Vehicle driving assistance systems

Abstract

To provide an operation support device of a vehicle, which can perform proper intervention control in accordance with a position of an own vehicle in an intersection, when the own vehicle turns (turns right or turns left) in the intersection by automatic operation.SOLUTION: An operation support control unit 21, when determining that an own vehicle M turns in a direction of a first crossing Cr1 from an intersection in front of the vehicle, examines whether or not there is a second crossing Cr2 which is adjacent to the first crossing Cr1, before the own vehicle M enters the intersection; and when there is the second crossing Cr2, generates a correct route Rc leading to a target route generated on the first crossing Cr1 and a quasi-correct route Rs leading to an extension line from the second crossing. Subsequently, the unit sets an estimated entering route Vc in the intersection for the own vehicle M, calculates a lateral position distance Lc from the estimated entering route Vc to the correct route Rc in a vehicle width direction and a lateral position distance Ls from the estimated entering route to the quasi-correct route Rs, and switches an entering direction of the own vehicle M to the quasi-correct route Rs side, when a difference (Lc-Ls) between both lateral position distances Lc and Ls is equal to a predetermined length.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a vehicle driving support device configured to perform intervention control to cause the vehicle to proceed in the direction of an adjacent second intersection when it is unable to turn completely into the first intersection at the turning destination when the vehicle turns (right or left) at an intersection with multiple branches.

Background Art

[0002] When a driver (operator) sets a destination, this type of driving support device sets a driving route from the current location to the destination on a road map and supports all or part of the driving or automatically drives on behalf of the driver. When providing driving support, a target route for the vehicle to proceed is set on the driving route in front of the vehicle. Then, the position where the vehicle is actually traveling is acquired from a sensing device such as a camera, and the deviation amount of the vehicle position (lateral vehicle position) with respect to the target route is measured, and the steering angle is feedback-controlled so that this deviation amount converges to the target route (deviation amount = 0).

[0003] Also, in driving support on general roads, when the driving route of the vehicle is set in the direction of turning (right or left) at an intersection, the control unit acquires road information (position information, lane width information, etc.) in the turning direction from the road map database. Then, based on the current vehicle position information (vehicle position information) of the vehicle in front of the intersection and the road information at the turning destination acquired from the road map database, the control unit sets a target route for turning the vehicle from the current position through the intersection.

[0004] For example, Patent Document 1 (Japanese Unexamined Patent Application Publication No. 2021-160625) discloses a technique in which the center line set in the lane in front of the intersection where the vehicle is traveling and the center line set in the lane at the left-turn destination are connected by a clothoid curve set within the intersection to set a target route, and the vehicle is made to travel along this target route.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Japanese Patent Publication No. 2021-160625 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] The driver assistance technologies disclosed in the aforementioned literature attempt to guide the vehicle along a target path set at an intersection. However, the curvature of the target path set within the intersection is relatively large, and therefore the vehicle also needs to turn with a large steering angle. However, the turning characteristics of vehicles during driving differ from vehicle type to vehicle, and in some cases, the vehicle may turn while clearly deviating from the target path. If the deviation from the target path is large, it becomes difficult to return the vehicle to the target path within the intersection, even with feedback control of the steering angle.

[0007] As a result, when passing through an intersection and entering the lane to turn, the vehicle deviates significantly from the target path, which compromises driving stability. Therefore, when turning at an intersection, conventional uniform feedback control based solely on the target path has limitations in providing driving assistance that properly guides the vehicle into the lane to turn.

[0008] The present invention aims to provide a vehicle driving assistance device that can perform appropriate intervention control according to the estimated path within an intersection when turning at an intersection. [Means for solving the problem]

