JP7565012B2 - Vehicle interior acoustic control system - Google Patents

Description

The present invention relates to a vehicle interior acoustic control device that is configured to prevent the operating noise of auxiliary equipment in the vehicle interior from being heard by passengers in the vehicle interior.

In the vehicle cabin, an accessory having a drive mechanism configured to operate based on the drive of a motor, gears, etc. may be installed. An example of an accessory is a HUD (head-up display) device. The HUD device reflects visible light emitted from an LCD (liquid crystal display) using a reflector, and then projects the reflected visible light onto the display panel of the HUD device or onto the windshield or other external surface of the HUD device so that passengers in the vehicle cabin can view the visible light as an image. Such a HUD device has a drive mechanism configured to drive the reflector, display panel, etc.

In auxiliary equipment such as the above-mentioned HUD device, the operating noise of the drive mechanism may cause discomfort and strangeness to the occupants in the vehicle cabin. For example, examples of operating noise of the drive mechanism that may cause discomfort and strangeness to the occupants include motor noise and gear meshing noise. Therefore, various vehicle cabin acoustic adjustment devices have been proposed to prevent such operating noise of the drive mechanism from being heard by the occupants. One example of such a vehicle cabin acoustic adjustment device is a HUD device that has a Helmholtz resonator. (See, for example, Patent Document 1.)

JP 2017-154712 A

However, the Helmholtz resonator used in the above example of the vehicle interior acoustic control device can only suppress the operating noise of an auxiliary device that has a peak sound pressure level that appears at a predetermined constant resonance frequency. In contrast, the resonance frequency of the operating noise generated by an auxiliary device such as a HUD device can change due to the temperature environment around the auxiliary device, deterioration of the auxiliary device over time, etc. Therefore, the above example of the vehicle interior acoustic control device cannot efficiently prevent the auxiliary device's operating noise from being heard by the occupants when the operating noise of the auxiliary device changes, etc.

In light of this situation, it is desirable for the vehicle interior acoustic control system to be able to efficiently prevent the operation sounds of auxiliary equipment from being heard by occupants while minimizing discomfort and odd sensations felt by occupants.

In order to solve the problem, one embodiment of a vehicle interior acoustic control device is a vehicle interior acoustic control device configured to suppress the operation sound of an auxiliary device provided in the vehicle interior from being heard by occupants in the vehicle interior, and includes a sound output unit configured to be able to output sound toward the vehicle interior, a masking sound generation unit configured to be able to generate a masking sound for masking the operation sound of the auxiliary device, a startup sound generation unit configured to be able to generate a startup sound that is emitted when the vehicle is started, and a control unit configured to output the startup sound generated by the startup sound generation unit from the sound output unit. The startup sound generating unit is configured to generate a first startup sound consisting of a first sound, a second sound that is higher in pitch than the first sound, and a second startup sound consisting of the masking sound generated by the masking sound generating unit, and the control unit is configured to output the first startup sound generated by the startup sound generating unit from the sound output unit when the auxiliary is set not to perform an operation that produces the operating sound, and to output the second startup sound generated by the startup sound generating unit from the sound output unit when the auxiliary is set to perform an operation that produces the operating sound.

In one embodiment of the vehicle interior acoustic control device, it is possible to effectively prevent the operation sounds of auxiliary equipment from being heard by occupants while preventing the occupants from feeling discomfort or strangeness.

FIG. 1 is a schematic diagram showing a vehicle having a vehicle interior acoustic control device according to an embodiment. FIG. 2 is a plan view that shows a vehicle according to one embodiment, with an upper portion of the passenger compartment omitted. FIG. 3 is a cross-sectional view of a HUD device. FIG. 4 is a graph for explaining the sound ranges of the first sound, the second sound, the masking sound, and the auxiliary sound. FIG. 5 is a timing chart showing a case where the first startup sound is output in the vehicle interior acoustic control device according to the embodiment. FIG. 6 is a timing chart showing a case where the second startup sound is output in the vehicle interior acoustic control device according to the embodiment. FIG. 7 is a flowchart for explaining an acoustic adjustment method using a vehicle interior acoustic adjustment device according to one embodiment.

