Vehicle approach notification device and vehicle lamp

Abstract

To effectively notify other road users of an approach of a vehicle.SOLUTION: A vehicle approach notification device 100 includes: a sound emitting device 110; and a controller 120 that adjusts the pitch of the sound according to the surrounding environment of a vehicle 10 for at least one of a low-sound component of a vehicle approach notification sound 102 and a high-sound component of the vehicle approach notification sound 102 higher than the low-sound component, and operates the sound emitting device 110 so as to emit the low-sound component and the high-sound component as the vehicle approach notification sound 102. The sound emitting device 110 and the controller 120 may be installed on a vehicle lamp.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a vehicle approach warning device and a vehicle lamp. [Background technology]

[0002] Conventionally, there is known a vehicle approach notification device that notifies the surroundings of an approaching vehicle by sound (see, for example, Patent Document 1). The vehicle approach notification sound is generally designed to have a volume peak in each of two different frequency bands. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-179802 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned vehicle approach notification device, the volume of the vehicle approach notification sound is changed depending on the situation outside the vehicle, such as the presence or absence of other traffic such as pedestrians or bicycles.

[0005] The present invention has been made in view of the above circumstances, and one exemplary purpose of an embodiment of the present invention is to effectively notify other road users of the approach of a vehicle. [Means for solving the problem]

[0006] In order to solve the above problems, a vehicle approach warning device of one embodiment of the present invention includes a sound producing device and a controller that adjusts the pitch of at least one of the low-pitched components of the vehicle approach warning sound and the high-pitched components of the vehicle approach warning sound that are higher than the low-pitched components in accordance with the vehicle's surrounding environment, and operates the sound producing device to emit the low-pitched components and the high-pitched components as the vehicle approach warning sound.

[0007] According to this aspect, by adjusting the pitch of at least one of the low-pitched and high-pitched components of the vehicle approach warning sound in accordance with the surrounding environment of the vehicle, it is possible to effectively notify other traffic of the approaching vehicle.

[0008] The controller may adjust the treble components to be higher when a pedestrian or bicycle is detected around the vehicle compared to when a pedestrian or bicycle is not detected around the vehicle. Since the higher the sound, the higher the directionality, so by making the treble components of the vehicle approaching warning sound higher, it is possible to effectively notify pedestrians and other road users in the direction in which the vehicle approaching warning sound is heading (for example, in front of the vehicle) of the approach of the vehicle.

[0009] The controller may increase the volume of at least one of the low and high frequency components when a pedestrian or a bicycle is detected around the vehicle, compared to when a pedestrian or a bicycle is not detected around the vehicle. In this way, the increased volume can effectively notify other traffic of the approach of the vehicle.

[0010] The controller may adjust the low-frequency components to be lower when the brightness of the surroundings of the vehicle exceeds the brightness threshold value, compared to when the brightness of the surroundings of the vehicle is lower than the brightness threshold value. When the surroundings of the vehicle are bright, such as during the daytime, it is expected that the vehicle approaching warning sound is relatively easily drowned out by surrounding noise. Since lower sounds tend to spread more easily in the surroundings, by lowering the low-frequency components of the vehicle approaching warning sound, it is possible to effectively notify other road users of the approach of the vehicle.

[0011] The controller may increase the volume of at least one of the low-pitched and high-pitched components when the brightness of the surroundings of the vehicle exceeds the brightness threshold value, compared to when the brightness of the surroundings of the vehicle is below the brightness threshold value. In this way, the increase in volume can effectively notify other traffic of the approach of the vehicle.

[0012] The sound generating device and the controller may be mounted in a vehicle lamp, and the controller may control the vehicle lamp, thereby enabling the vehicle approach notification device to be integrated into the vehicle lamp.

[0013] Another aspect of the present invention is a vehicle lamp that includes a lamp unit, a sound generating device operable to emit a vehicle approach warning sound including a low-pitched component and a high-pitched component higher than the low-pitched component, and a controller that adjusts the low-pitched component to be lower when the lamp unit is off compared to when the lamp unit is on, and operates the sound generating device to emit the low-pitched component and the high-pitched component as the vehicle approach warning sound.

