Notification sound output control device and notification sound output control program

Abstract

To properly output a notification sound for notifying a moving body such as a pedestrian of approach of a vehicle.SOLUTION: A notification sound output control device 1 outputs a notification sound for notifying a moving body of the approach of a vehicle from a notification sound output part. The notification sound emission control device includes a surrounding circumstance specifying part 2a for specifying a surrounding circumstance of the moving body, and an emission mode control part 2d for controlling an emission mode of the notification sound from the notification sound emission part according to the surrounding circumstance of the moving body specified by the surrounding circumstance specifying part.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a notification sound output control device and a notification sound output control program. [Background technology]

[0002] For example, vehicles such as hybrid electric vehicles (HVs) and electric vehicles (EVs) are required to constantly output sound within a specified speed range. A technology has been proposed that generates noise when a vehicle enters a noise generation zone, such as a crosswalk, to alert pedestrians of the vehicle's approach. However, this technology has the drawback of generating a uniform noise when the vehicle enters the noise generation zone, which can be disruptive to the surrounding environment if the vehicle is traveling in a residential area or late at night or early in the morning. Furthermore, since the noise is not directional, the sound leaks into the vehicle cabin with little distance attenuation, causing stress for the driver and passengers. Regarding this issue, for example, Patent Document 1 discloses a technology that searches for pedestrians around the vehicle and changes the directionality of the warning sound depending on the number of pedestrians detected. That is, if one pedestrian is detected, the warning sound is output from a super-directional speaker directed toward that one pedestrian, and if multiple pedestrians are detected, the warning sound is output from a semi-directional speaker directed toward the multiple pedestrians. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7019253 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the technology disclosed in Patent Document 1 is a method of selecting a speaker that will output a warning sound from among multiple speakers with different directivities based on the number of pedestrians, and does not take into consideration the surrounding environment of the pedestrians.

[0005] The present invention has been made in consideration of the above-mentioned circumstances, and its purpose is to provide an alarm sound output control device and an alarm sound output control program that can appropriately output an alarm sound to notify moving objects such as pedestrians of the approach of a vehicle. [Means for solving the problem]

[0006] The notification sound output control device (1) described in claim 1 causes a notification sound output unit to output a notification sound to notify a moving object of an approaching vehicle. The notification sound output control device includes a surrounding environment identification unit (2a) that identifies the surrounding environment of the moving object, and an output mode control unit (2d) that controls the output mode of the notification sound from the notification sound output unit in accordance with the surrounding environment of the moving object identified by the surrounding environment identification unit.

[0007] The output mode of the warning sound to notify a moving object, such as a pedestrian, of the approach of a vehicle is controlled in accordance with the surrounding environment of the moving object. By controlling the output mode of the warning sound in consideration of the surrounding environment of the moving object, the warning sound can be output appropriately. [Brief explanation of the drawings]

[0008] [Figure 1] Functional block diagram showing the overall configuration of one embodiment [Figure 2] FIG. 1 shows an embodiment in which a camera and a speaker are mounted. [Figure 3] Flowchart showing first control processing [Figure 4] Diagram showing the relative positions of pedestrians and guardrails [Figure 5] A diagram showing the relative positions of pedestrians and crosswalks [Figure 6] Flowchart showing second control processing [Figure 7]A diagram showing the degree of congestion of surrounding vehicles [Figure 8] Flowchart showing third control processing [Figure 9] A diagram showing a vehicle turning right at a T-junction [Figure 10] FIG. 10 is a diagram showing a manner in which a pedestrian in the right-turning direction of a vehicle is identified; [Figure 11] A diagram showing a vehicle turning left and entering a facility on the side of the road. [Figure 12] FIG. 10 is a diagram showing a manner in which a pedestrian in the left-turn direction of a vehicle is identified; [Figure 13] Flowchart showing fourth control processing [Figure 14] A diagram showing the width of the road on which the vehicle is traveling DETAILED DESCRIPTION OF THE INVENTION

