Autonomous Driving Assistance System

Abstract

To provide an automatic drive assisting system that is able to prevent sudden deceleration control not intended by a driver.SOLUTION: An automatic drive assisting system 1 that, based on road map information acquired by a road map information acquisition unit 12b and information on a traveling environment ahead of an own vehicle acquired by a camera unit 21, acquires a traveling environment in a predetermined range of a target traveling path ahead of the own vehicle, comprises: an intersection detecting unit 22b that, based on the traveling environment in the predetermined range of the target traveling path, detects a set of intersections shorter than a predetermined interval within the predetermined range of the target traveling path ahead of the own vehicle; and an ACC set vehicle speed change unit 22c that, if the intersection detecting unit detects the set of intersections shorter than the predetermined interval, changes a first ACC set vehicle speed to a second ACC set vehicle speed.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an automated driving assistance system that changes an upper limit of vehicle speed in order to suppress sudden deceleration control on roads with multiple intersections that are closely spaced apart. [Background technology]

[0002] When the driver (operator) sets a destination, the automated driving assistance system sets a driving route from the current location to the destination and automatically drives the vehicle on all or part of the route instead of the driver. When driving autonomously on public roads, this automated driving assistance system recognizes the driving environment in front of the vehicle using sensing devices such as cameras, and constantly monitors the presence or absence of preceding vehicles, the color of traffic lights, the direction indicated by arrow signals, etc.

[0003] If a preceding vehicle is detected on the target driving route ahead of the vehicle, the adaptive cruise control (ACC) function equipped in the autonomous driving assistance system will be activated and will control the vehicle's speed to a specified speed based on the distance to the preceding vehicle, relative vehicle speed, etc. This ACC function also recognizes the color of the traffic lights installed at the intersection based on forward environmental information obtained from the on-board camera, etc., and when the color of the lights is green (green light), the vehicle will travel at the ACC set vehicle speed set by the driver, with the road's speed limit as the upper limit.

[0004] As an example of such an automated driving assistance system, Patent Document 1 discloses a driving assistance device that varies the assistance mode (assistance level) to be provided depending on the status of each traffic light when there are consecutive intersections where traffic lights are installed. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2011-221757 A Summary of the Invention [Problem to be solved by the invention]

[0006] In a scene where a vehicle is traveling straight on a road with two consecutive intersections with traffic lights, if the automated driving assistance system determines that the traffic light at the nearest intersection is green based on information about the driving environment ahead obtained from an in-vehicle camera, etc., the system passes through the nearest intersection at the ACC set vehicle speed. After that, when the automated driving assistance system recognizes that the traffic light at the farther intersection is red, it performs deceleration control to stop the vehicle before the stop line at the farther intersection.

[0007] However, when the distance between two intersections is short, the autonomous driving assistance system must perform sudden deceleration control that is not intended by the driver in order to stop at an intersection where the light is red, resulting in a deterioration of ride comfort for passengers.

[0008] The present invention has been made in consideration of the above circumstances, and aims to provide an automatic driving assistance system that can suppress sudden deceleration control that is not intended by the driver. [Means for solving the problem]

[0009] An autonomous driving assistance system according to one embodiment of the present invention is an autonomous driving assistance system that acquires a driving environment within a predetermined range of a target route ahead of the host vehicle based on road map information acquired by a road map information acquisition unit and driving environment information ahead of the host vehicle acquired by a camera unit, the autonomous driving assistance system comprising: an intersection detection unit that detects a pair of intersections having an interval shorter than a predetermined interval within the predetermined range of the target route ahead of the host vehicle based on the driving environment within the predetermined range of the target route; and when the intersection detection unit detects a pair of intersections having an interval shorter than the predetermined interval, a first ACC set vehicle speed that has been set is increased. , slower than the first ACC set vehicle speed an ACC set vehicle speed change unit for changing the ACC set vehicle speed to a second ACC set vehicle speed; The intersection detection unit detects whether or not there is a pair of intersections whose interval is shorter than a distance traveled by the host vehicle traveling at the first ACC set vehicle speed until the host vehicle stops while continuing to decelerate at a preset upper limit of deceleration. do. Effect of the Invention

