A directional sound emitting method capable of realizing sound field adjustment

Abstract

The application provides a directional sound emitting method capable of realizing sound field control and adjustment. The method is based on loudspeaker array to realize directional sound emission. According to known sound field and transmission path information, sound source information is obtained through a reverse design method. When the sound source is a group of loudspeaker arrays, a user can adjust the sound field directivity according to requirements, and then the sound source intensity of the loudspeaker array is obtained through the reverse design method. The application can emit sound in a directional manner according to the user's preference and the sound field directivity specified by the user. On the basis of directional sound emission, the sound pressure of the sound field can be adjusted. The different requirements of multiple users for the sound field are met.

Description

TECHNICAL FIELD

[0001] The present application relates to the intelligent NVH technology of automobile, and particularly relates to a directional sound emitting method capable of realizing sound field control and adjustment. BACKGROUND

[0002] The directional sound emitting technology is increasingly widely applied in the automobile industry. The roadside pedestrian warning sound needs to be provided when the electric vehicle is running at low speed. In order to avoid environmental pollution caused by noise, people hope that the warning sound outside the vehicle can be transmitted to the area where the pedestrians are located, and has no effect on other areas. For the vehicle interior, the driver and the passengers have different needs for sound. People hope that the loudspeaker system in the vehicle interior can realize the function of directional sound emission, and send the sound required by the driver and the passengers to the specified position respectively. By realizing the directional sound emission in the vehicle interior, the driver and the passengers can experience different sound field effects and are not affected by each other. The methods capable of realizing the directional sound emission of the vehicle currently proposed mainly include loading the audible sound wave into the ultrasonic wave by using the ultrasonic transducer to realize the directional transmission. However, the ultrasonic wave has poor adjustable performance, and the sound field is difficult to be adjusted according to the user demand. Another method currently proposed is to realize the function of directional sound emission by adjusting the angle of the loudspeaker according to the user demand. Because the angle of the loudspeaker cannot be adjusted to meet the sound field demand of multiple users at the same time, this method is difficult to be applied in the vehicle interior.

[0003] Therefore, it is necessary to develop a new directional sound emitting method capable of being applied in the vehicle, realizing the directional sound emission according to the user demand, and meeting the different requirements of multiple passengers in the vehicle interior for the sound field. SUMMARY

[0004] The purpose of the present application is to provide a directional sound emitting method capable of realizing sound field adjustment, based on the loudspeaker array, realizing the directional sound emission according to the user demand, and meeting the different requirements of the user for the sound field.

[0005] The technical scheme of the present application is as follows:

[0006] The technical principle of the directional sound emitting method capable of realizing sound field control and adjustment described in the present application is as follows:

[0007] The sound source of the target sound field is q, and the sound signal of q at N receiving points in the sound field is

[0008]

[0009] The target sound field is reconstructed by M loudspeakers, and the reconstruction method is

[0010]

[0011] The sound source intensity of the loudspeaker is

[0012]

[0013] The user can modify the target sound field directivity according to the requirement. The desired sound field obtained after modifying the sound field directivity is

[0014]

[0015] To obtain the desired sound field, the sound source intensity of the loudspeaker is adjusted to

[0016]

[0017] Based on the above principle, the present application proposes a directional sound emitting method capable of adjusting the sound field. The implementation steps of the method include:

[0018] Step 1: determining a target sound source q, which is the sound that needs to be played in the sound field.

[0019] Step 2: determining a target sound field p through the target sound source q and the sound field parameters, wherein the sound field parameters are the transfer functions from the target sound source q to the sound field control points, and the target sound field p is the sound field to be controlled and adjusted.

[0020] Step 3: adjusting the target sound field p through the sound field directivity vector b, and obtaining a desired sound field p'; the desired sound field is the sound field after control and adjustment.

[0021] Step 4: determining the intensity Q' of the loudspeaker array through the reverse design method, wherein the loudspeaker array is a sound emitting unit group containing a plurality of loudspeakers.

[0022] Step 5: loading the sound source intensity information of each loudspeaker calculated to the loudspeaker array and making it emit sound, and the sound field directivity generated by the loudspeaker array is the sound field directivity specified by the user.

