicles) (for example, the distance from the left end or the right end of the traveling lane to the center position in the vehicle width direction of the own vehicle) is calculated and output. The marking line includes a white line, a yellow line, and the like, but an example of the white line will be described below as an example.

The information about the target acquired by the surrounding sensor 16 (including the parameter indicating the relative relationship between the own vehicle and the target) is referred to as "target information". The surrounding sensor 16 repeatedly transmits the target information to the driving support ECU 10 every time a predetermined sampling time elapses. The ambient sensor 16 does not necessarily have to include both a radar sensor and a camera sensor, and may include, for example, only the radar sensor or only the camera sensor.

The operation switch 17 is a switch operated by the driver. By operating the operation switch 17, the driver can select whether or not to execute the following inter-vehicle distance control, which will be described later. Further, the driver can select whether or not to execute the lane keeping control described later by operating the operation switch 17.

The yaw rate sensor 18 detects the yaw rate of the own vehicle and outputs the actual yaw rate YRt.

The engine ECU 20 is connected to the engine actuator 21. The engine actuator 21 includes a gasoline fuel injection, a spark ignition type, and a throttle valve actuator that changes the opening degree of the throttle valve of the internal combustion engine 22. The engine ECU 20 can change the torque generated by the internal combustion engine 22 by driving the engine actuator 21. The torque generated by the internal combustion engine 22 is transmitted to drive wheels (not shown) via a transmission (not shown). Therefore, the engine ECU 20 can control the driving force of the own vehicle and change the acceleration state (acceleration) by controlling the engine actuator 21. In addition, instead of or in addition to the internal combustion engine 22, an electric motor may be used as a vehicle drive source.

The brake ECU 30 is connected to the brake actuator 31. The brake actuator 31 is provided in a hydraulic circuit between a master cylinder (not shown) that pressurizes hydraulic oil by the pedaling force of the brake pedal 12a and a friction brake mechanism 32 provided on the left, right, front, and rear wheels. The brake actuator 31 adjusts the hydraulic pressure supplied to the wheel cylinder built in the brake caliper 32b of the friction brake mechanism 32 in response to an instruction from the brake ECU 30. When the wheel cylinder is operated by the oil pressure, the brake pad is pressed against the brake disc 32a and a friction braking force is generated. Therefore, the brake ECU 30 can control the braking force of the own vehicle and change the acceleration state (deceleration, that is, negative acceleration) by controlling the brake actuator 31.

The steering ECU 40 is a well-known control device for an electric power steering system, and is connected to a motor driver 41. The motor driver 41 is connected to the steering motor 42. The steering motor 42 is incorporated in a "steering mechanism (not shown) including a steering handle SW, a steering shaft US connected to the steering handle SW, a steering gear mechanism, and the like" of the vehicle. The steering motor 42 generates torque by the power supplied from the motor driver 41, and the steering assist torque can be applied or the left and right steering wheels can be steered by this torque. That is, the steering motor 42 can change the steering angle (steering angle) of the own vehicle.

The navigation ECU 50 is connected to a GPS receiver 51 that receives GPS signals for detecting the position of its own vehicle, a map database 52 that stores map information, and a touch panel display 53 that is a human-machine interface. .. The navigation ECU 50 is adapted to guide the route of the own vehicle based on the position of the own vehicle and the map information. The map information stored in the map database 52 includes road parameters for each section of the road. For example, on the road information, the number of lanes of the road, the width of the road, the slope, and the like are associated with each section of the road. The navigation ECU 50 repeatedly transmits road information (including the number of lanes) to the driving support ECU 10 every time a predetermined time elapses. The driving support ECU 10 can determine whether or not an adjacent lane exists based on the road information.

<Prerequisite control>
Next, the outline of the control performed by the present implementation device will be described. The driving support ECU 10 can execute "following inter-vehicle distance control" and "lane keeping control".

・ Follow-up vehicle-to-vehicle distance control (ACC: Adaptive Cruise Control)
The following vehicle-to-vehicle distance control determines the inter-vehicle distance between the preceding vehicle (the vehicle subject to ACC tracking, which will be described later) and the own vehicle, which is in the front region of the own vehicle and is traveling in front of the own vehicle, based on the target information. It is a control that causes the own vehicle to follow the preceding vehicle while maintaining the distance. The following vehicle-to-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, Japanese Patent No. 4929777, etc.). Therefore, it will be briefly described below.

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

More specifically, when the following vehicle-to-vehicle distance control is required, the driving support ECU 10 selects the ACC tracking target vehicle based on the target information acquired by the surrounding sensor 16. For example, in the driving support ECU 10, the relative position of the target (n) specified from the lateral distance Dfy (n) of the detected target (n) and the inter-vehicle distance Dfx (n) is the vehicle speed of the own vehicle and the own vehicle. Whether or not the vehicle exists in a predetermined tracking target vehicle area so that the longer the distance in the traveling direction of the own vehicle estimated based on the yaw rate of the vehicle, the smaller the absolute value of the lateral distance with respect to the traveling direction. To judge. Then, when the relative position of the target (n) exists in the tracking target vehicle area for a predetermined time or longer, the driving support ECU 10 selects the target (n) as the ACC tracking target vehicle. When there are a plurality of targets whose relative positions exist in the tracking target vehicle area for a predetermined time or longer, the driving support ECU 10 uses the targets having the smallest inter-vehicle distance Dfx (n) among the targets. Is selected as the ACC tracking target vehicle.

