JP2016179802A - Vehicle approach notification device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle approach notification device enabling an easy notification of a vehicle approach to pedestrians and the like, despite changes in surrounding environments.SOLUTION: A vehicle approach notification device 12 comprises a camera 14, an operation button 20, an arithmetic unit 16, and a speaker 18. The roll of the vehicle approach notification device 12 is, in response to conditions such as situations outside vehicle, to generate prescribed notification sound signals, and to produce sound of a notification sound that is based on the notification sound signals. By an installation of the vehicle approach notification device 12 according to the present embodiment in a vehicle 10, the pedestrians and the like can more reliably recognize an approach of the vehicle 10.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vehicle approach notification device, and more particularly to a vehicle approach notification device that notifies a pedestrian or the like of the approach of a vehicle in an easily understandable manner.

  Conventional vehicles are mainly of a type that travels using an engine as a drive source, and pedestrians can recognize a vehicle approaching from behind or from a blind spot by an engine sound emitted by the vehicle. However, since a vehicle using an electric motor as a drive source such as an electric vehicle or a hybrid vehicle does not emit an engine sound, it is difficult for a pedestrian to recognize the approach of the vehicle by the engine sound of the vehicle.

  Therefore, in order to make it easier for pedestrians to recognize the approach of the vehicle, a notification sound is generated in an electric vehicle or a hybrid vehicle.

  Patent Document 1 describes a vehicle approach alarm device that changes a frequency component of an alarm sound according to a situation such as day and night. Specifically, referring to [0023] of this document, the low frequency component is increased in the daytime sound generation data, while the high frequency component is increased in the nighttime sound generation data. As a result, it is possible to generate an alarm sound that is easy to hear for pedestrians both in the daytime and at night.

  Patent Document 2 describes a vehicle approach notification device that can individually correct the level of each frequency constituting a synthesized signal sound. Specifically, referring to [0028] etc. of this document, the frequencies of the four frequency components constituting the synthesized sound signal are gradually increased so that the pitch of the notification sound gradually increases as the vehicle speed increases. To be high.

  Patent Document 3 describes a sound generator that changes a specific frequency component of sound to be generated depending on a running state. Specifically, referring to [0012] etc. of this document, the engine start sound, the travel start sound, the low speed travel sound, etc. are recorded in advance, and any one of these sounds is recorded depending on the situation of the vehicle. , Is pronounced from the speaker.

  Patent Document 4 describes a vehicle approach notification device that generates an approach notification sound toward a specific pedestrian or the like. Specifically, referring to [0069] of this document, an approach notification sound is emitted from a speaker to a pedestrian or the like based on the intention of the occupant.

  Patent Document 5 describes a vehicle approach notification device that automatically switches the sound generation direction depending on whether the vehicle is moving forward or backward. Specifically, referring to [0053] and the like of this document, when the driver detects that the vehicle has been reversely operated by operating the shift lever, ultrasonic waves are applied toward the rear of the vehicle. Is emitted.

  Patent Document 6 describes an approach warning sound generating device that synthesizes and generates a modulated signal modulated by surrounding information. Specifically, with reference to [0024] and the like, the approach warning sound generator synthesizes and emits a modulation signal in which information around the vehicle is superimposed on engine pseudo sound. Thereby, the approach warning sound notifies the pedestrian or the like of the approach of the vehicle, and at the same time, the approach of the other vehicle can be transmitted together.

JP 2012-218862 A JP 2013-205478 A JP 2004-136831 A JP 2008-162477 A JP 2011-50184 A JP 2011-201368 A

  However, in the invention described in the above-mentioned patent document, there is a problem that it is not always easy to easily notify the pedestrian or the like of the approach of the vehicle.

  Specifically, in the invention described in Patent Document 1, since the frequency component of the increased portion is determined in advance during the daytime or at night, the notification sound is finely controlled according to the situation around the vehicle. There was a problem that could not be done. Such problems are the same for the inventions described in Patent Document 2, Patent Document 3, Patent Document 4, and Patent Document 5.

  Further, in the invention described in Patent Document 6, an approach warning sound including a modulation signal modulated according to the surrounding situation is emitted to the outside, but this modulation signal indicates ambient information, It is not intended to make vehicle approach easier to understand. Therefore, in the invention described in Patent Document 6, it is difficult to improve the intelligibility of the approach warning sound.

  The present invention has been made in view of such problems, and an object of the present invention is to make it possible to easily notify a pedestrian or the like of the approach of a vehicle even if the surrounding environment has changed. The object is to provide a vehicle approach notification device.

