Subsequent vehicle approaching notification device

Abstract

To suppress an unnecessary notification to a driver.SOLUTION: A subsequent vehicle approaching notification device comprises: a detection device (18) capable of detecting an approach of a subsequent vehicle (2) to the own vehicle (1); and a notification device (22) that notifies a driver of the own vehicle (1) of the approach of the subsequent vehicle (2) to the own vehicle (1). When the approach of the subsequent vehicle (2) to the own vehicle (1) is detected, the driver of the own vehicle (1) is notified of the approach of the subsequent vehicle (2) to the own vehicle (1) if a turn signal of the subsequent vehicle (2) is not operating, and notification to the driver of the own vehicle (1) of the approach of the subsequent vehicle (2) to the own vehicle (1) is discontinued if the turn signal of the subsequent vehicle (2) is operating.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a following-vehicle approach notification device.

Background Art

[0002] In a vehicle configured to warn a following vehicle when the following vehicle approaches the host vehicle and there is a risk of the following vehicle colliding with the host vehicle, when there is a risk of the following vehicle colliding with the host vehicle and it is determined that the following vehicle is in the overtaking operation of the host vehicle, there is a known warning device that cancels the warning to the following vehicle (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] On the other hand, when a following vehicle approaches the host vehicle from behind, there is no immediate risk of collision, but there is a possibility of aggressive driving. Therefore, in this case, it can be said that it is preferable to alert the driver of the host vehicle that a following vehicle is approaching. Also in this case, when the following vehicle changes lanes when approaching the host vehicle, it can be said that it is preferable to cancel the alert to the following vehicle. However, in practice, it is difficult to accurately determine whether the following vehicle has changed lanes, and there is a problem that even if the following vehicle has changed lanes, the driver of the host vehicle will be alerted.

Means for Solving the Problems

[0005] In order to solve such problems, according to the present invention, there is provided a detection device capable of detecting the approach of a following vehicle that travels following the host vehicle behind the host vehicle, a notification device that notifies the driver of the host vehicle of the approach of the following vehicle to the host vehicle, and a processor. When the processor detects that the approach of a following vehicle that travels following the host vehicle behind the host vehicle is detected by the detection device, the processor acquires the operation information of the direction indicator of the following vehicle. When the direction indicator of the following vehicle is not operating, the notification device notifies the driver of the host vehicle of the approach of the following vehicle to the host vehicle. When the direction indicator of the following vehicle is operating, there is provided a following vehicle approach notification device that cancels the notification by the notification device to notify the driver of the host vehicle of the approach of the following vehicle to the host vehicle.

Advantages of the Invention

[0006] It is possible to suppress unnecessary notifications to the driver.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0008] First, the terms used in the present invention will be described. In the present invention, the vehicle that is the control target according to the present invention is referred to as the "host vehicle", and the vehicle that travels following the host vehicle behind the host vehicle is referred to as the "following vehicle". FIG. 1 schematically shows the host vehicle 1 as viewed from above, and FIG. 2 shows the functional configuration of the host vehicle 1 shown in FIG. 1. Note that this host vehicle 1 is capable of both manual driving and autonomous driving. Referring to FIG. 2, reference numeral 10 denotes a vehicle drive unit for applying a driving force to the drive wheels of the vehicle 1, 11 denotes a braking device for braking the vehicle 1, 12 denotes a steering device for steering the vehicle 1, and 13 denotes an electronic control unit mounted in the vehicle 1, respectively. As shown in FIG. 2, the electronic control unit 13 comprises a digital computer, and includes a CPU (processor) 15, a memory 16 composed of a ROM and a RAM, and an input / output port 17 which are interconnected by a bidirectional bus 14.

[0009] On the other hand, as shown in FIG. 2, a detection device 18 including various sensors necessary for the host vehicle 1 to perform autonomous driving is installed in the host vehicle 1. This detection device 18 includes sensors for detecting the state of the host vehicle 1 and sensors for detecting the surroundings of the host vehicle 1. In this case, as sensors for detecting the state of the host vehicle 1, an acceleration sensor, a speed sensor, an azimuth sensor, and a geomagnetic sensor are used, and as sensors for detecting the surroundings of the host vehicle 1, cameras for photographing the front, sides, and rear of the host vehicle 1, and lidars (LIDARs), radars, clearance sonars, etc. for detecting the front, sides, and rear of the host vehicle 1 are used.