[0009] The present invention relates to a vehicle driving assistance device comprising: an environmental information acquisition unit that acquires environmental information in front of the vehicle; a target route setting unit that sets a target route for the vehicle; and a control unit that drives the vehicle along the target route set by the target route, wherein the control unit comprises: an intersection determination unit that determines whether or not there is an intersection in front of the vehicle based on the environmental information acquired by the environmental information acquisition unit; a right / left turn determination unit that, if the intersection determination unit determines that there is an intersection, checks whether or not the vehicle will turn right or left at the intersection; a multi-intersection determination unit that, if the right / left turn determination unit determines that the vehicle will turn right or left, checks whether or not there is a second intersection adjacent to the first intersection to which the vehicle will turn right or left; and if the multi-intersection determination unit determines that there is a second intersection In this case, the system includes: a route generation unit that generates a primary route connected to the target route generated at the first intersection and a secondary primary route connected to the second intersection before the vehicle enters the intersection; an estimated route setting unit that sets an estimated route for the vehicle within the intersection based on the vehicle's behavior; a lateral position distance calculation unit that calculates the lateral position distance on the primary route side from the estimated route set by the estimated route setting unit to the primary route in the vehicle width direction and the lateral position distance on the secondary primary route side to the secondary primary route; a lateral position distance comparison unit that compares the two lateral position distances calculated by the lateral position distance calculation unit; and an intervention control unit that, if the lateral position distance comparison unit determines that the lateral position distance on the primary route side is longer than the lateral position distance on the secondary primary route side by a predetermined amount, sets the direction of travel of the vehicle toward the secondary primary route. [Effects of the Invention]

[0010] According to the present invention, when it is determined that the vehicle will turn right or left at the intersection ahead, it checks whether there is a second intersection adjacent to the first intersection to which the vehicle will turn right or left. If it is determined that there is a second intersection, it generates a primary path leading to the target path generated at the first intersection and a secondary primary path leading to the second intersection before the vehicle enters the intersection. Based on the vehicle's behavior, it sets the estimated path of the vehicle within the intersection, calculates the lateral position distance on the primary path side from the estimated path to the primary path in the vehicle width direction and the lateral position distance on the secondary primary path side to the secondary primary path, and if it is determined that the lateral position distance on the primary path side is longer than a predetermined amount than the lateral position distance on the secondary primary path side, it sets the direction of the vehicle to the secondary primary path side. Thus, appropriate intervention control can be performed according to the estimated path of the vehicle within the intersection. [Brief explanation of the drawing]

[0011] [Figure 1] Schematic diagram of the driver assistance system [Figure 2] Flowchart showing the routine for generating driving paths when turning left or right. [Figure 3] Flowchart showing the positive path generation subroutine [Figure 4] Flowchart showing the quasi-correct path generation subroutine [Figure 5A] Flowchart showing the intervention control decision routine during turns (Part 1) [Figure 5B] Flowchart showing the intervention control decision routine during turns (Part 2) [Figure 6] Flowchart showing a subroutine for controlling quasi-correct pathway intervention [Figure 7] Conceptual diagram showing intervention control categories [Figure 8] Diagram illustrating the process of generating the correct and semi-correct paths when turning left at a multi-way intersection. [Figure 9] Diagram illustrating the behavior of a vehicle when turning left at a multi-way intersection. [Figure 10] Diagram illustrating the state when the target path of the vehicle is set to the original path direction. [Modes for carrying out the invention]

[0012] An embodiment of the present invention will be described below with reference to the drawings. The vehicle M (Figures 8 to 10) is equipped with a driver assistance device 1 that enables autonomous driving without driver intervention in automated driving sections (such as highways and specific sections of general roads). This driver assistance device 1 comprises a locator unit 11 and a driver assistance control unit 21 as a control unit. Furthermore, the locator unit 11 is provided with a map locator calculation unit 12 and a road map database 13.

[0013] The map locator calculation unit 12, the driving support control unit 21, and the forward driving environment recognition unit 26d provided in the camera unit 26 (described later) are composed of a microcontroller equipped with a CPU, RAM, ROM, rewritable non-volatile memory (flash memory or EEPROM), and peripheral devices. The ROM stores programs and fixed data necessary for the CPU to execute each process. The RAM is provided as the CPU's work area and temporarily stores various data from the CPU. The CPU is also called an MPU (Microprocessor) or processor. Alternatively, a GPU (Graphics Processing Unit) or GSP (Graph Streaming Processor) may be used instead of the CPU. Alternatively, a selective combination of CPU, GPU, and GSP may be used.

[0014] Furthermore, a GNSS (Global Navigation Satellite System) receiver 14, a vehicle status sensor 15, and a route information input unit 16 are connected to the input side of the map locator calculation unit 12.

