JP2011207391A - Sound producing apparatus for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sound producing apparatus for a vehicle notifying a pedestrian of recognition of an obstacle by a driver of a vehicle.SOLUTION: The sound producing apparatus for a vehicle notifying outside the vehicle of a vehicle's approach includes: an original tone generating unit 2 generating an original tone of an approaching sound for recognition of the vehicle's approach; a modulation tone generating unit 4 generating a modulation tone from the original tone; a sound pressure setting unit 5 setting a sound pressure of the approaching sound of the modulation tone; a speaker 6 producing outside the vehicle the approaching sound of the modulation tone with the set sound pressure; an obstacle detection unit 7 detecting the obstacle outside the vehicle; a sight line direction detection unit 8 detecting the sight line direction of the driver of the vehicle; and a control unit 10 controlling at least either one of the modulation tone generating unit 4 and the sound pressure setting unit 5 so as to change the approaching sound when the sight line direction of the driver and the direction in which the obstacle is present agree to each other.

Description

  The present invention relates to a vehicular sound generation device, and more particularly to a vehicular sound generation device that is suitable for being mounted on a low-noise vehicle such as an electric vehicle and a hybrid vehicle and that notifies the vehicle approach to the outside of the vehicle.

  A low-noise vehicle has less noise when traveling than a conventional automobile, and thus a pedestrian may not notice the approach of the vehicle. For this reason, in order to make a pedestrian or a person riding a bicycle notice the approach of the vehicle, it has been proposed to generate a running pseudo sound from the vehicle.

  The following Patent Document 1 discloses a technique for generating a pseudo sound of tire noise or engine idling sound. Patent Document 2 below discloses a technique for generating a pseudo sound according to an area where a vehicle is traveling.

JP 2009-40318 A JP 2005-253236 A

By the way, these pseudo sounds are nothing but noise for the surroundings of the vehicle, and also reduce the advantage of the low noise vehicle such as high quietness.
Even if the pedestrian notices the approach of the vehicle by the pseudo sound, the pedestrian does not know whether the driver of the vehicle is aware of the pedestrian.

  Therefore, an object of the present invention is to provide a sound generator for a vehicle that can notify an obstacle that the driver of the vehicle recognizes the obstacle.

  In order to achieve the above object, a vehicular sound generation device according to the present invention is a vehicular sound generation device that notifies the outside of a vehicle of the approach of the vehicle, and generates an original tone color of an approaching sound for recalling the approach of the vehicle. Original tone color generating means, modulated tone color generating means for generating a modulated tone color from the original tone color, sound pressure setting means for setting the sound pressure level of the approaching sound of the modulated tone color, and modulation to the outside of the vehicle with the set sound pressure level Sound generation means for generating a timbre approaching sound, obstacle detection means for detecting an obstacle outside the vehicle, gaze direction detection means for detecting the gaze direction of the driver of the vehicle, the gaze direction of the driver and the direction of presence of the obstacle And a control means for controlling at least one of the modulation tone generation means and the sound pressure setting means so as to change the approaching sound when they match.

  According to the present invention configured as described above, an obstacle including a pedestrian or a person riding a bicycle can be obtained by changing the approaching sound when the driver's line-of-sight direction matches the direction in which the obstacle exists. It is possible to confirm that the driver has noticed the presence of an obstacle. As a result, an effect of reducing the anxiety of the obstacle can be expected. Thus, according to the present invention, it is possible to notify the pedestrian that the driver of the vehicle recognizes the obstacle.

  In the present invention, it is preferable that the control unit includes a modulation tone generation unit and a sound pressure setting unit so that the approaching sound is discontinuously changed when the line-of-sight direction of the driver coincides with the direction in which the obstacle exists. At least one of them is controlled.

In this way, by changing the approaching sound discontinuously, when the driver is looking at the obstacle obscurely but does not recognize it as an obstacle, the recognition level of the driver is raised. As a result, the driver can recognize the obstacle.
Furthermore, if the approaching sound is changed discontinuously by suddenly changing the timbre of the approaching sound or the sound pressure of the approaching sound, it is easy for humans who are obstacles to notice the change of the approaching sound. Become.

In the present invention, it is preferable that the control unit lowers the sound pressure of the approaching sound after the driver's line-of-sight direction coincides with the direction of the obstacle to be lower than the sound pressure of the approaching sound before matching. In addition, the sound pressure setting means is controlled.
As described above, after the driver notices an obstacle, the sound pressure of the approaching sound is reduced, thereby suppressing unnecessary noise generation by the sound producing device.

