JP2009043146A - Vehicle approach notification system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve recognizability of notification sound by enhancing the detection precision of peripheral environmental sound. <P>SOLUTION: Sound pressure data resulting from excluding sound pressure data of a frequency band of a notification sound signal of a user's vehicle from a frequency analysis result of a peripheral environmental sound signal in a frequency analyzer 34 is obtained by a user's vehicle notification sound frequency band excluding device 36. An evaluation sound pressure level of the peripheral environmental sounds is obtained from the obtained sound pressure data by a sound pressure level judgement device 38; and when the evaluation sound pressure level of the peripheral environmental sound is judged to be equal to or lower than a prescribed sound pressure level, a notification sound generator 22 is controlled in accordance with a table prestored in a notification sound sound pressure controller 40 so that the sound pressure level of the notification sound of the user's vehicle may be higher than the evaluation sound pressure level of the peripheral environmental sound by a prescribed value. Therefore, the sound pressure level of the peripheral environmental sound can be detected with a high precision without being affected by the notification sound of the user's vehicle 10, and the notification sound superior in recognizablity can be emitted from a speaker 12 to the outside of the vehicle. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vehicle approach notification device, and more particularly, to a vehicle approach notification device that is mounted on a low-noise vehicle such as an electric vehicle or a hybrid vehicle to make a pedestrian or other notification object aware of the approach of the vehicle.

2. Description of the Related Art Conventionally, a vehicle approach notification device is known that is mounted on a low-noise vehicle such as an electric vehicle or a hybrid vehicle so as to notice the approach of the vehicle to a notification target such as a pedestrian (see, for example, Patent Document 1). In this technique, a starting sound, a traveling sound, and a simulated sound of acceleration or deceleration during traveling are generated, and the simulated sound volume is adjusted according to the surrounding environmental sound.
Japanese Patent Laid-Open No. 7-182587

  However, in the technique of Patent Document 1, when adjusting the volume of the pseudo sound (notification sound) according to the ambient environment sound, the detected ambient environment sound includes the notification sound generated from the own vehicle. Sound detection accuracy decreases. For this reason, in order to improve the recognition of the notification sound, it is necessary to improve the detection accuracy of the ambient environmental sound.

  In consideration of the above facts, an object of the present invention is to provide a vehicle approach notification device that can improve the recognition of notification sound by increasing the detection accuracy of ambient environmental sound.

  The vehicle approach notification device according to the first aspect of the present invention is generated by a notification sound signal generating means for generating a notification sound signal for generating a notification sound for notifying the approach of the vehicle, and the notification sound signal generating means. A notification sound generating means for generating a notification sound based on the notification sound signal, an environmental sound detecting means for detecting a surrounding environmental sound around the vehicle, and the vehicle from the surrounding environmental sound detected by the environmental sound detecting means Determining means for determining the sound pressure level of the surrounding environmental sound excluding the sound corresponding to the frequency band of the notification sound, and when the sound pressure level of the surrounding environmental sound is not more than a predetermined value based on the determination result of the determining means Comprises control means for controlling the notification sound generating means so that a notification sound having a sound pressure level greater than the sound pressure level of the surrounding environmental sound is generated.

  The notification sound generating means generates a notification sound based on the notification sound signal that notifies the approach of the vehicle generated by the notification sound signal generating means. The determining means determines the sound pressure level of the ambient environmental sound obtained by excluding the sound corresponding to the frequency band of the notification sound of the host vehicle from the ambient environmental sound detected by the environmental sound detecting means. Further, when the sound pressure level of the ambient environmental sound is less than or equal to a predetermined value based on the determination result of the determining means, the control means is configured to generate a notification sound having a sound pressure level greater than the sound pressure level of the ambient environmental sound. Controls the sound generation means. Therefore, the ambient sound can be detected with high accuracy without being affected by the notification sound of the host vehicle, and the notification sound generating means can be controlled. As a result, it is possible to generate a notification sound having excellent cognition with respect to the surrounding environmental sound.

  According to a second aspect of the present invention, in the vehicle approach notification device according to the first aspect, the determination unit analyzes the frequency of the surrounding environmental sound detected by the environmental sound detection unit, and at least the vehicle's own vehicle is determined from the frequency analysis result. The sound pressure level of the ambient sound is determined by excluding the sound pressure level corresponding to the frequency band of the notification sound signal.

  The determination means analyzes the frequency of the ambient environmental sound detected by the environmental sound detection means, and excludes at least the sound pressure level corresponding to the frequency band of the notification sound signal of the own vehicle from the frequency analysis result. Determine the sound pressure level. For this reason, the sound pressure level of the surrounding environmental sound can be determined by completely excluding the sound corresponding to the frequency band of the notification sound of the own vehicle from the surrounding environmental sound around the vehicle.