[0010] According to the automatic driving assistance system of the present invention, it is possible to suppress sudden deceleration control that is not intended by the driver. [Brief description of the drawings]

[0011] [Figure 1] Schematic diagram of the autonomous driving assistance system [Diagram 2] An explanatory diagram of a road where the traffic lights at the intersection in front and the traffic lights at the intersection in the back are consecutive [Diagram 3] A flowchart showing an example of a process for controlling a change in the ACC set vehicle speed DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, one embodiment of the present invention will be described with reference to the drawings. In the drawings used in the following explanation, the scale of each component is different so that each component can be recognized on the drawing. The present invention is not limited to the quantity of components, the shapes of components, the size ratios of the components, and the positional relationships of each component shown in these drawings.

[0013] First, a schematic configuration of an automatic driving assistance system according to an embodiment of the present invention will be described below with reference to the functional block diagram of FIG.

[0014] The automatic driving assistance system 1 shown in Fig. 1 is mounted on a host vehicle M (see Fig. 2). This automatic driving assistance system 1 has a locator unit 11 as a means for detecting the position of the host vehicle M (host vehicle position), a camera unit 21 as a means for acquiring forward driving environment information, and a vehicle control unit 22 as a vehicle control means.

[0015] Locator unit 11 estimates the vehicle's position on a road map and acquires road map data around the vehicle's position. Meanwhile, camera unit 21 acquires driving environment information ahead of vehicle M, and recognizes the lane markings dividing the left and right sides of the driving lane, the road shape, the presence or absence of a preceding vehicle, traffic lights, etc. Furthermore, camera unit 21 obtains the road curvature at the center of the lane markings, the inter-vehicle distance and relative speed to the preceding vehicle, etc.

[0016] Locator unit 11 has map locator calculation unit 12 and high-precision road map database (abbreviated as road map DB in FIG. 1) 16 as a storage means. This map locator calculation unit 12, forward driving environment recognition unit 21d (described later), and vehicle control unit 22 are configured with a well-known microcomputer equipped with a CPU, RAM, ROM, etc., and peripheral devices thereof, and programs to be executed by the CPU, fixed data such as base maps, etc. are stored in advance in the ROM.

[0017] A GNSS (Global Navigation Satellite System) receiver 13, an autonomous driving sensor 14, and a destination information input device 15 are connected to the input side of the map locator calculation unit 12. The GNSS receiver 13 receives positioning signals transmitted from a plurality of positioning satellites. The autonomous driving sensor 14 enables autonomous driving in an environment where the reception sensitivity from the GNSS satellites is low and the positioning signals cannot be effectively received, such as driving in a tunnel, and is composed of a vehicle speed sensor, a gyro sensor, a longitudinal acceleration sensor, and the like. The map locator calculation unit 12 obtains a travel distance and a direction based on the speed (vehicle speed) of the host vehicle M detected by the vehicle speed sensor, the angular velocity detected by the gyro sensor, and the longitudinal acceleration detected by the longitudinal acceleration sensor, and performs localization based on the obtained travel distance and direction.

[0018] The destination information input device 15 is a terminal device operated by a person in the vehicle, such as a driver or a passenger. The destination information input device 15 can collectively input a series of information required for setting a driving route in the map locator calculation unit 12, such as inputting the setting of a destination and intermediate points (such as a service area on a highway).

[0019] Specifically, destination information input device 15 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 map locator calculation unit 12 by wire or wirelessly.

[0020] When the driver or passenger operates destination information input device 15 to input information about the destination and route points (facility name, address, telephone number, etc.), this input information is read into map locator calculation unit 12. Then, map locator calculation unit 12 sets the position coordinates (latitude, longitude) of the input destination and route points.

[0021] The map locator calculation unit 12 includes a vehicle position estimation calculation unit 12a as a vehicle position estimation means, a road map information acquisition unit 12b, and a target course setting calculation unit 12c as a target course setting means. The vehicle position estimation calculation unit 12a acquires position coordinates (latitude, longitude) that are position information of the vehicle M based on a positioning signal received by the GNSS receiver 13. In an environment where a valid positioning signal cannot be received from a positioning satellite due to a decrease in sensitivity of the GNSS receiver 13, the vehicle position estimation calculation unit 12a estimates the position coordinates of the vehicle M based on a signal from the autonomous driving sensor 14.