[0010] FIG. 1 shows an example of the sensors installed in the host vehicle 1. In the example shown in FIG. 1, the host vehicle 1 is provided with front cameras 3a and 3b for photographing the front of the host vehicle 1, a rear camera 4 for photographing the rear of the host vehicle 1, a long-range millimeter-wave radar 5 for emitting millimeter waves toward the front of the host vehicle 1, mid-range millimeter-wave radars 6a and 6b for emitting millimeter waves toward the sides of the host vehicle 1, long-range millimeter-wave radars 7a and 7b for emitting millimeter waves toward the rear of the host vehicle 1, lidars 8a, 8b, 8c, and 8d for irradiating laser light toward the sides of the host vehicle 1, and a clearance sonar 9 for emitting ultrasonic waves toward the rear of the host vehicle 1. Note that the installation methods of the cameras and sensors shown in FIG. 1 are merely examples, and there are various methods for the installation methods of these cameras and sensors.

[0011] Returning again to FIG. 2, the host vehicle 1 is provided with a GNSS (Global Navigation Satellite System) receiver 19, a map data storage device 20, a navigation device 21, and a notification device 22 that notifies the driver of the surrounding situation. The GNSS receiver 19 can detect the current position of the host vehicle 1 (for example, the latitude and longitude of the host vehicle 1) based on information obtained from a plurality of artificial satellites. Therefore, the current position of the host vehicle 1 can be acquired by this GNSS receiver 19. As this GNSS receiver 19, for example, a GPS receiver is used. Further, the map data storage device 20 stores map data and the like necessary for the travel of the host vehicle 1. This map data also includes information on roads. These various sensors 18, GNSS receiver 19, map data storage device 20, navigation device 21, and notification device 22 are connected to the electronic control unit 13. Further, the vehicle 1 is equipped with a communication device 23 connected to the electronic control unit 13.

[0012] In the example shown in FIG. 2, the host vehicle 1 can be manually driven, and when there is a request for travel control by automatic driving for the host vehicle 1, it is possible to cause the host vehicle 1 to perform travel control by automatic driving. In the example shown in FIG. 2, the vehicle drive unit 10 of the host vehicle 1 is composed of an electric motor driven by a secondary battery or an electric motor driven by a fuel cell, and the drive wheels are driven and controlled by these electric motors according to the output signal of the electronic control unit 13. Further, in the example shown in FIG. 2, when there is a request for travel control by automatic driving for the vehicle 1, the braking control of the vehicle 1 is performed by the braking device 11 according to the output signal of the electronic control unit 13, and the steering control of the vehicle 1 is also performed by the steering device 12 according to the output signal of the electronic control unit 13.

[0013] Figure 3 shows road 30 as viewed from above. In Figure 3, 31 is a white line, 32 is a passing lane, and 33 is a driving lane. Figure 3 shows the host vehicle 1 traveling in driving lane 33 and a following vehicle 2 traveling in driving lane 33 following the host vehicle 1. Also, Figure 3 shows a case where the following vehicle 2 approaches the host vehicle 1 while the host vehicle 1 is traveling in driving lane 33. In this case, although there is no immediate risk of the following vehicle 2 colliding with the host vehicle 1, there is a possibility of provoking driving by the following vehicle 2. Therefore, in this case, it can be said that it is preferable to alert the driver of the host vehicle 1 that the following vehicle 2 is approaching the host vehicle 1 from behind.

[0014] Therefore, in the embodiment according to the present invention, when the following vehicle 2 approaches the host vehicle 1 from a distant position to the position shown in Figure 3, the driver of the host vehicle 1 is alerted that the following vehicle 2 is approaching the host vehicle 1. In this case, this alert is made by the notification device 22 in the form of text display or voice. When the approach of the following vehicle 2 is notified by text display, for example, a display such as "A following vehicle is approaching" is made on the display screen of the meter installed on the dashboard inside the vehicle cabin. In this case, using head-up display technology, text such as "A following vehicle is approaching" can also be projected onto the front windshield. Also, when the approach of the following vehicle 2 is notified by voice, a voice such as "A following vehicle is approaching" is generated from a speaker installed on the dashboard inside the vehicle cabin. Thus, in the embodiment according to the present invention, the approach of the following vehicle 2 to the host vehicle 1 is notified by at least one of text display and voice.