  According to a third aspect of the present invention, in the vehicle approach notification device according to the first or second aspect, when the sound pressure level of the surrounding environmental sound is equal to or lower than the predetermined value, the sound pressure level of the notification sound of the own vehicle Is set to a sound pressure level that is higher than the sound pressure level of the surrounding environmental sound by a certain value.

  When the sound pressure level of the surrounding environment sound is equal to or lower than the predetermined value, the sound pressure level of the notification sound of the own vehicle is set to a sound pressure level that is higher than the sound pressure level of the surrounding environment sound by a certain value. For this reason, the recognition of the notification sound of the own vehicle can be improved.

  According to a fourth aspect of the present invention, in the vehicle approach notification device according to any one of the first to third aspects, when a sound pressure level of the ambient environmental sound exceeds the predetermined value, a predetermined predetermined value is set. A sound pressure level notification sound is generated.

  When the sound pressure level of the ambient environmental sound exceeds a predetermined value, a notification sound having a predetermined sound pressure level set in advance is generated. For this reason, when the sound pressure level of surrounding environmental sound exceeds a predetermined value, it is possible to prevent the sound pressure level of the notification sound of the own vehicle from becoming too large.

  The present invention according to claim 1 can improve the recognition of the notification sound by increasing the detection accuracy of the ambient environmental sound.

  According to the second aspect of the present invention, the sound pressure level of the ambient environmental sound can be determined by completely excluding the sound corresponding to the frequency band of the notification sound of the own vehicle from the ambient environmental sound around the vehicle.

  The present invention according to claim 3 can improve the recognition of the notification sound of the host vehicle.

  According to the fourth aspect of the present invention, it is possible to prevent the sound pressure level of the notification sound of the own vehicle from becoming too large when the ambient environmental sound is loud.

  An embodiment of a vehicle approach notification device according to the present invention will be described with reference to FIGS.

In the figure, the arrow UP indicates the upward direction of the vehicle, and the arrow FR indicates the forward direction of the vehicle. FIG. 1 shows a vehicle 10 as a low noise vehicle equipped with the vehicle approach notification device according to this embodiment. It is shown by the perspective view seen from diagonally forward.

  The vehicle 10 is a hybrid car provided with a traveling engine and a motor as an example of a low noise vehicle.

  As shown in FIG. 1, a pair of speakers 12 is provided at the front end portion 10 </ b> A of the vehicle 10, and these speakers 12 are connected to a control device 14 provided in the engine room 10 </ b> B of the vehicle 10 with a wire harness. Etc. are electrically connected.

  FIG. 2 is a block diagram showing a vehicle approach notification device according to this embodiment.

  As shown in FIG. 2, the control device 14 includes a notification sound signal generation device 20 as a notification sound signal generation unit and a notification sound generation device 22 as a notification sound generation unit. Further, the notification sound generating device 22 includes a speaker amplifier, and the notification sound generating device 22 is connected to the speaker 12 constituting a part of the notification sound generating means.

  The notification sound signal generating device 20 reproduces, for example, a notification sound signal from the audio data stored in the built-in memory and outputs the notification sound signal to the notification sound generating device 22. The notification sound generating device 22 sends the notification sound from the speaker 12 to the outside of the vehicle. Pronounce.

  As shown in FIG. 1, a microphone 16 as environmental sound detection means is provided on the front end upper part 10 </ b> C of the vehicle 10.

  As shown in FIG. 2, the control device 14 includes a microphone amplifier (amplifier) 32 that constitutes a part of the environmental sound detection means. Further, the control device 14 includes a frequency analyzer 34, a vehicle notification sound frequency band excluding device 36, a sound pressure level determining device 38, and a notification sound pressure controller 40 as control means, which constitute determination means.

  The microphone amplifier 32 is connected to the microphone 16 and amplifies ambient sound signals outside the vehicle obtained from the microphone 16.

  The frequency analyzer 34 is connected to the microphone amplifier 32, and performs frequency analysis on the ambient environment sound signal to obtain sound pressure data for each frequency as shown in FIG.

  In FIG. 4, the hatched portion indicates the frequency distribution of the ambient environmental sound, and the blackened portion indicates the frequency distribution of the notification sound of the host vehicle.

  The own vehicle notification sound frequency band excluding device 36 is connected to the frequency analyzer 34 and excludes sound pressure data of the frequency band of the notification sound of the own vehicle stored in advance from the result of frequency analysis of the surrounding environment sound signal. Then, as shown in FIG. 5, the sound pressure data from which the sound pressure data in the frequency band of the notification sound of the host vehicle is excluded is obtained from the frequency analysis result of the ambient sound signal.