[0009] An embodiment will be described below with reference to the drawings. The notification sound output control device 1 shown in FIG. 1 is mounted on a vehicle such as a hybrid vehicle or an electric vehicle. The notification sound output control device 1 outputs a notification sound around the vehicle to notify, for example, pedestrians, bicycle drivers, motorcycle drivers, and other people around the vehicle, of an approaching vehicle. Pedestrians, bicycle drivers, motorcycle drivers, and other people who are to be notified of the approaching vehicle correspond to moving objects. Hereinafter, the target to which the notification sound is output will be described as a pedestrian; however, the target to which the notification sound is output also includes bicycle drivers, motorcycle drivers, and other people.

[0010] The alert sound output control device 1 may be provided as a dedicated electronic control device (ECU (Electronic Control Unit)), or may be incorporated into an integrated ECU that integrates multiple functions together with other functions. The alert sound output control device 1 is connected to an in-vehicle network such as a CAN (Controller Area Network) (registered trademark), and as will be described later, is capable of detecting, for example, the steering angle and the operating state of the turn signals, and referencing map data implemented in the navigation ECU. The alert sound output control device 1 also turns its power on and off in conjunction with, for example, the power on and off of an accessory.

[0011] The alert sound output control device 1 has a control unit 2. The control unit 2 is mainly configured with a microcomputer having a CPU, ROM, RAM, I / O, etc., and controls the operation of the alert sound output control device 1 by executing software processing by having the CPU execute a computer program stored in a non-transient physical storage medium, and hardware processing by a dedicated electronic circuit.

[0012] A vehicle is equipped with multiple cameras and multiple speakers. Specifically, as shown in FIG. 2, vehicle A is equipped with a front camera 3 that captures images in front of the vehicle, a rear camera 4 that captures images behind the vehicle, a right camera 5 that captures images on the right side of the vehicle, and a left camera 6 that captures images on the left side of the vehicle. The front camera 3 is located, for example, near the rearview mirror inside the vehicle A and periodically outputs camera images capturing the field of view in front of the vehicle. The rear camera 4 is located, for example, near the rear bumper of vehicle A and periodically outputs camera images capturing the field of view behind the vehicle. The right camera 5 is located, for example, near the right door mirror 7 of vehicle A and periodically outputs camera images capturing the field of view on the right side of the vehicle. The left camera 6 is located, for example, near the left door mirror 8 of vehicle A and periodically outputs camera images capturing the field of view on the left side of the vehicle. The angles of view of the cameras 3 to 6 are set to capture a 360-degree view around vehicle A by partially interpolating each other.

[0013] Vehicle A is also equipped with a front speaker 9 that outputs a warning sound toward the front of the vehicle, a rear speaker 10 that outputs a warning sound toward the rear of the vehicle, a right side speaker 11 that outputs a warning sound toward the right side of the vehicle, and a left side speaker 12 that outputs a warning sound toward the left side of the vehicle. Each of the speakers 9 to 12 corresponds to a warning sound output unit. The front speaker 9 is disposed, for example, in the front part of the front bumper of vehicle A and is a speaker that can output a warning sound in a specified direction within a movable range based on the front of the vehicle along the vehicle length direction. The rear speaker 10 is disposed, for example, in the center of the rear bumper of vehicle A and is a speaker that can output a warning sound in a specified direction within a movable range based on the rear of the vehicle along the vehicle length direction. The right side speaker 11 is disposed, for example, in the right door of vehicle A and is a speaker that can output a warning sound in a specified direction within a movable range based on the right side of the vehicle along the vehicle width direction. The left side speaker 12 is disposed, for example, on the left door of the vehicle A, and is a speaker that can output a warning sound in a specified direction within a movable range based on the left side of the vehicle along the vehicle width direction. Each of the speakers 9 to 12 is configured so that the volume and directionality of the output can be adjusted.

[0014] The control unit 2 includes a surrounding environment determination unit 2a, a traveling direction determination unit 2b, a road width determination unit 2c, and an output mode control unit 2d. These units 2a to 2d execute a notification sound output control program.