[0015] On the other hand, when the following vehicle 2 changes lanes from the driving lane 33 to the passing lane 32, there is no need for a warning. At this time, if a warning is given, it can be said that it is very troublesome for the driver of the host vehicle 1. Therefore, when the following vehicle 2 changes lanes, it is desirable to cancel the warning. However, when the following vehicle 2 changes lanes, the following vehicle 2 often changes lanes after getting closer to the host vehicle 1 than the position shown in FIG. 3. However, when the following vehicle 2 gets closer to the host vehicle 1 than the position shown in FIG. 3 in this way, a warning will be given. Therefore, in practice, it is quite difficult to cancel the warning when the following vehicle 2 changes lanes.

[0016] On the other hand, when changing lanes, usually the direction indicator is activated. FIG. 4 schematically shows an example of the direction indicator in the host vehicle 1. In the example shown in FIG. 4, the direction indicator includes a pair of front turn lamps 40a and 40b arranged on the front surface of the host vehicle 1, a pair of rear turn lamps 41a and 41b arranged on the rear surface of the host vehicle 1, and a pair of door mirror turn lamps 42a and 42b arranged on the door mirrors of the host vehicle 1. Note that FIG. 4 shows a state where the front turn lamp 40a, the rear turn lamp 41a, and the door mirror turn lamp 42a are periodically lit.

[0017] Incidentally, when changing lanes, it is usually common to activate the turn signal well before changing lanes. On the other hand, it is easy to determine whether the turn signal is activated or not. For example, the rear camera 4 can detect whether the turn signal of the following vehicle 2 is lit, and thus, based on the captured image data by the rear camera 4, it is possible to determine whether the turn signal of the following vehicle 2 is activated. Also, in the embodiments according to the present invention, vehicle-to-vehicle communication is possible between the following vehicle 2 and the communication device 23. Therefore, it is also possible to obtain the operation information of the turn signal of the following vehicle 2 by this vehicle-to-vehicle communication and determine whether the turn signal of the following vehicle 2 is activated based on the obtained operation information. Thus, in the embodiments according to the present invention, when the following vehicle 2 approaches the host vehicle 1, it is determined whether the turn signal of the following vehicle 2 is activated, and when the turn signal of the following vehicle 2 is activated, the attention call is stopped.

[0018] In addition, in order to achieve the present invention, in the embodiments according to the present invention, as shown in FIG. 2, a detection device 18 capable of detecting the approach of the following vehicle 2 to the host vehicle 1 and a notification device 22 for notifying the driver of the host vehicle 1 of the approach of the following vehicle 2 to the host vehicle 1 are provided. In this case, in the detection device 18, for example, the detection outputs of the long-distance millimeter-wave radars 7a and 7b are used to detect the approach of the following vehicle 2 to the host vehicle 1. In this case, for example, the presence of the following vehicle 2 is confirmed based on the detection outputs of the long-distance millimeter-wave radars 7a and 7b, and the distance D between the host vehicle 1 and the following vehicle 2 and the relative speed ΔV between the host vehicle 1 and the following vehicle 2 are calculated based on the detection outputs of the long-distance millimeter-wave radars 7a and 7b.

[0019] On the one hand, in an embodiment according to the present invention, the time to collision TTC until the following vehicle 2 collides with the host vehicle 1 is calculated by dividing the distance D between the host vehicle 1 and the following vehicle 2 by the relative speed ΔV, and this calculated time to collision TTC is used as a trigger when starting the following vehicle approach notification. The threshold value X of this time to collision TTC is, for example, set to 9 seconds. When the time to collision TTC becomes equal to or less than the threshold value X, for example, when it becomes 9 seconds or less, the following vehicle approach notification, that is, the notification of the approach of the following vehicle 2 is started. In addition, if the turn signal is activated before the time to collision TTC becomes equal to or less than the threshold value X, the following vehicle approach notification, that is, the notification of the approach of the following vehicle 2 can be cancelled. Also, in this case, if the turn signal is activated before the inter-vehicle distance D becomes less than a preset distance, it is also possible to cancel the following vehicle approach notification, that is, the notification of the approach of the following vehicle 2.

