KR20230009148A - Sound system for vehicle and sound output method using the system - Google Patents

Abstract

According to the present invention, a sound outputting method of a sound system for a vehicle comprises: a step of enabling a rear side warning system to transmit collision risk information generated based on detection information obtained by detecting a rear vehicle to the sound system for a vehicle; and a step of enabling the sound system for a vehicle to generate and output an ultrasonic warning sound through at least one parametric speaker selected among the plurality of parametric speakers installed inside a vehicle.

Description

Vehicle sound system and its sound output method {SOUND SYSTEM FOR VEHICLE AND SOUND OUTPUT METHOD USING THE SYSTEM}

The present invention relates to a method for outputting sound for a vehicle, and more particularly, to a method for outputting sound for a vehicle for outputting independent sounds for each occupant.

A typical vehicle audio system includes a speaker that outputs a sound source in the vehicle. When a single speaker is installed in a vehicle, since the speaker transmits sound sources in all directions within the vehicle, each occupant cannot hear different sound sources.

In order to provide different sound sources for each occupant, a plurality of speakers need to be installed in a vehicle. At this time, each speaker is installed at an appropriate location close to the corresponding passenger seat.

In this way, when a plurality of speakers are installed in a vehicle, interference may occur between a sound source output from one speaker and a sound source output from another speaker, and thus the sound quality of the sound source output from each speaker is degraded.

An object of the present invention is to provide a vehicle audio system and its sound output method for preventing interference that may occur between a sound source heard by each occupant and a sound source heard by other top boxes in a situation where occupants in a vehicle listen to different sound sources. is to do

Another object of the present invention is to output an ultrasonic warning sound (stereoscopic sound) when a blind spot detection (BSD) vehicle is detected in the lane-changing direction of the own vehicle in conjunction with a Blind Spot Detection (BSD) system to warn the driver of the risk of collision. It is to provide a sound system for a vehicle that warns and a sound output method thereof.

The foregoing and other objects, advantages and characteristics of the present invention, and methods of achieving them will become clear with reference to the embodiments described below in detail in conjunction with the accompanying drawings.

In order to achieve the above object, a sound output method of a vehicle sound system according to an aspect of the present invention provides collision risk information generated based on detection information obtained by detecting a rearward vehicle by a rear side warning system, and is transmitted to the vehicle sound system. sending to; and according to the collision risk information, the vehicle sound system generates and outputs an ultrasonic warning sound through at least one parametric speaker selected from among a plurality of parametric speakers installed in the vehicle.

In an embodiment, the outputting may include, when the collision risk information includes the identification information of the rear vehicle indicating that the detected rear vehicle is a left rear vehicle or a right rear vehicle, the driver's seat through a parametric speaker for the driver. It may be a step of generating and outputting an ultrasonic alarm sound focused on the left rear or the right rear.

In an embodiment, the outputting may be a step of generating and outputting the ultrasonic warning sound whose volume is adjusted based on the headway distance between the subject vehicle and the rear vehicle included in the collision risk information.

In an embodiment, the outputting may include a driver's seat through a driver's parametric speaker according to the collision risk information including identification information of the rear vehicle indicating that the detected rear vehicle is a left rear vehicle or a right rear vehicle. generating an ultrasonic alert sound focused on the left rear or the right rear; and adjusting and outputting the volume of the generated ultrasonic warning sound according to the collision risk information including the inter-vehicle distance between the rear vehicle and the subject vehicle.

In an embodiment, the outputting may be a step of outputting the ultrasonic warning sound to the rear or front seat of the driver's seat according to the collision risk information including the comparison result of the reference time and the expected collision time with the rear vehicle. can

In an embodiment, the collision risk information includes identification information of the rear vehicle indicating that the detected rear vehicle is a left rear vehicle or a right rear vehicle, an inter-vehicle distance between the rear vehicle and the subject vehicle, a reference time and the rear vehicle and generating an ultrasonic warning sound focused on the left rear or right rear of the driver's seat through a parametric speaker for the driver, according to the identification information of the rear vehicle, and the outputting of the comparison result of the predicted collision time of ; adjusting the volume of the generated ultrasonic warning sound according to the headway distance; and outputting the ultrasonic alarm sound whose volume is adjusted through a parametric speaker for the driver or a parametric speaker installed near all seats including the driver's seat, according to a result of the comparison.

In an embodiment, the outputting may include generating the ultrasonic alert sound; and outputting the generated ultrasonic alarm sound through the selected at least one parametric speaker, wherein the generating of the ultrasonic alarm sound includes a first sound system installed near a first seat in a vehicle. If a parametric speaker and a second parametric speaker installed near a second seat are included, generating an anti-phase signal for an audio signal output from the second parametric speaker; generating a transmission signal by synthesizing an audio signal (g(t)) that the occupant of the first seat wants to hear through the first parametric speaker and the anti-phase signal; and generating the ultrasonic alert sound by modulating the transmission signal.