[0022] The road map information acquisition unit 12b performs map matching of the position coordinates of the vehicle M and the position coordinates (latitude, longitude) of the destination set by the destination information input device 15 on a road map stored in the high-precision road map database 16. Then, the road map information acquisition unit 12b identifies both positions and transmits road map information from the current vehicle position to the destination and its surroundings to the target course setting calculation unit 12c.

[0023] The high-precision road map database 16 is a large-capacity storage medium such as an HDD, and stores high-precision road map information (dynamic map). This high-precision road map information includes lane data (lane width data, lane center position coordinate data, lane travel azimuth data, speed limit data, etc.) required for automatic driving, and this lane data is stored at intervals of several meters for each lane on the road map.

[0024] The target path setting calculation unit 12c first creates a driving route connecting the current position and the destination, which are map-matched by the road map information acquisition unit 12b, on a road map. Next, the target path setting calculation unit 12c sequentially sets and updates a target path (straight ahead, turning right or left at an intersection, driving lanes such as the left lane, center lane, right lane, etc. if going straight, and lateral positions within the lanes, etc.) for automatically driving the vehicle M on this driving route, up to several hundred to several kilometers ahead of the vehicle M. The information on the target path is read by the vehicle control unit 22.

[0025] On the other hand, the camera unit 21 is fixed to the upper center of the front part of the vehicle interior of the vehicle M, and has an in-vehicle camera (stereo camera) consisting of a main camera 21a and a sub-camera 21b arranged at symmetrical positions on either side of the center in the vehicle width direction, an image processing unit (IPU) 21c, and a forward driving environment recognition unit 21d. This camera unit 21 performs predetermined image processing on driving environment image information captured by both cameras 21a and 21b of a predetermined imaging area If (see FIG. 2) in front of the vehicle M by the IPU 21c.

[0026] The forward driving environment recognition unit 21d reads the driving environment image information image-processed by the IPU 21c, and recognizes the forward driving environment (forward driving environment information) based on the driving environment image information. The forward driving environment to be recognized includes the road shape (the road curvature [1 / m] at the center of the dividing line dividing the left and right, and the width between the left and right dividing lines (vehicle width)) of the traveling path (host vehicle traveling path) on which the host vehicle M is traveling, intersections, the lighting color of traffic lights, road signs, pedestrians, bicycles, and other crossing people, etc.

[0027] The vehicle control unit 22 also includes a vehicle control calculation unit 22a, an intersection detection unit 22b, and an ACC set vehicle speed change unit 22c, and the input side of the vehicle control unit 22 is connected to the target route setting calculation unit 12c of the map locator calculation unit 12, the forward driving environment recognition unit 21d of the camera unit 21, and the driving information detection unit 26 as a driving information detection means, etc. The vehicle control unit 22 acquires the driving environment of a predetermined range of the target route ahead of the host vehicle M based on the road map information around the target route set by the target route setting calculation unit 12c and the forward driving environment information recognized by the forward driving environment recognition unit 21d. The driving information detection unit 26 is a collective term for various sensors that detect driving information of the host vehicle M necessary for autonomous driving, such as the vehicle speed (host vehicle speed), acceleration / deceleration, arrival time to the stop line, inter-vehicle distance between the host vehicle M and the preceding vehicle, and relative vehicle speed.

[0028] Furthermore, connected to the output side of the vehicle control unit 22 are a steering control unit 31 that drives the vehicle M along the target travel path, a brake control unit 32 that decelerates and stops the vehicle M by applying forced braking, an acceleration / deceleration control unit 33 that controls the vehicle speed of the vehicle M, and an alarm device 34 that alerts the driver to an alarm according to the situation recognized based on the driving environment ahead.