[0020] FIG. 5 shows a routine for executing a following vehicle approach notification process for notifying the driver of the host vehicle 1 that the following vehicle 2 has approached the host vehicle 1. This routine is repeatedly executed in the electronic control unit 13 of the host vehicle 1.

[0021] Referring to FIG. 5, first, in step 50, based on the detection outputs of the long-distance millimeter-wave radars 7a and 7b, it is determined whether a following vehicle 2 that travels following the host vehicle 1 is detected behind the host vehicle 1. When the following vehicle 2 is not detected, the processing cycle ends. On the other hand, when the following vehicle 2 is detected, the process proceeds to step 51, and the distance D between the host vehicle 1 and the following vehicle 2 is calculated based on the detection outputs of the long-distance millimeter-wave radars 7a and 7b. Next, in step 52, it is determined whether the distance D between the host vehicle 1 and the following vehicle 2 is shorter than a preset limit distance Dr. When it is determined that the distance D exceeds the limit distance Dr, the processing cycle ends. This limit distance Dr indicates the longest distance at which the presence of the following vehicle 2 traveling following the host vehicle 1 behind the host vehicle 1 can be accurately recognized by the long-distance millimeter-wave radars 7a and 7b and the distance D between the host vehicle 1 and the following vehicle 2 can be accurately calculated. In an embodiment according to the present invention, this limit distance Dr is set to 80 m.

[0022] On the other hand, in step 52, when it is determined that the distance D between the host vehicle 1 and the following vehicle 2 is shorter than the limit distance Dr, the process proceeds to step 53, and based on the temporal change of the distance D between the host vehicle 1 and the following vehicle 2, the relative speed ΔV between the host vehicle 1 and the following vehicle 2 is calculated. Next, in step 54, the operation information of the direction indicator of the following vehicle 2 is acquired. In this case, in one embodiment according to the present invention, the operation information of the direction indicator of the following vehicle 2 is acquired from the captured image data by the rear camera 4. In another embodiment according to the present invention, the operation information of the direction indicator of the following vehicle 2 is acquired by vehicle-to-vehicle communication between the host vehicle 1 and the following vehicle 2.

[0023] Next, in step 55, based on the operation information of the direction indicator of the following vehicle 2 obtained in step 54, it is determined whether the direction indicator of the following vehicle 2 is operating. When it is determined that the direction indicator of the following vehicle 2 is operating, the processing cycle ends. On the other hand, when it is determined that the direction indicator of the following vehicle 2 is not operating, the process proceeds to step 56, and the time to collision TTC until the following vehicle 2 collides with the host vehicle 1 is calculated by dividing the distance D between the host vehicle 1 and the following vehicle 2 by the relative speed ΔV. Next, in step 57, It is determined whether this time to collision TTC is less than or equal to the threshold value X. When it is determined that this time to collision TTC is longer than the threshold value X, for example, 9 seconds, the processing cycle ends.

[0024] In contrast, in step 57, when it is determined that the time to collision TTC is less than or equal to the threshold value X, the process proceeds to step 58, and a process of starting a following vehicle approach notification, that is, a notification of the approach of the rear vehicle 2, is performed. The notification of the approach of the rear vehicle 2 to the host vehicle 1 is continuously performed while the time to collision TTC is less than or equal to the threshold value X. Thus, in the embodiment according to the present invention, when the direction indicator of the rear vehicle 2 is actuated before the time to collision TTC becomes less than or equal to the threshold value X, the following vehicle approach notification, that is, the notification of the approach of the rear vehicle 2, is stopped from being performed. As can be seen from the flowchart shown in FIG. 5, even after the time to collision TTC becomes less than or equal to the threshold value X, when the direction indicator of the rear vehicle 2 is actuated, the following vehicle approach notification, that is, the notification of the approach of the rear vehicle 2, is immediately stopped from being performed.

[0025] As described above, the following-vehicle approach notification device according to the present invention includes a detection device 18 capable of detecting the approach of a following vehicle 2 that travels following the host vehicle 1 behind the host vehicle 1, a notification device 22 that notifies the driver of the host vehicle 1 of the approach of the following vehicle 2 to the host vehicle 1, and a processor 15. In the present invention, when the approach of the following vehicle 2 that travels following the host vehicle 1 behind the host vehicle 1 is detected by the detection device 18, the processor 15 acquires the operation information of the direction indicator of the following vehicle 2. At this time, when the direction indicator of the following vehicle 2 is not operating, the notification device 22 notifies the driver of the host vehicle 1 of the approach of the following vehicle 2 to the host vehicle 1, and when the direction indicator of the following vehicle 2 is operating, the notification device 22 is stopped from notifying the driver of the host vehicle 1 of the approach of the following vehicle 2 to the host vehicle 1.