The vehicle equipped with the vehicle interior acoustic control device according to one embodiment will be described below together with the vehicle equipped with the device. The vehicle equipped with the vehicle interior acoustic control device according to this embodiment is an automobile having a vehicle interior space. However, such a vehicle may be a vehicle other than an automobile having a vehicle interior space.

2 and 3 used in the description of this specification, directions based on the vehicle 1 are indicated as follows. In Figs. 2 and 3, the front and rear of the vehicle are indicated by single-sided arrows F and B, respectively. In Fig. 2, the left and right directions when facing the front of the vehicle are indicated by single-sided arrows L and R, respectively. The width direction of the vehicle is indicated by single-sided arrows L and R. Furthermore, in Fig. 3, the top and bottom of the vehicle are indicated by single-sided arrows U and D, respectively. Note that, hereinafter, directions simply referred to as "front," "rear," "left," "right," "up," "down," "front-rear direction," "width direction," and "up-down direction" refer to directions based on the vehicle 1.

"Outline of vehicle interior acoustic control system and vehicle"
An outline of a vehicle interior acoustic control device 10 and a vehicle 1 according to this embodiment will be described with reference to Figures 1 to 6. That is, the vehicle interior acoustic control device 10 and the vehicle 1 according to this embodiment are generally configured as follows. With reference to Figures 1 to 3, the vehicle interior acoustic control device 10 is configured to be able to prevent operating sounds of an auxiliary machine 20 provided in a vehicle interior 2 of the vehicle 1 from being heard by passengers in the vehicle interior 2.

Referring to Figures 1 and 3, the auxiliary equipment 20 provided in the passenger compartment 2 of the vehicle 1 according to this embodiment has a drive mechanism 21 configured to operate based on the drive of a motor, gears, etc. In this embodiment, the auxiliary equipment 20 is, as an example, a HUD (head-up display) device 20. However, the auxiliary equipment is not limited to a HUD device. For example, the auxiliary equipment may be an electric tilt-telescopic steering wheel, an electric power seat, a car navigation system with a drivable display, etc.

As shown in Figures 1 and 2, the vehicle interior acoustic control device 10 has a sound output unit 11 configured to be able to output sound toward the vehicle interior 2. As shown in Figure 1, the vehicle interior acoustic control device 10 has a masking sound generation unit 12 configured to be able to generate a masking sound for masking the operating sound of the HUD device 20. The vehicle interior acoustic control device 10 has a startup sound generation unit 13 configured to be able to generate a startup sound that is emitted when the vehicle 1 is started. The vehicle interior acoustic control device 10 has a control unit 14 configured to output the startup sound generated by the startup sound generation unit 13 from the sound output unit 11.

As shown in FIG. 4, in such a vehicle interior acoustic control device 10, the startup sound generating unit 13 is configured to be able to generate a first startup sound and a second startup sound. The first startup sound is made up of a first sound. The second startup sound is made up of a second sound that is higher in pitch than the first sound, and a masking sound generated by the masking sound generating unit 12.

In FIG. 4, the horizontal axis X indicates the range or frequency (kHz). The range of the first sound, i.e., the frequency band in which the first sound has a higher sound pressure level (dB) than other frequency bands, is indicated by a double-sided arrow P1. The range of the second sound, i.e., the frequency band in which the second sound has a higher sound pressure level than other frequency bands, is indicated by a double-sided arrow P2. The range of the masking sound, i.e., the frequency band in which the masking sound has a higher sound pressure level than other frequency bands, is indicated by a double-sided arrow Q. The range of the operating sound of the HUD device 20, i.e., the frequency band in which the operating sound of the HUD device 20 has a higher sound pressure level than other frequency bands, is indicated by a double-sided arrow M.

