CONTROL APPARATUS FOR VEHICLE

A control apparatus for a vehicle includes a first speaker and a second speaker. The first speaker is disposed at a front part of the vehicle and toward a right side in a vehicle width direction of the vehicle. The first speaker is configured to output a notification sound that notifies the surroundings of the vehicle of an approach of the vehicle. The second speaker is disposed at the front part of the vehicle and toward a left side in the vehicle width direction. The second speaker is configured to output the notification sound. The first speaker and the second speaker have an integrated structure with respect to each other and are opposed to each other in the vehicle width direction. The first speaker and the second speaker are configured to simultaneously receive, from an amplifier, a same audio signal as each other on which the notification sound is based.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority from Japanese Patent Application No. 2023-151079 filed on Sep. 19, 2023, the entire contents of which are hereby incorporated by reference.

BACKGROUND

The disclosure relates to a control apparatus for a vehicle which is adapted to control a notification sound that notifies the surroundings of an approach of the vehicle.

In recent years, there are vehicles that are able to travel without using an engine, such as an electric vehicle or a hybrid vehicle. These vehicles do not output an engine sound, making it difficult for a person such as a pedestrian to recognize the approach of the vehicle in response to the engine sound of the vehicle.

At present, in each country, the vehicle able to travel without using the engine, such as the electric vehicle or the hybrid vehicle, is being legally regulated so as to notify a person such as the pedestrian of the approach of the vehicle by outputting a notification sound. In addition, the notification sound including a sound pressure equal to or higher than a specified value is to be outputted as the notification sound that is to be outputted from the vehicle able to travel without using the engine.

For example, according to Japanese laws or regulations, the vehicle able to travel without using the engine is to output a sound pressure equal to or higher than a specified value in two frequency bands among frequency bands in which frequencies from 160 Hz to 5 kHz are divided by 16 every ⅓ octave, from the start of the vehicle to a timing at which the vehicle reaches 20 km/h.

Japanese Unexamined Patent Application Publication (JP-A) No. 2014-15187 discloses a vehicle presence notification apparatus that includes a first notification sound generation device and a second notification sound generation device. The first notification sound generation device causes a notification sound based on a high-frequency sound to be outputted toward the front of a vehicle. The second notification sound generation device causes a notification sound based on a low-frequency sound to be outputted downward from the vehicle.

The high-pitched notification sound from the first notification sound generation device has high directivity and is outputted toward the front of the vehicle. The high-pitched notification sound is outputted to a predetermined range on the front side of the vehicle, and is actively delivered to a pedestrian in front of the vehicle.

The low-pitched notification sound from the second notification sound generation device has low directivity and is outputted downward from the vehicle. The low-pitched notification sound is reflected on a road surface to be outputted to a wide range around the vehicle, and is actively delivered to pedestrians on sides of the vehicle and at the rear of the vehicle.

SUMMARY

An aspect of the disclosure provides a control apparatus for a vehicle. The control apparatus includes a first speaker and a second speaker. The first speaker is disposed at a front part of the vehicle and toward a right side in a vehicle width direction of the vehicle. The first speaker is configured to output a notification sound. The notification sound is configured to notify the surroundings of the vehicle of an approach of the vehicle. The second speaker is disposed at the front part of the vehicle and toward a left side in the vehicle width direction. The second speaker is configured to output the notification sound. The first speaker and the second speaker have an integrated structure with respect to each other and are opposed to each other in the vehicle width direction. The first speaker and the second speaker are configured to simultaneously receive, from an amplifier, a same audio signal as each other on which the notification sound is based.

DETAILED DESCRIPTION

The vehicle presence notification apparatus disclosed in JP-A No. 2014-15187 includes a first notification sound generation device intended for a pedestrian in front of the vehicle, and a second notification sound generation device intended for pedestrians on sides of the vehicle and at the rear of the vehicle. This structure makes different from each other the directions in which the notification sounds are outputted, which necessitates an increase in the volume of notification sounds to be outputted from the first notification sound generation device and the second notification sound generation device in order to meet the requirements of applicable laws or regulations. Accordingly, this structure can lead to an increase the volume of the notification sound leaking into a vehicle compartment of the vehicle, thus making it difficult to ensure quietness of the vehicle compartment in the vehicle.

It is desirable to provide a control apparatus for a vehicle which makes it possible to achieve quietness in a vehicle compartment.

