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 right (or turns left) in the intersection.SOLUTION: An operation support control unit 21, when determining that an own vehicle M turns right (or turns left) in an intersection in front of the vehicle, generates, on the intersection, a correct route Rc leading to a target route generated on a lane which the vehicle enters after turning right (or turning left) and an incorrect route Re leading to an oncoming lane which the vehicle enters after turning right (or turning left). Subsequently, the unit calculates a lateral position distance Lc from a position Vp of the own vehicle to the correct route Rc in a vehicle width direction and a lateral position distance Le from the position of the own vehicle to the incorrect route Re, and compares both lateral position distances Lc and Le with each other, and compares the lateral position distance Lc with a preset intervention threshold Ls2 when the compared results show Lc≥Le. The unit returns a direction of entering of the own vehicle M to the correct route Rc, by weak intervention control when the compared result shows Lc≤Ls2 and by strong intervention control when the result shows Lc>Ls2.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a vehicle driving assistance device configured to, when the host vehicle turns right or left within an intersection, generate a correct route and an incorrect route in the intersection, and perform intervention control to return the host vehicle to the correct route side when the host vehicle is traveling along the incorrect route side.

Background Art

[0002] When a driver (operator) sets a destination, this type of driving assistance device sets a travel route from the current position to the destination on a road map, assists all or part of the driving, or automatically causes the vehicle to travel instead of the driver. For driving assistance, a target route along the travel route ahead of the host vehicle where the host vehicle should travel is set. Then, the position where the host vehicle is actually traveling is acquired from a sensing device represented by a camera or the like, the amount of deviation of the host vehicle position (lateral position of the host vehicle) relative to the target route is measured, and feedback control is performed on the steering angle such that this deviation converges to the target route (deviation amount = 0).

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

[0004] For example, Patent Document 1 (Japanese Unexamined Patent Publication No. 2021-160625) discloses a technology in which a center line set on a lane before an intersection where the host vehicle is traveling and a center line set on a left-turn destination lane are connected by a clothoid curve set in the intersection to set a target route, and the host vehicle is caused to travel along the target route.

Prior Art Literature

Patent Literature

[0005] [Patent Document 1] Japanese Patent Publication No. 2021-160625 [Overview of the project] [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 for a right or left turn, the vehicle deviates significantly from the target path, compromising driving stability. Therefore, when turning right or left at an intersection, conventional uniform feedback control based solely on the target path has limitations in providing driving assistance that ensures the vehicle enters the correct lane for the right or left turn.

[0008] The present invention aims to provide a vehicle driving assistance device that can perform appropriate intervention control according to the vehicle's position within an intersection when turning right or left 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 vehicle position estimation unit that estimates the position of the vehicle on the road; 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, wherein the control unit includes: 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 determines whether or not the vehicle will turn right or left at the intersection if the intersection determination unit determines that there is an intersection; and a right / left turn determination unit that determines whether or not the vehicle will turn right or left at the intersection, and the control unit that determines the vehicle will turn right or left at the target route generated at the destination of the right or left turn. A route generation unit that generates a correct route and an incorrect route that leads to the oncoming lane after a right or left turn before the vehicle enters the intersection; a lateral position distance calculation unit that calculates the lateral position distance on the correct route side from the position of the vehicle estimated by the vehicle position estimation unit to the correct route in the vehicle width direction and the lateral position distance on the incorrect route side to the incorrect route; a lateral position distance comparison unit that compares the two lateral position distances calculated by the lateral position distance calculation unit; a control determination comparison unit that, if the lateral position distance comparison unit determines that the lateral position distance on the correct route side is longer than the lateral position distance on the incorrect route side, compares the lateral position distance on the correct route side with a preset intervention threshold; and if the control determination comparison unit determines that the lateral position distance on the correct route side is shorter than the intervention threshold, The first weak brake If intervention control is performed and it is determined that the lateral position distance on the positive pathway side is longer than the intervention threshold, Rather than the first intervention control strong Brake 2 The system includes an intervention control unit that performs intervention control to return the vehicle's direction of travel to the correct path. [Effects of the Invention]

