JP2014238708A - Vehicle warning device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To curb the occurrence of a situation that a warning to call driver's attention is not perceived by a driver.SOLUTION: A vehicle warning device first acquires current position information indicating a current position of an own vehicle through a GPS receiver. In addition, the vehicle warning device: calculates a required time T1 until the own vehicle reaches a next intersection on the basis of the current position of the own vehicle detected by the GPS receiver and a travel speed V1 thereof detected by a vehicle speed sensor (S30); then, determines whether or not the required time T1 is less than a predetermined first determination time indicating that an environment requires a driver of the own vehicle to be warned (S70); when determining that the required time T1 is less than the first determination time (S70: YES), displays a predetermined first preceding stimulus image to stimulate visual perception of the driver with a predetermined first setting contrast which is set slightly higher than a threshold (S90).

Description

  The present invention relates to a vehicle alert device that alerts a driver of a vehicle.

  Conventionally, in order to alert the driver to an object to be noted without making the driver feel bothersome, the display time is within the range of subthreshold perception (for example, 50 milliseconds to 150 milliseconds). There is known one that displays a visual stimulus image to a driver (see, for example, Patent Document 1).

  In addition, it is known that in the section where the host vehicle is approaching the intersection, a sub-threshold visual stimulus is given to the driver with a presentation time of about 50 milliseconds in order to alert the driver to the vicinity of the intersection. (For example, refer to Patent Document 2).

JP 2006-133967 A JP 2011-81547 A

  The alerting by the techniques described in Patent Documents 1 and 2 is an appropriate method for notifying the driver of the potential danger, in other words, notifying the driver prior to the actualization of the danger. Because the potential danger does not always change to an apparent risk, displaying a potential danger with a visual stimulus above the threshold or sounding an alarm sound with an auditory stimulus above the threshold does not change to an apparent risk. This is because it is troublesome for the driver.

  However, the degree to which the driver perceives a visual stimulus existing at a certain position in the driver's visual field is affected by the visual stimulus existing around the driver. Therefore, the subthreshold advance stimulus by the techniques described in Patent Documents 1 and 2 is affected by visual stimuli caused by the driving environment such as the color of the road, the color of the other vehicle, and the light intensity of the sun. As a result, there is a concern that the prior stimulus may not be perceived by the driver.

  This invention is made | formed in view of such a problem, and it aims at suppressing generation | occurrence | production of the situation where alerting with respect to a driver is not perceived by the driver.

In order to achieve the above object, a vehicle alert device according to the present invention includes position information acquisition means, environmental information acquisition means, display determination means, and stimulus image display means.
In the vehicle alert system of the present invention, first, the position information acquisition unit acquires current position information indicating the current position of the host vehicle. Further, the environment information acquisition unit acquires travel environment information indicating the travel environment at the current position based on the current position information acquired by the position information acquisition unit. A display determination condition that is set in advance indicates that the display determination unit is an environment that needs to alert the driver of the host vehicle based on the travel environment information acquired by the environment information acquisition unit. It is determined whether or not is established. Then, when the display determination unit determines that the display determination condition is satisfied, the stimulus image display unit has a visual stimulation image that is a preset image for stimulating the driver's vision slightly above the threshold. In this way, display is performed with a preset contrast which is a preset contrast.

  The vehicle alert device configured in this way displays a visual stimulus image to stimulate the driver's vision when the current position of the host vehicle is an environment that needs to alert the driver. indicate. The visual stimulus image is displayed with a contrast slightly above the threshold. For this reason, the visual stimulus image is less affected by the visual stimulus caused by the driving environment around the host vehicle, and is more easily perceived by the driver than the image displayed within the range of the subthreshold perception. Thereby, generation | occurrence | production of the situation where the alerting to a driver is not perceived by the driver can be suppressed. Further, since the visual stimulus image is displayed with a contrast slightly above the threshold, it is possible to suppress the occurrence of a situation in which the driver feels bothered by the display of the visual stimulus image.

  The “contrast slightly above the threshold” is the contrast that most people can perceive, but some people cannot perceive.