In an embodiment, the generating of the anti-phase signal may include an attenuation coefficient according to an audio signal output from the second parametric speaker and a distance from the second parametric speaker to an occupant seated in the second seat. It may be a step of generating the anti-phase signal by using.

In an embodiment, the step of modulating the transmission signal E(t) to generate an ultrasonic alarm sound may be a step of modulating the transmission signal E(t) with an amplitude of an ultrasonic signal according to an amplitude modulation scheme. can

A vehicle audio system according to another aspect of the present invention includes a plurality of parametric speakers installed in a vehicle and outputting ultrasonic alarm sounds; a communication interface that communicates with a blind spot warning system; and to output the ultrasonic warning sound through a driver's parametric speaker among the plurality of parametric speakers or all of the plurality of parametric speakers according to the collision risk information received from the blind spot warning system through the communication interface. It includes a controller that controls

Here, the collision risk information includes identification information of the rear vehicle indicating that the detected rear vehicle is a left rear vehicle or a right rear vehicle, an inter-vehicle distance between the rear vehicle and the subject vehicle, and a collision between a reference time and the rear vehicle. Comparison of expected times may be included.

According to the present invention, there is provided a vehicle audio system that delivers independent sound for each occupant using a parametric speaker. Accordingly, when the occupants of the vehicle including the driver want to listen to different music, each occupant can individually hear only desired sounds without interference.

In addition, according to the present invention, when a rear-side vehicle is detected in the lane-changing direction of the subject vehicle in conjunction with the BSD system, an ultrasonic warning sound is focused by using a parametric speaker at the rear left or rear right point of the driver's seat. ), the driver can recognize the driving situation three-dimensionally by hearing the ultrasonic alarm sound.

In addition, according to the present invention, by adjusting the volume of the ultrasonic warning sound based on the headway distance between the subject vehicle and the rear vehicle, the driver can appropriately adjust the concentration of attention on the vehicle in the rear side to relieve tension.

In addition, according to the present invention, when there is a high risk of collision with a rearward vehicle during a lane change process, by outputting an ultrasonic warning sound through all parametric speakers installed near all seats, the driver as well as all occupants can prepare for a collision. let it be

1 is a diagram showing an array form of ultrasonic transducers included in a parametric speaker according to an embodiment of the present invention.
FIG. 2 is a diagram for explaining the magnitude of a signal at a focus point where each signal reaches when the ultrasonic transducers shown in FIG. 1 output signals according to different delay times.
3 is a diagram schematically illustrating an interference phenomenon between a sound output from a driver's seat speaker and a sound output from a rear right speaker installed close to a rear right seat according to an embodiment of the present invention.
4 is a flowchart illustrating a sound output method of a vehicle sound system according to an embodiment of the present invention.
FIG. 5 is a diagram showing the positions of the occupants in the vehicle and parametric speakers used by each occupant to help understand the flow chart shown in FIG. 4 .
6 is a configuration diagram of a vehicle audio system according to an embodiment of the present invention.
7 is a flowchart illustrating a sound output method of a vehicle sound system according to another embodiment of the present invention.
FIG. 8 is a configuration diagram of a sound system for a vehicle according to another embodiment of the present invention for implementing the sound output method shown in FIG. 7 .

The embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art, and the following examples may be modified in many different forms, and the scope of the present invention is as follows It is not limited to the examples. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the spirit of the invention to those skilled in the art. In addition, each component in the following drawings is exaggerated for convenience and clarity of explanation, and the same reference numerals refer to the same elements in the drawings. As used herein, the term “and/or” includes any one and all combinations of one or more of the listed items.

The present invention is characterized in providing different independent sounds for each occupant. Therefore, when the occupants of the vehicle want to listen to different music, it is possible to provide each occupant with desired sound quality without interference of the sound heard by other occupants and without reducing the intensity of the sound heard by the other occupants. there is.

To this end, the present invention is configured to include a parametric speaker outputting directional sound.

On the other hand, when sound is output in the driver's seat direction using a parametric speaker, the sound output in the driver's seat direction interferes with the sound that passengers in the rear seat hear through the parametric speaker (or general speaker) installed close to the rear seat. can give

Such interference can be minimized when acoustic energy (sound energy) is concentrated only at a specific point. The present invention provides a method for allowing signals output from an ultrasonic transducer of a parametric speaker to reach only a specific desired point at the same time by using an ultrasonic beam focusing method.

Since the position of the occupant is fixed in the vehicle, the delay time of the interference signal can be known, and the sound source each occupant hears can be known from the audio system.

Therefore, the method according to the present invention minimizes mutual interference by using an active noise canceling method that simultaneously outputs antiphase information of sounds (eg, music) heard by other occupants.

As such, if mutual interference between sounds is minimized, independent sounds may be provided for each occupant, and each occupant may hear a preferred sound (eg, music).