[0014] According to this embodiment, when the vehicle lamp is not turned on, that is, when it is typically bright around the vehicle such as during the daytime, the low-pitched components of the vehicle approaching warning sound are made lower than when it is not. Since lower sounds tend to spread more easily in the surroundings, it is possible to effectively notify other road users of the approach of a vehicle.

[0015] The controller may increase the volume of at least one of the low and high frequency components when the lamp unit is off, compared to when the lamp unit is on. In this way, the increased volume can effectively notify other traffic of the approach of a vehicle.

[0016] Any combination of the above components and any transformation of the present invention into a method, device, system, computer program, etc. are also effective as aspects of the present invention. Effect of the Invention

[0017] According to the present invention, it is possible to effectively notify other road users of the approach of a vehicle. [Brief description of the drawings]

[0018] [Figure 1] 1 is a block diagram illustrating a vehicle approach notification device according to an embodiment of the present invention; [Diagram 2]2(a) and 2(b) are diagrams that illustrate an example of a vehicle approach notification sound of the vehicle approach notification device according to the embodiment. [Diagram 3] 4 is a flowchart showing an example of a control process of the vehicle approach notification device according to the embodiment. [Figure 4] 4 is a schematic diagram showing generation of a vehicle approach notification sound in the control process shown in FIG. 3. [Diagram 5] 6 is a flowchart showing another example of the control process of the vehicle approach notification device according to the embodiment. [Figure 6] 6 is a schematic diagram showing generation of a vehicle approach notification sound in the control process shown in FIG. 5. FIG. [Figure 7] 1 is a block diagram illustrating an example of a vehicle lamp incorporating a vehicle approach notification device according to an embodiment. [Figure 8] FIG. 11 is a block diagram illustrating an example of a vehicle lamp incorporating a vehicle approach notification device according to an embodiment of the present invention. [Figure 9] 9 is a flowchart showing an example of a process for adjusting a vehicle approach notification sound in the vehicle lamp shown in FIG. 8. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] The present invention will be described below with reference to the drawings based on preferred embodiments. The embodiments are illustrative and do not limit the invention, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention. The same or equivalent components, members, and processes shown in each drawing are given the same reference numerals, and duplicated descriptions are omitted as appropriate. The scale and shape of each part shown in each drawing are set for convenience to facilitate explanation, and are not to be interpreted as being limiting unless otherwise specified. In addition, the terms "first", "second", etc. used in this specification or claims do not indicate any order or importance, but are intended to distinguish one configuration from another. In addition, some of the members that are not important in explaining the embodiment in each drawing are omitted.

[0020] FIG. 1 is a block diagram showing a schematic diagram of a vehicle approach notification device 100 according to an embodiment. The vehicle approach notification device 100 is also called AVAS (Acoustic Vehicle Alerting System) and is mounted on a vehicle 10. The vehicle approach notification device 100 can notify the vicinity of the vehicle 10 of the approach of the vehicle 10 by a vehicle approach notification sound 102. The vehicle approach notification sound 102 is also called AVAS sound. The vehicle approach notification device 100 can notify other road users, such as pedestrians, bicycles, and other vehicles, of the approach of the vehicle 10, which is useful for improving safety. In particular, when the vehicle 10 uses an electric motor as a driving source for driving, such as a hybrid car or an electric car, the motor sound at low speeds is quiet and the approach of the vehicle 10 is difficult to notice, so the vehicle approach notification sound 102 by the vehicle approach notification device 100 is useful.

[0021] The vehicle approach notification device 100 includes at least one sound generating device 110 and a controller 120 that controls the sound generating device 110 .

[0022] The sound producing device 110 is a device for emitting the vehicle approaching warning sound 102, and may include, for example, a speaker. The sound producing device 110 may be installed at the front of the vehicle 10 so as to emit sound toward the outside of the vehicle, so that the vehicle approaching warning sound 102 can be effectively delivered to other road users, such as pedestrians and cyclists, in the traveling direction of the vehicle 10 (for example, in front of the vehicle 10). In the illustrated example, the vehicle approaching warning device 100 has one sound producing device 110, but multiple sound producing devices 110 may be provided.

[0023] The vehicle approach warning sound 102 may include, for example, a simulated engine sound that simulates an engine sound. Additionally or alternatively, the vehicle approach warning sound 102 may include a voice message indicating the approach of the vehicle 10.