[0015] The host vehicle state sensor 15 detects the running state of the host vehicle M, and is a general term for a vehicle speed sensor, a steering angle sensor, a yaw rate sensor, a longitudinal and lateral acceleration sensor, a wiper switch, and the like. The route information input unit 16 is a terminal device operated by a passenger (mainly a driver), and can input a series of information required when setting a driving route in the map locator calculation unit 12, such as a destination and a via point. Specifically, the route information input unit 16 is an input unit of a car navigation system (for example, a touch panel of a monitor), a mobile terminal such as a smartphone, a personal computer, etc., and is connected to the map locator calculation unit 12 by wire or wirelessly.

[0016] When the passenger operates the route information input unit 16 to input information on a destination or a via point (facility name, address, telephone number, etc.), this input information is read by the map locator calculation unit 12. When a destination or a via point is input, the map locator calculation unit 12 sets the position coordinates (latitude, longitude, altitude) thereof.

[0017] The map locator calculation unit 12 includes a host vehicle position estimation calculation unit 12a that estimates the current position of the host vehicle, a driving route from the host vehicle position to the destination (and the via point), and a driving route / target route setting calculation unit 12b as a target route setting unit that sets a target route for automatically driving the host vehicle M in an automatic driving section (a specific section of a highway or an ordinary road, etc.).

[0018] In addition, the road map database 13 is a large-capacity storage medium such as an HDD, and stores well-known high-precision road map information (local dynamic map). This high-precision road map information stores road data required for automatically driving the host vehicle M.

[0019] The host vehicle position estimation calculation unit 12a acquires the current position coordinates (latitude, longitude, altitude) of the host vehicle M based on the positioning signal received by the GNSS receiver 14, and map-matches this position coordinate to the high-precision road map information to estimate the position of the host vehicle on the road map (current position).

[0020] The driving route / target route setting calculation unit 12b refers to high-precision road map information stored in the road map database 13 based on the location information (latitude, longitude, altitude) of the vehicle's position estimated by the vehicle position estimation calculation unit 12a and the location information (latitude, longitude, altitude) of the input destination (and waypoints). The driving route / target route setting calculation unit 12b constructs a driving route connecting the vehicle's position and the destination (or the destination via the waypoints if waypoints are set) on the high-precision road map information, according to pre-set route conditions (recommended route, fastest route, etc.).

[0021] The driving route / target path setting calculation unit 12b then sets a target path for the vehicle M to drive autonomously, extending several kilometers ahead of the vehicle M. The target path is set, for example, to the center of the lane in which the vehicle M will travel (center of the left and right lane markings).

[0022] Furthermore, the driver assistance device 1 is equipped with a camera unit 26 that recognizes the driving environment in front of the vehicle M. The camera unit 26 is fixed to the upper center of the front part of the interior of the vehicle M and has an on-board camera (stereo camera) consisting of a main camera 26a and a sub-camera 26b arranged symmetrically on either side of the center in the width direction of the vehicle, an image processing unit (IPU) 26c, and a forward driving environment recognition unit 26d. The camera unit 26 captures reference image data with the main camera 26a and comparison image data with the sub-camera 26b. Then, both image data are processed according to a predetermined method by the IPU 26c.

[0023] The forward driving environment recognition unit 26d reads reference image data and comparison image data processed by the IPU 26c, recognizes the same object in both images based on their parallax, and calculates its distance data (distance from the vehicle M to the object) using the principle of triangulation, thereby recognizing forward driving environment information, which is information about the surrounding environment in front of the vehicle.

[0024] The forward driving environment recognition unit 26d of the camera unit 26 is connected to the input side of the driver assistance control unit 21. Furthermore, this driver assistance control unit 21 is connected to the map locator calculation unit 12 via an in-vehicle communication line (e.g., CAN: Controller Area Network) so as to be able to communicate bidirectionally.

[0025] On the other hand, the output side of this driver assistance control unit 21 is connected to a brake drive unit 31, an electric power steering motor (EPS) drive unit 32, an acceleration / deceleration control unit 33, a monitor that notifies the driver of information to alert them, a speaker and other notification devices 34, and the like.