  In the present invention, it is preferable that the control unit repeatedly shifts the fundamental frequency and the frequency component of the harmonic sequence of the fundamental frequency to a predetermined treble side before the driver's line-of-sight direction matches the obstacle presence direction. A modulated tone with an infinite scale that transitions at a speed is generated, and after the driver's line of sight matches the direction in which the obstacle exists, a modulated tone with a reduced transition speed or a stopped transition is generated. In this way, the modulation tone generation unit is controlled.

  The infinite scale has the effect of making a person who hears this an illusion of a continuous increase in frequency while substantially maintaining the frequency characteristics of the original timbre. For this reason, the approach of the vehicle can be felt more strongly. After the driver of the vehicle visually recognizes the obstacle, the driver can avoid the danger, and the dangerous state is alleviated as compared with the state in which the driver does not recognize each other. Therefore, by reducing the transition speed of the infinite scale or stopping the transition, unnecessary noise generation by the sound generator can be suppressed.

In addition, in the present invention, it is preferable that the memory further has a memory that stores the original tone color generation data of the approaching sound in association with the running state of the vehicle, and the original tone color generating means has the original tone color corresponding to the running state of the vehicle. Data for generation is read and an original tone color is generated.
Thereby, the original tone color according to the running state of the vehicle is generated. As a result, when the approaching sound is recalled by the approaching sound, it can be expected that the running state of the vehicle such as the speed and acceleration of the vehicle is also recalled at the same time.

  In the present invention, it is preferable that the vehicle includes an avoidance operation detection unit that detects that the driver has performed an avoidance operation for avoiding an obstacle by the driver, and the control unit changes the approach sound before and after the avoidance operation. As described above, at least one of the modulated tone color generation means and the sound pressure setting means is controlled.

  In this way, if the approaching sound is changed when the driver's line-of-sight direction matches the obstacle's direction, and the driver's avoidance operation is taken, a pedestrian or a person riding a bicycle Obstacles including can also confirm that the driver took an avoidance action. As a result, an effect of further reducing the anxiety of the obstacle can be expected. Thus, according to the present invention, it is possible to notify a pedestrian that the driver of the vehicle has taken an avoidance action.

  Further, according to the vehicle sound producing device of the present invention, the vehicle sound producing device for notifying the outside of the vehicle of the vehicle, the original sound color generating means for generating the original sound color of the approaching sound for recalling the approach of the vehicle A modulation tone generation means for generating a modulation tone from the original tone color, a sound pressure setting means for setting the sound generation pressure of the approaching sound of the modulation tone, and the approaching sound of the modulation tone outside the vehicle with the set sounding sound pressure And a avoidance operation detecting means for detecting that the driver has performed an avoidance operation for avoiding an obstacle by the driver, and the control means changes the approach sound before and after the avoidance operation. As described above, at least one of the modulated tone color generation means and the sound pressure setting means is controlled.

  According to the present invention configured as described above, an obstacle including a pedestrian or a person riding a bicycle is recognized by the driver by the driver by changing the approach sound when the avoidance operation by the driver is taken. It is possible to confirm that the avoidance action is taken. As a result, an effect of reducing the anxiety of the obstacle can be expected. Thus, according to the present invention, it is possible to notify the pedestrian that the driver of the vehicle has taken action to recognize and avoid the obstacle.

  According to the vehicle sound producing device of the present invention, it is possible to notify the obstacle that the driver of the vehicle recognizes the obstacle.

It is a block diagram which shows the structure of the vehicle sound generator by 1st Embodiment of this invention. It is a top view which shows typically arrangement | positioning of the sensor in the vehicle by 1st Embodiment of this invention. (A) is a graph which shows the frequency distribution of the sound pressure of the original tone color in 1st Embodiment, (B) is a graph which shows the frequency characteristic of the gain of an initial stage modulation filter, (C) is a change. It is a graph which shows the frequency characteristic of the gain of a later modulation filter, (D) is a graph which shows the frequency distribution of the sound pressure of a modulation | alteration timbre. It is a flowchart which shows the action | operation of the sound generator for vehicles by 1st Embodiment of this invention. (A) is a graph which shows the frequency characteristic of the sound pressure of the original tone color in 2nd Embodiment, (B) is a graph which shows the frequency characteristic of the gain of an initial stage modulation filter, (C) is a change. It is a graph which shows the frequency characteristic of the gain of a subsequent modulation filter, and (D) is a graph which shows the frequency characteristic of the sound pressure of a modulation | alteration timbre.

