Vehicle warning system

Abstract

To provide a vehicle alarm device capable of making a driver quickly recognize an existence of an overtaking vehicle under a jam road state.SOLUTION: A vehicle alarm device comprises: a circumference information acquisition part that acquires rear side information of a vehicle V; a notification device that is operated in a mode in which a driver of the vehicle V can visually and audibly recognize; and a notification control device that notifies an existence of an alarm object by making the notification device operate in a predetermined notification mode in the case where the existence of the alarm object in rear dead angle regions AL1 and AR1 and rear access notification regions AL2 and AR2, which are defined to the rear side of the vehicle V on the basis of the rear side information. In the case where the existence of a first alarm object Vc is recognized, the notification control device makes the notification device operate under the first mode, and switches the notification mode from the first mode to a second mode in the case where the existence of a second alarm object Vf with a possibility of an overtaking between the vehicle V and the first alarm object Vc during the operation of the notification device under the first mode is recognized.SELECTED DRAWING: Figure 2B

Description

Technical Field

[0001] The present invention relates to a vehicle warning device. More specifically, it relates to a vehicle warning device that notifies a driver of the presence of a warning target at the rear side of a vehicle.

Background Art

[0002] In recent years, in order to improve traffic safety, the installation of a Blind Spot Information System (hereinafter abbreviated as "BSI system") in vehicles has been promoted (see Patent Document 1). In the BSI system shown in Patent Document 1, a predetermined area at the rear side of the vehicle corresponding to the driver's blind spot is monitored by a radar or a camera, and when it is recognized that another vehicle exists in this area, for example, an image suggesting the presence of the other vehicle is displayed on an indicator. According to the invention described in Patent Document 1, the driver can quickly recognize the presence of another vehicle at the rear side by visually recognizing the indicator.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Here, an operation example of the conventional BSI system will be described by taking the case of driving on a congested one-way two-lane road as shown in FIG. 2B. In the example shown in FIG. 2B, the BSI system mounted on the host vehicle V recognizes another vehicle Vc traveling at substantially the same speed as the host vehicle V at the rear side thereof as a warning target, and notifies the driver of the presence of this other vehicle Vc by displaying an image on an indicator.

[0005] Furthermore, as shown in Figure 2B, if both lanes are congested, a motorcycle Vf may slip through between them. However, conventional BSI systems do not anticipate the existence of such slipping vehicles. Therefore, even if a motorcycle 9c approaches vehicle V while the system is already recognizing another vehicle Vc as a warning target and informing the driver of the presence of this warning target, the system cannot inform the driver of the presence of this motorcycle Vf. As a result, the driver of vehicle V cannot recognize the presence of motorcycle Vf until it is sufficiently close to vehicle V or until motorcycle Vf overtakes vehicle V.

[0006] The present invention aims to provide a vehicle warning device that allows drivers to quickly recognize the presence of vehicles that are trying to squeeze through traffic in congested road conditions. [Means for solving the problem]

[0007] (1) The vehicle warning device according to the present invention (for example, the vehicle warning device 3 described later) comprises: an ambient information acquisition unit (for example, the ambient information acquisition unit 4 described later) that acquires ambient information of a vehicle (for example, the vehicle V described later); a notification device (for example, the notification device 5 described later) that operates in a manner that can be recognized by the driver of the vehicle by sight or hearing; and a notification control device (for example, the notification control device 6 described later) that, when it recognizes the presence of a warning target to the rear side of the vehicle based on the ambient information, activates the notification device in a predetermined notification manner to notify the presence of the warning target, wherein the notification control device activates the notification device in a first manner when it recognizes the presence of a first warning target, and switches the notification manner from the first manner to the second manner when it recognizes the presence of a second warning target that may slip between the vehicle and the first warning target while the notification device is operating in the first manner.

[0008] (2) In this case, if the notification control device detects the operation of the turn signal switch (for example, the turn signal switch 14 described later) toward the first alarm target side while the notification device is operating under the first or second mode, it is preferable to switch the notification mode from the first or second mode to the third mode.

[0009] (3) In this case, the notification device includes an image display device (for example, an image display device 52 described later) that displays an image on a display screen that can be recognized by the driver, and the notification control device preferably displays a notification image (for example, a notification image P described later) on the display screen that suggests the presence of the first warning target under the first embodiment, displays the notification image with a higher brightness than under the second embodiment, and displays the notification image with a higher brightness than under the third embodiment or flashes the notification image.

[0010] (4) In this case, the notification device is equipped with an image display device (for example, an image display device 52 described later) that displays an image on a display screen visible to the driver, and the notification control device preferably displays a notification image on the display screen that indicates the presence of the first warning target under the first embodiment, flashes the notification image under the second embodiment, and flashes the notification image at a shorter interval than under the third embodiment.