[0026] Here, the brake drive unit 31 drives a brake actuator (not shown) and adjusts the brake fluid pressure supplied to the wheel cylinders of the brake calipers on each wheel, thereby forcibly decelerating the vehicle M to a predetermined speed. The EPS drive unit 32 drives an EPS motor (not shown) provided in an electric power steering (EPS) device to control the steering of the vehicle M while driving. The acceleration / deceleration control unit 33 controls the driving force of the drive source (engine, electric motor, etc.) (engine braking and regenerative braking) and, in coordinated control with the brake drive unit 31, converges the vehicle speed to the target vehicle speed while driving.

[0027] Incidentally, in autonomous driving, the target path is basically set to the center of the driving lane. Therefore, even when the driver assistance control unit 21 makes a turn (right or left) at an intersection using autonomous driving, the target path is set to the center of the driving lane at the first intersection Cr1, which is the destination of the turn. Accordingly, the driver assistance control unit 21 transmits a drive signal corresponding to the target steering angle that traces the target path to the EPS drive unit 32 (feedforward control).

[0028] In this case, the driver assistance control unit 21 calculates a steering angle correction amount that converges the amount of deviation between the target path set by the map locator calculation unit 12 and the vehicle's position (lateral position) estimated by the camera unit 26 and the vehicle position estimation calculation unit 12a to the target path (deviation amount = 0). Then, it corrects the target steering angle with this steering angle correction amount (feedback control) and drives the EPS drive unit 32 with the corrected target steering angle.

[0029] Furthermore, feedback control has a certain delay time, and if the amount of deviation is large, it is difficult to immediately converge the deviation amount relative to the target path because it would impair driving stability.

[0030] This feedback control is designed to converge the deviation amount to the target path, but it does not determine whether the actual path taken by the vehicle during the feedback control is able to turn towards the first intersection Cr1. Therefore, if the correction by the feedback control is insufficient, it is possible that the vehicle's path may veer into the oncoming lane of the first intersection Cr1.

[0031] In particular, at multi-lane intersections, the angles formed with adjacent lanes are often acute. For example, the intersection shown in Figure 8 is a five-way intersection, and the first intersection Cr1, which the vehicle M is traveling in and intends to turn left, is connected to the intersection at an acute angle. Therefore, the driver assistance control unit 21 generates a target path with a large curvature within the intersection. If it is difficult to guide the vehicle M along the target path with a large curvature generated at the intersection, the vehicle M will fail to make the turn and will enter the oncoming lane.

[0032] The driver assistance control unit 21 in this embodiment generates a positive path Rc that leads to the first intersection Cr1 on which the vehicle M is about to turn within the intersection of multiple roads. Furthermore, the driver assistance control unit 21 generates a quasi-positive path Rs that leads to the second intersection Cr2 adjacent to the first intersection Cr1 on which the vehicle M is about to turn within the intersection.

[0033] Then, when the vehicle M is attempting to turn within the intersection along the correct path Rc towards the first intersection Cr1, if it is determined that it cannot complete the turn, intervention control is performed to guide the vehicle M towards the quasi-correct path Rs, for which no driving route has been set.

[0034] The route generation at multi-way intersections performed by the driver assistance control unit 21 is specifically carried out according to the right / left turn route generation routine shown in Figure 2. Furthermore, the control of the driving state according to the vehicle's position is specifically carried out according to the turn intervention control determination routine shown in Figures 5A and 5B. In the following, the routine shown in Figure 2 will be explained first, and then the routines shown in Figures 5A and 4B will be explained.

[0035] In the routine shown in Figure 2, first, in step S1, it is checked whether there is an intersection within a predetermined distance (for example, 200 m) in front of the vehicle M. Whether or not there is an intersection is obtained, for example, from forward driving environment information recognized by the forward driving environment recognition unit 26d of the camera unit 26, high-precision road map information stored in the road map database 13, or from vehicle-to-infrastructure communication. The forward driving environment recognition unit 26d, the road map database 13, and vehicle-to-infrastructure communication correspond to the environmental information acquisition unit of the present invention. Furthermore, the processing in step S1 corresponds to the intersection determination unit of the present invention.