Further, the driving support ECU 10 calculates the target acceleration Gtgt according to any of the following equations (1) and (2). In the equations (1) and (2), Vfx (a) is the relative speed of the ACC tracking target vehicle (a), k1 and k2 are predetermined positive gains (coefficients), and ΔD1 is the “ACC tracking target”. It is an inter-vehicle deviation (= Dfx (a) -Dtgt) obtained by subtracting the "target inter-vehicle distance Dtgt" from the inter-vehicle distance Dfx (a) of the vehicle (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 SPD of the own vehicle 100 (that is, Dtgt = Ttgt · SPD).

When the value (k1, ΔD1 + k2, Vfx (a)) is positive or “0”, the driving support 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 support 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 there is no target in the tracking target vehicle area, the driving support ECU 10 determines the target speed and the vehicle speed SPD so that the vehicle speed SPD of the own vehicle matches the "target speed set according to the target inter-vehicle time Ttgt". The target acceleration Gtgt is determined based on.

The driving support ECU 10 controls the engine actuator 21 by using the engine ECU 20 and controls the brake actuator 31 by using the brake ECU 30 as necessary so that the acceleration of the vehicle matches the target acceleration Gtgt. As described above, the driving support ECU 10 has a "ACC control unit 10a that executes the following vehicle-to-vehicle distance control (ACC)" that is functionally realized by the CPU.

-Lane maintenance control The driving support ECU 10 executes the lane maintenance control when the lane maintenance control is required by the operation of the operation switch 17 during the execution of the following inter-vehicle distance control.

In lane keeping control called LTC (Lane Trace Control), the driving support ECU 10 determines (sets) a target traveling line (target traveling path) by utilizing the preceding vehicle locus, the white line, or both of them. The driving support ECU 10 has the lateral position of the own vehicle (that is, the position of the own vehicle in the vehicle width direction with respect to the road) near the target traveling line in the "traveling lane in which the own vehicle is traveling (own vehicle traveling lane)". A steering torque is applied to the steering mechanism to change the steering angle of the own vehicle so as to be maintained, thereby supporting the steering operation of the driver (for example, JP-A-2008-195402, JP-A-2009-). (Refer to Japanese Patent Application Laid-Open No. 190464 and Japanese Patent Application Laid-Open No. 2010-6279). The lane keeping control may also be referred to as "TJA (Traffic Jam Assis)".

Hereinafter, lane keeping control using the target driving line determined based on the preceding vehicle trajectory will be described. This control is also referred to as "steering follow-up control". A preceding vehicle in which the preceding vehicle trajectory is used to determine a target traveling line may be referred to as a "steering following preceding vehicle". The driving support ECU 10 identifies the preceding vehicle (that is, the steering following preceding vehicle) 110, which is the target for creating the preceding vehicle locus L0 for determining the target traveling line, in the same manner as the ACC following target vehicle.

Next, as shown in FIG. 2, the driving support ECU 10 identifies the steering following preceding vehicle 110, which is a target for creating the preceding vehicle locus L0, and steers the position of the own vehicle 100 at predetermined time intervals. The preceding vehicle locus L0 is created based on the target information including the position information of the following preceding vehicle 110. In the xy coordinates shown in FIG. 2, the central axis extending in the front-rear direction of the own vehicle 100 is the x-axis, the axis orthogonal to this is the y-axis, and the current position of the own vehicle 100 is the origin (x = 0, These are the coordinates for which y = 0).

Each symbol shown in FIG. 2 is as follows.
dv: Distance dv in the y-axis direction (substantially the road width direction) between the center position of the own vehicle 100 at the current position (x = 0, y = 0) in the vehicle width direction and the preceding vehicle locus L0.
θv: The deviation angle between the direction (tangential direction) of the preceding vehicle locus L0 corresponding to the current position (x = 0, y = 0) of the own vehicle 100 and the traveling direction (+ direction of the x-axis) of the own vehicle 100. Yaw angle).
Cv: Curvature of the preceding vehicle locus L0 at the position (x = 0, y = dv) corresponding to the current position (x = 0, y = 0) of the own vehicle 100 Cv': Curvature change rate (arbitrary of the preceding vehicle locus L0) Curvature change amount per unit distance (Δx) at the position of (x = x0, x0 is an arbitrary value))

For example, the driving support ECU 10 stores (buffers) position coordinate data (preceding vehicle position information) representing the position of the steering following preceding vehicle 110 in the RAM each time a predetermined sampling time elapses. The driving support ECU 10 uses the position coordinate data of the steering following preceding vehicle 110 stored in the RAM as the position and traveling direction of the own vehicle 100 at the time when the respective position coordinate data are acquired, and the position and traveling direction of the own vehicle at the present time. Based on the difference between, and, the current position is converted into the position coordinate data of the above-mentioned xy coordinates with the origin (x = 0, y = 0). For example, (x1, y1), (x2, y2), (x3, y3) and (x4, y4) in FIG. 2 are the position coordinate data of the steering following preceding vehicle 110 converted in this way (hereinafter, "conversion"). This is an example of (sometimes referred to as "post-position coordinates").

The driving support ECU 10 creates the preceding vehicle locus L0 by executing the curve fitting process using the converted position coordinates of the steering following preceding vehicle 110. For example, the curve used in the fitting process is a cubic function f (x). The fitting process is performed, for example, by the method of least squares. As described above, the driving support ECU 10 has a "traveling locus creating unit (traveling locus creating means) 10b for creating the preceding vehicle locus L0 of the preceding vehicle" realized by the CPU in terms of function.