  Further, in the present embodiment, the sound pressure data of the frequency band W of the notification sound of the own vehicle is obtained by excluding the sound pressure data of the frequency band W1 slightly wider than the frequency band W of the notification sound of the own vehicle. The sound pressure data completely excluded is obtained.

  Note that sound pressure data in the frequency band W equal to the frequency band W of the notification sound of the host vehicle may be excluded.

  The sound pressure level determination unit 38 is connected to the own vehicle notification sound frequency band excluding unit 36, integrates the sound pressure data of FIG. 5 to obtain the evaluation sound pressure level Y of the surrounding environment sound, and evaluates the surrounding environment sound. It is determined whether or not the sound pressure level Y is equal to or lower than a predetermined sound pressure level Y1.

  The notification sound pressure controller 40 is connected to the sound pressure level determiner 38. The notification sound pressure controller 40 stores a table for controlling the sound pressure of the notification sound of the host vehicle in advance, and the sound pressure of the notification sound is based on the determination result of the sound pressure level determination unit 38. To control.

  Specifically, when the evaluation sound pressure level Y of the surrounding environmental sound is equal to or lower than the predetermined sound pressure level Y1, as shown in FIG. The amplification factor of the notification sound generator 22 is controlled so that the sound pressure level is a predetermined value (ΔX) higher than the evaluation sound pressure level Y.

  When the evaluation sound pressure level Y of the ambient environmental sound exceeds the predetermined sound pressure level Y1, as shown in FIG. 6, the sound pressure level of the notification sound of the own vehicle is set to the predetermined sound pressure level X1. The amplification factor of the notification sound generating device 22 is controlled so as to be fixed to.

  Next, the operation of this embodiment will be described in detail.

  As shown in FIG. 2, in this embodiment, when the ambient environmental sound of the vehicle 10 is detected by the microphone 16, the ambient environmental sound signal is amplified by the microphone amplifier 32 connected to the microphone 16. Sound pressure data for each frequency shown in FIG. 4 is obtained by frequency analysis of the environmental sound signal in the frequency analyzer 34.

  Next, the sound pressure data of the frequency band W1 including the frequency band W of the notification sound of the own vehicle is excluded from the result of the frequency analysis of the surrounding environment sound signal by the frequency analyzer 34 in the own vehicle notification sound frequency band excluding device 36. By doing so, the sound pressure data shown in FIG. 5 is obtained.

  Next, the sound pressure level determination unit 38 integrates the sound pressure data of FIG. 5 to obtain the evaluation sound pressure level Y of the ambient environmental sound, and the evaluation sound pressure level Y of the ambient environmental sound is a predetermined sound pressure level. It is determined whether or not Y1 or less.

  In other words, as shown in the flowchart of FIG. 3, the sound pressure level determination unit 38 calculates the evaluation sound pressure level Y of the ambient environment sound in step S100, and then in step S102, the evaluation sound pressure of the ambient environment sound. It is determined whether the level Y is equal to or lower than a predetermined sound pressure level Y1.

  If it is determined in step S102 that the evaluation sound pressure level Y of the ambient environmental sound is equal to or lower than the predetermined sound pressure level Y1, the notification sound pressure controller 40 in step S104, as shown in FIG. The amplification factor of the notification sound generator 22 is set so that the sound pressure level of the notification sound of the host vehicle becomes a sound pressure level higher than the evaluation sound pressure level Y of the surrounding environmental sound by a predetermined value (ΔX) in accordance with a table stored in advance. To control.

  For this reason, the sound pressure level of the surrounding environmental sound of the host vehicle 10 can be detected with high accuracy without being affected by the notification sound of the host vehicle 10. As a result, a notification sound having excellent cognition with respect to the surrounding environmental sound can be generated from the speaker 12 to the outside of the vehicle.

  On the other hand, as shown in the flowchart of FIG. 3, when it is determined in step S102 that the evaluation sound pressure level Y of the surrounding environment sound is not lower than the predetermined sound pressure level Y1, that is, the evaluation sound pressure of the surrounding environment sound. If it is determined that the level Y exceeds the predetermined sound pressure Y1, the notification sound pressure controller 40 in step S106, according to a prestored table, as shown in FIG. The amplification factor of the notification sound generator 22 is controlled so that the sound pressure level of the notification sound of the own vehicle becomes constant (predetermined sound pressure level X1).

  For this reason, when the surrounding environment sound is loud (the sound pressure level is high), it is possible to prevent the sound pressure level of the notification sound of the own vehicle from becoming too large.

  In the present embodiment, sound pressure data having a frequency band W1 that is slightly wider than the frequency band W of the notification sound of the host vehicle is excluded. For this reason, it is possible to obtain sound pressure data in which the sound pressure data in the frequency band W of the notification sound of the host vehicle is completely excluded. As a result, the sound pressure level of the ambient environmental sound can be detected with higher accuracy.