[0024] 2(a) and 2(b) are diagrams that show an example of the vehicle approach warning sound 102 of the vehicle approach warning device 100 according to the embodiment. FIG. 2(a) shows an example of the frequency characteristics of the vehicle approach warning sound 102 obtained by Fast Fourier Transformation (FFT), and FIG. 2(b) shows an example of the frequency characteristics of the vehicle approach warning sound 102 obtained by 1 / 3 octave band analysis. Thus, the vertical axis of FIG. 2(a) and FIG. 2(b) represents the volume, i.e., the sound pressure level [dBA], and the horizontal axis represents the frequency [Hz]. The vehicle approach warning sound 102 that is the basis of such frequency analysis is measured according to a measurement method that is specified with respect to the legal volume requirements that the vehicle approach warning sound 102 must satisfy.

[0025] In this embodiment, as shown in FIG. 2(a) and FIG. 2(b), the vehicle approach warning sound 102 includes a low-pitched component 102a set in a first band 104a and a high-pitched component 102b set in a second band 104b. The first band 104a and the second band 104b are separated from each other. The low-pitched component 102a predominates in the first band 104a, and the high-pitched component 102b predominates in the second band 104b. That is, the low-pitched component 102a has a volume peak at at least one first peak frequency ω1, and the high-pitched component 102b has a volume peak at at least one second peak frequency ω2. The first peak frequency ω1 is included in the first band 104a, and the second peak frequency ω2 is included in the second band 104b. The second band 104b is higher than the first band 104a, and therefore the second peak frequency ω2 is higher than the first peak frequency ω1. Note that, as shown in FIG. 2(a), the bass component 102a may have multiple volume peaks in the first band 104a, and the treble component 102b may have multiple volume peaks in the second band 104b.

[0026] As an example, the first band 104a may be any frequency range set in the frequency range from 300 Hz to 1600 Hz. For example, the first band 104a may be defined to include 800 Hz (e.g., to have a center frequency of 800 Hz). In this case, the first peak frequency ω1 may be located at or near 800 Hz.

[0027] The second band 104b may be any frequency range higher than the first band 104a, for example, the second band 104b may be set in a frequency range of 2000 Hz or less. For example, the second band 104b may be defined to include 1600 Hz (for example, with 1600 Hz as a center frequency). In this case, the second peak frequency ω2 may be located at or near 1600 Hz.

[0028] The volume peak of the bass component 102a or the treble component 102b of the vehicle approach warning sound 102 may be, for example, greater than 40 dBA or greater than 50 dBA. Also, the volume peak may be, for example, less than 100 dBA or less than 90 dBA. The volume peak of the bass component 102a and the volume peak of the treble component 102b may be equal to or different from each other.

[0029] 1 is configured to adjust the pitch (i.e., frequency) and / or volume of at least one of the low-pitched component 102a and the high-pitched component 102b of the vehicle approach warning sound 102 so as to increase the audibility of the vehicle approach warning sound 102 in accordance with the surrounding environment of the vehicle, and to operate the sound generation device 110 to emit the low-pitched component 102a and the high-pitched component 102b as the vehicle approach warning sound 102. The controller 120 can be implemented as a combination of a processor (hardware) such as a CPU (Central Processing Unit) or a microcomputer, and a software program executed by the processor (hardware).

[0030] Thus, the controller 120 may include a memory 122 and a mixer 124 as shown in FIG.

[0031] The memory 122 may store sound source data related to the vehicle approach warning sound 102, for example, first sound source data representing the low frequency component 102a and second sound source data representing the high frequency component 102b. The memory 122 may include a non-volatile memory and / or a volatile memory. The memory 122 may store a software program that executes the audio signal processing according to the embodiment. The memory 122 may also store data used in such a software program, such as settings of the pitch and / or volume of the low frequency component 102a and the high frequency component 102b, and data obtained by executing the software program.