Hereinafter, the method of creating the preceding vehicle locus L0 will be specifically described. As shown in FIG. 3A, the preceding vehicle locus L0 is ^{defined by the cubic curve: f (x) = ax 3} + bx ² + cx + d. Using the relational expressions and conditions shown in FIG. 3B, the coefficients (a, b, c and d) of the cubic function f (x), the curvature Cv and the yaw angle shown in FIG. 3C are used. The relationship with θ etc. ”is derived. Therefore, the preceding vehicle locus L0 can be expressed as shown in the following equation (3). As is clear from the above, the preceding vehicle locus L0 can be determined by obtaining the coefficients a, b, c and d of the cubic function f (x) using the least squares method. Therefore, the curvature change rate Cv', the curvature Cv of the preceding vehicle locus L0 at the position corresponding to the current position of the own vehicle 100, the yaw angle θv, and the distance dv can be obtained.
f (x) = (1/6) Cv'・ x ³ + (1/2) Cv ・ x ² + θv ・ x + dv… (3)

When the driving support ECU 10 sets the preceding vehicle locus L0 as the target traveling line, the driving support ECU 10 is based on the relationship between the coefficients a, b, c and d of the created cubic function f (x) and the relationship shown in FIG. 3 (C). , Target track information required for steering follow-up control (lane keeping control) (that is, curvature Cv (and curvature change rate Cv') of the target drive line, yaw angle θv with respect to the target drive line, and road width direction with respect to the target drive line. Distance dv) is acquired.

The driving support ECU 10 calculates the target steering angle θ * by applying the curvature Cv, the yaw angle θv, and the distance dv to the following equation (4) every time a predetermined time elapses. Further, the driving support ECU 10 controls the steering motor 42 by using the steering ECU 40 so that the actual steering angle θ matches the target steering angle θ *. In the equation (4), Klta1, Klta2 and Klta3 are predetermined control gains.
θ * = Klta1 ・ Cv ＋ Klta2 ・ θv ＋ Klta3 ・ dv… (4)

Next, the lane keeping control using the target driving line determined based on the white line will be described. As shown in FIG. 4, the driving support ECU 10 has a “left white line” of the traveling lane in which the own vehicle 100 is traveling, based on the information transmitted from the surrounding sensor 16 (information that the camera sensor 16b can recognize). Get information about "LL and right white line LR". The driving support ECU 10 estimates the line connecting the acquired left white line LL and the right white line LR at the center position in the road width direction as the “center line of the traveling lane” LM. In this way, the driving support ECU 10 is functionally realized by the CPU as "a lane marking recognition unit (road marking means) 10c that estimates the center line LM, which is a line connecting the center positions between the white lines LL and LR." "have.

Further, the driving support ECU 10 determines the position and orientation of the own vehicle 100 in the traveling lane defined by the curve radius R and the curvature CL (= 1 / R) of the center line LM of the traveling lane and the left white line LL and the right white line LR. And, are calculated. More specifically, as shown in FIG. 4, the driving support ECU 10 has a y-axis direction (substantially a road) between the center position of the own vehicle 100 in the vehicle width direction and the center line LM of the traveling lane. The distance dL in the width direction) and the deviation angle θL (yaw angle θL) between the direction of the center line LM (tangential direction) and the traveling direction of the own vehicle 100 are calculated. These parameters are the target lane information (curvature CL (and rate of change of curvature) of the target lane) required for lane keeping control when the center line LM of the lane is set as the target lane, and the yaw angle θL with respect to the target lane. , And the distance dL in the road width direction with respect to the target driving line).

Then, in the equation (4), the driving support ECU 10 calculates the target steering angle θ * by replacing dv with dL, replacing θv with θL, and replacing Cv with CL, and the actual steering angle θ. Controls the steering motor 42 so that the steering angle θ * matches the target steering angle θ *.

The driving support ECU 10 may create a target traveling line by combining the preceding vehicle locus L0 and the central line LM of the traveling lane. More specifically, for example, as shown in FIG. 5, in the driving support ECU 10, the preceding vehicle locus L0 is a locus that maintains the shape (curvature) of the preceding vehicle locus L0 and is in the vicinity of the own vehicle 100. The preceding vehicle locus L0 is corrected so that the locus coincides with the position of the central line LM and the direction (tangential direction) of the central line LM. As a result, the locus maintains the shape of L0 of the preceding vehicle locus, and the error in the lane width direction is small. "Corrected preceding vehicle locus (sometimes referred to as" corrected preceding vehicle locus ") L0 *. Can be obtained as the target driving line. Then, the driving support ECU 10 acquires the target track information when the corrected preceding vehicle locus L0 * is set as the target travel line, calculates the target steering angle θ * from the target track information and the above equation (4), and calculates the target steering angle θ *. The steering motor 42 is controlled so that the actual steering angle θ matches the target steering angle θ *.

As described in (a) to (d) below, the driving support ECU 10 of the present implementation device sets a target traveling line according to the presence / absence of a preceding vehicle and the recognition status of the white line, and executes lane keeping control.
(A) When the left and right white lines can be recognized far away, the driving support ECU 10 sets a target traveling line based on the central line LM of the traveling lane and executes lane keeping control.
(B) When there is a steering-following preceding vehicle in front of the own vehicle and the left and right white lines cannot be recognized, the driving support ECU 10 sets a target traveling line based on the preceding vehicle locus L0 of the steering-following preceding vehicle. Execute steering follow-up control (lane keeping control).
(C) When there is a steering-following preceding vehicle in front of the own vehicle and the left and right white lines in the vicinity of the own vehicle can be recognized, the driving support ECU 10 can "recognize" the preceding vehicle locus L0 of the steering-following preceding vehicle. The corrected preceding vehicle locus L0 * corrected based on the "white line" is set as the target traveling line, and steering follow-up control (lane keeping control) is executed.
(D) When the steering following preceding vehicle does not exist in front of the own vehicle and the white line on the road cannot be recognized, the driving support ECU 10 cancels the lane keeping control.