[0011] (5) In this case, it is preferable that the image display device displays the image on at least one of the mirror surfaces of the external rearview mirrors (for example, the external rearview mirrors 51L, 51R described later) provided on both sides of the vehicle in the vehicle width direction.

[0012] (6) In this case, the notification device further comprises an acoustic control device (for example, an acoustic control device 54, described later) that causes a speaker (for example, a speaker 53, described later) installed in the passenger compartment of the vehicle to emit a warning sound, and it is preferable that the volume of the warning sound of the notification control device is louder than that of the first embodiment under the second or third embodiment.

[0013] (7) In this case, the notification device further comprises an acoustic control device (for example, an acoustic control device 54, described later) that causes a speaker (for example, a speaker 53, described later) provided in the passenger compartment of the vehicle to emit a warning sound, and in the second or third embodiment, it is preferable that the notification control device shortens the period of emission of the warning sound compared to the first embodiment. [Effects of the Invention]

[0014] (1) In the present invention, when the notification control device recognizes the presence of a warning target to the rear side of the vehicle based on information about the vehicle's surroundings, it activates the notification device in a predetermined notification mode to notify the driver of the presence of the warning target. In particular, in the present invention, when the notification control device recognizes the presence of a first warning target, it activates the notification device in a first mode to notify the driver of the presence of this first warning target. Furthermore, if the notification control device recognizes the presence of a second warning target that may slip between the vehicle and the first warning target while the notification device is operating in the first mode, it switches the notification mode from the first mode to the second mode. Thus, according to the present invention, by switching the notification mode from the first mode to the second mode, the driver can quickly recognize the presence of a second warning target that may slip between the vehicle and the first warning target, thereby improving traffic safety.

[0015] (2) In the present invention, if the notification control device detects the operation of the turn signal switch toward the first warning target while the notification device is operating under the first or second mode, the notification mode is switched from the first or second mode to the third mode. As a result, for example, if the driver attempts to change lanes toward the direction of the first or second warning target without being aware of the presence of the first or second warning target, the notification control device will activate the notification device under the third mode, so that the driver can quickly become aware of the presence of the first or second warning target.

[0016] (3) In the present invention, under the first embodiment, the notification control device displays a notification image on the display screen that suggests the presence of a first warning target, and under the second embodiment, displays this notification image with a higher brightness than in the first embodiment. This allows the driver to quickly recognize that a first warning target is located to the rear side of the vehicle, and that a second warning target may pass between the vehicle and the first warning target. Furthermore, under the third embodiment, the notification control device can make the driver more strongly aware than in the first or second embodiment that a first or second warning target is located in the direction in which they are about to move, by displaying this notification image with a higher brightness than in the second embodiment or by making this notification image flash.

[0017] (4) In the present invention, under the first embodiment, the notification control device displays a notification image on the display screen that suggests the presence of a first warning target, and under the second embodiment, the notification image is made to flash. This allows the driver to quickly recognize that a first warning target is located to the rear side of the vehicle, and that a second warning target may pass between the vehicle and the first warning target. Furthermore, under the third embodiment, the notification control device makes the notification image flash at a shorter interval than in the second embodiment, thereby making the driver more strongly aware than in the first or second embodiment that a first or second warning target is located in the direction in which they are about to move.

[0018] (5) When drivers check the surroundings of the vehicle in order to change lanes, they often visually check the external rearview mirrors. Therefore, the image display device can efficiently recognize the presence of a warning target by displaying an image on at least one of the mirror surfaces of the external rearview mirrors installed on both sides in the vehicle width direction.

[0019] (6) In the present invention, the notification control device can make the driver more aware of the presence of the first or second warning target by increasing the volume of the warning sound compared to the first embodiment under the second or third embodiment.

[0020] (7) In the present invention, in the second or third aspect, by shortening the sounding period of the warning sound compared to the first aspect, the driver can be made to strongly recognize the presence of the first or second warning target.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] [Figure 1] FIG. 1 schematically shows the configuration of a vehicle warning device according to an embodiment of the present invention and a vehicle equipped with this vehicle warning device. [Figure 2A] FIG. 2 is a plan view seen from above of a vehicle traveling on a two-lane road on one side and a plurality of other vehicles existing around it. [Figure 2B] FIG. 2 is a plan view seen from above of a vehicle traveling on a two-lane road on one side and a plurality of other vehicles existing around it. [Figure 3] FIG. 3 shows an example of the display of a notification image on the mirror surface of the right outside rearview mirror. [Figure 4] FIG. 4 is a flowchart showing the specific procedure of the right rear notification process for notifying the driver of the presence of a warning target within the right rear blind spot area or the right rear approach warning area of the vehicle. [Figure 5] FIG. 5 is a time chart showing the transition of the notification mode when the right rear notification process shown in FIG. 4 is executed under the situations shown in FIGS. 2A and 2B.