1 is a block diagram showing a configuration of a vehicle alert device 1. FIG. It is a flowchart which shows an intersection display process. It is a figure which shows an intersection alerting image and a 1st preceding stimulus image. It is a flowchart which shows a preceding vehicle display process. It is a figure which shows a preceding vehicle alert image and a 2nd preceding stimulus image. It is a flowchart which shows a contrast adjustment process. It is a 1st timing chart which shows operation | movement of the alerting device 1 for vehicles. It is a figure which shows the state by which the intersection alerting image and the 1st preceding stimulus image are displayed on the windshield WS. It is a 2nd timing chart which shows operation | movement of the alerting device 1 for vehicles. It is a figure which shows the state in which the preceding vehicle alert image and the 2nd preceding stimulus image are displayed on the display screen MD of the meter. It is a flowchart which shows a traffic jam display process. It is a figure which shows an oncoming lane warning image and a 3rd preceding stimulus image. It is a figure which shows the state by which the oncoming lane warning image and the 3rd preceding stimulus image are displayed on the display screen MD of the meter. It is a figure which shows the display method of the 1st prior stimulus image in another embodiment.

Embodiments of the present invention will be described below with reference to the drawings.
A vehicle alert device 1 of this embodiment is mounted on a vehicle, and as shown in FIG. 1, a head up display device 2 (hereinafter referred to as a HUD device 2), a meter 3, a GPS (Global Positioning) System) receiver 4, map database 5, vehicle speed sensor 6, radar device 7, road-to-vehicle communication device 8, dial switch 9, and control unit 10.

  The HUD device 2 irradiates display light for displaying an image from below the windshield toward the windshield. As a result, the driver visually recognizes the projected virtual image superimposed on the actual scenery in front of the vehicle.

  The meter 3 is a color display device having a display screen such as a liquid crystal display, for example, and is provided on an instrument panel (not shown) in front of the driver's seat to display various states of the vehicle.

The GPS receiver 4 receives a transmission radio wave from a GPS artificial satellite and detects a position coordinate of the vehicle.
The map database 5 stores map data (node data, link data, cost data, road data, terrain data, mark data, intersection data, temporary stop point data, facility data, etc.).

The vehicle speed sensor 6 detects the traveling speed of the vehicle on which the vehicle alert device 1 is mounted.
The radar device 7 detects a distance and a relative speed with respect to a vehicle existing ahead (hereinafter referred to as a preceding vehicle) by transmitting a radar wave toward the front of the vehicle and receiving a reflected radar wave. .

  The road-to-vehicle communication device 8 acquires road traffic information (such as traffic congestion information and traffic regulation information) by performing wireless communication with a road device (not shown) installed in the vicinity of the travel route of the vehicle. .

The dial switch 9 detects the rotation angle of a dial knob (not shown) operated by the driver when adjusting the contrast (described later).
The control unit 10 is mainly configured by a known microcomputer including a CPU, a ROM, a RAM, an I / O, a bus line connecting these components, and the like. The control unit 10 executes various processes based on inputs from the GPS receiver 4, the map database 5, the vehicle speed sensor 6, the radar device 7, the road-vehicle communication device 8, and the dial switch 9, and the HUD device 2 and the meter 3. To control.

In the vehicle alert device 1 configured as described above, the control unit 10 executes an intersection display process, a preceding vehicle display process, and a contrast adjustment process, which will be described later.
First, the procedure of the intersection display process executed by the control unit 10 will be described. The intersection display process is a process that is repeatedly executed during the operation of the vehicle alert device 1.

  When this intersection display process is executed, as shown in FIG. 2, the control unit 10 first calculates a distance L1 to an intersection where the host vehicle passes next (hereinafter referred to as a target intersection) in S10. Specifically, first, the position of the target intersection is read from the map database 5 based on the current position of the host vehicle detected by the GPS receiver 4. Then, a distance L1 from the current position of the host vehicle to the position of the target intersection is calculated.

  In S20, a vehicle speed signal indicating the traveling speed V1 of the host vehicle is acquired from the vehicle speed sensor 6. In S30, a required time T1 until the target intersection is reached is calculated. Specifically, the required time T1 is calculated by the following equation (1) using the distance L1 calculated in S10 and the traveling speed V1 indicated by the vehicle speed signal acquired in S20.