Further, in the above situations (b) and (c), when an adjacent lane exists and an adjacent vehicle exists in the adjacent lane, the driving support ECU 10 has the preceding vehicle locus L0 and the adjacent vehicle as described later. Steering follow-up control is executed based on the traveling locus of the vehicle (that is, "adjacent vehicle locus"). As described above, the driving support ECU 10 has a "LTC control unit (steering follow-up control means, lane keeping control means) 10d" that is functionally realized by the CPU.

<Outline of operation>
In any of the above situations (b) and (c), there is another vehicle (adjacent vehicle) that is adjacent to the traveling lane in which the own vehicle is traveling and that travels in the area in front of the own vehicle. In this case, it is better to set the target driving lane (in other words, the target driving track information) by using the traveling locus of the adjacent vehicle, so that the own vehicle can be stably driven along the vicinity of the center of the traveling lane. In some cases. However, for example, when an adjacent vehicle overtakes the own vehicle while traveling in the overtaking lane, the adjacent vehicle trajectory of the adjacent vehicle is created for the first time after the adjacent vehicle is newly (first) detected by the surrounding sensor 16. The time to reach is short. Therefore, the amount of position information of the adjacent vehicle that can be acquired by the time of the first creation of the adjacent vehicle locus may be small. In this case, the accuracy of the created adjacent vehicle trajectory may not be good. Such a problem also occurs when the own vehicle is traveling in the overtaking lane and overtaking another vehicle traveling in the normal lane.

In order to solve this problem, the present implementation device creates an adjacent vehicle locus by utilizing the preceding vehicle locus L0 of the steering-following preceding vehicle. This is due to the following reasons. In the vicinity of the own vehicle, it is highly possible that the road shape (curvature) of the adjacent lane is substantially the same as the road shape (curvature) of the traveling lane. Therefore, it is highly likely that the curvature of the adjacent vehicle locus is substantially the same as the curvature of the preceding vehicle locus L0. Therefore, by creating an adjacent vehicle locus by utilizing the preceding vehicle locus L0, it is possible to suppress a decrease in the accuracy of the adjacent vehicle locus.

Explaining a simple flow of processing, the present implementation device first determines whether or not the inter-vehicle distance between the adjacent vehicle and the own vehicle (Dfx (b) described later) is equal to or less than a predetermined threshold value. This is because when the above-mentioned inter-vehicle distance is equal to or less than the threshold value, the amount of the position information of the adjacent vehicle that can be acquired may be small. When the above-mentioned inter-vehicle distance is equal to or less than the threshold value, the present implementing device determines whether or not the steering-following preceding vehicle is stably traveling along the traveling lane. Then, when it is determined that the steering-following preceding vehicle is stably traveling along the traveling lane, the present implementation device creates an adjacent vehicle trajectory by utilizing the preceding vehicle trajectory of the steering-following preceding vehicle.

<Details of processing>
Hereinafter, the process of creating the adjacent vehicle locus will be described with reference to FIG. In the example of FIG. 6, the driving support ECU 10 executes the following inter-vehicle distance control (ACC). Further, it is premised that the driving support ECU 10 executes lane keeping control based on both the preceding vehicle locus L0 and the adjacent vehicle locus under the condition that all of the following three conditions are satisfied.
-The left white line and the right white line for setting the center line LM of the traveling lane cannot be recognized by the camera sensor 16b. That is, at present, the driving support ECU 10 does not execute the lane keeping control based on the central line LM of the traveling lane.
-There is a steering-following preceding vehicle in the front area of the own vehicle.
-There is an adjacent lane adjacent to the traveling lane in which the own vehicle is traveling, and there is an adjacent vehicle traveling in the front area of the own vehicle in the adjacent lane.

In the example shown in FIG. 6, the own vehicle 100 is traveling in the traveling lane 610, and the steering following preceding vehicle 110 is traveling in the front region of the own vehicle 100 in the traveling lane 610. Further, the adjacent vehicle 111 is traveling in the front region of the own vehicle 100 and is traveling in the adjacent lane 620 adjacent to the right side of the traveling lane 610.

(Selection of adjacent vehicle)
When such a situation occurs, the driving support ECU 10 first selects an adjacent vehicle from the adjacent lane 620. When the target is present in the adjacent vehicle area having the same width (length in the road width direction) as the follow-up target vehicle area for a predetermined time, the driving support ECU 10 selects the target as the adjacent vehicle. The adjacent vehicle area is an area in which the tracking target vehicle area is translated to the adjacent lane 620 side by the width (width) of the traveling lane. In the example of FIG. 6, the driving support ECU 10 selects the adjacent vehicle 111 from the adjacent lane 620.

The driving support ECU 10 determines whether or not the adjacent vehicle locus L1 of the selected adjacent vehicle 111 has already been created. When the adjacent vehicle locus L1 of the selected adjacent vehicle 111 has not been created yet, that is, the adjacent vehicle 111 is newly selected at the current calculation timing, and the adjacent vehicle locus L1 of the adjacent vehicle 111 is created for the first time. In this case, the driving support ECU 10 executes the following processing.