[0023] The present application has the following advantages:

[0024] The present application realizes directional sound emission based on the loudspeaker array, and obtains the sound source information through the reverse design method according to the known sound field and transfer path information. When the sound source is a loudspeaker array, the user can adjust the sound field directivity according to the requirement, and then obtain the sound source intensity of the loudspeaker array through the reverse design method. The loudspeaker array can realize the directional sound emission function, and the directional sound emission effect meets the expected target set by the user. The present application can emit sound directionally according to the sound field directivity specified by the user. On the basis of directional sound emission, the sound pressure of the sound field can be adjusted. At the same time, the different requirements of multiple users for the sound field are met. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 The flowchart in the present embodiment.

[0026] Figure 2 This is the sound field caused by the target sound source in this implementation case.

[0027] Figure 3 This represents the sound field caused by the loudspeaker array in this implementation example.

[0028] Figure 4 In this implementation case, directional sound generation is achieved by adjusting the sound field directivity.

[0029] The reference numerals in the attached figures are as follows: 101-target sound source q, 102-target sound field p, 103-desired sound field p', 104-speaker array intensity Q', 105-speaker array. Detailed Implementation

[0030] The implementation steps and directional sound generation effect of this invention will be further explained below with reference to the accompanying drawings.

[0031] See Figure 1 The main steps of the directional sound generation method proposed in this invention, which enables sound field control and adjustment, include:

[0032] Step 1: Determine the target sound source q of the system. Here, the target sound source and sound field parameters are usually known information.

[0033] Step 2: Determine the target sound field p of the system using q and the sound field parameters, which is the sound field caused by the target sound source.

[0034] The specific implementation method is as follows:

[0035] Based on the target sound source q, the sound signals at N receiving points in the sound field are:

[0036]

[0037] in, Let q be the transfer function between the target sound source q and the N sound field control points.

[0038] The target sound field p is reconstructed using M loudspeakers. The reconstruction method is as follows:

[0039]

[0040] in M represents the sound source intensity of the loudspeaker array, and M represents the number of loudspeakers. The transfer function matrix is ​​given by M loudspeakers to N receiving points in the target sound field; the sound source intensity Q of the loudspeaker array can generate the target sound field p.

[0041] Step 3: Adjust the target sound field p using the sound field directivity vector b to obtain the desired sound field p'. This involves selecting a certain number of acoustic reference points within the sound field, setting the sound field control vector according to user preferences, modifying the sound at the acoustic reference points, and obtaining the desired sound field.

[0042] The method for implementing step 3 is as follows:

[0043] N sound reference points are selected in the sound field, and these reference points are distributed throughout the target sound field region to obtain the target sound field. Using the sound field adjustment vector b={α d α b Modify the sound pressure amplitude at N sound reference points to create a difference in the sound pressure amplitude of the target sound field in the transmission direction and the non-transmission direction, where {α} b} represents the correction coefficient for the sound field in the specified transmission direction, {α} d} represents the correction coefficient for the sound field in the specified non-transmission direction; the modified sound field becomes the desired sound field p′={p b ,p d The direction of sound transmission is denoted as {p}. b}, the sound that is not transmitted in the direction of transmission is denoted as {p}. d}

[0044] Step 4: Determine the strength Q' of the loudspeaker array using a reverse design method.

[0045] This step involves determining the transfer function matrix from the loudspeaker to the acoustic reference point in advance, based on the loudspeaker location and system characteristics. Then, using the desired sound field information and the system transfer function matrix, the sound source intensity information for each loudspeaker is calculated.

[0046] The method for implementing step 4 is as follows:

[0047] Based on the desired sound field information p′ and the pre-set transfer matrix H, the sound source intensity Q′ of each loudspeaker is calculated; the transfer matrix H is obtained in advance based on the position information of the loudspeaker array and the position information of the sound field reference point; the desired sound field is the sound field p′ after adjustment in step 3; the sound source intensity Q′ of the loudspeaker array can generate the desired sound field p′.

[0048] Step 5: The loudspeaker array with a sound source intensity of Q' can achieve directional sound emission, and the directivity of the sound field it produces is the directivity of the sound field specified by the user, which can meet the user's needs.

[0049] The above steps are explained in detail below with reference to the accompanying drawings:

[0050] like Figure 1The sound field shown is caused by a target sound source. Assume there exists a known sound source with intensity q in the sound field. The sound field response caused by this source is p. Typically, the target sound field p can be determined in advance based on the system characteristics and the sound source intensity.