[0029] The vehicle control calculation unit 22a performs predetermined control on the steering control unit 31, the brake control unit 32, and the acceleration / deceleration control unit 33, and automatically drives the host vehicle M along a target route on a road map set by the target route setting calculation unit 12c based on a positioning signal indicating the host vehicle position received by the GNSS receiver 13. At that time, the vehicle control calculation unit 22a performs known adaptive cruise control (ACC control) and lane keeping (ALK: Active Lane Keep) control based on the forward driving environment recognized by the forward driving environment recognition unit 21d, and follows the preceding vehicle when a preceding vehicle is detected, and drives the host vehicle M along the driving lane at a first ACC set vehicle speed set by the driver with the speed limit of the road as the upper limit when a preceding vehicle is not detected.

[0030] The intersection detection unit 22b constantly detects whether or not a pair of intersections having an interval shorter than a predetermined interval exists within a predetermined range (e.g., 300 [m]) of the target route ahead of the vehicle M, based on the driving environment of a predetermined range of the target route ahead of the vehicle M acquired by the vehicle control unit 22. Specifically, the intersection detection unit 22b constantly detects whether or not a pair of intersections that satisfy the condition of formula (1) exists within a predetermined range (e.g., 300 [m]) of the target route ahead of the vehicle M. V 2 ACC / 2a max >d···(1) However, V ACC is the first ACC set vehicle speed [m / s] set by the driver, etc., a max is the deceleration rate of the automatic deceleration control [m / s 2 ], and d is the distance between the two intersections [m].

[0031] When the intersection detection unit 22b detects a pair of intersections whose interval is shorter than a predetermined interval, the ACC set vehicle speed change unit 22c changes the first ACC set vehicle speed set by the driver, etc. to a second ACC set vehicle speed. Specifically, when the intersection detection unit 22b detects a pair of intersections that satisfy formula (1), the ACC set vehicle speed change unit 22c changes the first ACC set vehicle speed to the second ACC set vehicle speed calculated by formula (2). √(d×2a max ) · · · (2) If, after changing to the second ACC set vehicle speed, the intersection detection unit 22b no longer detects a pair of intersections whose interval is shorter than a predetermined interval, the ACC set vehicle speed change unit 22c changes the second ACC set vehicle speed to the first ACC set vehicle speed set by the driver or the like.

[0032] Here, the change control process of the ACC set vehicle speed will be described in more detail with reference to Fig. 2. In the example of Fig. 2, the host vehicle M will be described as traveling straight through two intersections, a near intersection (hereinafter referred to as "near intersection") 41 and a far intersection (hereinafter referred to as "far intersection") 42.

[0033] The near intersection 41 is equipped with a near traffic light (hereinafter referred to as the "near traffic light") 41a and a near stop line (hereinafter referred to as the "near stop line") 41b, and the rear intersection 42 is equipped with a rear traffic light (hereinafter referred to as the "rear traffic light") 42a and a rear stop line (hereinafter referred to as the "rear stop line") 42b.

[0034] When the vehicle control unit 22 determines, based on the forward driving environment recognized by the forward driving environment recognition unit 21d of the camera unit 21, that the traffic light 41a at the upcoming intersection 41 allows proceeding (green light or arrow signal light is on), the vehicle control unit 22 controls the vehicle to pass through the upcoming intersection 41 at a first ACC set vehicle speed set by the driver, etc.

[0035] After that, when the vehicle control unit 22 determines that the rear traffic light 42a of the rear intersection 42 is not advancing (red light) based on the forward driving environment recognized by the forward driving environment recognition unit 21d of the camera unit 21, the vehicle control unit 22 controls the brake control unit 32 and the acceleration / deceleration control unit 33, etc., to perform deceleration control in order to stop the vehicle before the rear stop line 42b. At this time, if the distance between the front intersection 41 and the rear intersection 42 is d [m], if this distance d [m] is shorter than a predetermined interval, a sudden deceleration control that is not intended by the driver is required, and the ride comfort is deteriorated. Note that the distance d [m] is the distance between the front intersection 41 and the rear intersection 42, but is not limited thereto, and may be the distance between the front traffic light 41a and the rear traffic light 42a, or the distance between the front stop line 41b and the rear stop line 42b.