[0010] According to the present invention, when the environmental information acquisition unit determines that there is an intersection ahead of the vehicle based on the environmental information acquired, it determines whether the vehicle will turn right or left at the intersection. If it determines that the vehicle will turn right or left, it generates a correct path leading to the target path generated at the turn destination and an incorrect path leading to the oncoming lane at the turn destination before the vehicle enters the intersection. Furthermore, it calculates the lateral position distance on the correct path side to the path in the vehicle width direction from the vehicle's position and the lateral position distance on the incorrect path side to the incorrect path, compares them, and if it is determined that the lateral position distance on the correct path side is longer than the lateral position distance on the incorrect path side, it compares the lateral position distance on the correct path side with a preset intervention threshold. If it is determined that the lateral position distance on the correct path side is shorter than the intervention threshold, The first weak brake If intervention control is performed and it is determined that the lateral position distance on the positive pathway side is longer than the intervention threshold, Rather than the first intervention control strong Brake 2 By implementing intervention control to return the vehicle's direction of travel to the correct path, appropriate intervention control can be performed according to the vehicle's position 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 correct and incorrect path generation subroutines [Figure 4A] Flowchart showing the driving assistance control routine when turning left or right (Part 1) [Figure 4B] Flowchart showing the driving assistance control routine when turning left or right (Part 2) [Figure 5] flowchart showing the dead zone control subroutine [Figure 6] Diagram illustrating the process of generating correct and incorrect paths when turning left. [Figure 7] An explanatory diagram showing the vehicle's position relative to the correct and incorrect routes generated during a left turn. [Figure 8] Diagram illustrating the process of generating correct and incorrect paths when turning right. [Figure 9] Explanatory diagram showing the vehicle position relative to the correct route and incorrect route generated when turning right MODE FOR CARRYING OUT THE INVENTION

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. A host vehicle M (see FIG. 6) is equipped with a driving support device 1 for causing the vehicle to travel autonomously without depending on a driver's operation in an automatic driving section (such as a specific section of an expressway or a general road). This driving support device 1 includes a locator unit 11 and a driving support control unit 21 serving 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 a forward traveling environment recognition unit 26d provided in a camera unit 26 described later are configured by a microcontroller including a CPU, a RAM, a ROM, a rewritable non-volatile memory (flash memory or EEPROM), and peripheral devices. The ROM stores programs, fixed data, and the like necessary for the CPU to execute each process. The RAM is provided as a work area for the CPU, and temporarily stores various data processed by the CPU. Note that the CPU is also called an MPU (Microprocessor) or a processor. A GPU (Graphics Processing Unit) or a GSP (Graph Streaming Processor) may be used instead of the CPU. Alternatively, a selective combination of a CPU, a GPU, and a GSP may be used.

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

[0015] The own vehicle state sensor 15 detects the traveling state of the own vehicle M, and is a general term for a vehicle speed sensor, a yaw rate sensor, a longitudinal acceleration sensor, a turn signal switch, and the like. The route information input unit 16 is a terminal device operated by a passenger (mainly a driver), and is capable of inputting a series of information required when setting a travel route in the map locator calculation unit 12, such as a destination and waypoints. 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, or the like, and is connected to the map locator calculation unit 12 via a wired or wireless connection.

[0016] When a passenger operates the route information input unit 16 to input information of a destination and waypoints (such as facility name, address, telephone number, etc.), the input information is read by the map locator calculation unit 12. When a destination and waypoints are input, the map locator calculation unit 12 sets the position coordinates (latitude, longitude, altitude) thereof.

[0017] The map locator calculation unit 12 includes a vehicle position estimation calculation unit 12a serving as a vehicle position estimation unit that estimates a current position of the own vehicle, and a travel route / target route setting calculation unit 12b serving as a target route setting unit that sets a travel route from the own vehicle position to the destination (and waypoints) and a target route for automatically traveling the own vehicle M in an autonomous driving section (for example, an expressway).

[0018] Further, 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 when autonomously driving the own vehicle M.

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

[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.

[0023] Then, both image data are processed by the IPU26c according to a predetermined procedure. The forward driving environment recognition unit 26d reads the reference image data and comparison image data processed by the IPU26c, 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 the 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 right or left turn at an intersection using autonomous driving, the target path is set to the center of the driving lane after the right or left 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] The target path set for the lane to which the vehicle is turning right or left, as described above, is set while the vehicle M is traveling in the lane before turning right or left. Furthermore, the deviation from the target path is calculated while the vehicle M is turning right or left at the intersection. The deviation from the target path when turning right or left at an intersection tends to be relatively large. Therefore, in the feedback control that corrects this deviation, the feedback control to converge this deviation to the target path continues even on the road after turning right or left at the intersection.