It should be noted that a front-rear direction of the drawings indicates a longitudinal direction of a vehicle11, a left-right direction of the drawings indicates a vehicle width direction of the vehicle11, and a vertical direction of the drawings indicates a height direction of the vehicle11.

FIG.1is a plan diagram illustrating the vehicle11including the control apparatus for the vehicle10according to an example embodiment. Hereinafter, the control apparatus for the vehicle10may be simply referred to as a “vehicle control apparatus10”.FIG.2is a block diagram illustrating the vehicle control apparatus10.FIG.3Ais a cross-sectional diagram illustrating structures of a first speaker12and a second speaker13of the vehicle control apparatus10.FIG.3Bis a graph illustrating a state of notification sounds to be outputted from the first speaker12and the second speaker13of the vehicle control apparatus10.FIG.4is a plan diagram illustrating a sound pressure measurement test of the vehicle control apparatus10.FIG.5is a cross-sectional diagram illustrating a modification example of structures of the first speaker12and the second speaker13of the vehicle control apparatus10.

Referring toFIG.1, the vehicle11may be any electric vehicle such as a battery electric vehicle (BEV), a hybrid electric vehicle (HEV), or a plug-in hybrid electric vehicle (PHEV).

According to Japanese laws or regulations, the vehicle11able to travel without using an engine is to output a sound pressure equal to or higher than a specified value in two frequency bands among frequency bands in which frequencies from 160 Hz to 5 kHz are divided by 16 every ⅓ octave, from the start of the vehicle11to a timing at which the vehicle11reaches 20 km/h. Further, as will be described later in greater detail, a sound pressure measurement test according to Japanese laws or regulations defines the requirements to be described with reference toFIG.4.

The vehicle control apparatus10according to the example embodiment includes a first speaker12and a second speaker13both illustrated by way of example inFIG.2. The first speaker12and the second speaker13are each a device that notifies the surroundings of the vehicle11of a notification sound. For example, as indicated by a dotted line14inFIG.1, the first speaker12and the second speaker13are provided at a front part of the vehicle11. The first speaker12and the second speaker13may be disposed in a tuft between a front grille15and an unillustrated radiator. A dashed-dotted line16may indicate a center line CL of the vehicle11in the vehicle width direction. In some embodiments, the first speaker12and the second speaker13may be disposed line-symmetrically with respect to the center line CL of the vehicle11. The first speaker12is opposed toward a right side of the vehicle11in the vehicle width direction, and the second speaker13is opposed toward a left side of the vehicle11in the vehicle width direction.

Referring toFIG.2, the vehicle control apparatus10may include a vehicle control processor21, a vehicle state detector22, an amplifier23, the first speaker12, and the second speaker13.

The vehicle control processor21may include devices including, for example, a central processing unit (CPU), a read-only memory (ROM), and a random-access memory (RAM). The vehicle control processor21may be an electronic control unit (ECU) having one or more processors configured to execute various calculations adapted to control, for example, an unillustrated driving device of the vehicle11, such as a motor.

The vehicle control processor21may include an unillustrated storage. The storage may be configured by a nonvolatile memory such as an electrically erasable programmable read-only memory (EEPROM). The storage may store various pieces of data necessary for the calculations to be executed by the vehicle control processor21and one or more programs executable by the one or more processors. The storage may store data such as audio data of the notification sound that meets the requirements of applicable laws or regulations.

The vehicle state detector22may be a sensor configured to detect a traveling state of the vehicle11. Non-limiting examples of the vehicle state detector22may include a vehicle speed sensor. The vehicle speed sensor may detect a speed of the vehicle11and output a detection signal obtained by the detection to the vehicle control processor21. Based on the detection signal, the vehicle control processor21may determine whether the traveling state of the vehicle11corresponds to a state in which the notification sound is to be outputted in accordance with the applicable laws or regulations.

The amplifier23may convert the audio data of the notification sound received from the vehicle control processor21into an audio signal, and output the audio signal to the first speaker12and the second speaker13. As will be described later in greater detail, the amplifier23may be coupled to the first speaker12and the second speaker13, and outputs the same audio signal to the first speaker12and the second speaker13at the same timing or simultaneously. The amplifier23and the first and the second speakers12and13may be coupled to each other to cause the first speaker12and the second speaker13to receive the same audio signal from the amplifier23at the same timing or simultaneously.