[0036] If it is determined that there is an intersection, the process proceeds to step S2. If it is determined that there is no intersection, the routine is exited.

[0037] When the system proceeds to step S2, the target route set by the driving route / target route setting calculation unit 12b of the map locator calculation unit 12 is read, and it is checked whether the target route is generated in a direction that involves turning at an intersection. Even if the target route is set in a straight direction, if the driver turns on the turn signal switch before reaching an intersection, it is determined that there is an intention to turn. In this case, the target route is rerouted in the direction that the vehicle M will turn. Furthermore, the processing in step S2 corresponds to the right / left turn determination unit of the present invention.

[0038] If the driver assistance control unit 21 determines that the target route is set to turn at an intersection, it proceeds to step S3. If it determines that the target route is set to go straight, it exits the routine.

[0039] Step S3 involves checking whether the direction of the vehicle M's turn is a multi-way intersection. In this embodiment, a multi-way intersection refers to a situation where, relative to the lane the vehicle M is traveling in, there are at least two intersecting roads in the direction of the turn, and each of them leads to the same intersection. For example, in Figure 8, relative to the lane the vehicle M is traveling in, the first and second intersecting roads Cr1 and Cr2 are connected to the direction in which the vehicle M intends to turn (turn left in the figure) from the intersection through automated driving.

[0040] If, in step S3, the direction of the turn of the vehicle M is determined to be a multi-way intersection, the process proceeds to step S4. If there is only one intersection in the direction of the turn, the routine is exited. Note that the processing in step S3 corresponds to the multi-way intersection determination unit of the present invention.

[0041] Step S4 generates a positive path at the intersection. This positive path is generated according to the positive path generation subroutine shown in Figure 3. In this subroutine, first, in step S11, the target path is read. Then, in step S12, a positive path Rc is generated within the intersection based on this target path. Specifically, it is generated by connecting the endpoint of the target path before entering the intersection and the target path at the intersection endpoint after the bend using the two-point curvature (see Figure 8). Therefore, this positive path Rc may be the target path generated within the intersection as is.

[0042] Next, the process proceeds to step S13, where the generated data for the positive path Rc is stored in non-volatile memory, and then the process proceeds to step S5 in Figure 2.

[0043] In step S5 of Figure 2, a quasi-correct path is generated within the intersection, connecting the first intersection Cr1, which the vehicle M intends to turn at, to the second intersection Cr2, which is adjacent to it. This quasi-correct path is generated according to the quasi-correct path generation subroutine shown in Figure 4.

[0044] In this subroutine, first, in step S21, road information for the second intersection CR2 adjacent to the first intersection Cr1 is acquired. This road information is obtained, for example, from high-precision road map information stored in the road map database 13, or from vehicle-to-infrastructure communication, or from forward driving environment information recognized by the camera unit 26. The information acquired includes the lane width of the driving lane of the second intersection Cr2, the edges of the intersection, etc.

[0045] Next, the process proceeds to step S22, where the endpoint of the target path before entering the intersection and the extension of the center of the lane width of the second intersection Cr2 are connected by a two-point curvature to generate a quasi-correct path Rs within the intersection (see Figure 8). Then, the process proceeds to step S23, where the data of the generated quasi-correct path Rs is stored in non-volatile memory, and the process proceeds to step S6 in Figure 2. Note that the processing in steps S4 and S5 corresponds to the path generation unit of the present invention.

[0046] In step S6 of Figure 2, it is checked whether the vehicle M has entered the intersection. If it is still before the intersection, the process returns to step S4 and steps S4 and S5 are repeated. On the other hand, if it is determined that the vehicle has entered the intersection, the process proceeds to step S7, the route flag Fr is set (Fr←1), and the routine is exited. The correct route data obtained in step S4 and the quasi-correct route data obtained in step S5 are sequentially overwritten until just before entering the intersection, and the latest data is stored. The initial value of the route flag Fr is 0.

[0047] The value of the path flag Fr, the data for the positive path Rc, and the data for the quasi-positive path Rs are read by the turn-time intervention control determination routine shown in Figures 5A and 5B.