[0030] 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.

[0031] This feedback control is designed to converge the deviation amount to the target path, and does not take into account whether the actual path taken by the vehicle during the feedback control is passable on the road to which it is turning right or left. Therefore, if the correction by the feedback control is insufficient, it is possible that the vehicle's path may drift into the oncoming lane at the destination of the right or left turn.

[0032] Therefore, in the driving support control unit 21 according to this embodiment, a normal target path and a misdirected path Re that leads to the oncoming lane after a right or left turn are set within the intersection, and the unit checks where the vehicle M is located between the target path and the misdirected path Re, and controls the driving state of the vehicle M accordingly.

[0033] The setting of the target route and incorrect route Re, 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 right / left turn driving assistance control routine shown in Figures 4A and 4B. In the following, the routine in Figure 2 will be explained first, and then the routines shown in Figures 4A and 4B will be explained.

[0034] 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.

[0035] Furthermore, 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. Also, 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] Step S2 checks whether the target route is generated in a direction that involves turning right or left at an intersection. Even if the target route is set in a straight line, if the driver turns on the turn signal switch before reaching an intersection, it is determined that the driver intends to turn right or left. In this case, the target route is rerouted in the direction of turning right or left. Furthermore, the processing in step S2 corresponds to the right / left turn determination unit of the present invention.

[0038] If it is determined that vehicle M will turn right or left at the intersection, the process proceeds to step S3. If it is determined that vehicle M will go straight through the intersection, the process is exited.

[0039] When the process proceeds to step S3, the correct path Rc and incorrect path Re are generated in the direction that the vehicle M will turn right or left at the intersection, and the routine is exited. Note that the processing in step S3 corresponds to the path generation unit of the present invention.

[0040] The processing in step S3 is carried out according to the correct and incorrect route generation subroutines shown in Figure 3. In this subroutine, first, in step S11, road information in front of the vehicle M is read. This road information includes the distance from the current position of the vehicle M to the intersection, the size of the intersection, the position information of the connection end with the intersection in the direction of a right or left turn, road width information, number of lanes information, etc.

[0041] 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. In this case, it is difficult to obtain road information for a right or left turn from the forward driving environment information recognized by the forward driving environment recognition unit 26d of the camera unit 26 from the current position M of the vehicle. Therefore, it is unclear whether the target route generated for the road in the direction of the right or left turn is correctly set relative to the actual lane, and there is a possibility of large errors.

[0042] Next, proceeding to step S12, the driver assistance control unit 21 checks from the road information acquired in step S11 whether the road to which the vehicle is to turn right or left has two or more lanes in one direction. If there are two or more lanes in one direction, the routine is exited. If there are two or more lanes in one direction, it is considered that even if the amount of deviation of the vehicle's lateral position relative to the target route is large, the vehicle M will not enter the oncoming lane.

[0043] Next, the process proceeds to step S13, where the driver assistance control unit 21 checks the road information to see if there is an oncoming lane on the road in the direction of the right or left turn. If there is no oncoming lane, the routine is exited. If there is an oncoming lane, the process proceeds to step S14. If there is no oncoming lane, the incorrect route described later cannot be generated, so it is excluded.

[0044] Step S14 generates a positive path Rc at the intersection. As shown by solid lines in Figures 6 to 9, the positive path Rc connects the target path set for the lane before entering the intersection with the target path set for the lane after turning right or left at the intersection.

[0045] Therefore, the target path set within the intersection may be considered the positive path Rc. Alternatively, the positive path Rc may be generated by the curvature between the two endpoints facing the intersection of the target path set in the lane before turning right or left and the target path set in the lane after turning right or left.

[0046] Next, the process proceeds to step S15 to generate the incorrect route Re. As shown by the dashed lines in Figures 6 to 9, the incorrect route Re detects the lane width of the opposing lane on the road in the direction of the right or left turn from the road information acquired in step S11, and generates a route in the center of it. Then, the route set on the opposing lane side and the endpoint facing the intersection of the target route set on the lane before entering the intersection are connected by the curvature between the two points, a route is generated within the intersection, and the generated route on the opposing lane is connected to this intersection to generate the incorrect route Re.

