CN112216266A

CN112216266A - Phase-control multi-channel sound wave directional transmitting method and system

Info

Publication number: CN112216266A
Application number: CN202011128604.6A
Authority: CN
Inventors: 傅建玲
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-10-20
Filing date: 2020-10-20
Publication date: 2021-01-12

Abstract

A phase-control multi-channel sound wave directional transmitting method and system receive virtual target information through a man-machine interaction module or an external information receiving module, and transmitted to the target detection module, which detects whether an actual target exists in the environment, and further detecting the type, number and spatial position of each target, transmitting the audio signal to be transmitted to the modulation module through sound effect conversion, modulating the ultrasonic carrier signal by the modulation module through the audio signal subjected to sound effect conversion, and then transmitting to the transmission control module, dividing the transmission array into sub-arrays corresponding to each target by the transmission control module according to the number and spatial position of each target, and calculates the transmitting delay needed by each ultrasonic transmitter in the sub-array according to the phase control method, after the transmitting delay, the modulated ultrasonic carrier signal is transmitted by each ultrasonic transmitter in the transmit subarray.

Description

Phase-control multi-channel sound wave directional transmitting method and system

Technical Field

The invention relates to the technical field of consumer electronics, in particular to a method and a system for directionally transmitting phase-control multi-channel sound waves.

Background

In daily work and life, people need to reduce the interference of noise when listening to specific sound, and meanwhile, the privacy when listening to the sound needs to be guaranteed. At present, people generally solve the problems by wearing earphones, but no matter the earphones are in-ear earphones or earmuff earphones, the ears are tired after being worn for a long time, and head movement is inconvenient when the earphones are worn due to the structural weight of the earphones, the power line of the earphones and the winding of the audio line. There is a directional sound emitting device in the prior art, which can emit sound in a directional manner, and only when a user is in a sound emitting path, the sound can be heard. In order to enable a user to hear the sound, the directional sound transmission device needs to be adjusted by an automatic mechanical device to always point to the user, the automatic mechanical device enables the directional sound transmission device to be difficult to miniaturize, the transmission direction cannot be changed rapidly, and the directional sound transmission device can only transmit in one direction at the same time. There is also an improved directional transmission acoustic apparatus that changes the direction of ultrasonic waves emitted by an ultrasonic transmission array as a whole by changing the phase of each ultrasonic transmitter in the ultrasonic transmission array so that the ultrasonic waves emitted by each ultrasonic transmitter have a certain regular phase difference. The equipment does not need to mechanically rotate the ultrasonic emission array when changing the ultrasonic direction, but can only emit the ultrasonic in one direction at the same time, cannot transmit different ultrasonic waves in different directions at the same time, and cannot realize multi-channel transmission.

Disclosure of Invention

Aiming at the problems of the prior art, the invention provides a phase-control sound wave directional transmitting method and a phase-control sound wave directional transmitting system which are simple and reliable, have good universality and can simultaneously transmit different sound waves processed by sound effect to a plurality of targets without mechanically rotating an ultrasonic array.

In order to solve the problems of the prior art, the invention adopts the following technical scheme:

a phase-controlled acoustic wave directional emission method comprises the following specific implementation steps:

step 1) firstly, detecting whether virtual target information exists in a human-computer interaction module or an external information receiving module, and then transmitting the virtual target information into a target detection module, wherein the information comprises: the virtual object type, the number of virtual objects and the spatial position of each virtual object.

Step 2) the target detection module receives the virtual target information, then uses a sensor in the target detection module to detect the surrounding environment, and detects whether a target exists around according to the surrounding environment detection data by combining a target detection algorithm, if so, the target information is further detected, and the target information comprises: target type, number of targets N and respective target spatial position (P)₁~P_N)，(P₁~P_N) Representing the spatial positions of the N actual targets; finally, the virtual target information and the actual target are obtainedThe label information is sent to the emission control module together with the results.

And 3) when the target detection module detects the received virtual target or the actual target, generating an ultrasonic carrier signal with adjustable frequency by using an ultrasonic carrier generation module.

And 4) receiving sound effect setting information in the human-computer interaction module or the external information receiving module, processing the audio signals needing to be transmitted to the N-path targets by using the sound effect processing module according to different requirements of the N targets (including virtual targets and actual targets) on sound effects in the sound effect setting, independently adjusting the amplitude and phase shift of sinusoidal signal components forming different frequencies of the audio signals in each path of audio signals of the N-path targets or changing the frequency of certain sinusoidal signal components in one path of audio signals in the sound effect processing module, and transmitting the adjusted N-path audio signals to the modulation module.

And 5) after the ultrasonic carrier signals are generated, modulating the ultrasonic carrier signals by using N paths of audio signals which need to be transmitted to N targets and are subjected to sound effect processing to obtain N paths of ultrasonic modulation signals.