T1 = L1 / V1 (1)
Thereafter, in S40, it is determined whether or not the distance L1 is equal to or less than a preset first determination distance (for example, 50 m in this embodiment). Here, when the distance L1 exceeds the first determination distance (S40: NO), the process proceeds to S70. On the other hand, when the distance L1 is less than or equal to the first determination distance (S40: YES), an intersection warning image for alerting the driver that the vehicle is approaching the intersection in S50 (described later) ) Is being displayed. Here, when the intersection warning image is being displayed (S50: YES), the process proceeds to S70. On the other hand, if the intersection warning image is not being displayed (S50: NO), the display of the intersection warning image is started by the HUD device 2 in S60, and the process proceeds to S70.

  In S70, it is determined whether the required time T1 is less than a preset first determination time (for example, 3 seconds in the present embodiment). If the required time T1 is equal to or longer than the first determination time (S70: NO), the process proceeds to S100. On the other hand, when the required time T1 is less than the first determination time (S70: YES), in S80, it is determined whether or not a first preceding stimulus image (described later) is being displayed. If the first preceding stimulus image is being displayed (S80: YES), the process proceeds to S100. On the other hand, when the first preceding stimulus image is not being displayed (S80: NO), the display of the first preceding stimulus image is started by the HUD device 2 in S90, and the process proceeds to S100. As a result, the HUD device 2 causes the preset first display time (for example, 0.5 seconds in the present embodiment) every time a preset first display cycle (for example, 1.5 seconds in the present embodiment) elapses. ) Continue to display the first preceding stimulus image. Further, the HUD device 2 changes the contrast of the first preceding stimulus image with respect to the intersection warning image within the first display time. Specifically, at the start of the first display time, the contrast is set to 0 (that is, the luminance of the intersection warning image is equal to the luminance of the first preceding stimulus image), and half of the first display time has elapsed. At the time, the first set contrast is set in advance (for example, 0.05 in this embodiment (in this embodiment, the luminance of the first preceding stimulus image is 0.05 times higher than the luminance of the intersection warning image)). As described above, the luminance of the first preceding stimulus image is gradually increased. Thereafter, the HUD device 2 gradually decreases the luminance of the first preceding stimulus image so that the contrast becomes 0 again at the end of the first display time.

  Note that “the contrast of the preceding stimulus image is α” means that the luminance of the preceding stimulus image is {(1 + α) × r} or {(1−α) × r}, where r is the luminance of the alert image. Say something.

  The first set contrast is determined by the following method, for example. First, for example, when the first prior stimulus image and the intersection warning image are viewed in the central visual field, for example, a contrast that can be perceived by 90% of the person but cannot be perceived by the remaining 10% of the person is determined. For example, the contrast at this time is 0.02. Then, the first preceding stimulus image is displayed in an area visually recognized by the driver driving the vehicle with the peripheral visual field (see FIG. 8C). Therefore, the first set contrast is set to a value larger than 0.02 (0.05 in the present embodiment) according to the distance between the driver's central visual field and the display area of the first preceding stimulus image during driving. The

  When the process proceeds to S100, it is determined whether or not the host vehicle has passed the target intersection. Here, when the own vehicle has not passed the target intersection (S100: NO), the intersection display process is temporarily ended. On the other hand, when the host vehicle passes the target intersection (S100: YES), the display of the intersection warning image and the first preceding stimulus image is terminated in the HUD device 2 in S110, and the intersection display process is temporarily terminated. .

  In addition, as shown in FIG. 3A, the above intersection warning image simplifies the intersection shape recognized by the driver when the driver is looking at the intersection located in front of the driver of the vehicle. It is composed of an intersection image II and a distance image DI indicating the distance to the intersection.

  Further, as shown in FIG. 3B, the first preceding stimulus image includes CI1 indicating a road that passes when the host vehicle turns right at the intersection indicated by the intersection image II, and a crossing that passes when the host vehicle turns left. CI2 indicating a sidewalk.

Next, the procedure of the preceding vehicle display process executed by the control unit 10 will be described. The preceding vehicle display process is a process that is repeatedly executed during the operation of the vehicle alert device 1.
When the preceding vehicle display process is executed, as shown in FIG. 4, the control unit 10 first determines in S210 whether there is a temporary stop point at an intersection where the host vehicle passes next (hereinafter referred to as a target intersection). Judge whether or not. Here, when there is no temporary stop point at the target intersection (S210: NO), the preceding vehicle display process is temporarily ended. On the other hand, when there is a temporary stop point at the target intersection (S210: YES), a distance L1 from the host vehicle to the target intersection is calculated in S220.