[0015] The surrounding environment identification unit 2a is equipped with an image analysis engine that analyzes camera images, and performs image analysis on camera images input from the front camera 3, rear camera 4, right-side camera 5, and left-side camera 6 using the image analysis engine to identify, for example, the surrounding environment of a pedestrian. The image analysis engine may be installed as a functional block separate from the control unit 2. The surrounding environment identification unit 2a, in addition to extracting feature points of a pedestrian to identify the pedestrian, also extracts feature points of a guardrail to identify the guardrail, extracts feature points of a crosswalk to identify the crosswalk, and extracts feature points of nearby vehicles to identify the nearby vehicles. The surrounding environment identification unit 2a also identifies the movement of pedestrians by relatively comparing multiple camera images taken at different times.

[0016] For example, when identifying the surrounding environment of a pedestrian, the surrounding environment identification unit 2a identifies the pedestrian's position, the degree of congestion of vehicles surrounding vehicle A, and whether or not there are pedestrians in the direction vehicle A is turning right or left.

[0017] When the surrounding environment identification unit 2a identifies the location of a pedestrian, for example, if it identifies the presence of a pedestrian and a guardrail through image analysis, it determines whether the pedestrian's location is in a safe area based on the positional relationship between the pedestrian and the guardrail. If the surrounding environment identification unit 2a determines that any pedestrian included in the camera image is in front of the guardrail as viewed from vehicle A, i.e., outside the guardrail, it determines that the pedestrian's location is not in a safe area. On the other hand, if the surrounding environment identification unit 2a determines that all pedestrians included in the camera image are behind the guardrail as viewed from vehicle A, i.e., inside the guardrail, it determines that the pedestrian's location is in a safe area.

[0018] When the surrounding environment identification unit 2a identifies the location of a pedestrian, for example, by image analysis to identify the presence of a pedestrian and a crosswalk, it determines whether the pedestrian's location is in a safe area based on the positional relationship between the pedestrian and the crosswalk. If the surrounding environment identification unit 2a determines that any pedestrian included in the camera image is on a road away from the crosswalk as seen from vehicle A, it determines that the pedestrian's location is not in a safe area. On the other hand, if the surrounding environment identification unit 2a determines that all pedestrians included in the camera image are on the crosswalk as seen from vehicle A, it determines that the pedestrian's location is in a safe area.

[0019] When the surrounding environment determination unit 2a determines the degree of congestion of surrounding vehicles around vehicle A, for example, when it identifies the presence of parked vehicles in a parking lot through image analysis, it determines the degree of congestion of surrounding vehicles by, for example, comparing the number of pixels occupied by the parked vehicles in the image frame with a predetermined number. If the surrounding environment determination unit 2a determines that the number of pixels occupied by parked vehicles in the image frame is less than the predetermined number, it determines that the degree of congestion of surrounding vehicles is less than a threshold and that the area is relatively empty. On the other hand, if the surrounding environment determination unit 2a determines that the number of pixels occupied by parked vehicles in the image frame is equal to or greater than the predetermined number, it determines that the degree of congestion of surrounding vehicles is equal to or greater than the threshold and that the area is relatively crowded.

[0020] When the surrounding environment identification unit 2a determines whether a pedestrian is present in the direction of a right or left turn of vehicle A, it detects, for example, the steering angle or the operating state of the turn signal to determine whether vehicle A is turning right or left, and when it identifies a pedestrian through image analysis, it determines that a pedestrian is present in the direction of a right or left turn of vehicle A.

[0021] The above example shows a case where the surrounding environment is identified by image analysis of camera images, but if vehicle A is equipped with a clearance sonar, the detection results of the clearance sonar may also be used in combination to identify the surrounding environment as necessary.