In particular, since the driver can listen to preferred music without being disturbed by the music the occupant is listening to, stress caused by driving can be reduced.

Hereinafter, a 'parametric speaker', an 'ultrasound beam focusing method', and an 'active noise control' method applicable to the present invention will be described.

Parametric speaker

Because sound waves have long wavelengths, they propagate in all directions.

In order to add directivity to sound waves, in the present invention, a parametric speaker is used that propagates sound only in a specific direction using ultrasonic waves having a short wavelength and generates sound using nonlinear characteristics of a medium.

A sound signal generated from an ultrasonic signal using a quasi-linear technique is expressed in Equation 1 below.

When the transmission signal E(t) is modulated with the amplitude of the ultrasonic signal according to the AM modulation method and transmitted as shown in Equation 2 below, the signal in the audible frequency band is expressed as Equation 3 below.

The variables included in Equations 1 and 2 can be defined as follows.

Therefore, when the signal generated as shown in Equation 4 is AM-modulated into an ultrasonic signal and transmitted, the occupant can hear the audio signal g(t).

Here, m is the modulation depth.

The angle of view of a sound wave has a characteristic of decreasing as the frequency increases. When a parametric speaker is used, sound waves can be transmitted at a beam angle of ultrasonic waves, and sound can be transmitted only in a specific direction.

Ultrasound beam focusing method

When the distance between the speaker and the driver is 50 cm or less, when a 20 cm speaker is implemented using 58 kHz ultrasonic transducers, the distance up to 72.4 cm becomes a near field area through Equation 5 below.

Therefore, in the embodiment of the present invention, ultrasonic waves are focused using an annular array speaker in which a plurality of ultrasonic transducers are arranged in a circular shape to form maximum sound pressure near the ears of the occupant.

1 is a diagram showing an array of ultrasonic transducers included in a parametric speaker according to an embodiment of the present invention, and FIG. 2 is a case where the ultrasonic transducers shown in FIG. 1 output ultrasonic waves according to a fixed delay time. , It is a diagram for explaining the magnitude of the signal at the focus where each ultrasonic wave arrives.

As shown in FIG. 1, when configuring a speaker using N ultrasonic transducers 10, the delay time (r ₀ /c, r at the output of each transducer 10 as shown in Equation 6 below) ₁ /c, r ₂ /c, … r _N-1 /c), as shown in FIG. 2, the signals reaching the focal point at the same time are focused (or synthesized), and the The size increases by N times. This is referred to as a 'time delay based transmission fixed convergence method'.

The signal focused at the focal point is redistributed as the distance increases, so that at other occupant positions, only a single transducer output is delivered again. Therefore, it is possible to transmit sound at a level that can be heard only at a specific occupant's position.

Here, P1(t, n) = P1(t - τ + t _n /c), τ is a fixed delay delay time, and c is a sound speed.

Active Noise Canceling Method

3 is a diagram schematically illustrating an interference phenomenon between a sound output from a driver's seat speaker and a sound output from a rear right speaker installed close to a rear right seat according to an embodiment of the present invention.

Since the interior space of a vehicle is narrow, sound waves can reach other occupants even though the speaker is directional and the sound energy is concentrated at a specific location (near the ears of the occupants) through focusing.

For example, as shown in FIG. 3 , a sound wave output from a parametric speaker 30 installed near a driver's seat reaches an occupant in a rear right seat. Therefore, the sound output from the parametric speaker 30 installed near the driver's seat and the sound output from the rear right speaker 50 may interfere with each other.

)를 사용하여 간섭을 제거한다. Since the vehicle sound system according to an embodiment of the present invention knows information about the sound sources heard by each occupant, the rear right speaker 50 generates an anti-phase signal for the output of the driver's seat speaker included in Equation 7 below (

) to remove the interference.

Here, r _{rear right seat} is the distance from the driver's seat speaker 30 to the rear right occupant, α is an attenuation coefficient according to the distance, g _drive () is an audio signal output from the driver's seat speaker 30, and g _{rear right seat} ( ) is an audio signal output from the rear right speaker 50 .

If 4 people are listening to different sound sources in a vehicle, Equation 7 above is configured to include 3 anti-phase signals, so that the sound source that each occupant is listening to interferes with the sound source that other occupants are listening to. eliminate the phenomenon.

That is, three anti-phase signals are included in the output of the rear right speaker 50. In this case, the three anti-phase signals are the anti-phase signal for the audio signal output from the driver's seat speaker 30, the anti-phase signal for the audio signal output from the front right speaker, and the audio signal output from the rear left speaker. contains an anti-phase signal for

4 is a flowchart illustrating a sound output method of a vehicle audio system according to an embodiment of the present invention, and FIG. 5 is a parameter used by passengers and each passenger to help understand the flowchart shown in FIG. 4 . It is a diagram showing the location of the metric speaker.