Hereinafter, embodiments of a sound generator for a vehicle according to the present invention will be described with reference to the accompanying drawings.
First, with reference to FIG. 1, the structure of the vehicle sound generator according to the embodiment of the present invention will be described. FIG. 1 is a block diagram illustrating a configuration of a vehicle sound producing device according to an embodiment.

  As shown in FIG. 1, the sound generator for a vehicle according to the embodiment generates an original condition color of an approaching sound for reminding the approach of the vehicle and the operating condition determination unit 1 in order to notify the approach of the vehicle to the outside of the vehicle. An original tone color generation unit 2, a memory 3 that stores data for generating original tone colors, a modulation tone generation unit 4 that generates a modulation tone from the original tone color, and a sound pressure setting that sets a sound generation sound pressure of an approaching sound of the modulation tone Unit 5, speaker 6 as sounding means for generating an approaching sound of a modulated tone to the outside of the vehicle with a set sounding sound pressure, obstacle detecting unit 7 for detecting an obstacle outside the vehicle, and the line of sight of the driver of the vehicle The gaze direction detection unit 8 that detects the direction, the avoidance operation detection unit 9 that detects that the driver has performed an avoidance operation for avoiding the obstacle by the driver, and the driver's gaze direction and the obstacle presence direction match. And before and after the avoidance operation In the case of either even without, to vary the proximity sound, and a control unit 10 for controlling at least one of modulation tone generating means and sound pressure setting means.

  The operating condition determination unit 1, the original tone color generation unit 2, the modulation tone generation unit 4, the sound pressure setting unit 5, the obstacle detection unit 7, the gaze direction detection unit 8, the avoidance operation detection unit 9, and the control unit 10 are, for example, an in-vehicle ECU This corresponds to a processing function in (electric control unit: electronic control unit) 100. These processing functions may be realized by executing a predetermined program in a computer, or may be realized by a microchip.

The operating condition determination unit 1 determines whether or not a condition for generating an approaching sound is satisfied. The determination condition is that the traveling vehicle speed detected by the vehicle speed sensor 11 is equal to or lower than a predetermined reference vehicle speed, for example, (0 <vehicle speed ≦ 20 km / h).
The vehicle speed sensor 11 is provided in the engine room in front of the vehicle C as shown in FIG. FIG. 2 is a schematic plan view of the vehicle.

Further, as another determination condition, there is a case where the horn switch (horn SW) 12 is operated even when the vehicle is stopped. This is because it is desirable for the determination condition to make a person around the vehicle aware that the vehicle has started when starting the stopped electric vehicle. Therefore, the approaching sound generated by the sounding device can be used as a warning means that is gentler than that of sounding a horn.
As shown in FIG. 2, the horn switch 12 is provided on the steering wheel of the driver's seat of the vehicle.

The original tone color generation unit 2 reads the original tone color generation data corresponding to the traveling state of the vehicle from the memory 3 and generates an original tone color. The memory 3 stores original tone color generation data in association with the traveling state of the vehicle. Examples of the running state of the vehicle include the vehicle speed detected by the vehicle speed sensor 11, the engine speed (or engine output) detected by the engine rotation sensor 13, and the accelerator opening detected by the accelerator opening sensor 14. .
The engine rotation sensor 13 and the accelerator opening sensor 14 are also provided in the engine room in front of the vehicle C, as shown in FIG.

  In the present embodiment, the memory 3 stores original tone color generation data in association with at least one of the vehicle speed, the engine speed, and the accelerator opening. Therefore, the original tone color generation unit 2 reads the original tone color generation data associated with at least one of the vehicle speed, the engine speed, and the accelerator opening, and generates the original tone color at the vehicle speed or the like.

FIG. 3A schematically shows the generated original tone color graph. The horizontal axis of this graph represents frequency, and the vertical axis represents sound pressure. A curve I in the graph indicates a frequency characteristic of the sound pressure of the original tone color.
The original tone color generation data may be generated using recorded data of tire noise and engine sound of a vehicle that is actually running, or may be generated as a synthesized sound.

The modulated tone color generation unit 4 generates a modulated tone color from the original tone color. For this purpose, the modulation tone generation unit 4 has a modulation filter function.
FIG. 3B schematically shows a graph showing the characteristics of the initialized modulation filter. The horizontal axis of this graph represents frequency, and the vertical axis represents gain (gain). Line II in the graph represents the frequency characteristic of the gain of the initialized modulation filter. As shown by the line II, this initialized modulation filter provides a constant gain g1 regardless of the frequency. For example, the gain g1 = 1.0 dB.