[0032] The mixer 124 may be configured to change the pitch and / or volume of the bass component 102a and the treble component 102b individually in accordance with a setting according to the surrounding environment of the vehicle, synthesize the bass component 102a and the treble component 102b, and output audio data representing the vehicle approach warning sound 102 obtained thereby. The mixer 124 may be configured to control the sound generating device 110 to emit the vehicle approach warning sound 102 generated by such synthesis. The mixer 124 may include a processor capable of processing audio signals, and may be implemented by the processor executing a software program stored in the memory 122.

[0033] The vehicle approach notification device 100 may also include a surroundings monitoring sensor 150 mounted on the vehicle 10 to acquire information related to the surrounding environment of the vehicle 10. The surroundings monitoring sensor 150 may be configured to monitor the traffic conditions around the vehicle 10, such as whether or not there are other traffic objects such as pedestrians or bicycles around the vehicle 10. The surroundings monitoring sensor 150 may be configured to generate information indicating the traffic conditions around the vehicle 10, for example, pedestrian / bicycle detection information indicating whether or not there are detection objects such as pedestrians or bicycles around the vehicle 10, and output this to the controller 120.

[0034] In this case, the surroundings monitoring sensor 150 may detect the presence or absence of a detection target such as a pedestrian by image processing or by using radio waves or light, and generate pedestrian / bicycle detection information. The configuration of the surroundings monitoring sensor 150 is not particularly limited, and may include, for example, a camera, LiDAR (Light Detection and Ranging, Laser Imaging Detection and Ranging), millimeter wave radar, or other sensors or radars. Such detection methods may employ various known methods, and will not be described in detail here.

[0035] Fig. 3 is a flowchart showing an example of a control process of the vehicle approach notification device 100 according to the embodiment. Fig. 4 is a schematic diagram showing generation of the vehicle approach notification sound 102 in the control process shown in Fig. 3. This process is executed by the controller 120 of the vehicle approach notification device 100 in a situation where the vehicle approach notification device 100 should emit the vehicle approach notification sound 102, such as when the vehicle 10 is traveling.

[0036] First, the bass component 102a and the treble component 102b are obtained (S30). The mixer 124 may read the first sound source data representing the bass component 102a and the second sound source data representing the treble component 102b from the memory 122, thereby obtaining the bass component 102a and the treble component 102b.

[0037] Furthermore, the above-mentioned pedestrian / bicycle detection information is acquired (S31). The mixer 124 may acquire this by receiving the pedestrian / bicycle detection information output from the surroundings monitoring sensor 150. Next, it is determined whether or not a pedestrian or a bicycle is detected around the vehicle 10 (S32). The mixer 124 can determine whether or not a pedestrian or a bicycle is detected around the vehicle 10 based on the acquired pedestrian / bicycle detection information.

[0038] If no pedestrian or bicycle is detected around the vehicle 10 (No in S32), the pitch and volume of the bass component 102a and the treble component 102b are not changed. In other words, the pitch and volume of the bass component 102a and the treble component 102b are maintained at the pitch and volume values ​​determined by the initial settings of the bass component 102a and the treble component 102b, respectively (S33). The initial settings of the bass component 102a and the treble component 102b are determined so as to be suitable for use as the vehicle approaching warning sound 102, and may be, for example, those illustrated in Fig. 2(a) and Fig. 2(b).

[0039] On the other hand, if a pedestrian or bicycle is detected around the vehicle 10 (Yes in S32), at least one of the pitch and volume of the low-pitched component 102a and the high-pitched component 102b is adjusted individually to increase the audibility of the vehicle approach warning sound 102 (S34).

[0040] In this example, the volume of the bass component 102a is increased compared to when no pedestrians or the like are detected around the vehicle 10, but the pitch of the sound is not changed. Therefore, the mixer 124 adjusts the bass component 102a so as to maintain the first band 104a and the first peak frequency ω1 of the bass component 102a as initially set, and to increase the volume of the bass component 102a from the initial setting. This adjustment is shown diagrammatically by the arrow 108a in FIG. 4.

[0041] The treble component 102b is increased in volume and pitched higher than when no pedestrians or the like are detected around the vehicle 10. Therefore, the mixer 124 adjusts the treble component 102b so that the frequency of the treble component 102b is increased from the initial setting and the volume of the treble component 102b is increased from the initial setting. As a result, the second band 104b and the second peak frequency ω2 of the treble component 102b are shifted to the higher frequency side compared to the initial setting (shown by the dashed line in FIG. 4). The adjustment of the volume and frequency is shown diagrammatically by the arrows 108b and 108c in FIG. 4.