In the sound output method according to an embodiment of the present invention, as shown in FIG. 5, four parametric speakers 30, 40, 50, and 60 are installed, and four passengers 32, 42, and and 62) are assumed to be in the vehicle. In addition, in the sound output method according to the embodiment of the present invention, only the sound output method from the first parametric speaker 30 is described, and the sound output method of each of the other parametric speakers 40, 50, and 60 is described. For this, it is replaced with a description of the sound output method from the first parametric speaker 30.

In addition, it is assumed that the four occupants 32, 42, 52, and 62 listen to different sound sources (hereinafter, audio signals) through respective parametric speakers.

First, in step S410, second to fourth audio signals causing interference with the first audio signal that the first occupant 32 (the driver) wants to hear through the first parametric speaker 30 are generated. A process of generating an anti-phase signal is performed. Here, the second to fourth audio signals are sound sources heard by the second to fourth occupants 42, 52, and 62, and are respectively output through the second to fourth parametric speakers 40, 50, and 60. to be.

)에 대한 제2 역-위상 신호(

)는, 제2 파라메트릭 스피커(40)로부터 출력되는 상기 제2 오디오 신호(

와 상기 제2 파라메트릭 스피커(40)로부터 상기 제1 좌석에 착석한 제1 탑승자(32, 운전자의 귀 근처)까지의 거리(도5의

)에 따른 감쇄 계수(

)를 이용하여 생성될 수 있다. 여기서, 거리(도5의

)에 따른 감쇄 계수(

)는 차량 내의 온도, 습도, 기압에 따라 결정되는 고정된 값으로서,

와 같이 지수함수 형태로 나타낼 수 있다. The second audio signal (

) for the second anti-phase signal (

) is the second audio signal output from the second parametric speaker 40 (

and the distance from the second parametric speaker 40 to the first occupant 32 (near the driver's ear) seated in the first seat (see FIG. 5)

) according to the attenuation coefficient (

) can be created using Here, the distance (of FIG. 5

) according to the attenuation coefficient (

) is a fixed value determined according to the temperature, humidity, and atmospheric pressure in the vehicle,

It can be expressed in exponential form as

)는 상기 제2 오디오 신호(

와 지수 함수 형태(e)로 표현되는 감쇄 계수(

)의 곱셈 연산에 의해 계산될 수 있다.

에서, 아래 첨자 fr은 'front right'의 약자이다.The second anti-phase signal (

) is the second audio signal (

and the attenuation coefficient expressed in the exponential form (e) (

) can be calculated by the multiplication operation of

, the subscript fr stands for 'front right'.

)에 대한 제3 역-위상 신호(

)는, 제3 파라메트릭 스피커(50)로부터 출력되는 상기 제3 오디오 신호(

)와 상기 제3 파라메트릭 스피커(50)로부터 상기 제1 좌석에 착석한 제1 탑승자(32, 운전자의 귀 근처)까지의 거리(도5의

)에 따른 지수함수 형태(e)의 감쇄 계수(

)를 이용하여 생성될 수 있다.

에서 아래 첨자 rr은 'rear right'의 약자이다.Similarly, the third audio signal (

) for the third anti-phase signal (

) is the third audio signal output from the third parametric speaker 50 (

) and the distance from the third parametric speaker 50 to the first occupant 32 (near the driver's ear) seated in the first seat (see FIG. 5).

Attenuation coefficient of the exponential form (e) according to ) (

) can be created using

In , the subscript rr is an abbreviation for 'rear right'.

)에 대한 제4 역-위상 신호(

)는, 제4 파라메트릭 스피커(60)로부터 출력되는 상기 제4 오디오 신호(

)와 상기 제4 파라메트릭 스피커(60)로부터 상기 제1 좌석에 착석한 제1 탑승자(32, 운전자의 귀 근처)까지의 거리(도5의

)에 따른 지수함수 형태(e)의 감쇄 계수(

)를 이용하여 생성될 수 있다.

에서, 아래 첨자 rl은 'rear left'의 약자이다.Similarly, the fourth audio signal (

) for the fourth anti-phase signal (

) is the fourth audio signal output from the fourth parametric speaker 60 (

) and the distance from the fourth parametric speaker 60 to the first occupant 32 (near the driver's ear) seated in the first seat (see FIG. 5).

Attenuation coefficient of the exponential form (e) according to ) (

) can be created using

, the subscript rl stands for 'rear left'.

,

및

)를 합성하여, 송신 신호(A)를 생성하는 과정이 수행된다. 생성된 송신 신호는 아래의 식 8과 같다.Subsequently, in step S420, the audio signal g _drive (t) that the occupant 32 of the first seat wants to hear through the first parametric speaker 30 and the second to fourth anti-phase signals (

,

and

), and a process of generating a transmission signal A is performed. The generated transmission signal is shown in Equation 8 below.