  The vehicle approach notification device of the present invention is a vehicle approach notification device that outputs a notification sound for reporting the approach of a vehicle to the surroundings, and a first notification sound signal indicating a first notification sound that is a normal notification sound; An additional sound signal indicating an additional sound of a specific frequency band to be added to the first notification sound; storage means for storing; and when a predetermined condition is satisfied, is added to the first notification sound signal. An additional sound determining means for determining a sound generation pressure and a sound generation time of the additional sound signal; and adding the additional sound signal to the first notification sound signal based on the determined sound generation sound pressure and the sound generation time. The mixing means for generating the second notification sound signal and the notification means for generating the second notification sound based on the second notification sound signal are provided.

  Furthermore, in the vehicle approach notification device according to the present invention, the first notification sound signal includes a first frequency component that increases sound pressure on a low frequency side and a second frequency component that increases sound pressure on a high frequency side. The additional sound signal includes a frequency component superimposed on the second frequency component.

  Furthermore, the vehicle approach notification device of the present invention is characterized in that the second notification sound signal generated by the mixing unit is amplified by the amplification unit and then input to the notification unit.

  Furthermore, the vehicle approach notification device of the present invention further comprises vehicle state detection means for detecting the state of the vehicle, and when the vehicle state detection means detects that the vehicle is moving backward, the notification The means is characterized in that the first notification sound and the second notification sound are alternately generated.

  Furthermore, the vehicle approach notification device of the present invention further includes an outside state detection unit that detects a state outside the vehicle, and the additional sound determination unit is configured to output the additional sound based on an output of the outside state detection unit. The sound generation pressure or the sound generation time of the signal is changed.

  Further, in the vehicle approach notification device according to the present invention, when the vehicle exterior state detection unit detects that the vehicle outside condition is daytime, the additional sound determination unit increases the sound pressure of the additional sound signal, When the state detection unit detects that the situation outside the vehicle is nighttime, the additional sound determination unit reduces the sound generation sound pressure of the additional sound signal.

  Further, in the vehicle approach notification device according to the present invention, when the vehicle outside state detection unit detects that the vehicle outside situation is an urban area, the additional sound determination unit extends the sound generation time of the additional sound signal, and the vehicle outside state If the detection means detects that the situation outside the vehicle is a suburb, the additional sound determination means shortens the sound generation time of the additional sound signal.

  Furthermore, in the vehicle approach notification device according to the present invention, the additional sound determination means is configured to generate a sound pressure and a sound output of the additional sound signal added to the first notification sound signal in response to an operation of a driver driving the vehicle. It is characterized by determining time.

  Furthermore, the vehicle approach notification device of the present invention is characterized in that the vehicle speed of the vehicle and the sound generation sound pressure of the additional sound signal have a positive correlation.

  The vehicle approach notification device according to the present invention is a vehicle approach notification device that outputs a notification sound for reporting the approach of a vehicle to the surroundings, and a first notification sound signal indicating a first notification sound that is a normal notification sound. Storage means for storing an additional sound signal indicating an additional sound of a specific frequency band added to the first notification sound, and when the predetermined condition is satisfied, the additional sound signal is added to the first notification sound signal. An additional sound determining means for determining a sound pressure and a sound generation time of the additional sound signal, and adding the additional sound signal to the first notification sound signal based on the determined sound pressure and the sound generation time. Thus, a mixing unit that generates a second notification sound signal and a notification unit that generates a second notification sound based on the second notification sound signal are provided. Therefore, the second notification sound is generated by determining the sound pressure and the sound generation time of the additional sound added to the first notification sound according to the situation of the vehicle itself or the outside of the vehicle. A second notification sound that can be easily recognized by a pedestrian or the like can be generated.

  Furthermore, according to the vehicle approach notification device of the present invention, the first notification sound signal includes a first frequency component in which the sound pressure increases on the low frequency side, and a second frequency component in which the sound pressure increases on the high frequency side, The additional sound signal includes a frequency component superimposed on the second frequency component. Therefore, since the additional sound has a relatively high frequency component, the second notification sound generated by adding the additional sound is easily recognized by a pedestrian or the like.

  Furthermore, according to the vehicle approach notification device of the present invention, the second notification sound signal generated by the mixing unit is amplified by the amplification unit and then input to the notification unit. Therefore, since the second notification sound after the additional sound is synthesized is amplified and generated, the notification sound is less likely to generate noise and less strange.