As shown in FIG. 5, the control unit 14 is configured to cause the sound output unit 11 to output a first startup sound generated by the startup sound generation unit 13 when the HUD device 20 is set to perform an operation that emits an operation sound (hereinafter, referred to as the "non-operation setting state" as necessary). As shown in FIG. 6, the control unit 14 is also configured to cause the sound output unit 11 to output a second startup sound generated by the startup sound generation unit 13 when the HUD device 20 is set to perform an operation that emits an operation sound (hereinafter, referred to as the "operation setting state" as necessary).

Furthermore, in the vehicle interior acoustic control device 10, the masking sound generating unit 12 can be configured to correct the frequency at the peak of the sound pressure level of the masking sound according to the cumulative number of operations of the HUD device 20.

"Vehicle Details"
2, the vehicle 1 can be configured in detail as follows. The vehicle 1 has an instrument panel 3 disposed toward the front of the passenger compartment 2. The vehicle 1 has a driver's seat 4a and a passenger seat 4b disposed rearward of the instrument panel 3. The driver's seat 4a and the passenger seat 4b are disposed side by side in the vehicle width direction. The driver's seat 4a and the passenger seat 4b form a front row seat group 4.

The vehicle 1 has at least one rear row seat group 5 arranged rearward of the front row seat group 4. The rear row seat group 5 consists of multiple rear seats 5a, 5b. In FIG. 2, the vehicle 1 has one rear row seat group 5 consisting of two rear seats 5a, 5b. However, the vehicle can also have one rear row seat group consisting of three or more rear seats. The vehicle can also have two or more rear row seat groups consisting of multiple rear seats and spaced apart from each other in the fore-and-aft direction.

The driver (not shown) of vehicle 1 sits in the driver's seat 4a. Occupants (not shown) other than the driver of vehicle 1 sit in the passenger seat 4b or one of the multiple rear seats 5a, 5b. Vehicle 1 has an ignition switch (hereinafter referred to as "IG switch" as necessary) 6 for starting the vehicle 1. When an occupant such as the driver turns the IG switch 6 to the on state, the engine, travel drive motor, and other drive sources start up. When an occupant such as the driver turns the IG switch 6 to the off state, the drive sources stop.

"Details of HUD device"
1 to 3, the HUD device 20 can be configured in detail as follows. As shown in Fig. 2, the HUD device 20 is disposed on the upper surface 3a of the instrument panel 3, closer to the driver's seat 4a in the vehicle width direction. As shown in Fig. 1 and 3, the HUD device 20 has a display panel 22 configured to be movable in the vertical direction between an unfolded state and a stored state. In Fig. 3, the display panel 22 in the unfolded state is shown by a solid line, and the display panel 22 in the stored state is shown by a virtual line.

As shown in FIG. 3, the display panel 22 is configured to be light-transmitting yet light-reflective. The display panel 22 in the unfolded state is disposed to face the driver's seat 4a in the front-to-rear direction. The driver can view the display projected on the unfolded display panel 22 while viewing the scenery located behind the unfolded display panel 22.

The HUD device 20 has an LCD (liquid crystal display) 23 configured to display a display to be projected onto a display panel 22. The HUD device 20 has a reflector 24 configured to reflect the display from the LCD 23 towards the display panel 22. In such a HUD device 20, a projection path (indicated by a one-sided arrow K in FIG. 3) is formed that runs from the LCD 23 through the reflector 24 to the display panel 22.

The HUD device 20 has a housing 25 that houses a display panel 22 in a stored state, an LCD 23, and a reflector 24. The housing 25 has an opening 25a formed in the upper part of the housing 25 to allow the display panel 22 and the projection path to pass through.

The drive mechanism 21 of the HUD device 20 has a motor 21a and a lead screw 21b that can be rotated by the drive of the motor 21a. The display panel 22 moves vertically between the deployed state and the stored state as indicated by the double-sided arrow H (shown in FIG. 3) in response to the rotation of the lead screw 21b.