MODE FOR CARRYING OUT THE INVENTION

[0022] Hereinafter, a vehicle warning device according to an embodiment of the present invention will be described with reference to the drawings.

[0023] Figure 1 is a schematic diagram showing the configuration of a vehicle warning device 1 and a vehicle V equipped with this vehicle warning device 1 according to this embodiment. The upper part of Figure 1 shows a plan view of the vehicle V, and the lower part of Figure 1 shows a side view of the vehicle V. In the following description, the vehicle V is described as a so-called right-hand drive four-wheeled vehicle in which the driver's seat is located on the right side in the vehicle width direction when viewed along the direction of travel, but the present invention is not limited to this. The vehicle may also be a so-called left-hand drive four-wheeled vehicle in which the driver's seat is located on the left side in the vehicle width direction when viewed along the direction of travel.

[0024] Vehicle V comprises a plurality of turn signals 11L, 11R, 12L, and 12R located outside the vehicle, a steering wheel 13 used by the driver for steering, a turn signal switch 14 located near the steering wheel 13, an external sensor unit 2 located on the vehicle body, and a vehicle warning device 3 that notifies the driver of the presence of a moving object around vehicle V based on detection signals from the turn signal switch 14 and the external sensor unit 2.

[0025] The front left turn signal 11L is located on the left side of the front of the vehicle V when viewed in the direction of travel, and the rear left turn signal 12L is located on the left side of the rear of the vehicle V when viewed in the direction of travel. The front right turn signal 11R is located on the right side of the front of the vehicle V when viewed in the direction of travel, and the rear right turn signal 12R is located on the right side of the rear of the vehicle V when viewed in the direction of travel. A control device (not shown) flashes the left turn signals 11L and 12L when the driver tilts the turn signal switch 14 upward, and flashes the right turn signals 11R and 12R when the driver tilts the turn signal switch 14 downward.

[0026] The external sensor unit 2 comprises a front camera unit 20, a rear camera unit 21, a plurality (for example, 5) of Lidar units 22a, 22b, 22c, 22d, 22e, and a plurality (for example, 5) of radar units 23a, 23b, 23c, 23d, 23e.

[0027] The front camera unit 20 is a camera that photographs the area in front of the vehicle V. The front camera unit 20 is mounted, for example, on the roof of the vehicle V, on the interior side, near the front windshield. The images captured by the front camera unit 20 are transmitted to the surrounding information acquisition unit 4 of the vehicle warning device 3, which will be described later.

[0028] The rear camera unit 21 is a camera that photographs the area behind the vehicle V. The rear camera unit 21 is mounted, for example, on the roof of the vehicle V, on the interior side, near the rear window. The images captured by the rear camera unit 21 are transmitted to the surrounding information acquisition unit 4.

[0029] Lidar units 22a to 22e are Light Detection and Ranging (LIDAR) devices that detect objects around the vehicle V by measuring scattered light from objects in response to pulsed laser irradiation. The first Lidar unit 22a is located on the right corner of the front of the vehicle V when viewed in the direction of travel, and detects objects slightly to the right of the front of the vehicle V. The second Lidar unit 22b is located on the left corner of the front of the vehicle V when viewed in the direction of travel, and detects objects slightly to the left of the front of the vehicle V. The third Lidar unit 22c is located in the center of the rear of the vehicle V in the width direction, and detects objects behind the vehicle V. The fourth Lidar unit 22d is located on the rear of the right side of the vehicle V, and detects objects slightly to the right and rear of the vehicle V. The fifth Lidar unit 22e is located on the rear of the left side of the vehicle V, and detects objects slightly to the left and rear of the vehicle V. The detection signals from these Lidar units 22a to 22e are transmitted to the surrounding information acquisition unit 4.

[0030] Radar units 23a to 23e are millimeter-wave radars that detect objects around the vehicle V by measuring the reflected waves from objects in response to millimeter-wave irradiation. The first radar unit 23a is located on the right corner of the front of the vehicle V when viewed in the direction of travel, and detects objects slightly to the right of the front of the vehicle V. The second radar unit 23b is located on the left corner of the front of the vehicle V when viewed in the direction of travel, and detects objects slightly to the left of the front of the vehicle V. The third radar unit 23c is located in the center of the front of the vehicle V in the width direction, and detects objects in front of the vehicle V. The fourth radar unit 23d is located on the right corner of the rear of the vehicle V when viewed in the direction of travel, and detects objects slightly to the right of the rear of the vehicle V. The fifth radar unit 23e is located on the left corner of the rear of the vehicle V when viewed in the direction of travel, and detects objects slightly to the left of the rear of the vehicle V. The detection signals from these radar units 23a to 23e are transmitted to the surrounding information acquisition unit 4.