The first speaker12and the second speaker13each may be a dynamic speaker, for example. The first speaker12and the second speaker13may output the notification sounds to the outside of the vehicle11, based on the audio signal received from the amplifier23.

Referring toFIG.3A, the first speaker12and the second speaker13may be provided at a location that is in a body frame and inside the tuft between the front grille15illustrated inFIG.1and the unillustrated radiator. The first speaker12is opposed toward the right side of the vehicle11in the vehicle width direction, and the second speaker13is opposed toward the left side of the vehicle11in the vehicle width direction. The first speaker12and the second speaker13may respectively include bobbins33and34around which respective voice coils31and32are wound. The bobbins33and34may have an integral structure with respect to each other via a yoke35.

In one embodiment, the voice coil31may serve as a “first voice coil”. In one embodiment, the voice coil32may serve as a “second voice coil”. In one embodiment, the bobbin33may serve as a “first bobbin”. In one embodiment, the bobbin34may serve as a “second bobbin”.

In the example embodiment, the bobbins33and34may be formed to have a linear shape. As indicated by a dotted line17, an axial center of the bobbin33of the first speaker12and an axial center of the bobbin34of the second speaker13may be coaxially positioned in the vehicle width direction of the vehicle11. The first speaker12and the second speaker13has the integral structure with respect to each other, and may be so disposed as to be line-symmetrical with respect to the center line CL, indicated by the dashed-dotted line16, in the vehicle width direction of the vehicle11.

The first speaker12may include: a frame36; a plate37fixed to the frame36; the voice coil31disposed between the plate37and the bobbin33; and a magnet38fixed to an end of the yoke35. The first speaker12may form a magnetic circuit by the yoke35, the magnet38, and the voice coil31wound around the bobbin33.

The second speaker13may include: a frame39; a plate42fixed to the frame39; the voice coil32disposed between the plate42and the bobbin34; and a magnet38fixed to the end of the yoke35. The second speaker13may form a magnetic circuit by the yoke35, the magnet38, and the voice coil32wound around the bobbin34.

In some embodiments, a direction of a current flowing through the voice coil31of the first speaker12may be the same as a direction of a current flowing through the voice coil32of the second speaker13. The first speaker12and the second speaker13may be coupled to the same amplifier23. The currents based on the same audio signal flow to the voice coils31and32at the same timing or simultaneously.

With this structure, a force that vibrates in the vehicle width direction of the vehicle11may be applied to the bobbins33and34as indicated by an arrow18, in accordance with the Fleming's left-hand law based on the magnetic circuits. As described above, the bobbins33and34may have the integrated structure via the yoke35, and the bobbins33and34may also vibrate in the same direction by the currents flowing in the same direction in the voice coils31and32.

Referring toFIG.3B, a vertical axis represents a sound pressure (dB), and a horizontal axis represents a time (t). In the first speaker12, a cone40may be coupled between the bobbin33and the frame36. In the second speaker13, a cone41may be coupled between the bobbin34and the frame39. An operation of the bobbins33and34may also cause the cones40and41to vibrate in the same direction in the vehicle width direction of the vehicle11.

When the bobbins33and34move to the right side of the vehicle11, the cone40may expand in a direction in which the cone40is pushed out with respect to the frame36, thus outputting the notification sound to the outside of the vehicle11, whereas the cone41may expand in a direction in which the cone41is drawn with respect to the frame39, thus outputting the notification sound toward the inside of the vehicle11. In contrast, when the bobbins33and34move to the left side of the vehicle11, the cone41may expand in a direction in which the cone41is pushed out with respect to the frame39, thus outputting the notification sound to the outside of the vehicle, whereas the cone40may expand in a direction in which the cone40is drawn with respect to the frame36, thus outputting the notification sound toward the inside of the vehicle11.

The vibration of the bobbins33and34in the same direction may cause the notification sound to be outputted from the first speaker12and the notification sound to be outputted from the second speaker13to have opposite phases with respect to each other as illustrated inFIG.3B. Thus, the notification sounds outputted from the first speaker12and the second speaker13toward the inside of the vehicle11may cancel out each other and offset each other, which helps to greatly reduce the notification sound that enter the inside of the vehicle11. This also achieves the notification sound that meets the applicable requirements of laws or regulations for the outside the vehicle, and helps to ensures quietness for a vehicle compartment of the vehicle11. Accordingly, an occupant of the vehicle11is able to enjoy, for example, a conversation, music, or the like, which helps to achieve a comfort upon traveling of the vehicle11.