(Calculation of inter-vehicle distance between own vehicle and adjacent vehicle)
The driving support ECU 10 calculates the inter-vehicle distance Dfx (b) between the own vehicle 100 and the adjacent vehicle 111 (n = b). The driving support ECU 10 determines whether or not the inter-vehicle distance Dfx (b) is equal to or less than a predetermined first threshold value Th1. When the inter-vehicle distance Dfx (b) is equal to or less than a predetermined first threshold value Th1, the driving support ECU 10 executes a driving condition determination process for the preceding vehicle, which will be described later.

(Judgment of driving conditions for the preceding vehicle)
The driving support ECU 10 determines whether the steering following preceding vehicle 110 satisfies a predetermined traveling condition (hereinafter, may be referred to as "stable traveling condition"). The predetermined stable traveling condition is a condition for determining whether or not the steering-following preceding vehicle is stably traveling along the traveling lane. Specifically, the stable running condition is satisfied when the magnitude of the amount of change in the position of the steering following preceding vehicle 110 with respect to the white line is equal to or less than a predetermined second threshold value Th2.

When the driving support ECU 10 recognizes at least "one of the left and right white lines of the traveling lane 610" while the own vehicle 100 is traveling, the distance Dhy in the road width direction between the recognized white line and the steering following preceding vehicle 110. Is calculated. In the example shown in FIG. 6, it is assumed that the left white line LL can be recognized by the peripheral sensor 16. The driving support ECU 10 calculates the distance Dhy in the road width direction between the left white line LL and the steering following preceding vehicle 110. The operation support ECU 10 has a large amount of change in the distance Dhy between the previous calculation timing (time t1) and the current calculation timing (time t2) (that is, the distance Dhy in the first predetermined time (t2-t1)). The first distance change amount, which is the magnitude of the change amount of), is calculated. The driving support ECU 10 determines whether or not the first distance change amount is equal to or less than a predetermined second threshold value Th2. When the first distance change amount is equal to or less than the predetermined second threshold value Th2, the driving support ECU 10 determines that the steering following preceding vehicle 110 satisfies the predetermined stable running condition.

It should be noted that it may be determined whether or not the steering following preceding vehicle 110 is stably traveling along the traveling lane 610 by utilizing the fixed object installed along the traveling lane 610. For example, it is assumed that a curb or guardrail is set along the left white line LL of the traveling lane 610, and the curb or guardrail can be recognized by the surrounding sensor 16. In this case, the driving support ECU 10 determines the amount of change in the distance Djy in the road width direction between the recognized curb or guardrail and the steering following preceding vehicle 110 as the first distance change amount (that is, the first predetermined amount). The magnitude of the amount of change in the distance Djy with respect to time (t2-t1)) may be calculated. The driving support ECU 10 may determine whether or not the amount of change is equal to or less than a predetermined second threshold value Th2. As described above, the driving support ECU 10 is functionally realized by the CPU, "whether the steering following preceding vehicle satisfies a predetermined stable driving condition (that is, the steering following preceding vehicle stably travels along the traveling lane). It has a determination unit (determination means) 10e "that determines (whether or not).

(Creation of adjacent vehicle trajectory)
When the inter-vehicle distance Dfx (b) is equal to or less than a predetermined first threshold Th1 and the steering-following preceding vehicle 110 satisfies a predetermined stable driving condition, the driving support ECU 10 determines the preceding vehicle locus L0 and the adjacent vehicle 111. The adjacent vehicle locus L1 is created based on the position coordinate data (adjacent vehicle position information).

As shown in FIG. 6, first, the driving support ECU 10 has the coordinates (X0, Y0) of the center position in the vehicle width direction of the steering following preceding vehicle 110 and the coordinates (X1, Y1) of the center position in the vehicle width direction of the adjacent vehicle 111. The distance L in the road width direction (in this example, the y-axis direction) between the two is calculated. The cubic function representing the preceding vehicle locus L0 is described as "f (x)", and the cubic function representing the adjacent vehicle locus L1 of the adjacent vehicle 111 is described as "g (x)". The operation support ECU 10 obtains g (x) by translating f (x) in the y-axis direction as shown in the following equation (5).
g (x) = f (x) + L ... (5)

When the adjacent vehicle 111 is located farther than the steering following preceding vehicle 110 with respect to the own vehicle 100, the driving support ECU 10 extends g (x) to the current x-coordinate X1 of the adjacent vehicle 111. Create L1. On the other hand, when the adjacent vehicle 111 is closer to the own vehicle 100 than the steering following preceding vehicle 110, the driving support ECU 10 is adjacent so as to shorten g (x) to the current x coordinate X1 of the adjacent vehicle 111. Create a vehicle trajectory L1.

On the other hand, when the inter-vehicle distance Dfx (b) is larger than the first threshold value Th1, the driving support ECU 10 creates the adjacent vehicle locus L1 based only on the position coordinate data of the adjacent vehicle 111 without utilizing the preceding vehicle locus L0. To do. It is considered that this is because the adjacent vehicle 111 is located far from the own vehicle 100 and the length of the created adjacent vehicle locus exceeds a certain level, so that the accuracy of the adjacent vehicle locus is unlikely to decrease. Because it is possible. The driving support ECU 10 executes a curve fitting process on the converted position coordinates of the adjacent vehicle 111 in the same manner as the procedure for creating the preceding vehicle locus L0 described above, thereby causing the adjacent vehicle locus L1 (= g (x)). To create.