[0036] Here, the deceleration rate a of the automatic deceleration control max [m / s 2 The upper limit of this deceleration a max [m / s 2 The upper limit of the force is set within a range that does not adversely affect the riding comfort of the passengers, for example, 0.3 to 0.4G (2.94 to 3.92 [m / s 2 ]) should be used.

[0037] The first ACC set vehicle speed is V ACCV is set to [m / s] ACC When traveling at a speed of [m / s], the deceleration a max [m / s 2 The distance that the host vehicle M travels while continuing to decelerate at [ ] and coming to a stop can be calculated using equation (3).

[0038] ∫(V ACC -a max t)dt (3) (However, the integral range is 0 to V ACC / a max ) By calculating the above formula (3), V ACC When traveling at a speed of [m / s], the deceleration a max [m / s 2 ] The distance traveled before stopping by continuing to decelerate is V 2 ACC / 2a max [m].

[0039] That is, the distance traveled before stopping, V 2 ACC / 2a max If the distance V [m] between the near intersection 41 and the far intersection 42 is equal to or less than the distance d [m] between the near intersection 41 and the far intersection 42, the vehicle can decelerate and stop without deteriorating the ride comfort. 2 ACC / 2a max When the distance d [m] between the near intersection 41 and the far intersection 42 is longer than the distance d [m] (satisfies the condition of formula (1)), the deceleration a max [m / s 2 ] and deceleration control must be performed, which results in a deterioration of the ride comfort for passengers.

[0040] Therefore, when the intersection detection unit 22b detects a pair of intersections whose interval is shorter than a predetermined interval, the ACC set vehicle speed change unit 22c changes the first ACC set vehicle speed set by the driver, etc., to a second ACC set vehicle speed calculated by equation (2).

[0041] The change control process for the ACC set vehicle speed will be described with reference to Fig. 3. The change control process for the ACC set vehicle speed in Fig. 3 is executed by the cruise control unit 22 at predetermined calculation intervals when the vehicle is in an automatic driving mode.

[0042] First, the driving control unit 22 acquires the driving environment within a predetermined range (e.g., 300 m) of the target travel route ahead of the vehicle M based on the road map information acquired by the road map information acquisition unit 12b and the forward driving environment (forefront driving environment information) recognized by the forward driving environment recognition unit 21d of the camera unit 21 (step S1).

[0043] Based on the driving environment acquired in step S1, the driving control unit 22 determines (step S2) whether or not a pair of intersections with an interval shorter than a predetermined interval has been detected within a predetermined range of the target route ahead of the vehicle M. The intersection detection unit 22b detects a pair of intersections with an interval shorter than the predetermined interval using the above-mentioned formula (1).

[0044] When the cruise control unit 22 determines that a pair of intersections with an interval shorter than a predetermined interval has been detected within a predetermined range of the target route ahead of the vehicle M, it changes the first ACC set vehicle speed to a second ACC set vehicle speed (step S3) and ends the process. The first ACC set vehicle speed is a vehicle speed set by the driver or the like, and the second ACC set vehicle speed is a vehicle speed calculated by the above-mentioned formula (2), and the second ACC set vehicle speed is slower than the first ACC set vehicle speed.

[0045] On the other hand, if the driving control unit 22 determines that a pair of intersections with a distance shorter than the specified interval has not been detected within a specified range of the target route ahead of the vehicle M, it determines whether the vehicle speed has been changed to the second ACC set speed (step S4).

[0046] If the cruise control unit 22 determines that the vehicle speed has not been changed to the second ACC set vehicle speed, it ends the process.

[0047] On the other hand, when the cruise control unit 22 determines that the vehicle speed has been changed to the second ACC set vehicle speed, it changes the second ACC set vehicle speed to the first ACC set vehicle speed (step S5) and ends the process. That is, when the vehicle speed has been changed to the second ACC set vehicle speed and a pair of intersections with an interval shorter than a predetermined interval is not detected within a predetermined range of the target travel route ahead of the vehicle M, the cruise control unit 22 returns the changed second ACC set vehicle speed to the original first ACC set vehicle speed.