Next, in step S430, a process of modulating the transmission signal A to generate an ultrasonic signal including the modulated transmission signal E(t) is performed. The modulated transmission signal E(t) is shown in Equation 9 below.

Here, m is the modulation depth.

Subsequently, in step S440, a process of outputting the generated ultrasonic signal by the first parametric speaker 30 is performed.

An ultrasonic signal including the modulated transmission signal E(t) is expressed as Equation 10 below.

Here, w ₀ is the frequency of the ultrasonic signal.

Meanwhile, in the step S440, the first parametric speaker 30 includes a plurality of ultrasonic transducers (10 in FIG. 1), and each ultrasonic transducer has a different delay time (for example, r ₀ /c, r ₁ /c, r ₂ /c, r _N-1 /c), the modulated ultrasonic signal is output in the direction of the first occupant.

6 is a configuration diagram of a vehicle audio system according to an embodiment of the present invention.

Referring to FIG. 6 , the vehicle audio system 100 includes an anti-phase signal generator 110 , a synthesizer 120 , a modulator 130 , a parametric speaker 140 and a controller 150 .

The anti-phase signal generator 110 may be a hardware module, a software module, or a combination thereof that processes step S410 of FIG. 4 .

When the first to third passengers are sitting in the first to third seats in the vehicle and the first to third passengers listen to different sound sources, the anti-phase signal generator 120 generates the second A second anti-phase signal for a second audio signal output from the second parametric speaker installed near the second seat as a second parametric speaker used by the occupant and a third parametric signal used by the third occupant As a metric speaker, an anti-phase signal including a third anti-phase signal for a third audio signal output from the third parametric speaker installed near the third seat is generated.

The second audio signal is an audio signal corresponding to a sound source desired to be heard by the second occupant, and the third audio signal is an audio signal corresponding to a sound source desired to be heard by the third occupant.

The second anti-phase signal is, for example, a signal calculated by multiplying the second audio signal and an attenuation coefficient in the form of an exponential function according to a distance from the second parametric speaker to the first occupant. .

The third anti-phase signal may be, for example, a signal calculated by multiplying the third audio signal and an attenuation coefficient in the form of an exponential function according to a distance from the third parametric speaker to the first occupant. there is.

The synthesizer 120 may be a software module, a hardware module, or a combination thereof that performs step S420 of FIG. 4 .

The synthesizer 120, for example, synthesizes the first audio signal that the first occupant wants to hear and the anti-phase signal including the first to third anti-phase signals to obtain a transmission signal A. generate

The modulator 130 may be implemented as a software module performing step S430 of FIG. 4, a hardware module, or a combination thereof.

The modulator 140 modulates the transmission signal A generated by the synthesizer 120 in an amplitude modulation manner to generate a modulated transmission signal E(t). Also, the modulator 140 generates an ultrasonic signal E(t)sin(w ₀ t) including the modulated transmission signal E(t).

A parametric speaker (140, hereinafter referred to as 'first parametric speaker') is installed near the first seat so that the first occupant can hear the first audio signal included in the ultrasonic signal. According to the control of 150, the ultrasonic signal is output.

The first parametric speaker 140 includes a plurality of ultrasonic transducers, and each ultrasonic transducer outputs the modulated ultrasonic signal toward the first occupant at different delay times under the control of the controller 150. do.

The controller 150 may be implemented with at least one processor that controls the output of the first parametric speaker 140 and simultaneously controls and executes the operations of the other components 110 to 140 .

Although the synthesizer 120 and the modulator 130 are shown separately in FIG. 6, they may be integrated into one block. In this case, synthesizer 120 may be designed to be included in modulator 130.

Also, the anti-phase signal generator 110, synthesizer 120, modulator 130, and controller 150 shown in FIG. 6 may be integrated into one hardware module. For example, anti-phase signal generator 110, synthesizer 120, and modulator 130 may be incorporated into controller 150. In this case, the controller 150 may be implemented as a single chip.

7 is a flowchart illustrating a sound output method of a vehicle sound system according to another embodiment of the present invention.

A sound output method according to another embodiment of the present invention relates to a sound output method of a vehicle sound system that works with a Blind Spot Detection (BSD) system.

As is well known, the BSD system is a convenience system that notifies the driver of a dangerous situation through LEDs on side mirrors when a blind spot of the vehicle or a rear vehicle approaching from the rear side is detected.

An automotive sound system that interworks with such a BSD system receives collision risk information from the BSD system, and based on the collision risk information, ultrasound is focused on the rear right or rear left side of the driver's seat by using the method described with reference to FIGS. 1 to 6 . output an alarm sound

By doing this, the driver can reduce the recognition time of a rear-side vehicle approaching from the rear-side of the driver's vehicle.

In addition, since the ultrasonic warning sound is focused on the rear right or rear left side of the driver's seat, the driver can hear the ultrasonic warning sound heard from the rear right or rear left side and perceive the approaching direction of the rear vehicle in three dimensions.