The operating sound of the HUD device 20 is generated by the driving of the motor 21a of the drive mechanism 21, the rotation of the lead screw 21b of the drive mechanism 21, etc. The drive mechanism can be configured so that the reflection angle of the reflector can be adjusted by a motor, gears, etc. In this case, operating sound may be generated when the reflection angle of the reflector is adjusted.

The operation of the HUD device 20 is an unfolding operation that moves the display panel 22 from a stored state to a deployed state. The HUD device 20 has an operation switching unit 27 that is configured to be able to switch between a non-operational setting state and an operation setting state. In the operation setting state, the HUD device 20 starts an operation of emitting an operation sound at the same time that the IG switch 6 is switched from the off state to the on state, or after a predetermined time has elapsed since this switching.

Specifically, the HUD device 20 starts the unfolding operation of the display panel 22 at the same time that the IG switch 6 is switched from the OFF state to the ON state while in the operational setting state, or after a predetermined time has elapsed since this switching. The HUD device 20 ends the unfolding operation when the display panel 22 is in the unfolded state. However, the HUD device can also start the unfolding operation of the display panel at the same time that an occupant such as a driver operates the operation switching unit to switch from a non-operation setting state to an operation setting state after the IG switch 6 is switched from the OFF state to the ON state.

"Details of the vehicle interior acoustic control device 10"
1, 2, and 4 to 6, the vehicle interior acoustic control device 10 according to this embodiment can be configured in detail as follows: As shown in Figures 1 and 2, the sound output section 11 of the vehicle interior acoustic control device 10 includes a plurality of speakers 11a, 11b, 11c, and 11d.

As shown in FIG. 2, specifically, the sound output unit 11 may include a first speaker 11a located outward in the vehicle width direction from the driver's seat 4a. The sound output unit 11 may include a second speaker 11b located outward in the vehicle width direction from the passenger seat 4b. The sound output unit 11 may include a third speaker 11c located on one side in the vehicle width direction from the rear row seats 5. The sound output unit 11 may include a fourth speaker 11d located on the other side in the vehicle width direction from the rear row seats 5.

The masking sound generating unit 12, the startup sound generating unit 13, and the control unit 14 of the vehicle interior acoustic control device 10 can be configured to include electronic components such as a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), flash memory, an input interface, an output interface, and an electric circuit in which such electronic components are arranged. The ROM can store various control constants, various maps, programs for executing various controls, and the like.

As shown in FIG. 1, for example, one ECU (Electric Control Unit) 15 may include the masking sound generating unit 12, the startup sound generating unit 13, and the control unit 14 of the vehicle interior acoustic control device 10. However, the masking sound generating unit, the startup sound generating unit, and the control unit are not limited to this. The masking sound generating unit, the startup sound generating unit, and the control unit may also be included in different ECUs. One of the masking sound generating unit, the startup sound generating unit, and the control unit may also be included in an ECU separate from the rest.

The masking sound generating unit 12 is configured to be able to count the cumulative number of operations of the HUD device 20. The masking sound generating unit 12 is configured to be able to store the cumulative number of operations of the HUD device 20. When the HUD device 20 is in operation, the masking sound generating unit 12 counts and stores the cumulative number of operations of the HUD device 20 so as to add 1 to the cumulative number of operations N of the HUD device 20 stored during the previous operation, and is configured to repeat such counting and storage.

Referring to FIG. 4, the startup sound generating unit 13 is configured to be able to generate a second preliminary startup sound consisting of a second sound. Regarding the relationship between the first sound in the first startup sound generated by the startup sound generating unit 13 and the second sound in the second startup sound generated by the startup sound generating unit 13, the range of the second sound is higher than the range of the first sound. Therefore, the second sound is more noticeable to passengers such as the driver than the first sound. In addition, it is preferable that the sound pressure level in the range of the second sound is higher than the sound pressure level in the range of the first sound.

The range of the operation sound of the HUD device 20 is approximately equal to the range of the masking sound. The range of the second sound includes the range of the operation sound of the HUD device 20 and the range of the masking sound. In other words, the range of the operation sound of the HUD device 20 and the range of the masking sound are within the range of the second sound. It is preferable that the sound pressure level in the range of the masking sound is greater than the sound pressure level in the range of the operation sound of the HUD device 20.