  Furthermore, according to the vehicle approach notification device of the present invention, further comprising vehicle state detection means for detecting the state of the vehicle, and when the vehicle state detection means detects that the vehicle is moving backward, The notification means alternately generates the first notification sound and the second notification sound. Therefore, since the notification sound sounds like an intermittent sound, the pedestrian can recognize that the vehicle is moving backward.

  Furthermore, according to the vehicle approach notification device of the present invention, it further comprises vehicle exterior state detection means for detecting an external state of the vehicle, and the additional sound determination means is based on the output of the vehicle exterior state detection means, Change the sound pressure or time of the additional sound signal. Therefore, the second notification sound generated by adding the additional sound can be an appropriate sound according to the situation outside the vehicle.

  Further, according to the vehicle approach notification device of the present invention, when the vehicle outside state detection means detects that the situation outside the vehicle is daytime, the additional sound determination means increases the sound generation sound pressure of the additional sound signal, When the state detection means detects that the situation outside the vehicle is nighttime, the additional sound determination means decreases the sound generation sound pressure of the additional sound signal. Therefore, the second notification sound generated by adding the additional sound can be easily recognized in the daytime and can be quiet in the nighttime.

  Further, according to the vehicle approach notification device of the present invention, when the vehicle exterior state detection means detects that the situation outside the vehicle is an urban area, the additional sound determination means extends the sound generation time of the additional sound signal, When the vehicle outside state detection means detects that the situation outside the vehicle is a suburb, the additional sound determination means shortens the sound generation time of the additional sound signal. Therefore, the second notification sound generated by adding the additional sound can be easily recognized in the urban area and quiet in the suburbs.

  Further, according to the vehicle approach notification device of the present invention, the additional sound determination means is a sound generation sound pressure of the additional sound signal added to the first notification sound signal in accordance with an operation of a driver driving the vehicle. And determine the pronunciation time. Therefore, a pedestrian who is not aware of the approach of the vehicle can be made to recognize the second notification sound more reliably.

  Furthermore, according to the vehicle approach notification device of the present invention, the vehicle speed of the vehicle and the sound generation sound pressure of the additional sound signal have a positive correlation. Therefore, it is possible to notify surrounding pedestrians and the like that the vehicle is moving at a relatively high speed.

It is a figure which shows the vehicle approach notification apparatus of this invention, (A) is a side view which shows a vehicle, (B) is a block diagram which shows a vehicle approach notification apparatus. It is a figure which shows the vehicle approach notification apparatus of this invention, (A) to (C) is a graph which shows the sound pressure of each sound source. It is a figure which shows the vehicle approach notification apparatus of this invention, (A) is a timing chart which shows the notification sound sounded, (B) is a graph which shows an additional sound signal, (C) and (D) It is a graph which shows the characteristic of an additional sound signal. It is a figure which shows the vehicle approach notification apparatus of this invention, and is a flowchart which shows the procedure of notification.

  Hereinafter, the vehicle approach notification device of the present embodiment will be described with reference to the drawings.

  With reference to FIG. 1, the schematic structure of the vehicle approach notification apparatus 12 of this form is demonstrated. FIG. 1A is a side view showing a vehicle 10 equipped with a vehicle approach notification device 12, and FIG. 1B is a block diagram showing a configuration of the vehicle approach notification device 12.

  With reference to FIG. 1 (A), the vehicle approach notification apparatus 12 of this form is provided in the vehicle 10 which is an electric vehicle, a hybrid vehicle, or a fuel cell vehicle, for example. When the vehicle 10 is an electric vehicle or the like, no engine sound is generated during traveling, so that pedestrians, bicycle riders and the like are not likely to notice the approach of the vehicle 10. Therefore, in this embodiment, the vehicle approach notification device 12 notifies the pedestrian or the like of the approach of the vehicle 10 by generating a notification sound.

  The vehicle approach notification device 12 includes a camera 14 (vehicle exterior state detection means), an operation button 20, an arithmetic unit 16, and a speaker 18 (report means). The role of the vehicle approach notification device 12 is to generate a predetermined notification sound signal in accordance with conditions such as the situation outside the vehicle and to generate a notification sound based on the notification sound signal toward the outside of the vehicle. When the vehicle approach notification device 12 of this embodiment is installed in the vehicle 10, a pedestrian or the like can more reliably recognize that the vehicle 10 is approaching.