[0042] For example, the shift amount of the frequency of the treble component 102b (e.g., the second peak frequency ω2) from the initial setting may be, for example, 500 Hz or more. Also, this frequency shift amount Δω may be, for example, 1000 Hz or less. The increase amount of the volume of the bass component 102a and the treble component 102b may be selected from the range of, for example, 5 dBA to 10 dBA.

[0043] Next, the low frequency component 102a and the high frequency component 102b are mixed together (S35). In this manner, the mixer 124 generates the vehicle approach warning sound 102 from the low frequency component 102a and the high frequency component 102b.

[0044] As an option, a frequency shift amount and a volume shift amount linked to the vehicle speed may be set for the generated vehicle approach warning sound 102 (S36). In this manner, a plurality of vehicle approach warning sounds 102 corresponding to different vehicle speeds may be generated.

[0045] Then, the generated vehicle approaching warning sound 102 is played (S37). Audio data or an audio signal representing the vehicle approaching warning sound 102 is output from the controller 120 to the sound generating device 110, and the sound generating device 110 emits the vehicle approaching warning sound 102. This is how the control process ends.

[0046] It is known that the higher the sound, the higher the directivity. Therefore, according to this embodiment, by making the treble component 102b of the vehicle approaching warning sound 102 higher in pitch, it is possible to effectively notify traffic, such as pedestrians in the direction in which the vehicle approaching warning sound 102 is heading (for example, in front of the vehicle 10), of the approach of the vehicle 10. In addition, increasing the volume of the low-pitched component 102a and the treble component 102b also helps to effectively notify other traffic of the approach of the vehicle 10.

[0047] Fig. 5 is a flowchart showing another example of the control process of the vehicle approach notification device 100 according to the embodiment. Fig. 6 is a schematic diagram showing generation of the vehicle approach notification sound 102 in the control process shown in Fig. 5. This process is executed by the controller 120 of the vehicle approach notification device 100 in a situation where the vehicle approach notification device 100 should emit the vehicle approach notification sound 102, such as when the vehicle 10 is traveling.

[0048] First, the bass component 102a and the treble component 102b are obtained (S50). The mixer 124 may read the first sound source data representing the bass component 102a and the second sound source data representing the treble component 102b from the memory 122, thereby obtaining the bass component 102a and the treble component 102b.

[0049] Also, brightness information indicating the brightness around the vehicle 10 is acquired (S51). Instead of or in addition to a sensor that detects the presence or absence of pedestrians, etc., the surroundings monitoring sensor 150 shown in Fig. 1 may include a brightness sensor such as an illuminometer that measures the brightness around the vehicle 10 and outputs brightness information indicating the measured brightness. The mixer 124 may acquire the brightness information by receiving it, which is output from the surroundings monitoring sensor 150.

[0050] Next, the brightness of the surroundings of the vehicle 10 is compared with the brightness threshold (S52). Based on the acquired brightness information, the mixer 124 can determine whether the brightness of the surroundings of the vehicle 10 exceeds the brightness threshold. The brightness threshold is set as a threshold for distinguishing between daytime and nighttime.

[0051] When the brightness around the vehicle 10 is below the brightness threshold (No in S52), that is, for example, at night, the pitch and volume of the bass component 102a and the treble component 102b are not changed. In other words, the pitch and volume of the bass component 102a and the treble component 102b are maintained at the pitch and volume values ​​determined by the initial settings of the bass component 102a and the treble component 102b, respectively (S53).

[0052] On the other hand, when the brightness around the vehicle 10 exceeds the brightness threshold value (Yes in S52), that is, for example, during the daytime, at least one of the pitch and volume of the low-pitched component 102a and the high-pitched component 102b is adjusted individually to increase the audibility of the vehicle approach warning sound 102 (S54).