Each of the first and second sounds can be music. That is, the first sound can be first music, and the second sound can be second music. Music is defined herein as having rhythm, melody, and harmony.

Referring to Figures 1, 5, and 6, the control unit 14 is configured to be able to determine whether the IG switch 6 has been switched from an off state to an on state. When the IG switch 6 has been switched from an off state to an on state, the control unit 14 is configured to be able to determine whether the HUD device 20 is in an operational setting state. When the HUD device 20 is not in an operational setting state, i.e., when the HUD device 20 is in a non-operational setting state, the control unit 14 is configured to output the first startup sound from the sound output unit 11 at the same time that the IG switch 6 is switched from an off state to an on state, or after a predetermined time has elapsed since this switching.

When the HUD device 20 is in an operational setting state, the control unit 14 is configured to output the second startup sound from the sound output unit 11 in a state in which the HUD device 20 is operating to emit an operating sound after the IG switch 6 is switched from an off state to an on state. The control unit 14 is configured to end the output of the second startup sound from the sound output unit 11 simultaneously with the end of the operation of the HUD device 20, in particular, the end of the unfolding operation of the display panel 22, or after a predetermined time has elapsed since this end.

The control unit 14 can also output a second preliminary startup sound from the sound output unit 11 during the period from when the IG switch 6 is switched from the off state to the on state to when the operation of the HUD device 20 starts. The control unit 14 can also output a second preliminary startup sound from the sound output unit 11 during the period from when the operation of the HUD device 20 ends, in particular, when a predetermined time has elapsed since the end of the unfolding operation of the display panel 22.

"Acoustic adjustment method using vehicle interior acoustic adjustment device"
7, the acoustic adjustment method using the vehicle interior acoustic control device 10 according to this embodiment will be described. First, the IG switch 6 is in the OFF state (step S1). It is determined whether the IG switch 6 has been switched from the OFF state to the ON state (step S2). If the IG switch 6 has not been switched from the OFF state to the ON state (NO), step S2 is executed again.

If the IG switch 6 is switched from the OFF state to the ON state (YES), it is determined whether the HUD device 20 is in an operational setting state (step S3). If the HUD device 20 is not in an operational setting state, i.e., if the HUD device 20 is in a non-operational setting state (NO), the first startup sound is output from the sound output unit 11 (step S4).

If the HUD device 20 is in an operating setting state (YES), 1 is added to the cumulative number of operations N of the HUD device 20 stored during the previous operation of the HUD device 20, thereby obtaining the latest cumulative number of operations (N+1) of the HUD device 20 (step S5). The masking sound is corrected to change the frequency at the peak of the sound pressure level of the masking sound according to the latest cumulative number of operations (N+1) of the HUD device 20 (step S6).

At this time, the masking sound is corrected so as to correspond to deterioration over time that accompanies an increase in the cumulative number of operations of the HUD device 20. The relationship between the increase in the cumulative number of operations of the HUD device 20 and deterioration over time can be determined in advance by experiments, usage records, simulations, etc. After that, a second startup sound consisting of a second sound that is higher in pitch than the first sound and the masking sound corrected in step S5 is output from the sound output unit 11 (step S7).

As described above, the vehicle interior acoustic control device 10 according to this embodiment is configured to suppress the operation sound of the auxiliary equipment 20 provided in the vehicle interior 2 of the vehicle 1 from being heard by occupants in the vehicle interior 2, and includes a sound output unit 11 configured to be able to output sound toward the vehicle interior 2, a masking sound generation unit 12 configured to be able to generate a masking sound for masking the operation sound of the auxiliary equipment 20, a startup sound generation unit 13 configured to be able to generate a startup sound that is emitted when the vehicle 1 is started, and a control unit 14 configured to output the startup sound generated by the startup sound generation unit 13 from the sound output unit 11. The startup sound generating unit 13 is configured to generate a first startup sound consisting of a first sound, a second sound that is higher in pitch than the first sound, and a second startup sound consisting of the masking sound generated by the masking sound generating unit 12, and the control unit 14 is configured to output the first startup sound generated by the startup sound generating unit 13 from the sound output unit 11 when the auxiliary device 20 is set not to perform an operation that produces the operating sound, and to output the second startup sound generated by the startup sound generating unit 13 from the sound output unit 11 when the auxiliary device 20 is set to perform an operation that produces the operating sound.