Further, even if the inter-vehicle distance Dfx (b) is equal to or less than a predetermined first threshold value Th1, if the steering-following preceding vehicle 110 does not satisfy the predetermined stable traveling condition, the driving support ECU 10 sets the preceding vehicle locus L0. The adjacent vehicle locus L1 is created based only on the position coordinate data of the adjacent vehicle 111 without utilizing it. This is compared with the case where the preceding vehicle locus L0 of the steering-following preceding vehicle 110 that is not traveling along the traveling lane 610 is reflected in the adjacent vehicle locus L1 and is created based only on the position coordinate data of the adjacent vehicle 111. This is because there is a high possibility that the accuracy of the adjacent vehicle locus L1 will be low.

If the adjacent vehicle locus L1 has already been created at the previous calculation timing, the driving support ECU 10 creates the adjacent vehicle locus L1 based on the position coordinate data of the adjacent vehicle locus L1 and the adjacent vehicle 111. For example, the driving support ECU 10 creates the adjacent vehicle locus L1 so as to extend the adjacent vehicle locus L1 to the x coordinate of the current position of the adjacent vehicle 111. The driving support ECU 10 refers to all of the coordinates of some arbitrary coordinates on the adjacent vehicle locus L1 and the coordinates of the adjacent vehicle 111 newly acquired between the previous calculation timing and the current calculation timing. The adjacent vehicle locus L1 may be created by executing the curve fitting process again. The function of creating the adjacent vehicle locus L1 is included in the traveling locus creating unit 10b.

(Calculation of target track information)
The driving support ECU 10 calculates the corrected curvature F_Cv, which is one of the target track information, based on the preceding vehicle locus L0 and the adjacent vehicle locus L1. The curvature of the preceding vehicle locus L0 at the position corresponding to the current position of the own vehicle 100 is described as "Cv_0", and the curvature of the adjacent vehicle locus L1 at the position corresponding to the current position of the own vehicle 100 is described as "Cv_1". Further, the weight with respect to the curvature CV_0 is described as "w0", and the weight with respect to the curvature Cv_1 is described as "w1". The driving support ECU 10 calculates the corrected curvature F_Cv based on the weighted average as shown in the following equation (6).

The weight w0 and the weight w1 may be set to different values, or may be the same value.

(Execution of steering follow-up control (lane keeping control))
The driving support ECU 10 replaces "Cv" in Eq. (4) with "F_Cv" and calculates the target steering angle θ *. The driving support ECU 10 controls the steering motor 42 by using the steering ECU 40 so that the actual steering angle θ matches the target steering angle θ *.

<Specific operation>
Next, the specific operation of the CPU of the driving support ECU 10 (sometimes referred to simply as "CPU") will be described. As one routine in the lane keeping control (LTC), the CPU executes the routine shown in FIG. 8 every time a predetermined calculation timing arrives. The CPU executes the routine shown in FIG. 8 when the following vehicle-to-vehicle distance control (ACC) is being executed and the lane keeping control (LTC) is requested by the operation of the operation switch 17. For convenience of explanation, the CPU does not execute the steering follow-up control in which the corrected preceding vehicle locus L0 * is set as the target traveling line as described in the above situation (c), but the corrected preceding vehicle locus L0 * is set as the target traveling line. The steering follow-up control set as may be executed.

Therefore, when the follow-up vehicle-to-vehicle distance control (ACC) is being executed and the lane keeping control (LCC) is required by the operation of the operation switch 17, the CPU will perform steps 800 to 8 when the predetermined timing is reached. The routine of is started and the process proceeds to step 805, and it is determined whether or not a predetermined execution condition is satisfied. The predetermined execution condition is satisfied when all of the following conditions 1 to 3 are satisfied.
(Condition 1): A steering-following preceding vehicle exists in the front region of the own vehicle. That is, there is a preceding vehicle that is in front of the own vehicle and is traveling in an area (following target vehicle area) in the traveling direction of the own vehicle.
(Condition 2): There is another vehicle traveling in the front region of the own vehicle in the adjacent lane adjacent to the traveling lane in which the own vehicle is traveling. That is, there is an adjacent vehicle traveling in a region (adjacent vehicle area) in front of the own vehicle that deviates from the traveling direction of the own vehicle in the road width direction.
(Condition 3): The left white line and the right white line for setting the center line LM of the traveling lane cannot be recognized far enough. That is, the CPU is not currently executing lane keeping control based on the central line LM of the traveling lane.

If the predetermined execution condition is not satisfied, the CPU determines "No" in step 805, directly proceeds to step 895, and temporarily ends this routine.

On the other hand, when the predetermined execution condition is satisfied, the CPU determines "Yes" in step 805, performs the processes of steps 810 to 820 described below in order, and proceeds to step 825.

Step 810: The CPU selects the target closest to the own vehicle among the targets existing in the tracking target vehicle area for a predetermined time or longer based on the target information sent from the surrounding sensor 16 as the steering tracking preceding vehicle. To do.
Step 815: As described above, the CPU creates the preceding vehicle locus L0 by performing curve fitting with respect to the converted position coordinates of the steering following preceding vehicle 110 selected in step 810.
Step 820: As described above, the CPU selects a target existing in the adjacent vehicle area as an adjacent vehicle (vehicle to be created for the adjacent vehicle locus).