[0047] Next, the process proceeds to step S16, where the data for the correct path Rc and the incorrect path Re generated in steps S14 and S15 are stored in non-volatile memory, and the routine is exited.

[0048] The data for the correct path Rc and the incorrect path Re are read by the right / left turn driving support control routine shown in Figures 4A and 4B. The aforementioned right / left turn driving path generation routine is executed at predetermined calculation cycles until just before the vehicle M enters the intersection. As a result, the data for the correct path Rc and the incorrect path Re stored in the non-volatile memory are sequentially updated with the latest data.

[0049] Next, the turning assistance control routine shown in Figures 4A and 4B will be described. In this routine, first, in step S21, 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 S22, where it is checked whether the vehicle M has entered an intersection based on the forward driving environment information read in step S21. If the vehicle has not yet entered an intersection, the routine is exited. On the other hand, if the vehicle M has entered an intersection, the process proceeds to step S23. In this embodiment, as shown in Figures 7 and 9, the vehicle position Vp represents the front end of the vehicle M and the center in the vehicle width direction. Therefore, the trajectory of this vehicle position Vp becomes the vehicle's path Vc.

[0051] Proceeding to step S23, the system checks whether the vehicle M (more precisely, the vehicle's position Vp) has passed through an intersection based on the forward driving environment information read in step S21.

[0052] If the system determines that vehicle M is currently in an intersection, it proceeds to step S24. If it determines that the vehicle has passed through the intersection, it exits the routine. In addition to forward driving environment information, the system may also determine whether or not the vehicle has passed an intersection by, for example, when the steering angle is returned to 0 [deg], by detecting the vehicle's position Vp from road map information, or by detecting when the turn signal switch is OFF.

[0053] In step S24, the latest data for the positive path Rc and the erroneous path Re stored in the non-volatile memory is read. Next, the process proceeds to step S25, where a dead band Zd is set between the positive path Rc and the erroneous path Re. As shown in Figures 6 and 8, the center of the dead band Zd is the midpoint of the shortest distance between the positive path Rc and the erroneous path Re, and this midpoint is set as the path threshold value SLc. Note that the processing in step S25 corresponds to the dead band setting unit of the present invention.

[0054] Furthermore, dead zone widths are set on both sides of the path threshold SLc, as shown by the dashed lines in the figure. These dead zone widths are set by referring to a pre-configured table, and increase as the shortest distance between the positive path Rc and the incorrect path Re increases. The area within these dead zone widths is the dead band Zd. Since the path threshold SLc is set midway between the positive path Rc and the incorrect path Re, it is far from both paths Rc and Re. Therefore, if the vehicle's position Vp is far from both the positive path Rc and the incorrect path Re, the vehicle's position Vp will be within the dead band Zd.

[0055] Next, the process proceeds to step S26, where the lateral distance Lc (lateral distance on the correct path side) between the correct path Rc generated at the intersection and the vehicle's position Vp is calculated. Then, the process proceeds to step S27, where the lateral distance Le (lateral distance on the incorrect path side) between the incorrect path Re generated at the intersection and the vehicle's position Vp is calculated (see Figures 7 and 9). Note that the processing in steps S26 and S27 corresponds to the lateral distance calculation unit of the present invention.

[0056] 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 right or left at an intersection, a discrepancy is likely to occur between the vehicle's position Vp and the correct path Rc set at the intersection due to the influence of turning characteristics which differ for each vehicle type.

[0057] As a result, when vehicle M travels in the lane after turning right or left at an intersection, the deviation from the target path becomes large, and it may be difficult to return to the target path with normal feedback control. Therefore, it is necessary to determine whether it is possible to travel when vehicle M enters the road after turning right or left while this deviation is large.

[0058] In steps S27 and below, when the vehicle M enters the road to which it is turning right or left, it is determined whether it is possible to continue driving under autonomous driving conditions based on the vehicle's position Vp and the lateral distances Lc and Le between the correct path Rc and the incorrect path Re.

[0059] First, in step S28, it is checked whether the vehicle's position Vp is within the dead band Zd. Note that the processing in step S28 corresponds to the dead band determination unit of the present invention.

[0060] If the vehicle's position Vp is within the dead zone Zd, the process proceeds to step S29, where dead zone control is performed and the routine is exited. On the other hand, if the vehicle's position Vp is outside the dead zone Zd, the process proceeds to step S30.