  In S230, based on the detection result of the radar device 7, it is determined whether there is a preceding vehicle. Here, if there is no preceding vehicle (S230: NO), the preceding vehicle display process is temporarily ended. On the other hand, when there is a preceding vehicle (S230: YES), in S240, the preceding vehicle distance information indicating the distance Lp between the host vehicle and the preceding vehicle is acquired from the radar device 7. In S250, the traveling speed V2 of the preceding vehicle is calculated from the radar device 7. Specifically, the relative speed information indicating the relative speed Vp between the host vehicle and the preceding vehicle is acquired from the radar device 7, and the vehicle speed signal indicating the traveling speed V1 of the host vehicle is acquired from the vehicle speed sensor 6. The traveling speed V2 is calculated from the equation (2).

V2 = Vp + V1 (2)
In S260, a distance L2 from the preceding vehicle to the target intersection is calculated. Specifically, the distance L2 is calculated by the following expression (3) using the distance L1 calculated in S220 and the distance Lp indicated by the preceding inter-vehicle distance information acquired in S240.

L2 = L1-Lp (3)
In S270, a required time T2 until the preceding vehicle reaches the target intersection is calculated. Specifically, the required time T2 is calculated by the following equation (4) using the distance L2 calculated in S260 and the traveling speed V2 calculated in S250.

T2 = L2 / V2 (4)
Thereafter, in S280, it is determined whether or not the distance L2 is equal to or less than a preset second determination distance (for example, 50 m in this embodiment). Here, if the distance L2 exceeds the second determination distance (S280: NO), the process proceeds to S310. On the other hand, when the distance L2 is less than or equal to the second determination distance (S280: YES), in S290, a preceding vehicle warning image for alerting the driver that the preceding vehicle exists (described later). Whether or not is being displayed. Here, when the preceding vehicle warning image is being displayed (S290: YES), the process proceeds to S310. On the other hand, when the preceding vehicle warning image is not being displayed (S290: NO), the display of the preceding vehicle warning image is started by the meter 3 in S300, and the process proceeds to S310.

  In S310, it is determined whether the required time T2 is less than a preset second determination time (for example, 3 seconds in the present embodiment). If the required time T2 is equal to or longer than the second determination time (S310: NO), the process proceeds to S340. On the other hand, if the required time T2 is less than the second determination time (S310: YES), it is determined in S320 whether or not a second preceding stimulus image (described later) is being displayed. If the second preceding stimulus image is being displayed (S320: YES), the process proceeds to S340. On the other hand, when the second preceding stimulus image is not being displayed (S320: NO), the display of the second preceding stimulus image is started by the meter 3 in S330, and the process proceeds to S340. Thereby, every time the second display cycle set in advance (for example, 1.5 seconds in the present embodiment) elapses, the meter 3 has a preset second display time (for example, 0.5 seconds in the present embodiment). The second preceding stimulus image is continuously displayed. The meter 3 changes the contrast of the second preceding stimulus image with respect to the background image within the second display time. Specifically, at the start of the second display time, the contrast is set to 0 (that is, the brightness of the background image is equal to the brightness of the second preceding stimulus image), and when half of the second display time has elapsed. The second preceding stimulus image is set to a preset second setting contrast (for example, 0.07 in this embodiment (that is, the luminance of the second preceding stimulus image is 0.07 times larger than the luminance of the background image)). Gradually increase the brightness. Thereafter, the meter 3 gradually decreases the luminance of the second preceding stimulus image so that the contrast becomes 0 again at the end of the second display time.

  Note that the second set contrast of the present embodiment is larger than the first set contrast. This is because the viewing angle of the driver to the display area (see FIG. 10C) of the second preceding stimulus image during driving is larger than the viewing angle to the display area of the first preceding stimulus image. Here, the horizontal direction of 0 degrees and the vertical direction of 0 degrees are both the front direction of the face.