[0053] In this example, the bass component 102a is increased in volume and lowered in tone compared to when the brightness around the vehicle 10 is below the brightness threshold. Therefore, the mixer 124 adjusts the bass component 102a so that the frequency of the bass component 102a is increased from the initial setting and the volume of the bass component 102a is increased from the initial setting. As a result, the first band 104a and the first peak frequency ω1 of the bass component 102a are shifted by Δω to the lower frequency side compared to the initial setting (shown by the dashed line in FIG. 6). The adjustment of the volume and frequency is shown diagrammatically by arrows 108d and 108e in FIG. 6.

[0054] The volume of the treble component 102b is increased compared to when the brightness around the vehicle 10 is below the brightness threshold, but the pitch of the sound is not changed. Therefore, the mixer 124 adjusts the treble component 102b so as to keep the second band 104b and the second peak frequency ω2 of the treble component 102b as initially set, and to increase the volume of the treble component 102b from the initial setting. This adjustment is shown diagrammatically by the arrow 108f in FIG. 6.

[0055] Next, the low frequency component 102a and the high frequency component 102b are mixed together (S55). In this manner, the mixer 124 generates the vehicle approach warning sound 102 from the low frequency component 102a and the high frequency component 102b.

[0056] As an option, a frequency shift amount and a volume shift amount linked to the vehicle speed may be set for the generated vehicle approach warning sound 102 (S56). In this manner, a plurality of vehicle approach warning sounds 102 corresponding to different vehicle speeds may be generated.

[0057] Then, the generated vehicle approaching warning sound 102 is played (S57). Audio data or an audio signal representing the vehicle approaching warning sound 102 is output from the controller 120 to the sound generating device 110, and the sound generating device 110 emits the vehicle approaching warning sound 102. This is how the control process ends.

[0058] When it is bright around the vehicle, such as during the day, it is expected that the vehicle approaching warning sound 102 is relatively likely to be drowned out by surrounding noise. It is also known that the lower the sound, the more likely it is to spread to the surroundings due to diffraction. Therefore, according to this embodiment, by making the bass component 102a of the vehicle approaching warning sound 102 lower, it is possible to effectively notify other traffic in the vicinity of the approach of the vehicle 10. In addition, increasing the volume of the bass component 102a and the treble component 102b also helps to effectively notify other traffic of the approach of the vehicle 10.

[0059] As a modified example, when the frequency of at least one of the low-pitched component 102a and the high-pitched component 102b is shifted, the unshifted sound as initially set may remain in the vehicle approach warning sound 102. When this is applied to the examples of Figures 3 and 4, the vehicle approach warning sound 102 may include the low-pitched component 102a, the high-pitched component 102b as initially set, and another high-pitched component 102b that is higher in pitch than the low-pitched component 102a. When applied to the examples of Figures 5 and 6, the vehicle approach warning sound 102 may include the low-pitched component 102a as initially set, another low-pitched component 102a that is lower in pitch than the low-pitched component 102a, and the high-pitched component 102b.

[0060] 7 is a block diagram showing an example of a vehicle lamp 20 incorporating a vehicle approach notification device 100 according to an embodiment. In this embodiment, the vehicle lamp 20 is a headlamp as an example, and includes a first lamp unit 20a as a left headlamp and a second lamp unit 20b as a right headlamp. Therefore, the first lamp unit 20a and the second lamp unit 20b are provided on the left and right sides of the front of the vehicle, and have substantially the same configuration except that they have a symmetrical structure.

[0061] Each of the first lamp unit 20a and the second lamp unit 20b includes a light source 22, an outer lens 24 arranged so that light emitted from the light source 22 passes through toward the front of the vehicle, and a lamp body 26 as a partition wall separating the light source 22 from the vehicle body. The configuration of the light source 22 is not particularly limited, and may include, for example, a semiconductor light-emitting element such as an LED (Light Emitting Diode) and a lighting circuit that drives the light-emitting element to light it. The outer lens 24 is integrated with the lamp body 26 so as to close the opening of the lamp body 26 on the vehicle front side, and constitutes a lamp housing 28 in which the light source 22 is arranged. In addition, the lamp housing 28 may house, for example, an inner lens for guiding the light of the light source 22 to the outer lens 24, optical components such as a reflector, a heat dissipation member for cooling the light source 22, and other lamp components.