FIG. 3C schematically shows a graph showing the characteristics of the modulation filter after the change. The horizontal axis of this graph represents frequency, and the vertical axis represents gain (gain). A curve III in the graph shows the frequency characteristic of the gain of the modulation filter after the change. As shown in the curve III, modulated filter after the change is a high-pass filter, the frequency component higher than a predetermined threshold frequency f _c, greater than the gain g ₃ to be applied to the frequency components below the threshold frequency f _c A gain g ₂ is selectively given. For example, the gain g ₂ = 0.0 dB and the gain g ₃ = −3 dB are preferable.

  Then, the modulated tone color generation unit 4 generates a modulated tone color from the original tone color using the initialized modulation filter or the modified modulation filter.

  FIG. 3D schematically shows a modulation tone color graph. The horizontal axis of the graph represents frequency, and the vertical axis represents sound pressure. A solid line IV in the graph indicates the frequency characteristic of the sound pressure of the modulated timbre generated by multiplying the original timbre of FIG. 3A by the initialized modulation filter of FIG. 3B. A broken line V in the graph indicates a frequency characteristic of the sound pressure of the modulated timbre generated by multiplying the original timbre of FIG. 3A by the modified modulation filter of FIG. Furthermore, the alternate long and short dash line VI in the graph is generated by multiplying the original tone color in FIG. 3A by a modulation filter with the gains g2 and g3 of the modulation filter after the change in FIG. In addition, the frequency characteristics of the sound pressure of the modulated timbre are shown.

As indicated by the solid line IV, when the initialized modulation filter of FIG. 3B is used, a modulation tone of the original tone color is generated substantially. Further, as shown by the dashed line V, when using a modulation filter after the change of FIG. 3 (C), the modulation tone sound pressure in the low frequency range than the threshold frequency f _c is suppressed is generated. Furthermore, as shown by the alternate long and short dash line VI, when the modulation filter with the gains g2 and g3 of the modulation filter after the change shown in FIG. 3C is used, a modulation tone that further suppresses the entire sound pressure is generated. Is done.

The sound pressure setting unit 5 sets the sound generation sound pressure of the approaching sound of the modulated tone color. In setting the sound generation sound pressure, it is desirable to set a sound pressure slightly higher than the sound pressure of the surrounding environment.
Note that the sound pressure of the surrounding environment of the vehicle is measured by the microphone 15 as the ambient environment sound pressure measuring means. As shown in FIG. 2, the microphone 15 is provided immediately before the windshield of the vehicle and in the vicinity of the center in the vehicle width direction.

Further, when the vehicle headlight is on, the pedestrian usually notices the approach of the vehicle by the light of the headlight. In such a case, it is not necessary to generate a loud approaching sound, and a small approaching sound is sufficient. Therefore, when the image picked up by the outside camera 16 is processed by the obstacle detection unit 7 and the surrounding environment is determined to be night, and the headlight of the vehicle is turned on, the set sound pressure is It is desirable to make it lower than the daytime set sound pressure.
In addition, as shown in FIG. 2, the vehicle exterior camera 16 is provided at the center in the vehicle width direction inside the windshield and near the ceiling of the passenger compartment.

  In addition, when there is a vehicle that produces an approaching sound near the host vehicle, a howling phenomenon may occur if the sound pressure is set slightly higher than the approaching sound of the opponent vehicle. . Therefore, it is desirable to set an appropriate upper limit value when setting the sound pressure.

From the speaker 6, an approaching sound of a modulated tone is generated outside the vehicle with the set sounding sound pressure. By sounding the approach of the modulated timbre in this way, it is possible to generate a sound that easily recalls the approach of the vehicle while suppressing noise from the sound producing device.
In addition, the speaker 6 is provided in the vehicle width direction center vicinity of the vehicle head, as shown in FIG.

  The obstacle detection unit 7 not only cuts off the surrounding environment day and night, but also extracts obstacles such as pedestrians and bicycles from the image captured by the outside camera 16. Furthermore, the obstacle detection unit 7 detects the direction in which the obstacle exists.

  The line-of-sight direction detection unit 8 detects the line-of-sight direction of the driver from an image captured by the in-vehicle camera 17 attached in the vehicle. As shown in FIG. 2, the in-vehicle camera 17 is provided near the passenger compartment ceiling above the driver seat inside the windshield. The line-of-sight direction may be detected based on the movement of the driver's eyeball, or may be detected based on the movement of the driver's head.