[0061] The dead zone control in step S29 is performed according to the dead zone control subroutine shown in Figure 5. In this subroutine, first, in step S41, the driver assistance control unit 21 activates the notification device 34 to alert the driver that the vehicle's position Vp is deviating from the correct path Rc.

[0062] Next, the process proceeds to step S42, where normal feedback control is executed and the routine is exited. In this dead band Zd, the vehicle's position Vp (described later) is not compared with the lateral position distances Lc and Le between the correct path Rc and the incorrect path Re, thus preventing control hunting.

[0063] On the other hand, when proceeding from step S28 to step S30, the correct route lateral position distance Lc and the incorrect route lateral position distance Le are compared. If the correct route lateral position distance Lc is shorter than the incorrect route lateral position distance Le (Lc<Le), that is, when it is determined that the vehicle position Vp is on the correct route Rc side of the dead band Zd, the routine exits. When the vehicle position Vp is on the correct route Rc side of the dead band Zd, it is determined that the vehicle position Vp can be converged to the target route set on the right-turn or left-turn destination lane by feedback control in normal steering control, and the routine exits without executing forced intervention such as steering control. As a result, normal feedback control is continued in autonomous driving.

[0064] When comparing the correct route lateral position distance Lc and the incorrect route lateral position distance Le, the dead band Zd clarifies whether the vehicle position Vp is closer to the correct route Rc or the incorrect route Re, and can prevent control hunting near the route threshold SLc. Note that the processing in step S30 corresponds to the lateral position distance comparison unit of the present invention.

[0065] Further, when the correct route lateral position distance Lc is longer than the incorrect route lateral position distance Le (Lc>Le), that is, when it is determined that the vehicle position Vp is on the incorrect route Re side of the dead band Zd, the process proceeds to step S31. In step S31, the correct route lateral position distance Lc is compared with a first threshold Ls1 serving as an alarm threshold. The first threshold Ls1 is set along the dead band width set on the incorrect route Re side of the dead band Zd, at a position that does not greatly deviate from the dead band Zd.

[0066] If Lc > Ls1, the system determines that the vehicle's position Vp is on the incorrect path Re side and proceeds to step S32. If Lc ≤ Ls1, the system determines that the vehicle's position Vp is not significantly deviating from the dead zone Zd towards the incorrect path Re side and branches off to step S33. In step S33, the system determines that the vehicle M can be returned to the dead zone Zd by feedback control in normal steering control, and the driver assistance control unit 21 activates the notification device 34 to warn the driver and exit the routine. The notification may state, for example, that the vehicle's position Vp is deviating from the target path set for the lane to turn right or left when entering the lane to turn right or left from an intersection.

[0067] Furthermore, in step S32, the lateral position distance Lc on the positive path side is compared with a second threshold Ls2, which is used as an intervention threshold. This second threshold Ls2 is set at a position relatively far from the dead band Zd, along the dead band width set on the erroneous path Re side of the dead band Zd. Note that the processing in steps S30 to S32 corresponds to the control determination comparison unit of the present invention.

[0068] If Lc ≤ Ls2, it is determined that the vehicle's position Vp is not significantly deviating from the dead band Zd, and the process proceeds to step S34. If Lc > Ls2, it is determined that the vehicle's position Vp is significantly deviating from the dead band Zd, and the process branches to step S35.

[0069] When the process proceeds to step S34, the driver assistance control unit 21 executes the first intervention control and exits the routine. The first intervention control executed by the driver assistance control unit 21 first activates the notification device 34 to notify the driver of the forced intervention, then 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 dead zone Zd direction. In this case, in order to prevent control hunting, the driver assistance control unit 21 continues the first intervention control until the lateral position distance Lc on the positive path side crosses the first threshold Ls1 and moves toward the dead zone Zd side. The processing in step S34 and step S35, which will be described later, corresponds to the intervention control unit of the present invention.

[0070] On the other hand, when branching to step S35, the driver assistance control unit 21 executes the second intervention control and exits the routine. The second intervention control executed by the driver assistance control unit 21 first activates the notification device 34 to notify the driver that a forced control intervention will be performed. Next, it sends a stronger brake drive signal to the brake drive unit 31 and a steering signal to the EPS drive unit 32. In this case, in order to prevent control hunting, the driver assistance control unit 21 continues the second intervention control until the lateral position distance Lc on the positive path side crosses the second threshold Ls2 and moves toward the first threshold Ls1 side.