Step 6) transmitting the N ultrasonic modulation signals to a transmitting control module, dividing the ultrasonic transmitting array into N sub-arrays by the transmitting control module according to the number of targets and the space position of each target, calculating the phase of each ultrasonic transmitter in each sub-array required to be shifted according to an ultrasonic array synthetic sound beam phase control method, and calculating the transmitting delay (according to the relation of the phase wavelength sound velocity of the ultrasonic in the air), (^t ₁₁，^t ₁₂，……），……（^t _N1，^t _N2，……）。

And 7) delaying the N paths of ultrasonic debugging signals obtained in the step 5) according to the transmission delay needed by each ultrasonic transmitter calculated in the step 6), sending the delayed signals to an ultrasonic transmitter power amplifier, and finally transmitting the delayed signals through the ultrasonic transmitters, wherein the N paths of modulated synthesized ultrasonic beams are transmitted to a target.

And (3) repeating the steps 2) to 7), namely continuously receiving the mechanical ultrasonic waves by each target, wherein the generated difference frequency sound wave component is the audio sound wave required to be received by the target after the mechanical ultrasonic waves pass through the self-demodulation effect.

In the step 2), if no target exists, the target detection module does not send data to the emission control module, and the system does not start the subsequent steps 3) -6) to work, so that the energy is saved and the energy consumption of the system is reduced.

In the step 5), two different modulation methods can be adopted, and the first method is as follows: if the amplitude of the mechanical ultrasonic waves is controlled by using the amplitude of the input voltage or current of the ultrasonic transmitter, the amplitude of the ultrasonic carrier waves is modulated by the audio frequency which needs to be transmitted to a target, and amplitude modulated waves are obtained.

In the step 5), two different modulation methods can be adopted, and the second method is as follows: if the amplitude-frequency characteristic of the ultrasonic transmitter is utilized, the frequency modulation method can be used to modulate the audio frequency to be transmitted to the target by combining the amplitude-frequency characteristic of the ultrasonic transmitter to obtain the frequency-modulated wave, and the frequency-modulated wave is influenced by the amplitude-frequency characteristic of the ultrasonic transmitter when being transmitted by the ultrasonic transmitter, so that the mechanical ultrasonic wave transmitted by the ultrasonic transmitter becomes the amplitude-modulated wave. The frequency amplitude characteristic of the ultrasonic transmitter means that under the condition that the input voltage or current is not changed, the amplitude of the mechanical ultrasonic wave emitted by the ultrasonic transmitter has a functional relationship with the ultrasonic frequency, and under different ultrasonic frequencies, the amplitude of the mechanical ultrasonic wave output by the ultrasonic transmitter is different, namely:

A=g(f) (1)

if f (t) represents the function relation between the ultrasonic carrier wave electrical signal frequency and the time t, f (t) is substituted into the formula (1) to obtain:

g[f(t)] (2)

namely, the amplitude function of the mechanical ultrasonic wave output by the ultrasonic transmitter at the moment t is obtained. Assuming that a function of the amplitude of the ith audio waveform to be transmitted and the time t is h (t), frequency modulation needs to be performed on the ultrasonic carrier signal, so that the amplitude a of the transmitted mechanical ultrasonic wave is in a linear relationship with h (t), that is:

A=a×h(t)+b (3)

a and b are real constants, and the formula (2) is substituted with (3) to obtain: a × h (t) + b = g [ f (t) ], then:

f(t)=g^-1[a×h(t)+b] (4)

selecting a section of monotonic interval of the function g (f), assuming that the abscissa corresponding to the minimum value point of the monotonic curve is Xp _ min, the ordinate is A _ min, the abscissa corresponding to the maximum value point is Xp _ max, and the ordinate is A _ max, obtaining the frequency f (t) of the ultrasonic carrier wave needing to be modulated at the moment t through a formula (4), and then carrying out frequency modulation operation on the ultrasonic carrier wave signal through a frequency modulation technical method to obtain the required frequency modulation ultrasonic carrier wave signal. In order to fully utilize the transmitting capability of the ultrasonic transmitter, the method for selecting g (f) the monotonous interval comprises the following steps: the interval closest to the linear function needs to be selected, and the interval with the largest frequency bandwidth should be selected under the condition that the degree of the proximity to the linear function is the same.

The ultrasonic wave transmitting direction phase control algorithm in the step 6) is determined according to the target space position, the distance d + l/2 of each transmitter in the transmitting array, the sound velocity v of the ultrasonic wave in the air and the shape of the ultrasonic wave transmitting array, according to the spatial geometrical relationship, the geometrical relationship is projected to two mutually vertical projection surfaces respectively, one projection surface selects a horizontal plane and looks from top to bottom, the other projection surface selects the side surface of the ultrasonic emission array as the projection surface, the delay or the advance emission time of each ultrasonic emitter on one projection surface is calculated first, then the delay or the advance emission time of each ultrasonic emitter on the other projection surface is calculated, and finally the calculation results of the two projection surfaces are synthesized, wherein the formula is (5), so that the delay or the advance emission time required by each ultrasonic emitter can be obtained finally.