  The avoidance operation detection unit 9 is based on the brake operation and the steering angle operation detected by the accelerator opening sensor 14, the brake sensor 18 and the steering angle sensor 19, and the driver performs an avoidance operation for the vehicle to avoid the obstacle. Detect that. For example, when the obstacle is in front of the vehicle, the driver raises the accelerator pedal to reduce the accelerator opening, or the driver performs a brake operation corresponds to the avoidance operation. Specifically, the avoidance operation may be detected when the accelerator is turned off or the brake lamp interlocking operation is performed in the past 5 seconds.

Moreover, when the driver operates the steering wheel to the left side opposite to the obstacle when the obstacle is on the left front side of the vehicle, it corresponds to the avoidance operation.
As shown in FIG. 2, the brake sensor 18 is provided in an engine room in front of the vehicle. The rudder angle sensor 19 is also connected to the steering shaft in the engine room.

Then, the control unit 10 changes the approaching sound when the obstacle presence direction detected by the obstacle detection unit 7 matches the driver's line-of-sight direction detected by the line-of-sight direction detection unit 8. Control at least one of the modulation tone generation unit 4 and the sound pressure setting unit 5.
Here, in determining the coincidence of the line-of-sight direction, for example, when the line-of-sight direction of the driver and the direction in which the obstacle is present coincide for 0.25 seconds or more in the past 5 seconds, the line-of-sight direction of the driver and the obstacle It is good to judge that the direction in which the is present matches.

  Furthermore, the control unit 10 controls at least one of the modulation tone generation unit 4 and the sound pressure setting unit 5 so as to change the approaching sound before and after the avoidance operation by the driver.

  In the first embodiment, the control unit 10 controls the modulation tone generation unit 4 until the obstacle presence direction matches the driver's line-of-sight direction, and the initialized modulation filter shown in FIG. Is used to generate a modulation tone of a substantially original tone shown by a solid line IV in FIG.

On the other hand, the control unit 10 controls the modulation tone generation unit 4 after the obstacle presence direction and the driver's line-of-sight direction coincide with each other, and uses the modified modulation filter in FIG. Figure shown in 3 (D) by the broken line curve V, the modulation tone sound pressure of the low frequency range is suppressed to produce than the threshold frequency f _c.

  Further, the control unit 10 controls the sound pressure setting unit 5 to lower the sound pressure of the approaching sound after the line-of-sight matching or after the avoiding action than the sound pressure of the approaching sound before the line-of-sight position matching or before the avoiding action. May be. Even in such a case, the sound pressure of the approaching sound may be rapidly reduced to change the approaching sound discontinuously. The discontinuous change in the approaching sound makes it easier for a human being who is an obstacle to notice the change in the approaching sound. In addition, it is expected that surrounding humans other than the obstacles can easily recognize the approaching sound due to the discontinuous change of the approaching sound.

  As a result, obstacles including pedestrians and bicycle riders that the driver has noticed the presence of an obstacle by changing the approach sound when the driver's line-of-sight direction matches the obstacle's direction of presence. You can notify things. As a result, an effect of reducing the anxiety of the obstacle can be expected.

  In addition, the control unit 10 may change the approaching sound discontinuously when the approaching sound is changed by controlling at least one of the modulation tone generation unit 4 and the sound pressure setting unit 5. By changing the approaching sound discontinuously, the driver's recognition level can be raised when the driver is looking at the obstacle obscurely but does not recognize it as an obstacle. As a result, the driver can recognize the obstacle. Furthermore, if the approaching sound is changed discontinuously by suddenly changing the timbre of the approaching sound or the sound pressure of the approaching sound, it is easy for humans who are obstacles to notice the change of the approaching sound. Become.

  The control unit 10 may control only the modulation tone generation unit 4, may control only the sound pressure setting unit 5, or controls both the modulation tone generation unit 4 and the sound pressure setting unit 5. May be.

Next, the operation of the vehicle sound producing device according to the embodiment will be described with reference to the flowchart of FIG.
First, the operating condition determination unit 1 acquires the vehicle speed from the vehicle speed sensor 11 (S1).

  Next, the operating condition determination unit 1 determines whether or not the vehicle speed V satisfies a condition of 0 <V ≦ 20 km / h (S2). When this condition is not satisfied (in the case of “NO” in S2), the operating condition determination unit 1 determines whether or not the horn switch (horn SW) 12 has been operated (ON) (S3).

  When the vehicle speed satisfies the above conditions (in the case of “YES” in S2), or when the horn switch 12 is operated (in the case of “YES” in S3), the original tone color generation unit 2 determines the vehicle running state. Data is acquired (S4). The running state data includes vehicle speed, engine speed, and accelerator opening.