[0048] In this routine, first, in step S31, the value of the route flag Fr is read. If Fr=0, it is determined that the vehicle M has not entered the intersection and the routine is exited. If Fr=1, it is determined that the vehicle M has entered the intersection and the process proceeds to step S32.

[0049] In step S32, the forward driving environment information of the vehicle M is read. This forward driving environment information is obtained from the forward driving environment information recognized by the forward driving environment recognition unit 26d of the camera unit 26. Alternatively, the forward driving environment information may be obtained by referring to the high-precision road map information stored in the road map database 13 based on the relationship between the target route set by the driving route / target route setting calculation unit 12b of the map locator calculation unit 12 and the current position of the vehicle.

[0050] Next, the process proceeds to step S33, where it is checked whether the vehicle M has passed through an intersection based on the forward driving environment information read in step S32. If the vehicle is still driving through the intersection, the process proceeds to step S34. If the vehicle has already passed through the intersection, the routine is exited. In this embodiment, as shown in Figure 9, the vehicle position Vp is defined as the front end of the vehicle M and the center in the vehicle width direction, and entry into and passing through an intersection is determined by this vehicle position Vp.

[0051] In step S34, the latest data for the positive route Rc and the quasi-positive route Rs stored in the non-volatile memory are read and matched to the intersections on the high-precision road map (see Figure 8). Next, the process proceeds to step S35, where the estimated route Vc of the vehicle M within the intersection is generated based on the vehicle's behavior. Note that the processing in step S35 corresponds to the estimated route setting unit of the present invention.

[0052] This vehicle behavior is the temporal change in steering angle detected by the steering angle sensor and yaw rate detected by the yaw rate sensor of the vehicle state sensor 15. From this temporal change, the estimated path Vc that the vehicle M will take when entering the intersection is generated (see Figure 10). Then, the process proceeds to step S36, where the lateral distance Lc between the positive path Rc and the estimated path Vc (lateral distance on the positive path side) is calculated. In step S37, the lateral distance Ls between the quasi-positive path Rs on the intersection and the estimated path Vc (lateral distance on the quasi-positive path side) is calculated (see Figure 10). Note that the processing in steps S36 and S37 corresponds to the lateral distance calculation unit of the present invention.

[0053] The driver assistance control unit 21 performs feedback control to correct the amount of lateral deviation from the target path so that the vehicle M travels along the target path. However, when turning at an intersection, there are limitations to steering the vehicle M with the electric power steering, and it may be difficult to keep the vehicle M traveling along the target path.

[0054] For example, as shown in Figure 9, if the curvature of the positive path Rc generated in the direction of the turn within the intersection (left turn in the figure) is large, it may be difficult to return to the positive path Rc direction with normal feedback control. As a result, the lateral position distance Lc on the positive path side between the positive path Rc and the estimated path Vc gradually increases, causing the vehicle to drift into the oncoming lane, and the convergence to the target path set in the lane in the direction of the turn (left turn in the figure) deteriorates.

[0055] Therefore, in the next steps S38-S40, it is determined whether the estimated path Vc can be converged to the target path after the bend. First, in step S38, the lateral position distance Lc on the positive path side and the lateral position distance Ls on the quasi-positive path side are compared.

[0056] If Lc ≤ Ls, the system determines that the vehicle M is moving from the positive path Rc towards the target path, and that it can converge to the target path through feedback control, and exits the routine. On the other hand, if Lc > Ls, the system determines that the vehicle M is closer to the quasi-positive path Rs, and proceeds to step S39.

[0057] Incidentally, as shown in Figure 10, the lateral position distance Lc on the positive path and the lateral position distance Ls on the quasi-positive path gradually change as the vehicle moves from the endpoint before the intersection to the endpoint at the exit of the intersection. In step S38, the lateral position distance Lc on the positive path and the lateral position distance Ls on the quasi-positive path are constantly compared from the time of entry into the intersection, and if Lc ≤ Ls due to the first intervention control or the second intervention control described later, the routine is exited.

[0058] In step S39, steps S39 and S40 determine how much the lateral position distance Lc on the positive path side is closer to the lateral position distance Ls on the quasi-positive path side by comparing the difference between the lateral position distance Lc on the positive path side and the lateral position distance Ls on the quasi-positive path side (Lc-Ls) with the first threshold Ls1 and the second threshold Ls2. The first threshold Ls1 and the second threshold Ls2 are fixed values ​​obtained in advance from experiments, and the relationship is Ls1 > Ls2 (see Figure 7).