  In S340, it is determined whether or not the preceding vehicle has passed the target intersection. Here, when the preceding vehicle has not passed the target intersection (S340: NO), the preceding vehicle display process is temporarily ended. On the other hand, if the host vehicle passes the target intersection (S340: YES), the display of the preceding vehicle warning image and the second preceding stimulus image is terminated on the meter 3 in S350, and the preceding vehicle display process is temporarily terminated. To do.

  As shown in FIG. 5 (a), the preceding vehicle warning image has a shape of the preceding vehicle recognized by the driver when the driver is looking at the preceding vehicle located in front of the driver of the vehicle. It consists of a simplified preceding vehicle image PI.

Further, as shown in FIG. 5B, the second preceding stimulus image is composed of a cover image CVI formed so as to cover the entire preceding vehicle image PI.
Next, a procedure of contrast adjustment processing executed by the control unit 10 will be described. The contrast adjustment process is a process that is repeatedly executed during the operation of the vehicle alert device 1.

  When this contrast adjustment process is executed, as shown in FIG. 6, the control unit 10 first receives an angle signal indicating the rotation angle of the dial knob (hereinafter referred to as the dial rotation angle) from the dial switch 9 in S410. get. In S420, the first setting is made in accordance with the dial rotation angle indicated by the angle signal by referring to the contrast setting map in which the correspondence relationship between the dial rotation angle and the first set contrast and the second set contrast is set in advance. Set values for contrast and second set contrast. In the contrast setting map, the first setting contrast and the second setting contrast are set to increase as the dial rotation angle increases.

When the process of S420 is completed, the contrast adjustment process is temporarily ended.
Next, operation | movement of the alerting device 1 for vehicles comprised in this way is demonstrated.
FIG. 7 is a timing chart showing the operation of the vehicle alert device 1 when the host vehicle is approaching the intersection.

  As shown in FIG. 7, first, when the own vehicle approaches the intersection and the distance to the intersection reaches 50 m, the display of the intersection warning image is started (see time t01). Thereafter, when the time required to reach the intersection is 3 seconds, the display of the first preceding stimulus image is started (see time t02). Thereby, every time the first display period (1.5 seconds in FIG. 7) elapses, the first preceding stimulus image is displayed continuously for the first display time (0.5 seconds in FIG. 7). Also, within the first display time, the contrast gradually increases from 0 to the first set contrast (0.05 in FIG. 7), and gradually decreases to 0 when the first set contrast is reached.

Then, when the host vehicle reaches the intersection, the display of the intersection warning image and the display of the first preceding stimulus image are completed (see time To).
Therefore, when the host vehicle is approaching the intersection and the distance to the intersection is long, the intersection warning image and the first preceding stimulus image are not displayed as shown in FIG. The driver visually recognizes the foreground object (the intersection and the preceding vehicle in FIG. 8) through the windshield WS. Then, when the distance to the intersection is less than 50 m, the intersection warning image IR is displayed on the windshield WS as shown in FIG. Furthermore, when the time required to reach the intersection is less than 3 seconds, as shown in FIG. 8C, the contrast with respect to the intersection warning image IR is between 0 and the first set contrast on the windshield WS. A changing first preceding stimulus image PS1 is displayed.

FIG. 9 is a timing chart showing the operation of the vehicle alert device 1 when the preceding vehicle of the host vehicle is approaching the intersection.
As shown in FIG. 9, first, when the preceding vehicle approaches the intersection and the distance to the intersection reaches 50 m, display of the preceding vehicle warning image is started (see time t11). After that, when the time required for the preceding vehicle to reach the intersection is 3 seconds, the display of the second preceding stimulus image is started (see time t12). Thereby, every time the second display period (1.5 seconds in FIG. 9) elapses, the second preceding stimulus image is displayed continuously for the second display time (0.5 seconds in FIG. 7). Further, within the second display time, the contrast gradually increases from 0 to the second set contrast (0.07 in FIG. 9), and gradually decreases to 0 when the second set contrast is reached.