  Next, the original tone color generation unit 2 reads out the original tone color generation data corresponding to the acquired traveling state, and generates the original tone color shown in FIG. 3A (S5).

  Next, the ambient environment data captured by the outside camera 16 and processed by the obstacle detection unit 7 and the ambient environment sound pressure data detected by the microphone 15 are acquired (S6). The obstacle detection unit 7 detects obstacles such as pedestrians and bicycles.

  Next, the line-of-sight direction detection unit 8 detects the line-of-sight direction of the driver from the driver image captured by the in-vehicle camera 17 (S7).

  Then, the control unit 10 determines whether or not the direction of the obstacle viewed from the driver detected by the obstacle detection unit 7 and the line-of-sight direction of the driver detected by the line-of-sight direction detection unit 8 match. (S8). If the line-of-sight directions do not match (if “NO” in S8), the control unit 10 causes the modulation tone generation unit 4 to select the initialized first modulation filter of FIG. 3B (S9).

  On the other hand, when the line-of-sight directions match (when “YES” in S8), the control unit 10 causes the modulation tone generation unit 4 to select the first modulation filter after the change in FIG. 3C (S10).

  Subsequently, the avoidance operation detection unit 8 determines whether or not there is an avoidance operation by the driver (S11). When the avoidance operation is not detected (in the case of “NO” in S11), the control unit 10 causes the modulation tone generation unit 4 to select the initialized second modulation filter of FIG. 3B (S12).

  On the other hand, when an avoidance operation is detected (in the case of “YES” in S11), the control unit 10 causes the modulation tone generation unit 4 to reduce the gain of the first modulation filter after the change in FIG. Is selected as the second modulation filter after the change (S13).

Next, the modulated tone color generation unit 4 generates a modulated tone color from the original tone color using the selected first and second modulation filters (S14).
Until the driver's line-of-sight direction coincides with the direction of the obstacle, the initialized first modulation filter shown in FIG. 3B is the same as the initialized second modulation filter shown in FIG. Using the filter, a modulated timbre substantially the same as the original timbre shown by the solid line IV in FIG. 3D is generated.

  Further, when the driver's line-of-sight direction matches the direction of the obstacle, but the avoidance operation by the driver is not detected, the changed first modulation filter shown in FIG. It is used in combination with the initialized second modulation filter shown. As a result, a modulated tone color in which the low frequency range is attenuated, which is indicated by a broken line V in FIG.

  Further, after the driver's line-of-sight direction coincides with the direction of the obstacle and the avoidance operation by the driver is detected, the first modulation filter after the change shown in FIG. The changed second modulation filter with a further reduced gain is used in combination with the changed second modulation filter, and the changed second modulation filter with a smaller gain is selected. As a result, a modulated timbre whose overall gain is suppressed as compared with the broken line V, which is indicated by a one-dot chain line VI in FIG.

Next, the sound pressure setting unit 5 sets the sound generation sound pressure of the approaching sound of the modulated tone (S15).
Here, the sound pressure setting unit 5 may set a sound pressure that is slightly higher than the ambient environment sound pressure measured by the microphone 15. Moreover, when it is determined that it is nighttime by the obstacle detection unit 7 that has processed an image captured by the camera 16 outside the vehicle, and the headlight is turned on, the sound pressure may be set to be lower.

Next, the speaker 6 generates the approaching sound of the modulated tone color outside the vehicle with the set sound generation sound pressure (S16).
In this way, unnecessary noise generation by the sound producing device can be suppressed.

  In the flowchart shown in FIG. 4, an example in which the behavior of the driver is detected in two stages of matching of the gaze direction and the avoiding operation will be described. However, in the present invention, only one of the matching of the gaze direction and the avoiding operation is performed. It is good also as one step to detect.

Next, a vehicle sound producing device according to a second embodiment of the present invention will be described with reference to FIG.
The configuration of the vehicular sound producing device according to the second embodiment is the same as that of the first embodiment shown in FIG. In the second embodiment, as shown by a curve I in FIG. 5A, an original tone color similar to the original tone color used in the first embodiment is used. However, in the second embodiment, the modulation filter used in the modulation tone generation unit 4 is different from that in the first embodiment. Therefore, the modulation filter will be described in detail.

  In the second embodiment, the control unit 10 causes the modulation tone generation unit 4 to transmit the fundamental frequency f0 and the frequencies f1, f2, of the harmonic sequence of the fundamental frequency f0 until the line-of-sight direction of the driver matches the direction of the obstacle. ... Generates a modulated timbre of an infinite scale in which components repeatedly transition to the high pitch side at a predetermined transition speed.