[0059] Here, the first threshold Ls1 is a value slightly lower than the limit value at which the vehicle M can be guided in the direction of the target path by the second intervention control described later, and is set in advance based on experiments, etc. Similarly, the second threshold Ls2 is a value slightly lower than the limit value at which the vehicle M can be guided in the direction of the target path by the first intervention control, which is weaker than the second intervention control described later, and is set in advance based on experiments, etc.

[0060] In step S39, the difference (Lc-Ls) is compared with the first threshold Ls1. If (Lc-Ls) ≤ Ls1, the driver assistance control unit 21 determines that it can guide the vehicle M to the target path through intervention control and proceeds to step S40. If (Lc-Ls) > Ls1, the driver assistance control unit 21 determines that it is difficult to guide the vehicle M to the target path and branches to step S43, where it performs quasi-correct path intervention control and exits the routine. Note that the processing in step S39 corresponds to the lateral position distance comparison unit of the present invention. Quasi-correct path intervention control will be described later.

[0061] In step S40, the difference (Lc-Ls) is compared with the second threshold Ls2. If (Lc-Ls) ≤ Ls2, the process proceeds to step S41, where the first intervention control is performed and the routine is exited. If (Lc-Ls) > Ls2, the process branches to step S42, where the second intervention control is performed and the routine is exited.

[0062] The first intervention control performed by the driver assistance control unit 21 in step S41 first activates the notification device 34 to notify the driver of the forced intervention. Next, it sends a gentle (weak) brake drive signal to the brake drive unit 31 and a steering signal to the EPS drive unit 32. As a result, the vehicle M decelerates within the intersection and corrects its direction of travel toward the target path.

[0063] Furthermore, in step S42, the second intervention control performed by the driver assistance control unit 21 first activates the notification device 34 to inform the driver that a forced control intervention will be performed. Next, it transmits a stronger brake drive signal to the brake drive unit 31 and a steering signal to the EPS drive unit 32.

[0064] As a result, vehicle M slows down significantly within the intersection and corrects its direction of travel towards the target path, preventing it from entering the oncoming lane within the intersection.

[0065] Furthermore, the quasi-positive pathway intervention control performed in step S43 is processed according to the quasi-positive pathway intervention control subroutine shown in Figure 6. Note that the processing in this step corresponds to the intervention control unit of the present invention.

[0066] In this subroutine, first, in step S51, the quasi-correct route Rs is set as the target route. That is, the driving support control unit 21 sends an instruction to the driving route / target route setting calculation unit 12b of the map locator calculation unit 12 to set the vehicle's path as the quasi-correct route Rs. The driving route / target route setting calculation unit 12b then reroutes the driving route to the driving lane side of the second intersection Cr2 connected to the quasi-correct route and sets a new target route in that driving lane.

[0067] Next, the process proceeds to step S52, where the notification device 34 is activated to inform the driver that the direction of travel of the vehicle M has been rerouted. Then, the process proceeds to step S53, where the driver assistance control unit 21 performs feedback control to converge the vehicle M to the newly set target path (quasi-correct path Rs) within the intersection, and then exits the routine.

[0068] As described above, when the vehicle M of this embodiment attempts to make a turn (right or left turn) at an intersection through autonomous driving, if the direction of the turn within the intersection is a multi-way intersection, the driving support control unit 21 generates a positive path Rc that connects to the first intersection Cr1 that the vehicle is attempting to turn, and also generates a quasi-positive path Rs that connects to the adjacent second intersection Cr2.

[0069] Next, the estimated path Vc within the intersection is set based on the behavior of the vehicle M before entering the intersection. Then, the lateral distances Lc and Ls from this estimated path Vc to the positive path Rc and the quasi-positive path Rs are calculated. If the lateral distance Lc on the positive path side is longer than the lateral distance Ls on the quasi-positive path side (Lc>Ls), and the difference (Lc-Ls) is longer than the first threshold Ls1 ((Lc-Ls)>Ls1), the target path is switched to the quasi-positive path Rs side. Then, the driving route / target path setting calculation unit 12b reroutes the driving route in the direction of the lane connected to the quasi-positive path and sets a new target path.