Then, when the preceding vehicle reaches the intersection, the display of the preceding vehicle warning image and the display of the second preceding stimulus image are ended (see time To).
Therefore, when the preceding vehicle is approaching the intersection and the distance to the intersection is long, as shown in FIG. 10 (a), the display image MD of the meter 3 displays the preceding vehicle warning image and the second image. 2. No prior stimulus image is displayed. Then, when the distance to the intersection is less than 50 m, the preceding vehicle warning image CR is displayed on the display screen MD of the meter 3 as shown in FIG. Further, when the time required to reach the intersection is less than 3 seconds, the contrast with respect to the background image BG is between 0 and the second set contrast on the display screen MD of the meter 3 as shown in FIG. The second preceding stimulus image PS2 that changes at is displayed.

  In the vehicle alert system 1 configured as described above, first, current position information indicating the current position of the host vehicle is acquired by the GPS receiver 4. Further, based on the current position of the host vehicle detected by the GPS receiver 4 and the traveling speed V1 of the host vehicle detected by the vehicle speed sensor 6, the time T1 required until the host vehicle reaches the next intersection is calculated. Calculate (S30). After that, it is determined whether or not the required time T1 is less than a preset first determination time indicating that the environment needs to call attention to the driver of the host vehicle (S70). When it is determined that the required time T1 is less than the first determination time (S70: YES), the first preceding stimulus image set in advance to stimulate the driver's vision is slightly above the threshold. In such a manner, display is performed with the first set contrast set in advance (S90).

  Further, the current position of the host vehicle detected by the GPS receiver 4, the traveling speed V1 of the host vehicle detected by the vehicle speed sensor 6, the distance Lp between the preceding vehicle detected by the radar device 7, and the radar device Based on the detected relative speed Vp with the preceding vehicle, a required time T2 until the preceding vehicle reaches the next intersection is calculated (S270). Thereafter, it is determined whether or not the required time T2 is less than a preset second determination time indicating that the environment needs to call attention to the driver of the host vehicle (S310). When it is determined that the required time T1 is less than the second determination time (S310: YES), the second preceding stimulus image set in advance to stimulate the driver's vision is slightly above the threshold. In such a manner, the image is displayed with the preset second setting contrast (S330).

  As described above, the vehicle alert device 1 has the first preceding stimulus image and the stimulus image for stimulating the driver's vision when the current position of the host vehicle is an environment that needs to alert the driver. A second preceding stimulus image is displayed. The first preceding stimulus image and the second preceding stimulus image are displayed with a contrast slightly above the threshold. For this reason, the first preceding stimulus image and the second preceding stimulus image are less susceptible to visual stimuli caused by the driving environment around the host vehicle, and are perceived by the driver than images displayed within the subthreshold perception range. It becomes easy to be done. Thereby, generation | occurrence | production of the situation where the alerting to a driver is not perceived by the driver can be suppressed. In addition, since the first and second preceding stimulus images are displayed with a contrast slightly above the threshold, the display of the first and second preceding stimulus images causes the driver to feel annoyance. Can be suppressed.

  In addition, the first preceding stimulus image is displayed so as to come into contact with the intersection warning image that is already displayed before the first preceding stimulus image is displayed. Similarly, the second preceding stimulus image is displayed so as to come into contact with the preceding vehicle warning image that is already displayed before the second preceding stimulus image is displayed.

  Thus, since the first preceding stimulus image is in contact with the intersection warning image, the contrast of the first preceding stimulus image needs to be set for the intersection warning image. Similarly, since the second preceding stimulus image is in contact with the preceding vehicle alert image, the contrast of the second preceding stimulus image needs to be set for the preceding vehicle alert image.

  And the brightness | luminance of the already displayed intersection warning image and preceding vehicle warning image is known. Therefore, the brightness of the first preceding stimulus image and the second preceding stimulus image required to make the contrast with respect to the intersection warning image and the preceding vehicle warning image be the first set contrast and the second set contrast respectively. Can be set to

  In addition, even when the driver blinks (about 150 milliseconds) and when the driver moves his / her line of sight to check left and right (about 300 milliseconds), the driver The first preceding stimulus image and the second preceding stimulus image are displayed in a first display time and a second display time (in this embodiment, for example, 0.5 seconds) set in advance so that the second preceding stimulus image can be perceived. Thereby, generation | occurrence | production of the situation where the alerting to a driver is not perceived by the driver can be suppressed.

  Further, the first set contrast and the second set contrast are adjusted according to the rotation angle of the dial knob operated by the driver (S420). Accordingly, it is possible to set appropriate first set contrast and second set contrast for each driver in response to the difference in contrast perception ability among drivers.