In step 825, the CPU determines whether or not a predetermined flag reset condition is satisfied. The flag reset condition is satisfied, for example, when any of the conditions 4 and 5 described below is satisfied.
(Condition 4): The adjacent vehicle was not selected at the previous calculation timing, and the adjacent vehicle was newly selected at the current calculation timing.
(Condition 5): The adjacent vehicle selected at the current calculation timing is different from the adjacent vehicle selected at the previous calculation timing.

Now, it is assumed that an adjacent vehicle is newly selected at this calculation timing. In this case, the above condition 4 is satisfied. Therefore, since the flag reset condition is satisfied, the CPU determines "Yes" in step 825 and proceeds to step 830. In step 830, the CPU sets the value of the flag F to "0" and proceeds to step 835.

In step 835, the CPU determines whether or not the flag F is "0". Now, since the flag F is "0", the CPU determines "Yes" and proceeds to step 840.

In step 840, the CPU determines whether or not the inter-vehicle distance Dfx (b) between the own vehicle 100 and the adjacent vehicle (n = b) selected in step 820 is equal to or less than a predetermined first threshold value Th1. To do. When the inter-vehicle distance Dfx (b) is equal to or less than the predetermined first threshold value Th1, the CPU determines “Yes” in step 840 and proceeds to step 845.

In step 845, the CPU determines whether or not the steering-following preceding vehicle satisfies the above-mentioned stable running condition. When the steering-following preceding vehicle satisfies the stable driving condition, the CPU determines "Yes" in step 845, and performs the processes of steps 850, 860, 870, and 875 in order as follows, and proceeds to step 895. Proceed to end this routine once.

Step 850: As described above, the CPU determines the adjacent vehicle locus based on the above-described method based on the position coordinate data (preceding vehicle position information) of the preceding vehicle locus L0 and the position coordinate data of the adjacent vehicle (adjacent vehicle position information). Create L1 (see, for example, equation (5) above).
Step 860: The CPU sets the value of the flag F to "1".
Step 870: The CPU calculates the modified curvature F_Cv, which is one of the target track information, based on the equation (6). Further, the CPU calculates the yaw angle θv with respect to the preceding vehicle locus L0 and the distance dv in the road width direction with respect to the preceding vehicle locus L0 as the target track information.
Step 875: The CPU sets a target travel line based on the target track information calculated in step 870, and executes lane keeping control along the target travel line.

On the other hand, if the inter-vehicle distance Dfx (b) is larger than the predetermined first threshold value Th1 at the time of executing the process of step 840, the CPU determines "No" in the step 840 and proceeds to step 855. Further, if the steering-following preceding vehicle does not satisfy the stable running condition at the time of executing the process of step 845, the CPU determines "No" in the step 845 and proceeds to step 855.

When the CPU proceeds to step 855, as described above, the CPU creates the adjacent vehicle locus L1 based only on the position coordinate data of the adjacent vehicle. After that, the CPU executes the processes of step 860, step 870, and step 875 in order, and then proceeds to step 895 to temporarily end this routine.

When the predetermined time elapses in this situation, the CPU restarts the process from step 800. When the CPU proceeds to step 805, the above-mentioned predetermined execution condition is satisfied again. Therefore, the CPU executes steps 805 to 810, 815, and 820.

Next, the CPU proceeds to step 825 and determines whether or not the flag reset condition is satisfied. In this case, the adjacent vehicle is selected at the previous calculation timing, and the adjacent vehicle is the same as the adjacent vehicle selected at the current calculation timing. Therefore, neither of the above-mentioned conditions 4 and 5 is satisfied. That is, the flag reset condition is not satisfied. Therefore, the CPU determines "No" in step 825 and proceeds directly to step 835. As a result, the value of the flag F is maintained at "1".

Next, in step 835, the CPU determines whether or not the flag F is "0". Now, since the flag F is "1", the CPU determines "No" and proceeds to step 865.

In step 865, the CPU creates the adjacent vehicle locus L1 based on the adjacent vehicle locus L1 and the position coordinate data of the adjacent vehicle as described above. The CPU may create the adjacent vehicle locus L1 by executing the same process as in step 855 in step 865. After that, the CPU executes the processes of step 870 and step 875 in order, proceeds to step 895, and temporarily ends this routine.

The present implementation device described above stably travels along a traveling lane of a preceding vehicle (that is, traveling along a traveling lane) that satisfies a predetermined stable traveling condition at the time of the first creation of the adjacent vehicle locus L1 of the detected adjacent vehicle 111. The adjacent vehicle locus L1 of the adjacent vehicle 111 is created by utilizing the preceding vehicle locus L0 of the preceding vehicle). Therefore, even if the position information of the adjacent vehicle 111 is small when the adjacent vehicle locus L1 is created for the first time, it is possible to suppress a decrease in the accuracy of the adjacent vehicle locus L1. As a result, since the target traveling line can be set by utilizing the adjacent vehicle locus with high accuracy in addition to the preceding vehicle locus, the own vehicle 100 can stably travel in the traveling lane.

The present invention is not limited to the above embodiment, and various modifications can be adopted within the scope of the present invention. For example, step 845 may be omitted. That is, the CPU may proceed to step 850 without determining whether or not the steering-following preceding vehicle satisfies the stable traveling condition, and generate the first adjacent vehicle locus based on the preceding vehicle locus and the adjacent vehicle position information. ..