In addition, by adjusting the volume of the ultrasonic warning sound according to the distance between the driving vehicle and the rear vehicle, the driver can perceive the distance from the rear vehicle three-dimensionally by listening to the ultrasonic warning sound with the adjusted volume. there is.

As such, since the driver can perceive a sense of direction and a sense of distance to the rear vehicle through the ultrasonic warning sound, the ultrasonic warning sound output from the parametric speaker can be viewed as stereophonic sound.

Hereinafter, a sound output method according to another embodiment of the present invention will be described in detail.

Referring to FIG. 7 , first, in S710, a process of determining whether the BSD system is in an ON or OFF state is performed. The BSD system can be turned on or off by a user interface (HMI) installed in the vehicle. The user interface may be an instrument panel having an input function and a display function. If the BSD system is in an on state, proceed to S720.

Subsequently, in S720, if the BSD system is turned on, the BSD system determines whether the direction lamp is turned on. For example, it is determined whether the left turn signal lamp is on or the right turn lamp is on. If the left turn signal lamp or the right turn lamp is on, S730 proceeds.

Subsequently, in S730, the BSD system starts detecting a vehicle behind. A rear vehicle may be detected by a rear detection sensor including a camera and/or radar installed on the rear bumper of the vehicle. When a rear vehicle is detected, S740 proceeds.

Subsequently, in S740, the BSD system determines whether the detected rear vehicle is a left rear vehicle or a right rear vehicle. In the case of a left rear vehicle, S750 proceeds, and in the case of a right rear vehicle, S760 proceeds.

First, in S750, the vehicle sound system receives collision risk information indicating that the detected rear vehicle is a left rear vehicle from the BSD system, and generates an ultrasonic warning sound focused on the left rear of the driver's seat.

The ultrasonic alarm sound focused on the rear left side may be generated from the processes performed by S410 to S440 of FIG. 4 , and a description thereof is replaced with the description with reference to FIG. 4 described above.

Meanwhile, when the detected rear vehicle is the right rear vehicle, in S760, the vehicle sound system receives collision risk information indicating that the detected rear vehicle is the right rear vehicle from the BSD system, and an ultrasonic alarm focused on the right rear of the driver's seat. generate

An ultrasonic alarm sound focused on the rear right side may also be generated from the processes performed by S410 to S440 of FIG. 4 , and the description thereof is replaced with the description with reference to FIG. 4 above.

Following S750 or S760, in S770, the vehicle sound system receives collision risk information including the distance between the vehicle and the rear vehicle from the BSD system, and adjusts the volume of the ultrasonic warning sound. At this time, the volume of the ultrasonic warning sound is adjusted to increase in inverse proportion to the distance between vehicles.

Subsequently, in S780, the BSD system calculates a Time To Collision (TTC) between the subject vehicle and the rear vehicle, and determines whether the calculated time to collision is equal to or less than a reference time (eg, 1 second). The BSD system determines that the collision risk is high if the collision expected time is less than or equal to the reference time, and determines that the collision risk is relatively low if it is the opposite.

If the predicted collision time is equal to or less than the reference time, S790 proceeds, and vice versa, S800 proceeds.

In S790, the vehicle sound system receives collision risk information indicating a high risk of collision from the BSD system, and outputs an ultrasonic warning sound whose volume is adjusted through parametric speakers installed near all seats in the vehicle.

In the S800, the vehicle sound system receives collision risk information indicating a low risk of collision from the BSD system, and outputs an ultrasonic warning sound whose volume is adjusted only to the left rear or right rear of the driver's seat through a parametric speaker installed near the driver's seat. do.

As described above, when a left-rear vehicle is detected, the sound system outputs an ultrasonic alarm so as to focus on the left rear of the driver's seat, and when a right-rear vehicle is detected, the ultrasonic alarm changes the focusing point to the right rear, , outputs an ultrasonic alarm so as to focus on the rear right side of the driver's seat. By doing this, the driver can audibly recognize the position of the rear vehicle and quickly recognize the rear vehicle.

In addition, by increasing the volume of the ultrasonic warning sound as the proximity distance of the rear vehicle is closer, the distance from the own vehicle to the rear vehicle can be audibly recognized.

In addition, when the predicted time for a collision with the rear vehicle during lane change of the subject vehicle is less than a standard time (eg, 1 second), an ultrasonic warning sound is output to all seats to prepare for a collision. In other situations, occupants can comfortably enjoy the sound source without being disturbed by the ultrasonic alarm sound.

Meanwhile, the flow of steps shown in FIG. 7 may be variously changed. For example, S750 and S770 may be performed in parallel or alternatively. Also, S730, S740, and S780 may be integrated into one step, and in this case, S750, S760, S770, S790, and S780 may be performed sequentially, in parallel, or selectively after the integrated step.