[0031] The vehicle warning device 3 comprises an ambient information acquisition unit 4 that acquires ambient information about the vehicle V, a notification device 5 that operates in a manner that can be recognized by the driver of the vehicle V visually or aurally, and a notification control device 6 that, when it recognizes the presence of a warning target to the rear side of the vehicle V based on ambient information, activates the notification device 5 in a predetermined notification manner to notify the driver of the presence of the warning target.

[0032] The surrounding information acquisition unit 4 is a computer that acquires surrounding information about the state of the vehicle V, particularly information such as the position, shape, type, and speed of roads and objects located on the left and right rear sides of the vehicle V (hereinafter collectively referred to as "rear-side information"), by performing sensor fusion processing on the detection results from some or all of the front camera unit 20, rear camera unit 21, rider units 22a to 22e, and radar units 23a to 23e. The surrounding information acquisition unit 4 transmits the acquired rear-side information to, for example, the notification control device 6.

[0033] The notification device 5 operates in a manner that can be perceived by the driver of the vehicle V visually or aurally, thereby notifying the driver of various information. More specifically, the notification device 5 comprises a left exterior rearview mirror 51L and a right exterior rearview mirror 51R provided on both sides of the vehicle width direction of the vehicle V, an image display device 52 that displays an image on at least one of the mirror surfaces of these exterior rearview mirrors 51L and 51R based on a command from the notification control device 6, a speaker 53 provided inside the vehicle, and an acoustic control device 54 that causes the speaker 53 to emit a warning sound based on a command from the notification control device 6.

[0034] In the following description, the notification device 5 will be described in a manner that allows the driver to perceive it both visually and aurally, but the present invention is not limited to this. The notification device 5 may be described in a manner that allows the driver to perceive it only visually or only aurally. Furthermore, in the following description, the image display device 52 will be described in a manner that uses the mirror surface of the external rearview mirrors 51L, 51R as a display screen, but the present invention is not limited to this. The image display device 52 may use a monitor or windshield installed inside the vehicle as a display screen and display an image on this display screen.

[0035] The notification control device 6 recognizes, based on the rear-side information transmitted from the surrounding information acquisition unit 4, any moving object located to the rear-side of the vehicle V that satisfies either the first or second warning target condition described later as a warning target. When a warning target is recognized, the notification device 5 is activated in a predetermined notification manner to notify the driver of the presence of this warning target.

[0036] Figures 2A and 2B are top-down plan views of vehicle V traveling on a two-lane road, and other vehicles Va, Vb, Vc, Vd, Ve, and Vf surrounding it. Figure 2B shows the state a few seconds after the state shown in Figure 2A.

[0037] The first alarm target condition defined for a moving object located to the rear side of vehicle V is that it is located within the left rear blind spot area AL1 or the right rear blind spot area AR1, which are defined on the left and right rear sides of vehicle V. As shown in Figures 2A and 2B, the left rear blind spot area AL1 and the right rear blind spot area AR1 are areas that are blind spots for the driver of vehicle V, that is, areas on the rear side of vehicle V that are difficult for the driver to see reflected in the mirror surfaces of the external rearview mirrors 51L and 51R. In other words, if another moving object is located within the rear blind spot areas AL1 and AR1, the alarm control device 6 recognizes the moving object located within these rear blind spot areas AL1 and AR1 as an alarm target. Therefore, in the example shown in Figures 2A and 2B, the alarm control device 6 mounted on vehicle V recognizes the other vehicle Vc located within the right rear blind spot area AR1 as an alarm target.

[0038] Furthermore, the second warning target condition defined for a moving object located to the rear side of vehicle V is that the object is located within the left rear approach warning area AL2 or the right rear approach warning area AR2, which are defined on the left and right rear sides of vehicle V, and that it satisfies a predetermined approach warning condition. Here, the approach warning condition is that the approach speed to vehicle V is equal to or greater than a predetermined speed. As shown in Figures 2A and 2B, the left rear approach warning area AL2 includes the left rear blind spot area AL1 and is defined to be a predetermined distance longer than the left rear blind spot area AL1 towards the rear in the direction of travel of vehicle V. The right rear approach warning area AR2 includes the right rear blind spot area AR1 and is defined to be a predetermined distance longer than the right rear blind spot area AR1 towards the rear in the direction of travel of vehicle V. In other words, the notification control device 6 recognizes a moving object located within the rear approach warning areas AL2 and AR2 and approaching vehicle V at an approach speed equal to or greater than a predetermined speed as a target for a warning. Therefore, in the example shown in Figure 2B, the notification control device 6 mounted on vehicle V recognizes other vehicle Vf, which is a motorcycle, as a warning target because it is located within the right rear approach warning area AR2 and is attempting to pass between vehicle V and other vehicle Vc, which has already been recognized as a warning target as described above.