  The camera 14 is composed of, for example, a stereo camera that is attached to the front upper part and faces forward in the vehicle interior of the vehicle 10. The camera 14 has a function of calculating a distance between the vehicle and an object located in front of the vehicle based on an image obtained by photographing the front of the vehicle through the windshield. Further, by analyzing the image obtained from the camera 14, it is possible to recognize pedestrians, bicycle riders, vehicles, buildings, roads, etc. existing in the image.

  The operation button 20 is, for example, a push button type button arranged near the driver's seat (for example, an instrument panel). In this embodiment, when the driver presses the operation button 20, a predetermined notification sound is generated from the speaker 18 for a predetermined time. Such an operation will be described later with reference to FIG.

  The arithmetic unit 16 has a function of performing a predetermined arithmetic processing based on information input from the camera 14 and the operation buttons 20 and outputting a notification sound signal indicating a notification sound generated by the arithmetic processing to the speaker 18. Have. As the arithmetic unit 16, a microcomputer (ECU (Electronic Control Unit)) having a predetermined storage circuit and an arithmetic circuit is employed.

  The speaker 18 is provided in the vicinity of the front end of the vehicle 10 and has a function of generating a notification sound that informs that the vehicle 10 is approaching.

  Referring to FIG. 1B, the vehicle approach notification device 12 includes a vehicle state detection unit 22 (vehicle state detection means) in addition to the operation button 20, the camera 14, the arithmetic unit 16, and the speaker 18 described above. ing. Each part which comprises the vehicle approach notification apparatus 12 is electrically connected mutually via connection means, such as a harness. The vehicle state detection unit 22, the operation button 20, and the camera 14 are connected to the input side terminal of the arithmetic unit 16. The speaker 18 is connected to the output side terminal of the arithmetic unit 16.

  The vehicle state detection unit 22 is a part that detects the state of the vehicle 10 itself. Specifically, the vehicle state detection unit 22 detects the operating state of the vehicle 10 such as the vehicle speed, the gear shift position, the engine oil pressure, the brake switch, and the tail lamp, and outputs an electrical signal indicating the operating state to the arithmetic unit 16.

  The vehicle speed of the vehicle 10 is used to determine whether or not it is a vehicle speed at which a notification sound should be reported.

  The gear shift position is used to determine whether the traveling state of the vehicle 10 is a stopped state (parking state), a forward state (drive state), or a reverse state (reverse state).

  The engine oil pressure indicates whether or not the vehicle 10 is running. If the engine oil pressure is greater than a certain value, it is determined that the engine is rotating. If the engine oil pressure is less than a certain value, the engine is stopped. To be judged.

  The brake switch is used to determine whether or not the vehicle 10 is traveling. If the brake switch remains on, it is determined that the brake is operating. If the brake switch remains off, it is determined that the brake is not operating.

  The taillight is used to determine whether the outside of the vehicle is daytime or nighttime. If the taillight is off, the outside of the vehicle is judged to be daytime, and if the taillight is on, the outside of the vehicle Judged to be at night.

  The operation button 20 is a part to be operated when it is determined that the driver should forcibly generate a notification sound in order to inform a pedestrian or the like of the approach of the vehicle 10. When the driver presses the operation button 20, an electric signal indicating that is input to the arithmetic unit 16.

  The camera 14 obtains image data by photographing the front of the vehicle 10. In this embodiment, it is determined whether or not there is a pedestrian or a bicycle around the front of the vehicle 10 by performing image processing on the obtained image data. Further, by processing the image data obtained from the camera 14 which is a stereo camera, the distance between the vehicle 10 and a pedestrian or the like existing in front of the vehicle 10 can be calculated. Information based on the image obtained by the camera 14 is input to the arithmetic unit 16.

  The calculation unit 16 includes a vehicle body environment calculation unit 24, a sound generation control unit 26, and a sound output unit 38.

  The vehicle body environment calculation unit 24 receives the outputs from the vehicle state detection unit 22, the operation button 20, and the camera 14, and performs predetermined calculation processing to perform information processing regarding the vehicle 10 itself and the surrounding environment. It is a part. The calculation result of the vehicle state detection unit 22 is input to the sound generation control unit 26.

  The sound generation control unit 26 is a part that generates a notification sound signal based on information input from the vehicle body environment calculation unit 24. The sound generation control unit 26 includes a sound generation condition calculation unit 28, a first storage unit 30, a second storage unit 32, an additional sound determination unit 34, and a mixer 36.