FIG. 8 is a configuration diagram of a sound system for a vehicle according to another embodiment of the present invention for implementing the sound output method shown in FIG. 7 .

Referring to FIG. 8 , the vehicle acoustic system 100 according to another embodiment of the present invention may communicate with the BSD system 200 through an in-vehicle communication network. Here, the in-vehicle communication network may be a Controller Area Network (CAN) or a Local Interconnect Network (LIN).

In FIG. 8 , communication interfaces for connecting the vehicle audio system 100 and the BSD system 200 to the vehicle internal communication network are omitted in order to simplify the drawing. Accordingly, the vehicle acoustic system 100 and the BSD system 200 may each be configured to further include a communication interface for accessing an in-vehicle communication network such as CAN or LIN.

A description of the vehicle audio system 100 is replaced with the content described with reference to FIG. 6 .

Since the present invention is not characterized by the hardware configuration included in the BSD system 200, the internal configurations of the BSD system 200 shown in FIG. 8 show only the minimum number of hardware configurations necessary to understand the present invention. only thing Accordingly, the BSD system 200 shown in FIG. 8 may further include known hardware configurations required for system design.

The user interface 210 (Human Machine Interface: HMI) provides an interfacing function between the BSD system 200 and a user (driver or passenger), and may be, for example, a display device having an input function such as a cluster in a vehicle. can The BSD system 200 can be turned on or off by user input through the HMI 210 .

The distance detection sensor 220 is a component that detects a rear vehicle approaching in the lane-changing direction of the driving vehicle, and may be lidar, radar, camera, or a sensor in which these are integrated.

The controller 230 is a component that controls and manages the overall operation of the BSD system 200, and may be implemented to include a processor consisting of at least one CPU, at least one GPU, or a combination thereof.

The controller 230 performs processes necessary to perform S710 to S800 shown in FIG. 7 .

In an embodiment, the controller 230 identifies whether a rear vehicle approaching in the lane-changing direction of the driving vehicle is a left rear vehicle or a right rear vehicle based on the detection information obtained by the distance sensor 200, and The collision risk information including the identification result is transmitted to the vehicle acoustic system 100 .

In an embodiment, the controller 150 of the vehicle sound system 100 outputs an ultrasonic warning sound focused on the left rear or right rear of the driver's seat based on the collision risk information including the identification result, a parameter installed near the driver's seat. Controls the output of the metric speaker (hereinafter referred to as 'parametric speaker for driver').

For example, when the controller 150 receives the collision risk information including the identification information of the rear vehicle indicating that the rear vehicle is the left rear vehicle, the controller 150 outputs a parametric alarm sound focused on the left rear of the driver's seat. Controls the output of the speaker, and when the collision risk information including the identification information of the rear vehicle indicating that the rear vehicle is the right rear vehicle is received, the driver's parametric speaker outputs an ultrasonic warning sound focused on the right rear of the driver's seat. control the output.

In an embodiment, the controller 230 calculates an inter-vehicle distance between the driving vehicle and the preceding vehicle, calculated based on the sensing information detected by the distance sensor 220, and collision risk information including the calculated inter-vehicle distance. is transmitted to the vehicle audio system 100.

In an embodiment, the controller 150 of the vehicle sound system 100 adjusts the volume of the ultrasonic warning sound focused on the left rear or right rear of the driver's seat based on the collision risk information including the inter-vehicle distance. Controls the output of the metric speaker.

For example, if the controller 150 receives collision risk information including the first headway distance from the BSD system 200, the controller 150 outputs an ultrasonic warning sound having a first sound level corresponding to the first headway distance so as to output a driver parameter. When the metric speaker is controlled and collision risk information including a second head-to-head distance smaller than the first head-to-head distance is received from the BSD system 200, an ultrasonic warning sound of a second sound level corresponding to the second head-to-head distance is sounded. Controls the driver's parametric speaker to output. At this time, the second sound level is greater than the first sound level. That is, the ultrasonic warning sound is adjusted to a volume that is inversely proportional to the distance between vehicles.

In an embodiment, the controller 230 may include the headway distance, the speed of the driving vehicle obtained from the vehicle speed sensor, the speed of the rear vehicle obtained through V2V communication or the roadside base station, the speed of the driving vehicle and the speed of the rear vehicle, and a steering sensor. A vehicle acoustic system (100) calculates a collision expected time (TTC) using the steering angle of a steering wheel obtained from ) to the controller 150.

In an embodiment, the controller 150 of the vehicle sound system 100 outputs an ultrasonic warning sound to the rear or front seats of the driver's seat (including the driver's seat and passenger's seat) based on the collision risk information including the collision risk step. Control the parametric speaker to

For example, when the controller 150 receives the collision risk information including a low collision risk level indicating that the TTC is equal to or longer than the reference time, the controller 150 outputs an ultrasonic warning sound to the rear left or right rear of the driver's seat through a parametric speaker for the driver. to control Additionally, the ultrasonic warning sound output to the rear or right rear may be an ultrasonic sound source whose volume is adjusted according to the distance between vehicles.