[0039] Based on the rear-side information transmitted from the surrounding information acquisition unit 4, if the notification control device 6 recognizes the presence of a warning target according to the procedure described above, it notifies the driver of the presence of the warning target by displaying a notification image in a predetermined manner on the mirror surface of the one of the two external rearview mirrors 51L and 51R located on both sides of the vehicle V in the vehicle width direction that the warning target is located, or by emitting a warning sound in a predetermined manner from the speaker 53. Specifically, if the notification control device 6 recognizes the presence of a warning target within the left rear blind spot area AL1 or the left rear proximity warning area AL2, it displays a notification image on the mirror surface of the left external rearview mirror 51L or emits a warning sound from the speaker 53. Also, if the notification control device 6 recognizes the presence of a warning target within the right rear blind spot area AR1 or the right rear proximity warning area AR2, it displays a notification image on the mirror surface of the right external rearview mirror 51R or emits a warning sound from the speaker 53.

[0040] Figure 3 shows an example of the display of the notification image P on the mirror surface of the right exterior rearview mirror 51R. More specifically, Figure 3 shows the case where the notification image P is displayed on the mirror surface of the right exterior rearview mirror 51R of a vehicle V traveling at the position shown in Figure 2B.

[0041] As shown in Figure 3, the mirror surface of the right exterior rearview mirror 51R of vehicle V reflects other vehicles Vc, which are located in the right rear blind spot area AR1, other vehicles Vd which are following vehicle Vc, other vehicles Vb which are following vehicle V, and other vehicles Vf which are attempting to slip between vehicle V and other vehicles Vc. When the notification control device 6 recognizes other vehicles Vc and other vehicles Vf as warning targets through the procedure described above, it notifies the driver of the presence of these warning targets by superimposing a notification image P on the upper right corner of the mirror surface of the right exterior rearview mirror 51R, which reflects multiple other vehicles as seen from the driver's perspective.

[0042] Figure 4 is a flowchart illustrating the specific procedure for the right rear warning process, which notifies the driver of the presence of a warning target within the right rear blind spot area AR1 or the right rear proximity warning area AR2 of vehicle V. The right rear warning process shown in Figure 4 is repeatedly executed by the warning control device 6 under a predetermined control cycle after the driver operates a start switch (not shown) and vehicle V becomes drivable. The specific procedure for the left rear warning process, which notifies the driver of the presence of a warning target within the left rear blind spot area AL1 or the left rear proximity warning area AL2 of vehicle V, is almost the same as the right rear warning process shown in Figure 4, so its illustration and detailed explanation are omitted.

[0043] First, in step ST1, the notification control device 6 performs a warning target recognition process to recognize a warning target that is located within the right rear blind spot area AR1 or the right rear approach warning area AR2, based on the rear-side information transmitted from the surrounding information acquisition unit 4, and then proceeds to step ST2.

[0044] In this alarm target recognition process, the notification control device 6 first extracts moving objects located within the right rear approach warning area AR2 based on rear-side information. Next, the notification control device 6 determines for each extracted moving object whether it satisfies either of the first or second alarm target conditions described above, and recognizes any moving object that satisfies either of the first or second alarm target conditions as an alarm target. Hereafter, the number of moving objects recognized as alarm targets by this alarm target recognition process will be referred to as the number of recognized objects.

[0045] Next, in step ST2, the notification control device 6 determines whether the number of recognized vehicles is 0 or not. If the result of the determination in step ST2 is YES, that is, if there are no vehicles to be warned in the right rear blind spot area AR1 or the right rear proximity warning area AR2 of vehicle V, the notification control device 6 proceeds to step ST3. In step ST3, the notification control device 6 terminates the right rear warning process without activating the notification device 5.

[0046] Furthermore, if the determination result of step ST2 is NO, that is, if at least one vehicle to be warned is present in the right rear blind spot area AR1 or the right rear proximity warning area AR2 of the vehicle V, the notification control device 6 proceeds to step ST4.

[0047] In step ST4, the notification control device 6 determines whether there is one vehicle recognized. If the result of the determination in step ST4 is YES, that is, if there is only one vehicle to be warned in the right rear blind spot area AR1 or the right rear proximity warning area AR2 of vehicle V, the notification control device 6 proceeds to step ST5. If the result of the determination in step ST4 is YES, that is, if there are two or more vehicles to be warned in the right rear blind spot area AR1 or the right rear proximity warning area AR2 of vehicle V, the notification control device 6 proceeds to step ST7.

[0048] In step ST5, the notification control device 6 determines whether the turn signal switch for the recognized warning target side (i.e., the driver's right side) is turned ON. If the result of the determination in step ST5 is NO, the notification control device 6 proceeds to step ST6.