[0071] As a result, vehicle M slows down significantly within the intersection, correcting its direction of travel towards the dead zone Zd, thus preventing it from entering the oncoming lane within the intersection.

[0072] As described above, when the vehicle M of this embodiment attempts to turn right or left at an intersection through automatic driving, the driver assistance control unit 21 first acquires road information for the turn destination and sets a target route for the vehicle M to take in the lane of the turn destination based on that road information. It also sets a route in the center of the oncoming lane of the turn destination. Then, it sets the correct route Rc by connecting the endpoint of the target route that the vehicle M is currently taking to enter the intersection with the endpoint of the target route set in the lane of the turn destination using the curvature between the two points. It also sets the incorrect route Re by connecting the endpoint of the target route that the vehicle M is currently taking to enter the intersection with the endpoint of the route set in the oncoming lane using the curvature between the two points.

[0073] Furthermore, if the driver assistance control unit 21 determines that the vehicle's position Vp has shifted to the incorrect path Re side at an intersection, it drives the EPS drive unit 32 to perform steering control to return the vehicle's position Vp to the correct path Rc side. This enables appropriate steering control according to the vehicle's position within the intersection. In addition, if it determines that steering intervention alone is insufficient to return the vehicle to the correct path side, the brake drive unit 31 operates to decelerate the vehicle, preventing the vehicle M from entering the oncoming lane.

[0074] Furthermore, the present invention is not limited to the embodiments described above, and for example, the driving support control unit 21 can also be applied when it only provides steering support during driving. [Explanation of Symbols]

[0075] 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...Forward driving environment recognition 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, Ls1...First threshold, Ls2...Second threshold, Lc... Lateral position distance on the positive path side, Le... Lateral position distance on the incorrect path side, M... Own vehicle, Rc... positive pathway, Re... Misdirected route, SLc...path threshold, Vc...Vehicle's path of travel, Vp... Vehicle position, Zd... Dead band

Claims

1. An environmental information acquisition unit that acquires environmental information in front of the vehicle, A vehicle position estimation unit that estimates the position of the vehicle on the road, The aforementioned target route setting unit sets the target route for the vehicle, A control unit that causes the vehicle to travel along the aforementioned target path. 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 route generation unit generates a correct route leading to the target route generated at the destination of the right or left turn, and an incorrect route leading to the oncoming lane at the destination of the right or left turn, before the vehicle enters the intersection. A lateral position distance calculation unit calculates the lateral position distance on the correct path side from the position of the vehicle estimated by the vehicle position estimation unit to the correct path in the vehicle width direction, and the lateral position distance on the incorrect path side to the incorrect 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 correct path is longer than the lateral position distance on the incorrect path, the control determination comparison unit compares the lateral position distance on the correct path with a preset intervention threshold. If the control determination comparison unit determines that the lateral position distance on the positive path side is shorter than the intervention threshold, it executes a first intervention control with weak braking, and if it determines that the lateral position distance on the positive path side is longer than the intervention threshold, it executes a second intervention control with stronger braking than the first intervention control, thereby returning the vehicle's direction of travel to the positive path side. A vehicle driving assistance device characterized by comprising the following:

2. The position of the vehicle in question is the front end of the vehicle and the center in the width direction. The vehicle driving assistance device according to claim 1.

3. The control determination comparison unit has an alarm threshold shorter than the intervention threshold. If the intervention control unit determines that the lateral position distance on the positive path side is shorter than the alarm threshold, it will not execute the first or second intervention controls and will only issue an alarm. The vehicle driving assistance device according to feature 1.

4. A deadband setting unit sets a deadband between the correct path and the incorrect path, A dead zone determination unit determines whether or not the vehicle's position is within the dead zone set by the dead zone setting unit. It further possesses, If the dead zone determination unit determines that the vehicle's position is within the dead zone, the lateral position distance comparison unit does not compare the lateral position distance on the correct path side with the lateral position distance on the incorrect path side. The vehicle driving assistance device according to claim 1.

5. The deadband set by the deadband setting unit is set to the center of the shortest distance between the correct path and the incorrect path. The vehicle driving assistance device according to feature 4.

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