[0070] Thus, according to this embodiment, if it is predicted that the vehicle M will not be able to turn in the direction of the first intersection Cr1 when it actually enters the intersection, the target path is switched to the quasi-correct path Rs set in the direction of the adjacent second intersection Cr2. Therefore, when the vehicle M enters the intersection, it can be safely guided to the second intersection Cr2 by appropriate intervention control according to the estimated path Vc, without being forced to turn in the direction of the first intersection Cr1.

[0071] Furthermore, the present invention is not limited to the embodiments described above, and for example, the driver assistance control unit 21 can also be applied when it only provides steering assistance during driving. [Explanation of Symbols]

[0072] 1…Driving assistance system, 11...Locator unit, 12...Map locator calculation unit, 12a... Vehicle position estimation calculation unit, 12b... Driving route / target route setting calculation unit, 13…Road map database, 14…GNSS receiver, 15... Vehicle status sensor, 16... Route information input section, 21…Driving support control unit, 26...Camera unit, 26a...Main camera, 26b... Sub-camera, 26c...Image processing unit, 26d...Forward driving environment recognition unit, 31...Brake drive unit, 32...EPS drive unit, 33...Acceleration / deceleration control unit, 34... Notification device, Cr1, Cr2…1st and 2nd intersections, Ls1, Ls2... First and second thresholds, Lc... Lateral position distance on the positive path side, Ls... Lateral position distance on the quasi-correct path side, M... Own vehicle, Rc... positive pathway, Rs... Quasi-foreign pathway, Vc…Estimated travel path, Vp... Own vehicle position

Claims

1. An environmental information acquisition unit that acquires environmental information in front of the vehicle, The aforementioned target route setting unit sets the target route for the vehicle, A control unit that causes the vehicle to travel along the target route set by the target route setting unit. In a vehicle driver assistance system equipped with, The control unit, An intersection determination unit determines whether or not there is an intersection in front of the vehicle based on the environmental information acquired by the environmental information acquisition unit, If the intersection determination unit determines that there is an intersection, the right / left turn determination unit determines whether the vehicle will turn right or left at the intersection, If the right / left turn determination unit determines that the vehicle will turn right or left, the multi-intersection determination unit checks whether there is a second intersection adjacent to the first intersection to which the vehicle will turn right or left. If the multi-intersection determination unit determines that there is a second intersection, the intersection is provided with a route generation unit that generates a primary route connecting to the target route generated at the first intersection and a secondary primary route connecting to the second intersection before the vehicle enters the intersection. An estimated route setting unit sets an estimated route for the vehicle within the intersection based on the vehicle's behavior, A lateral position distance calculation unit calculates the lateral position distance on the positive path side from the estimated path set by the estimated path setting unit to the positive path in the vehicle width direction, and the lateral position distance on the quasi-positive path side to the quasi-positive path, A horizontal position distance comparison unit compares the two horizontal position distances calculated by the horizontal position distance calculation unit, If the lateral position distance comparison unit determines that the lateral position distance on the positive path side is longer than the lateral position distance on the quasi-positive path side by a predetermined amount, the intervention control unit sets the direction of travel of the vehicle to the quasi-positive path side. A vehicle driving assistance device characterized by comprising the following:

2. The route generation unit generates the positive route using the curvature between two points: the endpoint where the vehicle faces the intersection and the endpoint of the target route generated at the first intersection that faces the intersection. The vehicle driving assistance device according to claim 1.

3. The route generation unit generates the quasi-correct route using the curvature between two points: the endpoint where the vehicle faces the intersection and the line extending to the intersection from the center of the lane width of the second intersection. A vehicle driving assistance device according to claim 1 or 2.

4. The target path setting unit sets the target path toward the second intersection when the intervention control unit sets the vehicle's direction of travel toward the quasi-correct path. The vehicle driving assistance device according to claim 1.

5. The estimated path indicates the center of the vehicle in the width direction. The vehicle driving assistance device according to claim 1.

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