[0022] The traveling direction identification unit 2b identifies the traveling direction of vehicle A, for example, by referring to road data included in map data implemented in the navigation ECU or by detecting the steering angle and the operation state of the turn signals. For example, when the traveling direction identification unit 2b determines that the steering angle is equal to or greater than a predetermined angle in the right turning direction or that the right turn signal is activated, the traveling direction identification unit 2b identifies the traveling direction of vehicle A as a right turn direction. For example, when the traveling direction identification unit 2b determines that the steering angle is equal to or greater than a predetermined angle in the left turning direction or that the left turn signal is activated, the traveling direction identification unit 2b identifies the traveling direction of vehicle A as a left turn direction. For example, when the traveling direction identification unit 2b determines that the steering angle is less than a predetermined angle in both the right turning direction and the left turning direction and that neither the right turn signal nor the left turn signal is activated, the traveling direction identification unit 2b identifies the traveling direction of vehicle A as a straight direction.

[0023] The road width determination unit 2c determines the width of the road on which the vehicle A is traveling by referring to road data included in map data implemented in the navigation ECU, for example.

[0024] The output mode control unit 2d controls the output mode of the alert sound from each speaker 9 to 12 depending on the surrounding environment of the pedestrian identified by the surrounding environment identification unit 2a. Specifically, when the surrounding environment identification unit 2a identifies that the pedestrian's location is in a safe area, the output mode control unit 2d reduces the volume of the alert sound from a normal volume. When the surrounding environment identification unit 2a identifies that the degree of congestion of vehicles surrounding vehicle A is equal to or greater than a threshold, the output mode control unit 2d increases the volume of the alert sound from a normal volume. When the traveling direction identification unit 2b identifies that vehicle A is traveling in a right-turn or left-turn direction, the output mode control unit 2d directs the alert sound in the traveling direction in which vehicle A is turning right or left. When the surrounding environment identification unit 2a identifies that a pedestrian is present in the right-turn or left-turn direction of vehicle A, the output mode control unit 2d increases the volume of the alert sound from a normal volume. When the road width of the road on which the vehicle A is traveling is identified by the road width identification unit 2c, the output mode control unit 2d varies the volume of the notification sound according to the identified road width.

[0025] Next, the operation of the above-described configuration will be described with reference to FIGS. The control unit 2 performs three processes to control the output mode of the warning sound: a first control process that controls depending on whether the pedestrian is located in a safe area; a second control process that controls depending on the degree of congestion of vehicles around vehicle A; a third control process that controls depending on the traveling direction of vehicle A; and a fourth control process that controls depending on the width of the road on which vehicle A is traveling. Each process will be explained below in order. For example, the control unit 2 may perform several of the first control process, second control process, third control process, and fourth control process simultaneously, or may perform one of the control processes with priority over the others.

[0026] (1) First control process (see Figures 3 to 5) When the first control process is started, the control unit 2 performs image analysis on the camera images input from the cameras 3 to 6 and determines whether or not a pedestrian has been identified in the traveling direction of the vehicle A (S1). When the control unit 2 determines that a pedestrian has not been identified (S1: NO), it outputs a warning sound from the front speaker 9 at a normal volume (S2) and ends the first control process.

[0027] When the control unit 2 determines that a pedestrian has been identified (S1: YES), it determines whether or not a safe area has been identified (S3). When the control unit 2 determines that a safe area has not been identified (S3: NO), it also outputs a warning sound from the front speaker 9 at the normal volume (S2), and ends the first control process.

[0028] When the control unit 2 determines that a safe area has been identified (S3: YES), it determines whether the pedestrian is located in a safe area (S4). When the control unit 2 determines that the pedestrian is not located in a safe area (S4: NO), it also causes the front speaker 9 to output the alert sound at the normal volume (S2) and ends the first control process. On the other hand, when the control unit 2 determines that the pedestrian is located in a safe area (S4: YES), it causes the front speaker 9 to output the alert sound at a volume lower than normal (S5) and ends the first control process.