[0062] The vehicle approaching notification device 100 includes, as in the above-described embodiment, a sound producing device 110 and a controller 120. The controller 120 may be configured to control the sound producing device 110 according to the embodiment, for example, to execute at least one of the control processes described with reference to Figures 3 and 4 and the control processes described with reference to Figures 5 and 6. The vehicle approaching notification device 100 may also include a surroundings monitoring sensor 150.

[0063] The sound producing device 110 is provided in at least one of the first lamp unit 20a and the second lamp unit 20b, and in the illustrated example, in each of both lamp units. In order to effectively produce sound toward the outside of the vehicle, the sound producing device 110 may be attached to the lamp housing 28 on the outside of the lamp housing 28. The sound producing device 110 may be attached to the bottom surface of the lamp body 26. The controller 120 may also be mounted in at least one of the lamp units, and may be attached to the lamp housing 28, for example.

[0064] The controller 120 is configured to control not only the sound generating device 110 but also the vehicle lamp 20. The controller 120 may be configured as a lamp ECU (Electronic Control Unit) that controls the first lamp unit 20a and the second lamp unit 20b.

[0065] While in the above-described embodiment, at least one of the bass component 102a and the treble component 102b of the vehicle approach warning sound 102 is adjusted based on a comparison between the measured brightness of the surroundings of the vehicle 10 and a brightness threshold, the adjustment may alternatively be performed in response to the on / off of the vehicle lamp 20. Such an embodiment is described below.

[0066] Fig. 8 is a block diagram showing an outline of another example of the vehicle lamp 20 incorporating the vehicle approach notification device 100 according to the embodiment. As in the embodiment shown in Fig. 7, the vehicle lamp 20 includes a first lamp unit 20a and a second lamp unit 20b, and each lamp unit includes an outer lens 24 and a lamp body 26 forming a lamp housing 28, and a light source 22 housed in the lamp housing 28. The lamp unit may be, for example, a low beam unit that forms a low beam light distribution pattern, and the vehicle lamp 20 includes a light switch 30 for switching the lamp unit, i.e., the light source 22, on and off by the driver's operation.

[0067] The vehicle approach notification device 100 includes a sound generating device 110 and a controller 120, as in the above-described embodiment. The sound generating device 110 is provided in at least one of the first lamp unit 20a and the second lamp unit 20b, and in the illustrated example, in each of the two lamp units. The controller 120 may be configured to control the sound generating device 110 according to the embodiment, for example, to execute the control process described with reference to FIG. 3 and FIG. 4 and the process described later with reference to FIG. 9. The controller 120 is configured to control not only the sound generating device 110 but also the vehicle lamp 20. The controller 120 can turn on and off the lamp unit in response to the on / off of the light switch 30.

[0068] Fig. 9 is a flowchart showing an example of an adjustment process of the vehicle approach notification sound 102 in the vehicle lamp 20 shown in Fig. 8. This process is executed by the controller 120 in a situation in which the vehicle lamp 20 should emit the vehicle approach notification sound 102, such as while the vehicle 10 is traveling.

[0069] First, the bass component 102a and the treble component 102b are obtained (S90). The mixer 124 may read the first sound source data representing the bass component 102a and the second sound source data representing the treble component 102b from the memory 122, thereby obtaining the bass component 102a and the treble component 102b.

[0070] Also, information indicating the on / off state of the lamp unit of the vehicle lamp 20 is acquired (S91). The mixer 124 can acquire the on / off information of the lamp unit from the light switch 30. Then, it is determined whether the lamp unit is on (S92). The mixer 124 can determine whether the lamp unit is on based on the acquired on / off information.

[0071] When the lighting unit is on (Yes in S92), that is, for example, at night, the pitch and volume of the bass component 102a and the treble component 102b are not changed. In other words, the pitch and volume of the bass component 102a and the treble component 102b are maintained at the pitch and volume values ​​determined by the initial settings of the bass component 102a and the treble component 102b, respectively (S93).

[0072] On the other hand, when the lighting unit is off (No in S92), that is, for example, during the daytime, at least one of the pitch and volume of the low-pitched component 102a and the high-pitched component 102b is adjusted individually to increase the audibility of the vehicle approach warning sound 102 (S94).