  FIG. 5B schematically shows a graph showing the characteristics of the initialized modulation filter. The horizontal axis of this graph represents frequency, and the vertical axis represents gain (gain). Line II in the graph indicates the frequency characteristic of the gain of the comb filter function 4a. As shown by line II, in this comb filter function 4a, a high gain g1 is given to some frequency components of f1, f2,..., F6 of the harmonic sequence of the fundamental frequency f0 at a certain time, and the others A low gain g2 is given to the frequency component. For example, the gain g1 = 1.2 dB and the gain g2 = 0.0 dB may be used.

Then, as indicated by the arrows in FIG. 5B, the gains are changed according to the envelope E while the frequencies of these fundamental frequencies f0 and their harmonics sequences f1 to f6 transition to the high frequency side over time. Yes. By using this initialized modulation filter, an infinite scale effect can be generated.
Note that the shape of the envelope E is not limited to a trapezoid, and may be, for example, a bell shape with a widening end.

  FIG. 5C schematically shows a graph showing the characteristics of the modulation filter after the change. The horizontal axis of this graph represents frequency, and the vertical axis represents gain (gain). Line III in the graph indicates the frequency characteristic of the gain of the modulation filter after the change. As shown by the line III, in the modulation filter after the change, a constant gain g4 is given regardless of the frequency. For example, the gain g4 = 0.0 dB. In the modulation filter after the change in FIG. 5C, the timbre does not transition to the high pitch side, and the infinite scale effect does not occur.

  Then, after the driver's line-of-sight direction coincides with the direction of the obstacle, the control unit 10 causes the modulation tone generation unit 4 to generate a modulation tone whose transition has stopped.

  In the second embodiment, the control unit 10 controls the modulation timbre generation unit 4 until it determines that the line-of-sight directions match, and generates a modulation timbre using the initialized modulation filter of FIG. Let

  FIG. 5D schematically shows a modulation tone color graph. The horizontal axis of the graph represents frequency, and the vertical axis represents sound pressure. A curve IV in the graph indicates the frequency characteristic of the sound pressure of the modulated timbre before matching the line-of-sight direction. As shown by the curve IV, the modulated tone color before matching the line-of-sight direction is based on the original tone color shown in FIG. Have each. These sound pressure peaks p0 to p6 transition to the high frequency side as the fundamental frequency and the frequency of the harmonic sequence thereof transition to the high frequency side. Thereby, the approaching sound of the modulated timbre can produce an infinite scale effect that makes the human who hears this illusion of a continuous increase in frequency.

  The sound pressure at each peak gradually increases in the low frequency region and gradually decreases in the high frequency region as the fundamental frequency transitions to the high frequency side. As a result, the fundamental frequency having a high gain and the frequency components of the harmonic sequence thereof fade in from the low frequency side, and fade out as the frequency component transitions to the high frequency side. Thereby, an infinite scale effect can be produced without a sense of incongruity.

  On the other hand, after determining that the line-of-sight directions match, the control unit 10 controls the modulation tone generation unit 4 to use the modified modulation filter in FIG. A modulated tone color substantially the same as the original tone color is generated. In this modulated tone, the fundamental frequency does not transit on the high frequency side and does not generate an infinite scale.

  In this way, the infinite scale has the effect of making a person who hears this an illusion of a continuous increase in frequency while substantially maintaining the frequency characteristics of the original tone color. For this reason, the approach of the vehicle can be felt more strongly. Then, after the line-of-sight direction coincides, by stopping the transition of the infinite scale, it is possible to suppress unnecessary noise generation by the sound generator. Further, by switching the modulation filter used in the modulation tone generation 4, the timbre of the approaching sound can be changed abruptly before and after the line-of-sight direction coincides.

  Note that the modulation filter selected after matching the line-of-sight direction is not the one shown in FIG. 5C, but the one that has reduced the peak frequency transition speed of the initialized modulation filter shown in FIG. 5B. May be. By switching the modulation filter before and after the behavior detection, the transition speed of the infinite scale can be rapidly reduced.

  Also, in the second embodiment, in addition to the case where the driver's line-of-sight direction and the direction of the obstacle coincide with each other, or in the case where an avoidance operation is performed by the driver, an infinite scale transition is performed. May be stopped or the transition speed may be reduced.

  In the above-mentioned embodiment, although the example which comprised this invention on the specific conditions was demonstrated, this invention can perform a various change and combination, and is not limited to this. For example, in the above-described embodiment, an example in which the control unit changes the approaching sound when an avoidance operation by the driver is detected after the driver's line of sight is coincident is described. It is also possible to change the approaching sound only by detecting.