  The sound generation condition calculation unit 28 performs a calculation for determining the sound generation sound pressure and the sound generation time of the additional sound signal based on the information input from the vehicle body environment calculation unit 24. Information to be considered here is whether the vehicle 10 is traveling at the driving speed of the vehicle, the motor, whether the vehicle 10 is in a forward or reverse state, whether the situation outside the vehicle is daytime or nighttime, It includes whether or not there are pedestrians or the like in the lane ahead, whether the outside of the vehicle is an urban area or a suburb, the road width, the number of buildings beside the road, the operation status of the operation buttons 20, and the like.

  The first storage unit 30 (storage unit) stores a first notification sound signal that is a normal notification sound. For example, a pseudo engine sound is employed as the first notification sound signal. Here, the first notification sound signal is a sound that is generated in order to notify the surroundings of the presence of the vehicle 10 driven by the motor when there is no pedestrian or the like in front of the vehicle 10.

  The second storage unit 32 (storage means) stores an additional sound signal added to the first notification sound signal. As the frequency band of the additional sound signal, for example, 2 KHz that is easily recognized by a pedestrian or the like is employed.

  The additional sound determination unit 34 (additional sound determination means) determines the sound generation sound pressure and sound generation time of the additional sound signal added to the first notification sound signal based on the condition calculated by the sound generation condition calculation unit 28. Yes.

  The mixer 36 (mixing means) gives the additional sound signal stored in the second storage unit 32 to the first notification sound signal stored in the first storage unit 30 as necessary. Specifically, if there is no pedestrian or the like in front of the vehicle 10, the mixer 36 does not give an additional sound signal to the first notification sound signal. On the other hand, when a pedestrian or the like is present in front of the vehicle 10, the mixer 36 adds an additional sound signal to the first notification sound signal to generate a second notification sound signal. At this time, the sound generation volume and sound generation time of the additional sound signal to be added are determined by the additional sound determination unit 34. In this embodiment, since the second notification sound signal is generated by adding the additional sound signal to the first notification sound signal in real time before the sound output unit 38 that is an amplifier, the notification sound to be generated is generated. The generation of noise is suppressed.

  The sound output unit 38 (amplifying unit) has a function of amplifying the notification sound signal generated by the mixer 36. The amplified notification sound signal is input to the speaker 18, and the speaker 18 generates a notification sound based on the notification sound signal toward the outside of the vehicle. In this embodiment, as will be described later, when a pedestrian or the like is present in front of the vehicle 10, the first notification sound and the second notification sound are sounded mutually.

  Next, the first notification sound signal, the additional sound signal, and the second notification sound signal will be described with reference to FIG. 2A is a graph showing the first notification sound signal, FIG. 2B is a graph showing the additional sound signal, and FIG. 2C is a graph showing the second notification sound signal. In these graphs, the horizontal axis represents frequency and the vertical axis represents sound pressure.

  Referring to FIG. 2A, the first notification sound signal generated in a situation where no pedestrian or the like is present in front of the vehicle 10 has a high sound pressure in two frequency bands. Specifically, the first notification sound signal has a first frequency component 40 in which the sound pressure increases on the low frequency side and a second frequency component 42 in which the sound pressure increases on the high frequency side (near 2 KHz). ing. By having the first frequency component 40 on the low frequency side, the first notification sound signal is easily recognized by elderly people with weak hearing. In addition, since the second frequency component 42 on the high frequency side is included, the second notification sound signal is easily recognized by young people.

  Referring to FIG. 2B, the additional sound signal that is appropriately given to the first notification sound signal described above is composed of frequency components in the vicinity of 2 KHz. That is, the frequency band of the additional sound signal is superimposed on the frequency band of the second frequency component 42 of the first notification sound signal shown in FIG.

  FIG. 2C shows a second notification sound signal generated by adding an additional sound signal to the first notification sound signal. The second notification sound signal shown in this figure is similar to the first notification sound signal described above, the first frequency component 44 in which the sound pressure increases on the low frequency side and the second frequency component in which the sound pressure increases on the high frequency side. 46. The second frequency component 46 of the second notification sound signal has a higher sound pressure than the second frequency component 42 of the first notification sound signal due to the addition of the additional sound signal. Thereby, the second notification sound signal is a sound that is more easily recognized by pedestrians or the like than the first notification sound signal. In this embodiment, the first notification sound and the second notification sound are generated from the speaker 18 mutually.

  With reference to FIG. 3, the notification method in this form is further demonstrated. 3A is a chart showing the sound generation pattern of the notification sound, FIG. 3B is a graph showing the additional sound signal, and FIG. 3C is a relationship between the vehicle speed and the sound generation pressure of the additional sound signal. FIG. 3D is a graph showing the relationship between the distance from a pedestrian and the like and the sound generation time of the additional sound signal.