（5）

In the formula (5), T_{Combination of Chinese herbs}Indicating that the ultrasonic transmitter emits the ultrasonic wave earliest relative to the ultrasonic array in which it is locatedDelay of the emission moment of the sound wave, T_{Level of}Representing the calculated delay, T, in horizontal projection of the ultrasonic transmitter with respect to the transmission instant at which the ultrasonic array at which it is located transmits the ultrasonic wave earliest_{Side surface}Which represents the calculated delay in the lateral projection of the ultrasound transmitter with respect to the emission instant at which the ultrasound array at which it is located emits ultrasound waves earliest.

The ultrasonic wave transmitting direction phase control algorithm in the step 6) above, when one side of the ultrasonic wave array is selected as the projection plane, and the ultrasonic wave transmitting array is in the parallel transmitting mode, that is: when the ultrasonic synthesized beam is not required to be focused or diverged, the transmitting time delta t required to be spaced by any two adjacent ultrasonic transmitters can be calculated by the formula (6):

△t=p/v=(d+l/2)×sin(θ)/v（6）

(6) wherein d is the distance between the outer surfaces of the ultrasonic transmitters, l is the distance between the outer surfaces of the ultrasonic transmitters and the central axis, (d + l/2) the distance between the central axes of the ultrasonic transmitters, p is the projection length of the distance between the central axes of the ultrasonic transmitters in the transmitting direction of the ultrasonic synthesized beam, and v is the sound velocity of the ultrasonic wave in the air.

In the ultrasonic transmitting array, it is assumed that there are k total ultrasonic transmitters, the ultrasonic transmitter farthest from the target is denoted as the ultrasonic transmitter No. 1, the ultrasonic transmitter No. 1 transmits first and numbers the ultrasonic transmitter closest to the target in sequence, the ultrasonic transmitter closest to the target is denoted as the ultrasonic transmitter No. k, and the ultrasonic transmitter No. k transmits last. No. i ultrasonic transmitter, relative to No. 1 ultrasonic transmitter total transmission time delay of moment of transmission:

（i-1）×△t，i∈(1,2,…k)（7）

the ultrasonic wave transmitting direction phase control algorithm in the step 6) above, when one side of the ultrasonic wave array is selected as the projection plane, and the ultrasonic wave transmitting array is in the focusing transmitting mode, that is: require ultrasonic synthetic beam focusingWhen the target is focused, in the ultrasonic emission array, a total of k ultrasonic emitters are assumed, the ultrasonic emitter farthest from the target is recorded as the No. 1 ultrasonic emitter, the No. 1 ultrasonic emitter emits the first and sequentially numbers the ultrasonic emitter closest to the target, the ultrasonic emitter closest to the target is recorded as the No. k ultrasonic emitter, and the No. k ultrasonic emitter emits the last. When a target is projected onto an ultrasonic emission array plane along the direction of an emission axis of an ultrasonic emitter and the projection of the target is positioned outside an ultrasonic emission array area, the emission moment of No. i ultrasonic emitter needs to be delayed by delta t relative to No. i-1 ultrasonic emitter_i-1，i∈(1,2,…k)，△t_i-1Calculated using equation (8):

△t_i-1=p_i-1/v=(d+l/2)×sin(θ_i-1)/v（8）

(5) in, theta_iThe included angle between the connecting line of the target to the center of the No. i ultrasonic transmitter and the No. i ultrasonic transmitting axis in the focusing mode and theta is shown in the focusing scene_iI e (1,2, … k) are different and can be calculated from the spatial location of the target, the spatial location of the ultrasound array, and the center-to-center spacing of the individual ultrasound emitters.

The ultrasonic wave transmitting direction phase control algorithm in the step 6) is, when one side of the ultrasonic wave array is selected as the projection plane, when the ultrasonic wave transmitting array is in the focusing transmitting mode, that is: when the ultrasonic synthesized beam is required to be focused to a target, on the side projection of the target and the ultrasonic emission array, when the target is projected onto the ultrasonic emission array plane along the emission axis direction of the ultrasonic emitters and the target projection is positioned in the ultrasonic emission array area, assuming that the array has a total of k ultrasonic emitters, and m ultrasonic emitters exist on the left side of the target projection₁An ultrasonic transmitter with m on the right₂An ultrasonic transmitter (m)₁+m₂= k), the array is divided into two parts, left and right, which are equivalent to two sub-arrays, left and right, respectively.