As another example, when the controller 150 receives the collision risk information including a high collision risk level indicating that the TTC is less than the reference time, the parametric speakers installed near all seats including the driver's seat and the passenger's seat emit an ultrasonic warning sound. control to output Additionally, the ultrasonic alarm sound output to all seats may be an ultrasonic sound source whose volume is adjusted according to the distance between vehicles.

The embodiments disclosed in this specification should be considered from an illustrative point of view rather than a limiting point of view. The scope of the present invention is shown in the claims rather than the foregoing description, and all differences within the equivalent range should be construed as being included in the present invention.

Claims (10)

transmitting, by the rear side warning system, collision risk information generated based on detection information obtained by detecting a rear vehicle to a vehicle sound system; and
Generating and outputting, by the vehicle sound system, an ultrasonic warning sound through at least one parametric speaker selected from among a plurality of parametric speakers installed in the vehicle, according to the collision risk information.
Sound output method of a vehicle sound system comprising a. In paragraph 1,
The outputting step is
When the collision risk information includes the identification information of the rear vehicle indicating that the detected rear vehicle is a left rear vehicle or a right rear vehicle, an ultrasonic alarm focused on the left rear or right rear of the driver's seat through a parametric speaker for the driver A sound output method of a vehicle sound system, which is a step of generating and outputting sound. In paragraph 1,
The outputting step is
and generating and outputting the ultrasonic warning sound whose volume is adjusted based on the inter-vehicle distance between the subject vehicle and the rear vehicle included in the collision risk information. In paragraph 1,
The outputting step is
According to the collision risk information including identification information of the rear vehicle indicating that the sensed rear vehicle is a left rear vehicle or a right rear vehicle, an ultrasonic alarm focused on the left rear or right rear of the driver's seat through a parametric speaker for the driver generating a sound; and
Adjusting and outputting the volume of the generated ultrasonic warning sound according to the collision risk information including the inter-vehicle distance between the rear vehicle and the subject vehicle
Sound output method of a vehicle sound system comprising a. In paragraph 1,
The outputting step is
and outputting the ultrasonic warning sound to a rear or front seat of a driver's seat according to the collision risk information including a comparison result of a reference time and an expected collision time with the rear vehicle. In paragraph 1,
The collision risk information includes identification information of the rear vehicle indicating that the detected rear vehicle is a left rear vehicle or a right rear vehicle, an inter-vehicle distance between the rear vehicle and the subject vehicle, a reference time and an expected collision time with the rear vehicle. Including the comparison result of
The outputting step is
generating an ultrasonic warning sound focused on the left rear or right rear of the driver's seat through a driver's parametric speaker according to the identification information of the rear vehicle;
adjusting the volume of the generated ultrasonic warning sound according to the headway distance; and
According to the comparison result, outputting the ultrasonic alarm sound whose volume is adjusted through a driver's parametric speaker or a parametric speaker installed near all seats including the driver's seat;
Sound output method of a vehicle sound system comprising a. In paragraph 1,
The outputting step is
generating the ultrasonic alert sound; and
Outputting the generated ultrasonic alarm sound through the selected at least one parametric speaker;
Generating the ultrasonic alert sound
When the vehicle sound system includes a first parametric speaker installed near a first seat in the vehicle and a second parametric speaker installed near a second seat,
generating an anti-phase signal for an audio signal output from the second parametric speaker;
generating a transmission signal by synthesizing an audio signal (g(t)) that the occupant of the first seat wants to hear through the first parametric speaker and the anti-phase signal; and
Modulating the transmission signal to generate the ultrasonic alarm sound
Sound output method of a vehicle sound system comprising a. In paragraph 7,
Generating the anti-phase signal,
generating the anti-phase signal using an audio signal output from the second parametric speaker and an attenuation coefficient according to a distance from the second parametric speaker to an occupant seated in the second seat. Sound output method of the sound system. In paragraph 7,
The step of generating an ultrasonic alarm sound by modulating the transmission signal E(t),
The step of modulating the transmission signal (E(t)) with an amplitude of an ultrasonic signal according to an amplitude modulation method. A plurality of parametric speakers installed in the vehicle and outputting ultrasonic alarm sounds;
a communication interface that communicates with a blind spot warning system; and
Control to output the ultrasonic warning sound through a driver's parametric speaker or all of the plurality of parametric speakers among the plurality of parametric speakers according to the collision risk information received from the blind spot warning system through the communication interface Including a controller that
The collision risk information includes identification information of the rear vehicle indicating that the detected rear vehicle is a left rear vehicle or a right rear vehicle, an inter-vehicle distance between the rear vehicle and the subject vehicle, a reference time and an expected collision time with the rear vehicle. A vehicle acoustic system comprising a comparison result of.

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