[0049] In step ST6, the notification control device 6 activates the notification device 5 in the first mode to notify the driver of the presence of the warning target and terminate the right rear notification process. More specifically, in the first mode, the notification control device 6 notifies the driver of the presence of the warning target by displaying a notification image P that suggests the presence of the warning target on the mirror surface of the right exterior rearview mirror 51R, as illustrated in Figure 3. In this first mode, it is preferable that the notification control device 6 keeps the notification image P constantly illuminated at a predetermined brightness. In this embodiment, in order to avoid bothering the driver, the case in which the notification control device 6 does not emit a warning sound in the first mode is described, but the present invention is not limited to this. The notification control device 6 may emit a warning sound at a volume and frequency that does not bother the driver.

[0050] In step ST7, the notification control device 6 determines whether the turn signal switch for the recognized warning target side (i.e., the driver's right side) has been turned ON. If the result of the determination in step ST7 is NO, the notification control device 6 proceeds to step ST8.

[0051] In step ST8, the notification control device 6 determines whether there is a warning target among all recognized warning targets that could potentially slip between vehicle V and other warning targets. More specifically, the notification control device 6 first identifies the warning target located closest to the right rear blind spot area AR1 from among all recognized warning targets as a parallel vehicle, and calculates the vehicle width distance between the side of vehicle V on the warning target side and the side of the parallel vehicle on the vehicle V side based on the rear side information. Next, the notification control device 6 calculates the vehicle width and speed difference with respect to vehicle V for all warning targets excluding the parallel vehicle, based on the rear side information. Then, the notification control device 6 determines that there is a warning target among all warning targets excluding the parallel vehicle that has a vehicle width shorter than the vehicle width distance between vehicle V and the parallel vehicle and a speed difference greater than a predetermined speed difference threshold.

[0052] If the result of step ST8 is NO, that is, if the notification control device 6 determines that there are no warning targets among all recognized warning targets that could potentially slip between vehicle V and other warning targets, it proceeds to step ST6 and activates the notification device 5 in the first mode to notify the driver of the existence of these warning targets.

[0053] If the result of step ST8 is YES, that is, if there is a warning target among all recognized warning targets that may slip between vehicle V and other warning targets, the notification control device 6 proceeds to step ST9. In step ST9, the notification control device 6 operates the notification device 5 in a second mode different from the first mode described above to notify the driver of the presence of a warning target that may slip through, and terminates the right rear warning process. More specifically, in the second mode, the notification control device 6 notifies the driver of the presence of a warning target by displaying a notification image P on the mirror surface of the right exterior rearview mirror 51R, similar to the first mode. In this second mode, it is preferable that the notification control device 6 displays the notification image P with a higher brightness than in the first mode in order to notify the driver of the presence of a warning target that may slip through. Also, as described above, if the notification image P is constantly illuminated in the first mode, the notification control device 6 may flash the notification image P at a predetermined period in the second mode. Furthermore, the notification control device 6 may also emit a warning sound at a louder volume or with a shorter sounding cycle than in the first mode, in conjunction with the display of the notification image P as described above, in order to notify the driver of the presence of a warning target that may slip through the lane.

[0054] If the result of the determination in step ST5 or step ST7 is YES, that is, if at least one warning target is recognized and the turn signal switch to the side of this warning target is turned ON, the notification control device 6 proceeds to step ST10. In step ST10, the notification control device 6 strongly notifies the driver of the presence of a warning target by operating the notification device 5 in a third mode different from the first and second modes described above, and terminates the right rear notification process. More specifically, in the third mode, the notification control device 6 notifies the driver of the presence of a warning target by displaying a notification image P on the mirror surface of the right exterior rearview mirror 51R, similar to the first and second modes. In this third mode, it is preferable that the notification control device 6 displays the notification image P with a higher brightness than in the second mode in order to strongly notify the driver of the presence of a warning target. Furthermore, as described above, if the notification image P is flashed at a predetermined interval under the second mode, the notification control device 6 may flash the notification image P at a shorter interval than under the third mode. In addition, in order to strongly notify the driver of the presence of the warning target, the notification control device 6 may emit a warning sound at a louder volume or a shorter sounding period than under the first mode in conjunction with the display of the notification image P as described above. Furthermore, in order to strongly notify the driver of the presence of the warning target more than under the second mode described above, the notification control device 6 may emit a warning sound at a louder volume or a shorter sounding period than under the second mode.

[0055] Next, we will explain the transition of the notification pattern when the right rear notification process shown in Figure 4 is executed under the conditions shown in Figures 2A and 2B, referring to the time chart shown in Figure 5. In the time chart in Figure 5, at time t0, vehicle V and other vehicles Va to Vf are in the positions shown in Figure 2A, and from time t1 onward, vehicle V and other vehicles Va to Vf are in the positions shown in Figure 2B.