In general, auxiliary equipment, particularly HUD equipment, tends to emit operating sounds that are unpleasant to occupants in the vehicle cabin when the vehicle is started. In contrast, in the vehicle interior acoustic control device 10 according to this embodiment, a first startup sound consisting of a first sound can be used as the startup sound that is constantly output from the sound output unit 11 when the vehicle 1 is started, particularly when the auxiliary equipment 20 is not operating to emit an operating sound, and a second startup sound consisting of a second sound and a masking sound can be used when the auxiliary equipment 20 is operating to emit an operating sound. Therefore, while preventing the occupants from feeling uncomfortable with the second startup sound as the startup sound that is constantly output when the auxiliary equipment 20 is operating to emit an operating sound, the masking sound of the second startup sound can efficiently prevent the occupants from hearing the operating sound of the auxiliary equipment 20.

The second sound of the second startup sound is higher pitched than the first sound of the first startup sound. Therefore, in the second startup sound, there is no difference in sound frequency between the operation sound of the HUD device 20 and the second startup sound, and this causes a cocktail party effect in which it becomes difficult for the occupant to hear sounds in the frequency range in which the operation sound of the HUD device 20 is produced, thereby suppressing the discomfort and strangeness felt by the occupant due to the masking sound. Therefore, it is possible to efficiently prevent the operation sound of the auxiliary device 20 from being heard by the occupant while suppressing the discomfort and strangeness felt by the occupant.

In the vehicle interior acoustic control device 10 according to this embodiment, the masking sound generating unit 12 is configured to correct the frequency at the peak of the sound pressure level of the masking sound according to the cumulative number of times the auxiliary equipment 20 operates. Therefore, even if the operating sound of the auxiliary equipment 20 changes due to deterioration of the auxiliary equipment 20 over time, it is possible to efficiently prevent the operating sound of the auxiliary equipment 20 from being heard by the occupants.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-mentioned embodiments, and the present invention can be modified and changed based on its technical concept.

Reference Signs List 1: vehicle, 2: vehicle interior, 10: vehicle interior acoustic control device, 11: sound output unit, 12: masking sound generation unit, 13: startup sound generation unit, 14: control unit, 20: auxiliary equipment, HUD device

Claims (2)

A vehicle interior acoustic control device configured to suppress operation sounds of auxiliary machinery provided in a vehicle interior from being heard by occupants in the vehicle interior,
a sound output unit configured to be able to output sound toward the vehicle interior;
a masking sound generating unit configured to generate a masking sound for masking the operation sound of the auxiliary machine;
a startup sound generating unit configured to generate a startup sound to be emitted when the vehicle is started;
a control unit configured to output the startup sound generated by the startup sound generation unit from the sound output unit,
the startup sound generation unit is configured to be capable of generating a first startup sound consisting of a first sound, a second sound that is higher in pitch than the first sound, and a second startup sound consisting of the masking sound generated by the masking sound generation unit;
the control unit is configured to, when the auxiliary equipment is set not to perform an operation of emitting the operating sound, output the first startup sound generated by the startup sound generation unit from the sound output unit, and when the auxiliary equipment is set to perform an operation of emitting the operating sound, output the second startup sound generated by the startup sound generation unit from the sound output unit. 2. The vehicle interior acoustic control system according to claim 1, wherein the masking sound generating unit is configured to correct a frequency at a peak of a sound pressure level of the masking sound in accordance with a cumulative number of operations of the auxiliary device.