[0029] As shown in Fig. 4, for example, when the control unit 2 identifies a guardrail 101 as a safe area, if the control unit 2 determines that any pedestrian W is on the near side of the guardrail 101 as viewed from the vehicle A, i.e., outside the guardrail 101, it determines that the position of the pedestrian W is not in a safe area and outputs a warning sound from the front speaker 9 at a normal volume. On the other hand, when the control unit 2 determines that all pedestrians W are on the far side of the guardrail 101 as viewed from the vehicle A, i.e., inside the guardrail 101, it determines that the position of the pedestrian W is in a safe area and outputs a warning sound from the front speaker 9 at a volume lower than normal. Fig. 4 illustrates an example in which one pedestrian W is identified, but if multiple pedestrians W are identified, it determines whether or not each of the multiple pedestrians W is in a safe area.

[0030] As shown in Fig. 5, for example, when the control unit 2 identifies the crosswalk 102 as a safe area, if it determines that any pedestrian W is on a road that is off the crosswalk 102 as seen from the vehicle A, it determines that the position of the pedestrian W is not in a safe area and outputs a warning sound from the front speaker 9 at a normal volume. On the other hand, when the control unit 2 determines that all pedestrians W are on the crosswalk 102 as seen from the vehicle A, it determines that the position of the pedestrian W is in a safe area and outputs a warning sound from the front speaker 9 at a volume that is lower than normal. Although Fig. 5 also illustrates an example in which one pedestrian W is identified, if multiple pedestrians W are identified, it determines whether or not each of the multiple pedestrians W is in a safe area.

[0031] By performing the control described above, it is possible to properly notify pedestrians who are not in a safe area of ​​the approach of vehicle A. On the other hand, it is possible to prevent a situation in which pedestrians who are in a safe area are subjected to unnecessary stress due to the output of an alarm sound. Although the inside of guardrail 101 and the crosswalk 102 are given as examples of safe areas, this can also be applied to other places where the safety of pedestrian W is ensured. In the above process, steps S1, S3, and S4 correspond to the surrounding environment identification procedure, and steps S2 and S5 correspond to the output mode control procedure.

[0032] (2) Second control process (see Figures 6 and 7) When the control unit 2 starts the second control process, it performs image analysis on the camera images input from the cameras 3 to 6 and determines whether or not a surrounding vehicle around vehicle A has been identified (S11). When the control unit 2 determines that a surrounding vehicle around vehicle A has not been identified (S11: NO), it outputs a warning sound from the front speaker 9 at a normal volume (S12) and ends the second control process.

[0033] When the control unit 2 determines that the surrounding vehicles around vehicle A have been identified (S11: YES), it compares the number of pixels occupied by the surrounding vehicles in the image frame with a predetermined number, for example, to determine the degree of congestion of the surrounding vehicles (S13). When the control unit 2 determines that the number of pixels occupied by the surrounding vehicles in the image frame is less than the predetermined number and determines that the degree of congestion of the surrounding vehicles is less than a threshold (S13: NO), it also outputs the warning sound from the front speaker 9 at a normal volume (S12) and ends the second control process. On the other hand, when the control unit 2 determines that the number of pixels occupied by the surrounding vehicles in the image frame is equal to or greater than a predetermined number and determines that the degree of congestion of the surrounding vehicles is equal to or greater than a threshold (S13: YES), it outputs the warning sound from the front speaker 9 at a volume that is increased above normal (S14) and ends the second control process.

[0034] 7, for example, when the control unit 2 determines that the number of parked vehicles B, which are nearby vehicles, in a parking lot is relatively small, it determines that the degree of congestion of nearby vehicles is below a threshold, and causes the alert sound to be output from the front speaker 9 at a volume that is higher than normal. On the other hand, when the control unit 2 determines that the number of parked vehicles B is relatively large, it determines that the degree of congestion of nearby vehicles is equal to or higher than a threshold, and causes the alert sound to be output from the front speaker 9 at a volume that is higher than normal.

[0035] By performing the control described above, it is possible to prevent a situation in which the warning sound is output at a volume higher than necessary when the degree of congestion of surrounding vehicles is relatively low and the number of pedestrians is expected to be relatively small. On the other hand, when the degree of congestion of surrounding vehicles is relatively high and the number of pedestrians is expected to be relatively large, it is possible to appropriately notify pedestrians of the approach of vehicle A. In the above-described processing, steps S11 and S13 correspond to the surrounding environment identification procedure, and steps S12 and S14 correspond to the output mode control procedure.