  Referring to FIG. 3A, in this embodiment, when a pedestrian or the like is present in front of the vehicle, a first period in which the first notification sound is generated and a second period in which the second notification sound is generated are repeated. ing. Here, the length D1 of the first period is, for example, 500 ms to 1 s, and the length D2 of the second period is, for example, 500 ms to 1 s. In this way, by repeatedly generating the first notification sound and the second notification sound, a pedestrian or the like existing around the vehicle 10 can easily recognize the notification sound. Further, when the vehicle 10 is moving backward, the notification sound is heard as an intermittent sound, and a pedestrian or the like who has heard the notification sound can recognize the backward movement of the vehicle 10.

  Referring to FIG. 3C, in this embodiment, the sound pressure of the additional sound signal is increased as the vehicle speed increases. That is, both have a positive correlation. Therefore, the sound pressure of the additional sound signal shown in FIG. 3B increases depending on the vehicle speed. By doing in this way, since approach of the vehicle 10 with a high vehicle speed can be notified to a pedestrian etc. more reliably, the effect which prevents the contact with the vehicle 10 and a pedestrian etc. becomes large.

  Further, in this embodiment, the sound pressure of the additional sound signal added is different between daytime and nighttime. Here, the sound pressure of the additional sound signal is larger in the daytime (solid line) than in the nighttime (dotted line). That is, the sound pressure of the second notification sound signal generated by adding the additional sound signal is larger in the daytime than in the nighttime. By making the second notification sound signal relatively large during the daytime, the second notification sound can be easily recognized by pedestrians and the like even in the daytime when the outside noise is large.

  Referring to FIG. 3D, in this embodiment, the sound generation cycle shown in FIG. 3A is variable in accordance with the distance from the pedestrian or the like. Here, as the distance from the pedestrian or the like increases, the period D2 (FIG. 3A) in which the second notification sound is generated is lengthened. The period D1 during which the first notification sound is generated is fixed to 1 s, for example. By doing in this way, it can be heard to a pedestrian etc. that a report sound changes gradually (for example, it sounds like a warning sound from a report sound), and can report the existence of vehicles 10 more certainly. it can.

  Further, in this embodiment, the sounding time of the second notification sound is longer in the urban area (solid line) than in the suburbs (dotted line). This makes it easy for pedestrians to recognize the notification sound in a noisy urban area, and prevents the notification sound from becoming too loud in a suburb with little noise.

  Based on FIG. 4, a method for making a notification using the vehicle approach notification device 12 having the above-described configuration will be described with reference to the respective drawings. Here, the following calculation for determining the condition of the additional sound is performed by the sound generation control unit 26 shown in FIG.

  First, it is determined whether or not the vehicle speed of the vehicle 10 is equal to or lower than a predetermined value (step S11). Here, the predetermined speed is, for example, a low speed of about 30 km / hr or less or about 20 km / hr. When a hybrid vehicle or the like is traveling at a low speed, pedestrians around the vehicle are not likely to notice the approach of the vehicle 10, so in this embodiment, as described below, a notification sound for reporting the presence of the vehicle 10 is generated. doing. If the vehicle speed is less than a certain value, the process proceeds to step S12 (YES in step S11). If the vehicle speed is faster than the certain speed (NO in step S11), the process does not proceed to the following steps and does not sound a notification sound (step S14). ).

  Next, it is determined whether or not the vehicle 10 is running on a motor (step S12). If the vehicle is running (YES in step S12), the process proceeds to step S15. On the other hand, if the motor is not running (NO in step S12), the pedestrian and the like can recognize the presence of the vehicle by the engine sound generated from the rotating engine, and thus the process does not proceed to the following step (step S14).

  In step S15, the gear position is determined. If the gear position is P (stop position), the vehicle 10 does not move, so there is no risk of contact with a pedestrian or the like, and the following steps are not performed (step S16). If the position of the gear is D (forward) or the like, the vehicle 10 is traveling, so the process proceeds to step S18 in order to generate a notification sound.

  On the other hand, if the position of the gear is R (reverse), a notification sound indicating reverse is generated to notify the surroundings that the vehicle 10 is moving backward. Specifically, as shown in FIG. 3A, the first notification sound and the second notification sound are repeatedly pronounced. Thereby, since the notification sound can be heard intermittently, a pedestrian or the like can recognize that the vehicle 10 is moving backward by this sound.