  Further, for example, in the above-described second embodiment, an example in which a modulated tone is generated by giving a high gain to a harmonic sequence for one fundamental frequency has been described. However, in the present invention, the fundamental frequency is not limited to one. Alternatively, a modulated tone color may be generated using a high gain for the harmonic series of each of a plurality of fundamental frequencies having different phases.

  In the second embodiment described above, an example in which the correction filter function has a frequency characteristic of a trapezoidal waveform gain has been described. However, in the present invention, the characteristic of the correction filter function is not limited to this, and for example, a widening bell You may give the frequency characteristic of the gain used as a waveform.

  The sound generating device for a vehicle according to the present invention can be used by being mounted on a vehicle having low noise during traveling such as an electric vehicle and a hybrid vehicle.

DESCRIPTION OF SYMBOLS 1 Operation condition determination part 2 Original tone color generation part 3 Memory 4 Tone modulation part 5 Sound generation sound pressure setting part 6 Speaker 7 Obstacle detection part 8 Gaze direction detection part 9 Avoidance operation detection part 10 Control part 11 Vehicle speed sensor 12 Horn switch 13 Engine Rotation sensor 14 Accelerator opening sensor 15 Microphone 16 Outside camera 17 Inside camera 18 Brake sensor 19 Rudder angle sensor 100 ECU

Claims (7)

A vehicular sound generation device that notifies the vehicle approach to the outside of the vehicle,
An original tone color generating means for generating an original tone color of an approaching sound for recalling the approach of a vehicle;
Modulation tone generation means for generating a modulation tone from the original tone color;
Sound pressure setting means for setting the sound pressure of the approaching sound of the modulated tone,
A sounding means for generating an approaching sound of the above-mentioned modulated tone outside the vehicle with a set sounding sound pressure;
Obstacle detection means for detecting obstacles outside the vehicle;
Gaze direction detection means for detecting the gaze direction of the driver of the vehicle;
Control means for controlling at least one of the modulated tone color generation means and the sound pressure setting means so as to change the approaching sound when the line-of-sight direction of the driver coincides with the direction in which the obstacle exists. A vehicle sound generator characterized by the above.   The control means controls at least one of the modulation tone generation means and the sound pressure setting means so that the approaching sound is discontinuously changed when the line-of-sight direction of the driver coincides with the direction in which the obstacle exists. The vehicular sound producing device according to claim 1, wherein:   The control means sets the sound pressure so that the sound pressure of the approaching sound after the line-of-sight direction of the driver and the direction of presence of the obstacle coincide with each other is lower than the sound pressure of the approaching sound before matching. The vehicle sounding device according to claim 1 or 2, wherein the means is controlled.   The control means repeatedly shifts the fundamental frequency and the frequency components of the harmonic sequence of the fundamental frequency to the treble side at a predetermined transition speed before the driver's line-of-sight direction matches the obstacle presence direction. An infinite scale timbre is generated, and after the driver's line-of-sight direction matches the obstacle presence direction, the transition speed is reduced or a modulated timbre with the transition stopped is generated. The vehicular sound generation device according to any one of claims 1 to 3, wherein the modulation tone generation unit is controlled. Furthermore, it has a memory that stores the original tone color generation data of the approaching sound in association with the running state of the vehicle,
5. The vehicle sound generation according to claim 1, wherein the original sound color generation means reads the original sound color generation data corresponding to the running state of the vehicle and generates the original sound color. 6. apparatus. An avoidance operation detecting means for detecting that the vehicle has performed an avoidance operation to avoid the obstacle by the driver;
6. The control unit according to claim 1, wherein the control unit controls at least one of the modulation tone generation unit and the sound pressure setting unit so as to change the approaching sound before and after the avoidance operation. The vehicle sound producing device according to the item. A vehicular sound generation device that notifies the vehicle approach to the outside of the vehicle,
An original tone color generating means for generating an original tone color of an approaching sound for recalling the approach of a vehicle;
Modulation tone generation means for generating a modulation tone from the original tone color;
Sound pressure setting means for setting the sound pressure of the approaching sound of the modulated tone,
A sounding means for generating an approaching sound of the above-mentioned modulated tone outside the vehicle with a set sounding sound pressure;
An avoidance operation detecting means for detecting that the driver has performed an avoidance operation for avoiding the obstacle by the driver,
The sound generator for a vehicle according to claim 1, wherein the control means controls at least one of the modulation tone generation means and the sound pressure setting means so as to change the approach sound before and after the avoidance operation.

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