[0036] (3) Third Control Process (see Figures 8 to 12) When the control unit 2 starts the third control process, it determines the traveling direction of the vehicle A, for example, by referring to road data included in map data implemented in the navigation ECU, or by detecting the steering angle or the operating state of the turn signals (S21). When the control unit 2 determines that the traveling direction of the vehicle A is neither a right turn direction nor a left turn direction (S21: NO), it outputs a warning sound from the front speaker 9 at a normal volume (S22), and ends the third control process.

[0037] On the other hand, when the control unit 2 determines that the traveling direction of vehicle A is a right turn direction or a left turn direction (S21), it directs the alert sound in the traveling direction of vehicle A (S23) and determines whether or not a pedestrian has been identified in the traveling direction of vehicle A (S24). When the control unit 2 determines that a pedestrian has not been identified (S24: NO), it also outputs the alert sound from the front speaker 9 at the normal volume (S22) and ends the third control process. On the other hand, when the control unit 2 determines that a pedestrian has been identified (S24: YES), it outputs the alert sound from the front speaker 9 at a volume that is increased above normal (S25) and ends the third control process.

[0038] As shown in Fig. 9, for example, when vehicle A turns right at a T-junction, the control unit 2 directs the alert sound in the right-turning direction of vehicle A and outputs it from the front speaker 9 at a normal volume. As shown in Fig. 10, when the control unit 2 identifies a pedestrian W in the right-turning direction of vehicle A, it outputs the alert sound from the front speaker 9 at a volume that is increased compared to normal. Although Fig. 10 illustrates an example in which one pedestrian W is identified, the same applies when multiple pedestrians W are identified.

[0039] As shown in Fig. 11, for example, when vehicle A turns left and enters a roadside facility, the control unit 2 directs the alert sound in the left-turning direction of vehicle A and outputs it from the front speaker 9 at a normal volume. As shown in Fig. 12, when the control unit 2 identifies a pedestrian W in the left-turning direction of vehicle A, it outputs the alert sound from the front speaker 9 at a volume that is increased compared to normal. Although Fig. 12 also illustrates an example in which one pedestrian W is identified, the same applies when multiple pedestrians W are identified.

[0040] By performing the control described above, when vehicle A turns right or left, the warning sound is output in the direction of travel of vehicle A, and if a pedestrian is present in the direction of travel of vehicle A, the pedestrian can be appropriately notified of the approach of vehicle A. In the above process, steps S21 and S24 correspond to the surrounding environment identification procedure, and steps S22, S23, and S25 correspond to the output mode control procedure.

[0041] (4) Third Control Process (see Figures 13 and 14) When the control unit 2 starts the fourth control process, it determines the road width of the road on which vehicle A is traveling by referring to road data included in map data implemented in the navigation ECU, for example (S31). If the control unit 2 determines that the road width of the road on which vehicle A is traveling is less than a threshold (S31: NO), it causes the notification sound to be output from the front speaker 9 at a volume that is increased compared to normal (S32) and ends the fourth control process. On the other hand, if the control unit 2 determines that the road width of the road on which vehicle A is traveling is equal to or greater than the threshold (S31: YES), it causes the notification sound to be output from the front speaker 9 at a normal volume (S33) and ends the fourth control process.

[0042] 14, when the control unit 2 determines that the road width of the road on which vehicle A is traveling is less than a threshold, the control unit 2 outputs the alert sound from the front speaker 9 at a volume that is increased compared to normal. On the other hand, when the control unit 2 determines that the road width of the road on which vehicle A is traveling is equal to or greater than the threshold, the control unit 2 outputs the alert sound from the front speaker 9 at a normal volume. Note that the volume of the alert sound may differ depending on the road width, and it may be configured such that when the control unit 2 determines that the road width of the road on which vehicle A is traveling is less than the threshold, the alert sound is output from the front speaker 9 at a normal volume, and when the control unit 2 determines that the road width of the road on which vehicle A is traveling is equal to or greater than the threshold, the alert sound is output from the front speaker 9 at a volume that is reduced compared to normal.