[0026] In this case, in one embodiment according to the present invention, the detection device 18 is capable of detecting the lighting of the direction indicator of the following vehicle 2, and when the lighting of the direction indicator of the following vehicle 2 is detected by the detection device 18, it is determined that the direction indicator of the following vehicle 2 is operating. Further, in another embodiment according to the present invention, a communication device 23 that performs vehicle-to-vehicle communication between the host vehicle 1 and the following vehicle 2 is provided, and the operation information of the direction indicator of the following vehicle 2 is acquired by this vehicle-to-vehicle communication.

[0027] Also, in the embodiment according to the present invention, when the approach of the following vehicle 2 that travels following the host vehicle 1 behind the host vehicle 1 is detected by the detection device 18, the inter-vehicle distance D between the host vehicle 1 and the following vehicle 2 is calculated based on the detection result of the detection device 18, and when the inter-vehicle distance D becomes equal to or less than a preset distance Dr, the operation information of the direction indicator of the following vehicle 2 is acquired.

[0028] In addition, in the embodiment according to the present invention, the time to collision TTC until the following vehicle 2 collides with the host vehicle 1 is calculated based on the detection result of the detection device 18. When the turn signal of the following vehicle 2 is not operating, when the calculated time to collision TTC becomes equal to or less than a preset time X, the approach of the following vehicle 2 to the host vehicle 1 is notified to the driver of the host vehicle 1 by the notification device 18. When the turn signal of the following vehicle 2 is operating, the notification by the notification device 18 to notify the driver of the host vehicle 1 of the approach of the following vehicle 2 to the host vehicle 1 is cancelled.

Description of Signs

[0029] 1 Host vehicle 2 Following vehicle 15 Processor 18 Detection device 23 Notification device

Claims

1. A following-vehicle approach notification device including a detection device capable of detecting the approach of a following vehicle that travels following the host vehicle behind the host vehicle, a notification device that notifies the driver of the host vehicle of the approach of a following vehicle to the host vehicle, and a processor, wherein when the processor detects the approach of a following vehicle that travels following the host vehicle behind the host vehicle by the detection device, the processor acquires the operation information of the turn signal of the following vehicle, when the turn signal of the following vehicle is not operating, the notification device notifies the driver of the host vehicle of the approach of the following vehicle to the host vehicle, and when the turn signal of the following vehicle is operating, the following-vehicle approach notification device stops the notification device from notifying the driver of the host vehicle of the approach of the following vehicle to the host vehicle.

2. The detection device is capable of detecting the lighting of the turn signal of the following vehicle, and when the processor detects the lighting of the turn signal of the following vehicle by the detection device, the processor determines that the turn signal of the following vehicle is operating. The following-vehicle approach notification device according to claim 1.

3. The following-vehicle approach notification device according to claim 1, further including a communication device that performs vehicle-to-vehicle communication between the host vehicle and the following vehicle, wherein the processor acquires the operation information of the turn signal of the following vehicle by the vehicle-to-vehicle communication.

4. When the processor detects the approach of a following vehicle that travels following the host vehicle behind the host vehicle by the detection device, the processor calculates the inter-vehicle distance between the host vehicle and the following vehicle based on the detection result of the detection device, and when the inter-vehicle distance becomes equal to or less than a preset distance, the processor acquires the operation information of the turn signal of the following vehicle. The following-vehicle approach notification device according to claim 1.

5. The processor calculates the time until the following vehicle collides with the host vehicle based on the detection result of the detection device. When the turn signal of the following vehicle is not operating, when the calculated time until collision becomes equal to or less than a preset time, the notification device notifies the driver of the host vehicle of the approach of the following vehicle to the host vehicle. When the turn signal of the following vehicle is operating, the notification device stops notifying the driver of the host vehicle of the approach of the following vehicle to the host vehicle. The following-vehicle approach notification device according to claim 1.

6. The following-vehicle approach notification device according to claim 1, wherein the notification of the approach of the following vehicle to the host vehicle is performed by at least one of text display and voice.

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