[0048] By the above-mentioned ACC set vehicle speed change control process, when the automatic driving assistance system 1 detects a set of intersections with a shorter interval than a predetermined interval within a predetermined range of the target travel path ahead of the vehicle M, the automatic driving assistance system 1 changes the first ACC set vehicle speed set by the driver or the like to a second ACC set vehicle speed that is slower than the first ACC set vehicle speed. As a result, the automatic driving assistance system 1 does not need to perform sudden deceleration control to stop the vehicle even if the illumination color of the rear traffic light 42a of the rear intersection 42 is red (red light) when passing through the nearby intersection 41, and the riding comfort of the passengers can be improved. As a result, the automatic driving assistance system 1 of this embodiment can suppress sudden deceleration control that is not intended by the driver.

[0049] It should be noted that the steps in the flowcharts in this specification may be executed in a different order, may be executed simultaneously, or may be executed in a different order each time, provided that this is not contrary to the nature of the steps.

[0050] The present invention is not limited to the above-described embodiment, and various changes and modifications can be made without departing from the spirit and scope of the present invention. [Explanation of symbols]

[0051] 1. Autonomous driving assistance system 11...Locator unit 12...Map locator calculation unit 12a... Vehicle position estimation calculation unit 12b…Road map information acquisition section 12c...Target course setting calculation section 13...GNSS receiver 14…Autonomous driving sensor 15...Destination information input device 16…High-precision road map database 21...Camera unit 21a…Main camera 21b…Sub camera 21c…Image Processing Unit (IPU) 21d…Front driving environment recognition unit 22...Vehicle control unit 22a... Vehicle control calculation unit 22b...Intersection detection section 22c…ACC set speed change section 26…Driving information detection unit 31...Steering control unit 32...Brake control unit 33...Acceleration / deceleration control unit 34…Alarm device 41…Next intersection 41a…Traffic light ahead 41b…Stop line 42…Intersection at the back 42a…Rear traffic light 42b…Back stop line If...imaging area

Claims

1. An automatic driving assistance system that acquires a driving environment of a predetermined range of a target route ahead of a host vehicle based on road map information acquired by a road map information acquisition unit and driving environment information ahead of the host vehicle acquired by a camera unit, an intersection detection unit that detects a set of intersections having an interval shorter than a predetermined interval within a predetermined range of the target route ahead of the host vehicle based on a driving environment within the predetermined range of the target route; an ACC set vehicle speed changing unit that changes a first ACC set vehicle speed that has been set to a second ACC set vehicle speed that is slower than the first ACC set vehicle speed when the intersection detection unit detects a pair of intersections whose interval is shorter than the predetermined interval; having The intersection detection unit detects whether there is a pair of intersections spaced apart from each other at an interval shorter than the distance traveled by the vehicle, while traveling at the first ACC set vehicle speed, until the vehicle continues to decelerate at a preset upper limit of deceleration and stops.

2. The intersection detection unit detects whether or not a pair of intersections that satisfy the following formula (1) is present within a predetermined range of the target route ahead of the host vehicle, based on a driving environment within a predetermined range of the target route, The autonomous driving assistance system according to claim 1, characterized in that, when the intersection detection unit detects that a set of intersections that satisfies the following formula (1) exists within a predetermined range of the target travel route ahead of the vehicle, the ACC set vehicle speed change unit changes the first ACC set vehicle speed to the second ACC set vehicle speed calculated by the following formula (2): V ２ ＡＣＣ / 2a ｍａｘ >d・・・(1) √(d×2a ｍａｘ )・・・(2) however, V ＡＣＣ : First ACC set speed a ｍａｘ : Deceleration rate of automatic deceleration control d: Distance between intersections It is.

3. The automatic driving assistance system according to claim 1 or 2, characterized in that, when the ACC set vehicle speed has been changed to the second ACC set vehicle speed, the ACC set vehicle speed change unit changes the second ACC set vehicle speed to the first ACC set vehicle speed if the intersection detection unit detects that there is no pair of intersections whose interval is shorter than the specified interval.

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