  In step S18, it is determined whether a pedestrian or the like is present in front of the vehicle 10. This determination is made using image data obtained by the camera 14 shown in FIG. If there is no pedestrian or the like ahead of the vehicle 10 (NO in step S18), a normal first notification sound is generated (step S19). Here, the first notification sound is a notification sound having the waveform shown in FIG.

  On the other hand, if a pedestrian or the like is present in front of the vehicle 10 (YES in step S18), the process proceeds to the following steps in order to generate a second notification sound that is more easily recognized by the pedestrian or the like than the first notification sound.

  In step S20, it is determined whether it is daytime (step S20), and if it is daytime (YES in step S20), the Hi mode is set to increase the sound pressure of the additional sound signal based on the vehicle speed (step S21) (FIG. 3 (solid line shown in (C)). On the other hand, if it is night (NO in step S20), the Lo mode is set to reduce the sound pressure of the additional sound signal based on the vehicle speed (step S22) (dotted line shown in FIG. 3C). Here, the determination of whether it is daytime can be performed using the lighting state of the light and the above-described image data.

  When the Hi mode is selected in step S21, it is determined whether or not the road on which the vehicle 10 travels is in an urban area (step S23). Judgment as to whether or not it is an urban area is made based on image data taken by the camera 14, and is determined to be an urban area when the traffic volume is more than a certain value or the number of buildings in the surrounding area is more than a certain value. Is done. On the other hand, if the traffic volume is less than a certain value, or if the number of buildings in the surrounding area is less than a certain value, it is determined as a suburb.

  When the road on which the vehicle 10 is traveling is in an urban area (YES in step S23), the sound generation time of the additional sound signal based on the vehicle speed is made relatively long (step S24) (Long mode). Specifically, the sounding time indicated by the solid line in FIG.

  Thereafter, in step S26, a notification sound based on the above-described conditions is generated outwardly from the speaker 18 (FIG. 1A). The notification sound generated in this step is in a state where the pronunciation time of the second notification sound is long and the sound pressure of the second notification sound is high. In general, when the outside of the vehicle is an urban area in the daytime, the noise is relatively high, so the motor-driven vehicle 10 is in an environment that is difficult for a pedestrian or the like to recognize. In this step, the approach time of the vehicle 10 is reported to a pedestrian or the like in an easy-to-understand manner by increasing the sounding time of the second reporting sound and increasing the sounding sound pressure.

  On the other hand, when the environment outside the vehicle is a suburb (NO in step S23), the sound generation time of the additional sound source based on the vehicle speed is relatively shortened (step S25) (short mode). Specifically, the sound generation time indicated by the dotted line in FIG.

  Thereafter, in step S27, a notification sound based on the above-described conditions is generated outward from the speaker 18 (FIG. 1A). The notification sound generated in this step is in a state where the sounding time of the second notification sound is short and the sounding sound pressure of the second notification sound is high. The notification sound generated in this step sounds slightly quieter than the notification sound generated in step 26. Therefore, it is suppressed that a report sound is heard too loudly in the suburbs.

  When the Lo mode with a low sound production sound pressure is adopted in step S22, it is determined whether or not the situation outside the vehicle is an urban area (step S28). This determination method is the same as step S23 described above.

  When the road on which the vehicle 10 travels is in an urban area (YES in step S28), the sound generation time of the additional sound signal based on the vehicle speed is made relatively long (step S29) (Long mode). Thereafter, in step S31, a notification sound based on the above-described conditions is generated outwardly from the speaker 18 (FIG. 1A). The notification sound generated in this step is in a state in which the second notification sound has a long sounding time and the second notification sound has a low sound pressure. The notification sound in this step sounds slightly quieter than in step 27. Accordingly, it is possible to suppress the notification sound from being excessively loud at night.

  On the other hand, when the environment outside the vehicle is a suburb (NO in step S28), the sound generation time of the additional sound source based on the vehicle speed is relatively shortened (step S30) (Short mode). Thereafter, in step S32, a notification sound based on the above-described condition is generated outward from the speaker 18 (FIG. 1A). The notification sound generated at this step is in a state where the sounding time of the second notification sound is short and the sounding sound pressure of the second notification sound is low. The notification sound generated in this step sounds slightly quieter than the notification sound generated in step 31. Therefore, the notification sound in this step is adjusted so as to have an appropriate level in the suburbs at night.