[0056] First, between times t0 and t1, the notification control device 6 performs a warning target recognition process (see step ST1 in Figure 4) and recognizes vehicle Vc, which is located within the right rear blind spot area AR1, as the first warning target from among multiple other vehicles Vb to Vf located to the rear side of vehicle V. Between times t0 and t1, other vehicles Vb and Vf are located outside the right rear proximity warning area AR2 and are therefore not recognized as warning targets. Also, between times t0 and t1, other vehicles Vd and Ve are located within the right rear proximity warning area AR2, but their approach speed to vehicle V is below a predetermined speed and therefore they are not recognized as warning targets. Thus, between times t0 and t1, the notification control device 6 recognizes only other vehicle Vc as a warning target, and therefore activates the notification device 5 in the first mode to notify the driver of the presence of this warning target. More specifically, in the first embodiment, the notification control device 6 notifies the driver of the presence of a warning target by continuously illuminating a notification image P at a predetermined first brightness on the mirror surface of the right exterior rearview mirror 51R, as illustrated in Figure 3.

[0057] Next, at time t1, as shown in Figure 2B, another vehicle Vf enters the right rear proximity warning area AR2 at a higher speed than vehicle V. Therefore, from time t1 onward, the notification control device 6 performs a warning target recognition process (see step ST1 in Figure 4) and continues to recognize other vehicle Vc, which is located in the right rear blind spot area AR1, as the first warning target from among the multiple other vehicles Vb to Vf located to the rear side of vehicle V, and recognizes other vehicle Vf, which has entered the right rear proximity warning area AR2, as the second warning target. Note that from time t1 onward, other vehicles Vb, Vd, and Ve are not recognized as warning targets for the same reasons as between time t0 and t1.

[0058] Furthermore, after time t1, the notification control device 6 determines that the width of the other vehicle Vf recognized as the second warning target is shorter than the widthwise distance between vehicle V and the first warning target, and that the speed difference is greater than the speed difference threshold, and therefore determines that this second warning target may slip between vehicle V and the first warning target (see step ST8 in Figure 4). For this reason, in response to recognizing the existence of the second warning target that may slip between vehicle V and the first warning target at time t1, the notification control device 6 switches the notification mode from the first mode to the second mode and continues to operate the notification device 5 (see step ST9 in Figure 4), thereby notifying the driver of the existence of this second warning target. More specifically, under the second mode, the notification control device 6 notifies the driver of the existence of the second warning target by flashing the notification image P between the first brightness and a second brightness set to be higher than the first brightness. In this second embodiment, the notification control device 6 may emit a warning sound from the speaker 53.

[0059] Subsequently, at time t2, the notification control device 6 detects that the driver has turned on the turn signal switches for the first and second warning targets (see step ST7 in Figure 4). Therefore, in response to detecting that the turn signal switches for the first and second warning targets have been turned on at time t2, the notification control device 6 switches the notification mode from the second mode to the third mode and continues to operate the notification device 5 (see step ST10 in Figure 4), thereby informing the driver that the first and second warning targets are present in the direction in which the driver intends to change lanes. More specifically, in the third mode, the notification control device 6 flashes the notification image P at a shorter period than in the second mode, between the second brightness level and the third brightness level which is lower than the first brightness level, thereby strongly informing the driver of the presence of these first and second warning targets. In this third mode, the notification control device 6 may also emit a warning sound from the speaker 53.

[0060] The vehicle warning device 3 according to this embodiment provides the following effects. (1) When the notification control device 6 recognizes the presence of a warning target in the rear side of vehicle V based on rear side information of vehicle V, it activates the notification device 5 in a predetermined notification mode to notify the driver of the presence of the warning target. In particular, in this embodiment, when the notification control device 6 recognizes the presence of a first warning target, it activates the notification device 5 in the first mode to notify the driver of the presence of this first warning target. Furthermore, when the notification control device 6 recognizes the presence of a second warning target that may slip between vehicle V and the first warning target while the notification device 5 is activated in the first mode, it switches the notification mode from the first mode to the second mode. Thus, according to this embodiment, by switching the notification mode from the first mode to the second mode, the driver can quickly recognize the presence of a second warning target that may slip between vehicle V and the first warning target, thereby improving traffic safety.

[0061] (2) If the notification control device 6 detects the operation of the turn signal switch 14 toward the first warning target while the notification device is operating under the first or second mode, it switches the notification mode from the first or second mode to the third mode. As a result, for example, if the driver attempts to change lanes toward the direction of the first or second warning target without being aware of the presence of the first or second warning target, the notification control device 6 will activate the notification device under the third mode, so that the driver can quickly become aware of the presence of the first or second warning target.