[0043] By performing the control described above, when the road width of the road on which vehicle A is traveling is less than the threshold, the distance from vehicle A to the road shoulder is relatively short, and the distance from vehicle A to pedestrian W on the side of the road is relatively short, it is possible to appropriately notify the pedestrian of the approach of vehicle A. On the other hand, when the road width of the road on which vehicle A is traveling is equal to or greater than the threshold, the distance from vehicle A to the road shoulder is relatively long, and the distance from vehicle A to pedestrian W on the side of the road is relatively long, it is possible to prevent a situation in which the alert sound is output at a volume higher than necessary. In the above-described processing, step S31 corresponds to the surrounding environment identification procedure, and steps S32 and S33 correspond to the output mode control procedure.

[0044] As described above, according to the embodiment, the following advantageous effects can be obtained. In the notification sound output control device 1, the output mode of the notification sound for notifying pedestrians of the approach of vehicle A is controlled in accordance with the surrounding environment of the pedestrian. By controlling the output mode of the notification sound in consideration of the surrounding environment of the pedestrian, the notification sound can be output appropriately.

[0045] The system determines whether the pedestrian is located in a safe area, such as inside a guardrail 101 or on a crosswalk 102, and if it determines that the pedestrian is not located in a safe area, the volume of the warning sound is output at a normal volume. On the other hand, if it determines that the pedestrian is located in a safe area, the volume of the warning sound is output at a lower volume than normal. This makes it possible to properly notify pedestrians who are not in a safe area of ​​the approach of vehicle A. On the other hand, it is possible to prevent a situation in which unnecessary stress is caused to pedestrians who are not in a safe area by the output of the warning sound.

[0046] The system identifies the degree of congestion of surrounding vehicles around vehicle A, and if it is determined that the degree of congestion of surrounding vehicles is below a threshold, it outputs the warning sound at a normal volume. On the other hand, if it is determined that the degree of congestion of surrounding vehicles is above the threshold, it outputs the warning sound at a volume that is higher than normal. When the degree of congestion of surrounding vehicles is relatively low and it is expected that there will be relatively few pedestrians, it is possible to prevent the warning sound from being output at a volume higher than necessary. On the other hand, when it is expected that the degree of congestion of surrounding vehicles is relatively high and there will be relatively many pedestrians, it is possible to appropriately notify pedestrians of the approach of vehicle A.

[0047] When it is determined that vehicle A is heading in a right or left turn direction, the warning sound is directed in the direction of vehicle A's right or left turn, and when it is determined that a pedestrian is present in the direction of vehicle A's right or left turn, the volume of the warning sound is increased more than usual. When vehicle A turns right or left, the warning sound is directed and output in the direction of vehicle A's travel, and if a pedestrian is present in vehicle A's direction of travel, the pedestrian can be appropriately notified of vehicle A's approach.

[0048] The width of the road on which vehicle A is traveling is identified, and the volume of the warning sound is varied depending on the width of the road on which vehicle A is traveling. When the width of the road on which vehicle A is traveling is less than a threshold, the distance from vehicle A to the road shoulder is relatively short, and the distance from vehicle A to pedestrian W on the side of the road is relatively short, the pedestrian can be appropriately notified of the approach of vehicle A. On the other hand, when the width of the road on which vehicle A is traveling is equal to or greater than the threshold, the distance from vehicle A to the road shoulder is relatively long, and the distance from vehicle A to pedestrian W on the side of the road is relatively long, it is possible to prevent a situation in which the warning sound is output at a volume higher than necessary.

[0049] Although the present disclosure has been described with reference to the embodiments, it is understood that the present disclosure is not limited to the embodiments or structures. The present disclosure also encompasses various modifications and modifications within the scope of equivalents. In addition, various combinations and forms, as well as other combinations and forms including only one element, more than one element, or less than one element, are also within the scope and spirit of the present disclosure.