In step 815, the Kalman filter may be used to generate the preceding vehicle locus L0. When the position information of the own vehicle and the position information of the steering-following preceding vehicle stored in the RAM are input to the Kalman filter provided in the driving support ECU 10, the curvature of the preceding vehicle locus L0 of the current position of the own vehicle 100 and the preceding vehicle are displayed from the Kalman filter. The rate of change in curvature of the locus L0, the yaw angle of the own vehicle 100 with respect to the preceding vehicle locus L0, and the distance between the preceding vehicle locus L0 and the current position of the own vehicle 100 are output. The CPU can obtain the coefficients a, b, c and d of the cubic function f (x) by using the relationship between the coefficient of the cubic function shown in FIG. 3C and the curvature, yaw angle and the like. it can.

The stable running conditions used in step 845 are not limited to the above examples. Instead of or in addition to the above-mentioned stable running condition, the condition of the amount of change in the position of the steering following preceding vehicle 110 with respect to another vehicle may be used. In the example shown in FIG. 6, it is assumed that the other vehicle 112 traveling in the rear region of the own vehicle 100 in the adjacent lane 620 can be recognized by the surrounding sensor 16. The driving support ECU 10 calculates the distance DIY in the road width direction between the other vehicle 112 (center position in the vehicle width direction) and the steering following preceding vehicle 110. The operation support ECU 10 has a large amount of change in the distance Diy between the previous calculation timing (time t1) and the current calculation timing (time t2) (that is, the distance Diy in the second predetermined time (t2-t1)). The second distance change amount, which is the magnitude of the change amount of), is calculated. This is because when the amount of change in the behavior of the steering-following preceding vehicle 110 with respect to the other vehicle 112 in the road width direction is large, it is considered that the steering-following preceding vehicle 110 is not stably traveling along the traveling lane 610. .. The driving support ECU 10 determines whether or not the second distance change amount is equal to or less than a predetermined third threshold value Th3. When the amount of change in the second distance is equal to or less than the predetermined third threshold value Th3, the driving support ECU 10 determines that the steering following preceding vehicle 110 satisfies the predetermined stable running condition.

In step 850, as shown in FIG. 7, the CPU may create the adjacent vehicle locus L1 based on the position coordinate data of the adjacent vehicle 111 and the position coordinate data of the steering following preceding vehicle 110. (Xb1, yb1) and (xb2, yb2) in FIG. 7 are the converted position coordinates of the adjacent vehicle 111 that can be acquired at the present time. (Xa1, ya1), (xa2, ya2) and (xa3, ya3) are a part of the converted position coordinates of the steering following preceding vehicle 110 used when creating the preceding vehicle locus L0. For example, the converted position coordinates of these steering-following preceding vehicles 110 convert the position coordinate data acquired before the time when the oldest position coordinate data (for example, (xb2, yb2)) of the adjacent vehicle 111 is acquired. These are the coordinates. The driving support ECU 10 translates the converted position coordinates of the steering following preceding vehicle 110 by a distance L in the y-axis direction. The driving support ECU 10 provides the converted position coordinates (that is, (xa1, ya1 + L), (xa2, ya2 + L) and (xa3, ya3 + L)) of the translated steering follow-up preceding vehicle 110 and the converted position coordinates of the adjacent vehicle 111. By executing the curve fitting process on ((xb1, yb1) and (xb2, yb2)), the adjacent vehicle trajectory L1 (= g (x)) may be created.

The apparatus of the present invention can also be applied to the case of executing the lane keeping control using the corrected preceding vehicle locus L0 *. That is, in the apparatus of the present invention, the curvature of the corrected preceding vehicle locus L0 * may be set to "Cv_0" of the equation (6).

Although FIGS. 6 and 7 show a road with two lanes each way, the scope of application of the present implementation device is not limited to this type of road. The implementation device may be applied to a road having three or more lanes each way.

In the present implementation device, the lane keeping control is executed only during the execution of the following inter-vehicle distance control (ACC), but the lane keeping control may be executed even if the following inter-vehicle distance control is not being executed. ..

10 ... Driving support ECU, 11 ... Accelerator pedal operation amount sensor, 12 ... Brake pedal operation amount sensor, 13 ... Steering angle sensor, 14 ... Steering torque sensor, 15 ... Vehicle speed sensor, 16 ... Surrounding sensor, 17 ... Operation switch, 18 ... Yaw rate sensor, 20 ... Engine ECU, 30 ... Brake ECU, 40 ... Steering ECU, 50 ... Navigation ECU.

Claims (1)

A preceding vehicle that is in front of the own vehicle and traveling in an area in the traveling direction of the own vehicle and an area that is in front of the own vehicle and deviates from the traveling direction of the own vehicle in the road width direction. The adjacent vehicle that is traveling is detected, and each time a predetermined time elapses, the preceding vehicle position information that specifies the position of the preceding vehicle with respect to the own vehicle and the position of the adjacent vehicle with respect to the own vehicle are specified. A detection means for acquiring the position information of an adjacent vehicle and
Creating a traveling locus, which is a traveling locus of the preceding vehicle, is created based on the preceding vehicle position information, and an adjacent vehicle locus, which is a traveling locus of the adjacent vehicle, is created based on the adjacent vehicle position information. Means and
A control means for executing steering follow-up control for changing the steering angle of the own vehicle so that the own vehicle travels according to the target traveling line determined based on the preceding vehicle locus and the adjacent vehicle locus.
With
The traveling locus creating means
At the time of the first creation of the adjacent vehicle trajectory of the newly detected adjacent vehicle after the adjacent vehicle is newly detected by the detection means, if only the adjacent vehicle position information for the newly detected adjacent vehicle is available. Instead, it is configured to create an adjacent vehicle locus of the newly detected adjacent vehicle based on the preceding vehicle locus or the preceding vehicle position information.
Driving support device.

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