  In the embodiment described above, the GPS receiver 4 is the position information acquisition means in the present invention, the processes in S30 and S270 are the environment information acquisition means in the present invention, and the processes in S70 and S310 are the display determination means in the present invention, S90 and S330. The process is the stimulus image display means in the present invention, and the process in S420 is the contrast adjustment means in the present invention.

As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, As long as it belongs to the technical scope of this invention, a various form can be taken.
For example, in the above embodiment, the contrast is set according to the luminance. However, when the preceding stimulus image is a color image, the R value, the G value, and the B value are set as the luminance values of the R value, the G value, and the B value, respectively. You may make it set contrast about each of these.

In the above embodiment, the preceding stimulus image is displayed near the intersection, but the preceding stimulus image may be displayed when the oncoming lane is congested.
Next, the procedure of the traffic jam display process executed by the control unit 10 to display the preceding stimulus image when the oncoming lane is jammed will be described. The traffic jam display process is a process that is repeatedly executed during operation of the vehicle alert device 1.

  When this traffic jam display process is executed, the control unit 10 first acquires map data around the current position of the host vehicle from the map database 5 in S510, as shown in FIG. In S520, it is determined whether there is an oncoming lane on the road on which the host vehicle is traveling based on the acquired map data. Here, when there is no oncoming lane (S520: NO), the traffic jam display process is temporarily ended.

  On the other hand, if there is an oncoming lane (S520: YES), an oncoming lane warning image (described later) for alerting the driver that there is an oncoming lane is displayed on the meter 3 at S530. In S540, traffic jam information is acquired via the road-to-vehicle communication device 8.

  Thereafter, in S550, based on the acquired traffic jam information, it is determined whether or not the opposite lane of the lane in which the host vehicle is traveling is jammed. Here, when the oncoming lane is not congested (S550: NO), the traffic jam display process is temporarily terminated. On the other hand, when the oncoming lane is congested (S550: YES), a third preceding stimulus image (described later) is displayed on the meter 3 at S560, and the traffic jam display process is temporarily terminated.

  As shown in FIG. 12A, the oncoming lane warning image includes a road surface image RSI showing the road surface, a driving lane image LI1 showing the driving lane of the host vehicle, and an oncoming lane image LI2 showing the oncoming lane. The center line image CLI shows a center line between the traveling lane and the opposite lane of the host vehicle. Further, the oncoming lane warning image is formed by arranging the traveling lane image LI1, the oncoming lane image LI2, and the centerline image CLI on the road surface image RSI. In the present embodiment, the maximum luminance is 255, the minimum luminance is 0, the luminance of the road surface image RSI is set to 60, and the luminance of the traveling lane image LI1, the oncoming lane image LI2, and the centerline image CLI is set to 255. .

  Further, as shown in FIG. 12B, the third preceding stimulus image is formed in a rectangular shape, on the background image AI1 disposed on a part of the road surface image RSI and on a part of the oncoming lane image LI2. It is comprised from the on-lane image AI2 arrange | positioned. In the present embodiment, the brightness of the on-background image AI1 is set to 63, and the brightness of the on-lane image AI2 is set to 242. That is, the background image AI1 is set to have a higher brightness than the road surface image RSI by a preset third set contrast (0.05 in the present embodiment). The on-lane image AI2 is set to have a lower luminance than the oncoming lane image LI2 by a preset third set contrast (0.05 in the present embodiment).

  Accordingly, as shown in FIG. 13A, when the opposite lane exists in the lane in which the host vehicle is traveling, the opposite lane warning image LR is displayed on the display screen MD of the meter 3. Further, as shown in FIG. 13B, when the oncoming lane is congested, the third preceding stimulus image PS3 is displayed on the display screen MD of the meter 3.

  In the vehicle alert system 1 configured as described above, first, current position information indicating the current position of the host vehicle is acquired by the GPS receiver 4. Further, based on the current position of the host vehicle detected by the GPS receiver 4, map data around the current position of the host vehicle is acquired, and traffic jam information is acquired through the road-to-vehicle communication device 8 (S510, S540). ). Thereafter, it is determined whether the oncoming lane is congested (S520, S550). When it is determined that the oncoming lane is congested (S520: YES, S550: YES), the third preceding stimulus image set in advance for stimulating the driver's vision is slightly above the threshold. In such a manner, display is performed at a preset third setting contrast (S560).