  Although the present invention has been described in detail with respect to specific embodiments, the present invention is not limited to the above-described embodiments, and various other embodiments are possible within the scope of the present invention. It will be apparent to those skilled in the art. For example, the arrangement positions and the numbers of the speakers 12 and the microphones 16 in the above embodiment are not limited to those in the above embodiment, and a plurality may be provided in other parts such as the rear part of the vehicle 10.

  Further, in the above embodiment, when the evaluation sound pressure level Y of the surrounding environmental sound is determined to be equal to or lower than the predetermined sound pressure level Y1, the sound pressure level of the notification sound of the own vehicle is set to the surroundings according to the table stored in advance. The notification sound generator 22 is controlled so that the sound pressure level is higher by a predetermined value (ΔX) than the evaluation sound pressure level Y of the environmental sound. Instead, the evaluation sound pressure level Y of the surrounding environmental sound is set to the predetermined sound pressure level Y. When the sound pressure level is determined to be equal to or lower than the sound pressure level Y2, the sound pressure level of the notification sound of the host vehicle is set to a sound pressure level lower than the evaluation sound pressure level Y of the surrounding environmental sound by a predetermined value (ΔX) according to the table stored in advance. As described above, the notification sound generating device 22 may be controlled, or the notification sound generating device 22 may be controlled so that the sound pressure level of the notification sound of the host vehicle is equal to the evaluation sound pressure level Y of the surrounding environment sound. Good.

  In the above embodiment, the notification target is a pedestrian, but the notification target is not limited to the pedestrian, and may be another notification target such as a person who is stationary or a person riding a bicycle.

It is the perspective view seen from the vehicle diagonal front which shows the vehicle carrying the vehicle approach notification apparatus which concerns on one Embodiment of this invention. It is a block diagram which shows the vehicle approach notification apparatus which concerns on one Embodiment of this invention. It is a flowchart which shows a part of control in the vehicle approach notification apparatus which concerns on one Embodiment of this invention. It is a graph which shows the result of having analyzed the frequency of the surrounding environmental sound in the vehicle approach notification apparatus which concerns on one Embodiment of this invention. It is the graph which excluded the frequency band of the notification sound of the own vehicle from the frequency analysis result of the surrounding environmental sound in the vehicle approach notification apparatus which concerns on one Embodiment of this invention. It is a graph which shows the relationship between the sound pressure level of the notification sound of the own vehicle in the vehicle approach notification apparatus which concerns on one Embodiment of this invention, and the evaluation sound pressure level of surrounding environmental sound.

Explanation of symbols

10 Vehicle 12 Speaker (Notification sound generating means)
14 control device 16 microphone (environmental sound detection means)
20 Notification sound signal generating device (notification sound signal generating means)
22 Notification sound generating device (notification sound generating means)
32 Microphone amplifier (environmental sound detection means)
34 Frequency analyzer (determination means)
36 Own vehicle notification sound frequency band remover (determination means)
38 Sound pressure level determiner (determination means)
40 Notification sound pressure controller (control means)

Claims (4)

A notification sound signal generating means for generating a notification sound signal for generating a notification sound for notifying the approach of the vehicle;
Notification sound generating means for generating a notification sound based on the notification sound signal generated by the notification sound signal generating means;
Environmental sound detection means for detecting ambient environmental sound around the vehicle;
Determination means for determining the sound pressure level of the ambient environmental sound obtained by excluding the sound corresponding to the frequency band of the notification sound of the host vehicle from the ambient environmental sound detected by the environmental sound detecting means;
When the sound pressure level of the surrounding environmental sound is equal to or lower than a predetermined value based on the determination result of the determining means, the notification sound is generated so that a notification sound having a sound pressure level higher than the sound pressure level of the surrounding environmental sound is generated. Control means for controlling the generating means;
A vehicle approach notification device comprising:   The determination unit analyzes the frequency of the ambient environmental sound detected by the environmental sound detection unit, and excludes at least the sound pressure level corresponding to the frequency band of the notification sound signal of the host vehicle from the frequency analysis result. 2. The vehicle approach notification device according to claim 1, wherein a sound pressure level of environmental sound is determined.   When the sound pressure level of the surrounding environmental sound is equal to or lower than the predetermined value, the sound pressure level of the notification sound of the own vehicle is set to a sound pressure level that is higher than the sound pressure level of the surrounding environmental sound by a certain value. The vehicle approach notification device according to claim 1 or 2.   4. A notification sound having a predetermined sound pressure level set in advance when the sound pressure level of the surrounding environmental sound exceeds the predetermined value. The vehicle approach notification device according to the item.

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