[0073] In this example, the bass component 102a is increased in volume and lowered in tone compared to when the lighting unit is on. Thus, the mixer 124 adjusts the bass component 102a so that the frequency of the bass component 102a is increased from the initial setting and the volume of the bass component 102a is increased from the initial setting. The treble component 102b is increased in volume compared to when the lighting unit is on, but the pitch is not changed. Such adjustments can be performed in the same manner as S54 in the embodiment described above with reference to Figs. 5 and 6.

[0074] Next, the low frequency component 102a and the high frequency component 102b are mixed together (S95). In this manner, the mixer 124 generates the vehicle approaching warning sound 102 from the low frequency component 102a and the high frequency component 102b.

[0075] As an option, a frequency shift amount and a volume shift amount linked to the vehicle speed may be set for the generated vehicle approach warning sound 102 (S96). In this manner, a plurality of vehicle approach warning sounds 102 corresponding to different vehicle speeds may be generated.

[0076] Then, the generated vehicle approaching warning sound 102 is played (S97). Audio data or an audio signal representing the vehicle approaching warning sound 102 is output from the controller 120 to the sound generating device 110, and the sound generating device 110 emits the vehicle approaching warning sound 102. This is how the process ends.

[0077] According to the embodiment of Fig. 8 and Fig. 9, when the vehicle lamp is not turned on, that is, when the surroundings of the vehicle are bright, such as during the daytime, the low-pitched components of the vehicle approaching warning sound are made lower than when the surroundings are not bright. As described above, the lower the sound, the more likely it is to spread to the surroundings, so that the approach of the vehicle can be effectively notified to other road users. In addition, the increase in the volume of the low-pitched components 102a and the high-pitched components 102b also helps to effectively notify other road users of the approach of the vehicle 10.

[0078] The present invention has been described using specific terms based on the embodiments, but the embodiments merely show one aspect of the principles and applications of the present invention, and many modifications and changes in arrangement are permitted to the embodiments without departing from the spirit of the present invention as defined in the claims. [Explanation of symbols]

[0079] 10 vehicle, 20 vehicle lamp, 20a, 20b lamp unit, 100 vehicle approach notification device, 102 vehicle approach notification sound, 102a low-pitched component, 102b high-pitched component, 110 sound generation device, 120 controller.

Claims

1. A sound generating device; adjusting the pitch of at least one of a low-pitched component of the vehicle approach notification sound and a high-pitched component of the vehicle approach notification sound that is higher than the low-pitched component in accordance with the surrounding environment of the vehicle; a controller that operates the sound generation device to emit the low-pitched component and the high-pitched component as the vehicle approach warning sound.

2. 2. The vehicle approach notification device according to claim 1, wherein the controller adjusts the treble components so that they are higher in pitch when a pedestrian or a bicycle is detected around the vehicle than when a pedestrian or a bicycle is not detected around the vehicle.

3. 3. The vehicle approach notification device according to claim 1, wherein the controller increases the volume of at least one of the low-frequency component and the high-frequency component when a pedestrian or a bicycle is detected around the vehicle, compared to when a pedestrian or a bicycle is not detected around the vehicle.

4. 2. The vehicle approach notification device according to claim 1, wherein the controller adjusts the bass components to be lower when the brightness of the surroundings of the vehicle exceeds a brightness threshold value compared to when the brightness of the surroundings of the vehicle is below the brightness threshold value.

5. 5. The vehicle approach notification device according to claim 1, wherein the controller increases the volume of at least one of the low-pitched component and the high-pitched component when the brightness of the surroundings of the vehicle exceeds a brightness threshold value, compared to when the brightness of the surroundings of the vehicle is below the brightness threshold value.

6. The sound generating device and the controller are mounted on a vehicle lamp, The vehicle approach notification device according to claim 1 , wherein the controller controls the vehicle lamp.

7. A lighting unit; a sound generating device operable to generate a vehicle approach warning sound including a low-pitched component and a high-pitched component higher than the low-pitched component; When the lighting unit is off, the bass component is adjusted to be lower than when the lighting unit is on; a controller that operates the sound generation device to emit the low-pitched component and the high-pitched component as the vehicle approach warning sound.

8. The vehicular lamp according to claim 7, wherein the controller increases the volume of at least one of the low-pitched component and the high-pitched component when the lamp unit is off, compared to when the lamp unit is on.

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