  As a result, the vehicle alert device 1 can suppress the occurrence of a situation in which the alert to the driver is not perceived by the driver, and can cause the driver to feel annoyed by displaying the third preceding stimulus image. Occurrence can be suppressed.

  Further, the third preceding stimulus image PS3 is displayed so as to come into contact with both the road surface image RSI and the oncoming lane image LI2. That is, the background image AI1 is shown in contact with the road surface image RSI, and the lane image AI2 is shown in contact with the oncoming lane image LI2. Therefore, the third set contrast is set for the road surface image RSI and the oncoming lane image LI2 so that the luminance of the background image AI1 and the on-lane image AI2 approaches the average value of the luminance of the road surface image RSI and the oncoming lane image LI2. The third preceding stimulus image PS3 is displayed.

  This suppresses an increase in contrast between the plurality of images constituting the third preceding stimulus image PS3, and suppresses the occurrence of a situation in which the driver feels bothered by the display of the third preceding stimulus image PS3. be able to.

  In this case, the processing of S510 and S540 is the environment information acquisition means in the present invention, the processing of S520 and S550 is the display determination means in the present invention, and the processing of S560 is the stimulus image display means in the present invention.

  Moreover, in the said embodiment, what showed a 1st prior stimulus image (2nd prior stimulus image) continuously within 1st display time (2nd display time) was shown. However, the contrast of the first preceding stimulus image (second preceding stimulus image) may be periodically changed at a frequency that can be perceived by the driver within the first display time (second display time). . For example, as shown in FIG. 14, display and non-display of the first preceding stimulus image may be switched at 14 Hz within the first display time.

  As described above, by periodically changing the first set contrast at a frequency that can be perceived by the driver, the driver can easily perceive the first preceding stimulus image. For this reason, even if it is a case where the driver | operator's fatigue and the capability to perceive contrast fall, it can suppress generation | occurrence | production of the situation where the alerting to a driver is not perceived by the driver.

  DESCRIPTION OF SYMBOLS 1 ... Vehicle alerting device, 2 ... HUD device, 3 ... Meter, 4 ... GPS receiver, 6 ... Vehicle speed sensor, 7 ... Radar device, 8 ... Road-to-vehicle communication device, 10 ... Control part

Claims (6)

Position information acquisition means (4) for acquiring current position information indicating the current position of the host vehicle;
Environmental information acquisition means (S30, S270, S510, S540) for acquiring driving environment information indicating the driving environment at the current position based on the current position information acquired by the position information acquisition means;
Based on the travel environment information acquired by the environment information acquisition means, is a display determination condition set in advance indicating that the environment needs to alert the driver of the host vehicle? Display judgment means (S70, S310, S520, S550) for judging whether or not,
When the display determination unit determines that the display determination condition is satisfied, a visual stimulus image that is a preset image for stimulating the driver's vision is set in advance so as to be slightly above the threshold. And a stimulus image display means (S90, S330, S560) for displaying at a set contrast which is the contrast of the vehicle. The stimulus image display means includes
2. The vehicle alert device according to claim 1, wherein the visual stimulus image is displayed so as to come into contact with an already displayed image that is an image that has already been displayed before the visual stimulus image is displayed. The stimulus image display means includes
When the visual stimulus image is displayed so as to be in contact with the plurality of already displayed images, the luminance of the visual stimulus image approaches the average value of the plurality of already displayed images, The vehicle alert system according to claim 2, wherein the visual stimulus image is displayed at the set contrast with respect to each of the already displayed images. The stimulus image display means includes
4. The vehicle alert device according to claim 1, wherein the set contrast is periodically changed at a frequency that can be perceived by the driver. 5. The stimulus image display means includes
5. The visual stimulus image is displayed for a display time set in advance so that the driver can perceive the display. 5. Vehicle alert device. The vehicle according to any one of claims 1 to 5, further comprising contrast adjustment means (S420) for adjusting the set contrast in accordance with an operation of an operation unit operated by the driver. Warning device for use.