[0051] like Figure 2 As shown, to achieve directional sound transmission, the target sound field p can be adjusted according to user needs. N sound reference points are selected within the sound field, distributed throughout the entire sound field region. The sound field adjustment vector b = {α} is then used. d α b Modify the sound pressure amplitude at N sound reference points to create a difference in the sound pressure amplitude of the target sound field in the transmission direction and the non-transmission direction. Where {α} b} represents the correction coefficient for the sound field in the specified transmission direction, {α} d} represents the correction coefficient for the sound field in the specified non-transmission direction. The modified sound field becomes the desired sound field p′={p b ,p d The direction of sound transmission is denoted as {p}. b}, Sounds that are not transmitted in the direction of travel are denoted as [p d}

[0052] like Figure 3 As shown, a desired sound field is generated using an array of M loudspeakers. The sound intensity of each of the M loudspeakers is calculated using the known desired sound field and a pre-defined transfer matrix H. This transfer matrix H can be obtained in advance based on the positions of the loudspeakers and the position information of the sound field reference point. During the sound field generation process, once the positions of the loudspeakers are determined, their sound intensity Q' only changes with the change of the target sound source intensity q.

[0053] The following is a practical example to illustrate the control effect of this directional sound technology, such as... Figure 4 As shown, this case reconstructs the sound field caused by a monopole sound source using four loudspeakers. Four reference points are selected in the sound field, and the sound field directivity corresponding to these four acoustic reference points is vector b. The corresponding directional sound control results are: (a) The sound field control vector for the four reference point positions is b = {1, 1, 1, 1} T (b) The sound field control vector for these four reference points is b = {1, 1, 0.02, 0.02}. T (c) The sound field control vector for these four reference points is b = {0.02, 0.02, 1, 1}. T .

Claims

1. A method for directional sound generation that enables sound field control and adjustment, characterized in that, Including the following steps: Step 1: Determine the target sound source q, which is the sound that needs to be played in the sound field; Step 2: Determine the target sound field p using the target sound source q and sound field parameters, where the sound field parameters are the transfer function from the target sound source q to the sound field receiving point, and the target sound field p is the sound field to be controlled and adjusted. Step 3: Adjust the target sound field p using the sound field directivity vector b to obtain the desired sound field. The desired sound field is the controlled and adjusted sound field. Step 4: Determine the strength of the speaker array using reverse engineering. The loudspeaker array is a group of sound-emitting units containing multiple loudspeakers; Step 5: Load the calculated sound source intensity information of each speaker into the speaker array and make it emit sound. The sound field directivity generated by the speaker array is the sound field directivity specified by the user.

2. The directional sound generation method for realizing sound field control and adjustment according to claim 1, characterized in that, The method for implementing step 2 is as follows: According to the target sound source q In the sound field N The sound signal at each receiving point is in, For the target sound source q and N Transfer function between receiving points; pass M Each speaker reconstructs the target sound field. p The reconstruction method is in The sound source intensity of the loudspeaker array. M This refers to the number of speakers; for M One speaker is placed in the target sound field. N The transfer function matrix of each receiving point; the sound source intensity of the loudspeaker array. Can generate target sound field .

3. The directional sound generation method for realizing sound field control and adjustment according to claim 2, characterized in that, The method for implementing step 3 is as follows: Select in the sound field N Several sound reference points are distributed throughout the target sound field region to obtain the target sound field. ; Using sound field adjustment vectors Revise N The sound pressure amplitude at each sound reference point causes a difference in the sound pressure amplitude of the target sound field in the direction of transmission and the non-transmission direction, among which... This is a correction factor for the sound field in the specified transmission direction. These are correction factors for the sound field in the specified non-transmission directions; the modified sound field becomes the desired sound field. The direction of its transmission is denoted as Sounds that do not travel in the direction of transmission are denoted as .

4. The directional sound generation method for realizing sound field control and adjustment according to claim 3, characterized in that, The implementation method of step 4 is as follows: Based on the desired sound field information The sound source intensity of each loudspeaker is calculated using the pre-defined transfer matrix H. The transfer matrix H is obtained in advance based on the position information of the loudspeaker array and the sound field reference point, and the desired sound field is the sound field adjusted in step 3. The sound source intensity of the loudspeaker array Can generate the desired sound field .

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