[0050] Although the configuration in which one each of the cameras 3 to 6 and the speakers 9 to 12 is mounted in the front, rear, left and right directions of the vehicle has been exemplified, the number of cameras and the number of speakers are arbitrary.

[0051] The control unit and the method described herein may be implemented by a special-purpose computer configured by configuring a processor and memory programmed to perform one or more functions embodied in a computer program. Alternatively, the control unit and the method described herein may be implemented by a special-purpose computer configured by configuring a processor with one or more dedicated hardware logic circuits. Alternatively, the control unit and the method described herein may be implemented by one or more special-purpose computers configured by combining a processor and memory programmed to perform one or more functions with a processor configured with one or more hardware logic circuits. Furthermore, the computer program may be stored as instructions executed by a computer on a computer-readable non-transitory tangible storage medium. [Explanation of symbols]

[0052] In the drawing, 1 is a notification sound output control device, 2 is a control unit, 2a is a surrounding environment identification unit, 2b is a traveling direction identification unit, 2c is a road width identification unit, 2d is an output mode control unit, and 9 to 12 are speakers (notification sound output units).

Claims

1. A notification sound output control device (1) that outputs a notification sound from a notification sound output unit to notify a moving object of an approaching vehicle, a surrounding environment determination unit (2a) for determining the surrounding environment of the moving body; An alert sound output control device comprising: an output mode control unit (2d) that controls the output mode of the alert sound from the alert sound output unit in accordance with the surrounding environment of the moving body identified by the surrounding environment identification unit.

2. The notification sound output control device according to claim 1 , wherein the surrounding environment specifying unit specifies whether the location of the mobile object is in a safe area as the surrounding environment of the mobile object.

3. The output mode control unit controls the output mode of the alert sound from the alert sound output unit to reduce the volume of the alert sound from a normal level when the surrounding environment determination unit determines that the location of the moving body is in a safe area.

4. The notification sound output control device according to claim 1 , wherein the surrounding environment specifying unit specifies a degree of congestion of vehicles surrounding the vehicle on which the device is mounted as the surrounding environment of the moving object.

5. 5. The warning sound output control device according to claim 4, wherein the output mode control unit increases the volume of the warning sound more than normal when the surrounding environment determination unit determines that the degree of congestion of vehicles surrounding the vehicle is above a threshold.

6. a traveling direction identification unit (2b) for identifying the traveling direction of a vehicle equipped with the device; The notification sound output control device according to claim 1 , wherein the output mode control unit controls the output mode of the notification sound from the notification sound output unit in accordance with the traveling direction of the vehicle identified by the traveling direction identification unit.

7. 7. The notification sound output control device according to claim 6, wherein the output mode control unit directs the notification sound in the direction in which the vehicle is turning right or left when the direction of travel determination unit determines that the vehicle's direction of travel is a right turn or a left turn.

8. The notification sound output control device according to claim 7 , wherein the surrounding environment specifying unit specifies, as the surrounding environment of the moving object, whether or not the moving object is present in a direction in which the vehicle is turning right or left.

9. 9. The notification sound output control device according to claim 8, wherein the output mode control unit increases the volume of the notification sound more than normal when the surrounding environment identification unit identifies that the moving object is present in the right or left turn direction of the vehicle.

10. a road width specifying unit (2c) for specifying the width of a road on which a vehicle equipped with the device is traveling; The notification sound output control device according to claim 1 , wherein the output mode control unit varies the volume of the notification sound depending on the width of a road on which the vehicle equipped with the device is traveling.

11. A control unit (2) of a notification sound output control device (1) that outputs a notification sound from a notification sound output unit to notify a moving body of an approaching vehicle, a surrounding environment identification step for identifying a surrounding environment of the moving object; An alert sound output control program that executes an output mode control procedure that controls the output mode of the alert sound from the alert sound output unit in accordance with the surrounding environment of the moving body identified by the surrounding environment identification procedure.

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