[0062] (3) In the first mode, the notification control device 6 displays a notification image P on the display screen that suggests the presence of the first warning target, and in the second mode, it displays this notification image P with a higher brightness than in the first mode. This allows the driver to quickly recognize that the first warning target is located to the rear side of the vehicle, and that there is a second warning target that may slip between the vehicle V and the first warning target. In the third mode, the notification control device 6 can make the driver more strongly aware than in the first or second mode that the first or second warning target is located in the direction in which they are about to move, by displaying this notification image P with a higher brightness than in the second mode or by making this notification image P flash.

[0063] (4) In the first mode, the notification control device 6 displays a notification image P on the display screen that suggests the presence of the first warning target, and in the second mode, it flashes the notification image P. This allows the driver to quickly recognize that the first warning target is located to the rear side of the vehicle, and that there is a second warning target that may slip between the vehicle V and the first warning target. In the third mode, the notification control device 6 flashes the notification image P at a shorter interval than in the second mode, thereby making the driver more strongly aware than in the first or second mode that the first or second warning target is located in the direction they are about to move.

[0064] (5) When drivers check the surroundings of the vehicle in order to change lanes, they often visually check the external rearview mirrors 51L and 51R. Therefore, the image display device 52 can efficiently recognize the presence of a warning target by displaying an image on at least one of the mirror surfaces of the external rearview mirrors 51L and 51R, which are provided on both sides in the vehicle width direction.

[0065] (6) Under the second or third mode, the notification control device 6 can make the driver more aware of the presence of the first or second warning target by increasing the volume of the warning sound compared to the first mode.

[0066] (7) Under the second or third mode, the notification control device 6 can make the driver more strongly aware of the presence of the first or second warning target by shortening the sounding period of the warning sound compared to the first mode.

[0067] Although one embodiment of the present invention has been described above, the present invention is not limited thereto. Within the scope of the spirit of the present invention, the details of the configuration may be modified as appropriate. [Explanation of symbols]

[0068] V...vehicle 14… Turn signal switch 2…External sensor unit 3. Vehicle warning system 4… Surrounding Information Acquisition Unit 5…Notification device 51L…Left car exterior rear view mirror 51R…Right car exterior rear view mirror 52…Image display device 53...Speaker 54…Sound control device 6…Notification control device

Claims

1. A surrounding information acquisition unit that acquires information about the vehicle's surroundings, A notification device that operates in a manner that can be recognized by the driver of the vehicle by sight or hearing, A vehicle warning device comprising: a warning control device that, when it recognizes the presence of a warning target in the rear side of the vehicle based on the surrounding information, activates the warning device in a predetermined notification manner to notify the presence of the warning target; The aforementioned notification control device is When the presence of the first alarm target is recognized within a first area defined to the rear side of the vehicle, the notification device is activated under the first mode. A vehicle warning device characterized in that, while the notification device is operating under the first mode, if the presence of a second warning target that may slip between the vehicle and the first warning target is recognized in a second area that is defined to the rear side of the vehicle, encompassing the first area and extending a predetermined distance further to the rear in the direction of travel of the vehicle than the first area, the notification mode is switched from the first mode to the second mode.

2. The vehicle warning device according to claim 1, characterized in that the notification control device switches the notification mode from the first or second mode to the third mode when it detects the operation of the turn signal switch to the first warning target side while the notification device is operating under the first mode or the second mode.

3. The aforementioned notification device includes an image display device that displays an image on a display screen that can be recognized by the driver, The aforementioned notification control device is In the first embodiment, a notification image indicating the presence of the first alarm target is displayed on the display screen. In the second embodiment, the notification image is displayed with a higher brightness than in the first embodiment. The vehicle warning device according to claim 2, characterized in that, under the third embodiment, the notification image is displayed with a higher brightness than in the second embodiment, or the notification image is made to flash.

4. The aforementioned notification device includes an image display device that displays an image on a display screen visible to the driver, The aforementioned notification control device is In the first embodiment, a notification image indicating the presence of the first alarm target is displayed on the display screen. In the second embodiment, the notification image is made to flash, The vehicle warning device according to claim 2, characterized in that, under the third embodiment, the notification image is flashed at a shorter period than in the second embodiment.

5. The vehicle warning device according to claim 3 or 4, characterized in that the image display device displays an image on at least one of the mirror surfaces of the external rearview mirrors provided on both sides of the vehicle in the vehicle width direction.

6. The aforementioned notification device further includes an acoustic control device that causes a warning sound to be emitted from a speaker installed in the passenger compartment of the vehicle. The vehicle warning device according to claim 3 or 4, characterized in that the notification control device increases the volume of the warning sound in the second or third embodiment compared to the first embodiment.

7. The aforementioned notification device further includes an acoustic control device that causes a warning sound to be emitted from a speaker installed in the passenger compartment of the vehicle. The vehicle warning device according to claim 3 or 4, characterized in that, under the second or third embodiment, the warning control device shortens the sounding period of the warning sound compared to the first embodiment.

Images