Referring toFIG.4, the following requirements are defined in the sound pressure measurement test according to the Japanese laws or regulations. For a forward movement of the vehicle11, microphones51are to be installed at a height of 1.2 meters from the ground at respective locations on both sides of the right and left ends of the vehicle11, i.e., on both sides of a front end of the vehicle11. The locations are two meters away from the center line CL in the vehicle width direction. Under such conditions, a measurement is performed as to whether the notification sound has a sound pressure equal to or higher than 45 dB. For a backward movement of the vehicle11, the microphones51are to be installed at the height of 1.2 meters from the ground at respective locations on both sides of the right and left ends of the vehicle11, i.e., on both sides of a rear end of the vehicle11. The locations are two meters away from the center line CL in the vehicle width direction. Under such conditions, a measurement is performed as to whether the notification sound has the sound pressure equal to or higher than 45 dB.

Upon the backward movement of the vehicle11that includes the vehicle control apparatus10according to the example embodiment, the notification sounds to be outputted from the first speaker12and the second speaker13provided at the front part of the vehicle11are to meet the sound pressure measurement test. In order to meet the requirements of the sound pressure measurement test, the notification sound may be outputted at the sound pressure higher than the sound pressure of 45 dB.

Accordingly, the notification sounds outputted from the cones40and41as a result of the expansion in the directions to be drawn toward the vehicle compartment of the vehicle11can also increase. However, the notification sounds outputted from the first speaker12and the second speaker13toward the vehicle compartment of the vehicle11cancel out each other and offset each other, which helps to greatly reduce the notification sound that enter the inside of the vehicle11.

In the vehicle control apparatus10according to the example embodiment, the bobbins33and34may be formed in the linear shape, and the axial center of the bobbin33of the first speaker12and the axial center of the bobbin34of the second speaker13may be coaxially positioned in the vehicle width direction of the vehicle11; however, any embodiment of the disclosure is not limited thereto. In some embodiments, respective ends of bobbins33A and34A to which the cones40and41are respectively coupled may be obliquely bent or curved forward as illustrated inFIG.5. This configuration helps to easily deliver the notification sound to a person such as the pedestrian at the front of the vehicle11. Also in this case, the first speaker12and the second speaker13may be disposed line-symmetrically with respect to the center line CL of the vehicle11in the vehicle width direction indicated by the dashed-dotted line16.

Further, as illustrated inFIG.3AandFIG.5, the first speaker12and the second speaker13may be disposed line-symmetrically with respect to the center line CL of the vehicle11in the vehicle width direction indicated by the dashed-dotted line16; however, any embodiment of the disclosure is not limited thereto. In some embodiments, when an effect of reducing an amount of entry of the notification sound into the vehicle11is to be achieved for a driver who drives the vehicle11, the first speaker12and the second speaker13may be disposed line-symmetrically in the vehicle width direction of the vehicle11in front of a steering wheel of a driver's seat. In addition, disposing at least the first speaker12and the second speaker13to oppose each other in the vehicle width direction of the vehicle11may allow the notification sounds outputted from the first speaker12and the second speaker13toward the inside of the vehicle11to cancel out each other and offset each other, which helps to achieve the effect of reducing the amount of the entry of the notification sound into the vehicle11.

Further, in the vehicle control apparatus10, the yoke35and the magnet38may be shared by the first speaker12and the second speaker13, and the first speaker12and the second speaker13may be integrated with each other in structure; however, any embodiment of the disclosure is not limited thereto. In some embodiments, the first speaker12and the second speaker13may be provided as separate structures and disposed line-symmetrically with respect to the center line CL of the vehicle11in the vehicle width direction indicated by the dashed-dotted line16.

Although some example embodiments of the disclosure have been described in the foregoing by way of example with reference to the accompanying drawings, the disclosure is by no means limited to the embodiments described above. It should be appreciated that modifications and alterations may be made by persons skilled in the art without departing from the scope as defined by the appended claims. The disclosure is intended to include such modifications and alterations in so far as they fall within the scope of the appended claims or the equivalents thereof.