  As described above, in this embodiment, when the pedestrian is confirmed forward, the second notification sound having a higher initial sound pressure than the normal first notification sound is generated. Further, the sound generation pressure and time of the second notification sound are adjusted according to the situation outside the vehicle. Therefore, it is possible to appropriately notify the pedestrian or the like of the approach of the vehicle 10 and to prevent the notification sound from being heard excessively loud.

  With reference to FIG.4 (B), the method to perform notification by a driver | operator's operation is demonstrated. When the driver wants to inform a pedestrian or the like existing in the traveling direction of the vehicle 10 that the vehicle 10 is present, the driver presses the operation button 20 (FIG. 1A) (YES in step 50). Then, a notification sound is forcibly generated from the speaker 18 (FIG. 1A) for a certain period of time (for example, several tens of seconds), so that a pedestrian or the like can recognize the presence of the vehicle 10. The notification sound generated at this step has a high sound pressure level of the second notification sound and a long sounding time. That is, the notification sound generated in this step is similar to the notification sound generated in step S26 described above.

  Such a pronunciation is generated only when the operation button 20 is operated, and is not generated unless the operation button 20 is pressed (step S52).

  As mentioned above, although embodiment of this invention was described, this invention is not limited to this, In the range which does not deviate from the summary of this invention, a change is possible.

DESCRIPTION OF SYMBOLS 10 Vehicle 12 Vehicle approach notification apparatus 14 Camera 16 Computation unit 18 Speaker 20 Operation button 22 Vehicle state detection part 24 Car body environment computation part 26 Sound generation control part 28 Sound condition calculation part 30 1st memory | storage part 32 2nd memory | storage part 34 Determination of additional sound Unit 36 mixer 38 sound output unit 40 first frequency component 42 second frequency component 44 first frequency component 46 second frequency component

Claims (9)

It is a vehicle approach notification device that outputs a notification sound for reporting the approach of the vehicle to the surroundings,
Storage means for storing a first notification sound signal indicating a first notification sound, which is a normal notification sound, and an additional sound signal indicating an additional sound of a specific frequency band added to the first notification sound;
An additional sound determination means for determining a sound pressure and a sound generation time of the additional sound signal to be added to the first notification sound signal when a predetermined condition is satisfied;
Mixing means for generating a second notification sound signal by adding the additional sound signal to the first notification sound signal based on the determined sound pressure and the sound generation time;
Notification means for generating a second notification sound based on the second notification sound signal;
A vehicle approach notification device comprising: The first notification sound signal includes a first frequency component that increases sound pressure on the low frequency side and a second frequency component that increases sound pressure on the high frequency side,
The vehicle approach notification device according to claim 1, wherein the additional sound signal includes a frequency component superimposed on the second frequency component.   3. The vehicle approach notification device according to claim 1, wherein the second notification sound signal generated by the mixing unit is amplified by an amplification unit and then input to the notification unit. . Vehicle state detection means for detecting the state of the vehicle,
When the vehicle state detection unit detects that the vehicle is moving backward, the notification unit alternately generates the first notification sound and the second notification sound. The vehicle approach notification device according to any one of claims 1 to 3. A vehicle outside state detection means for detecting a state outside the vehicle;
The said additional sound determination means changes the sound generation sound pressure or sound generation time of the said additional sound signal based on the output of the said vehicle exterior state detection means, The sound generation time in any one of Claim 1 to 4 characterized by the above-mentioned. Vehicle approach notification device. When the vehicle exterior state detection means detects that the vehicle exterior condition is daytime, the additional sound determination means increases the sound pressure of the additional sound signal,
6. The vehicle approach according to claim 5, wherein when the vehicle exterior state detection unit detects that the vehicle exterior state is nighttime, the additional sound determination unit decreases the sound generation sound pressure of the additional sound signal. Notification device. If the vehicle exterior state detection means detects that the situation outside the vehicle is an urban area, the additional sound determination means extends the sound generation time of the additional sound signal,
The said additional sound determination means shortens the sounding time of the said additional sound signal, if the said vehicle exterior state detection means detects that the condition outside a vehicle is a suburb, The sound generation time of the said additional sound signal is shortened. Vehicle approach notification device.   The additional sound determination means determines a sound generation pressure and a sound generation time of the additional sound signal added to the first notification sound signal according to an operation of a driver who drives the vehicle. The vehicle approach notification device according to any one of claims 1 to 7.   The vehicle approach notification device according to any one of claims 1 to 8, wherein a vehicle speed of the vehicle and a sound generation sound pressure of the additional sound signal have a positive correlation.

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