In the left subarray portion, the leftmost ultrasonic transmitter is farthest from the target and is noted as leftThe No. 1 ultrasonic emitter on the side sequentially numbers the ultrasonic emitter closest to the target, and then the ultrasonic emitter closest to the target is marked as the m < th > left₁Number ultrasonic emitter, m th left₁The ultrasonic transmitter emits the ultrasonic signal finally, and the time delay of the ultrasonic transmitter j on the left side relative to the ultrasonic transmitter j-1 on the left side is recorded as left delta t_j-1，j∈(1,2,…m₁) Left Δ t_j-1Calculated using equation (8):

left delta t_j-1=p_j-1/v=(d+l/2)×sin(θ_j-1)/v （9）

In the right subarray portion, the leftmost ultrasound transmitter is closest to the target, denoted as the m-th right subarray portion₂The number of the ultrasonic transmitters is sequentially numbered to the ultrasonic transmitter farthest from the target, the ultrasonic transmitter farthest from the target on the rightmost side is recorded as the No. 1 ultrasonic transmitter on the right side, and in the subarray part on the right side, the No. m ultrasonic transmitter on the right side₂The ultrasonic transmitter on the right transmits last, the ultrasonic transmitter No. 1 on the right transmits first, and the delay of the ultrasonic transmitter No. j on the right relative to the ultrasonic transmitter No. j-1 on the right is recorded as right delta t_j-1，j∈(1,2,…m₂) Right delta t_j-1Calculated using equation (8):

right delta t_j-1=p_j-1/v=(d+l/2)×sin(θ_j-1)/v （10）

At the target projection position, the target is reached nearest, and here, it is assumed that there exists a virtual ultrasonic transmitter, denoted as the X-th virtual ultrasonic transmitter, and obviously, the X-th virtual ultrasonic transmitter needs to transmit last in the whole array (including the left and right subarray portions). No. X virtual ultrasonic transmitter is m relative to the left₁The delay required for ultrasonic transmitter is:

T_m1=p_m1/v=X_off×sin(θ_m1)/v （11）

no. X virtual ultrasonic transmitter is m relative to the right₂The delay required for ultrasonic transmitter is:

T_m2=p_m2/v=(d+l/2-X_off)×sin(θ_m2)/v （12）

the needed delay of the No. X virtual ultrasonic transmitter relative to the No. 1 left virtual ultrasonic transmitter is obtained by the formulas (4-4) and (4-5), and is recorded as a left T, and the left T is calculated by the formula (4-6):

left T = left Δ T₁+ left Δ t₂+ … + left Δ t_m1-1+T_m1（13）

Similarly, the needed delay of the No. X virtual ultrasonic transmitter relative to the No. 1 on the right is obtained by formulas (4-4) and (4-5) and is recorded as right T, and the right T is obtained by calculation by formula (4-6):

right T = right Δ T₁+ right delta t₂+ … + right Δ t_m2-1+T_m2（14）

Suppose that the emitting time of the No. 1 left ultrasonic transmitter is t_leftAnd the transmitting time of the No. 1 ultrasonic transmitter on the right is t_rightAnd the transmitting time of the left No. 1 ultrasonic transmitter is the earliest transmitting time in the whole ultrasonic transmitting array, and because the transmitting time of the X virtual ultrasonic transmitter calculated by taking the left part as the reference should be equal to the transmitting time of the X virtual ultrasonic transmitter calculated by taking the right part as the reference, the following steps are provided:

t_right+ right T = T_left+ left T (15)

If t_leftIf =0, the right ultrasonic transmitter No. 1 may transmit at the following time:

t_right= left T-right T (16)

The emission time instant of each ultrasonic emitter in the array on one projection plane when the ultrasonic emission array is in the focused emission mode can be calculated by the formulas (8) to (16). In the same way, the transmitting delay of each ultrasonic transmitter in the array on the other projection plane perpendicular to the projection plane can be obtained, and the transmitting delays required by each ultrasonic transmitter calculated by the two projection planes are superposed to obtain the final transmitting delay of each ultrasonic transmitter, so that the ultrasonic array can transmit the synthesized ultrasonic parallel beam in any direction in the three-dimensional space or transmit the synthesized ultrasonic focusing beam to any point in the three-dimensional space.

In the step 6), since each target may move the spatial position, a situation that targets needing to receive different audio frequencies are shielded from each other on the transmission path of the synthesized ultrasonic beam may occur, and when the situation occurs, the system may quickly re-partition the size of each sub-array and re-allocate the target corresponding to each sub-array according to the real-time spatial position of the target, so as to avoid that no target not corresponding to the synthesized ultrasonic beam exists in the synthesized ultrasonic beam range of each sub-array, and at the same time, the target does not feel the interruption of audio frequency listening.

In the step 6), in the parallel transmission mode, when different targets exist in the range of the synthesized ultrasonic beam transmitted by one sub-array, the system automatically re-divides the sub-array, and avoids the target which does not need to receive the path of synthesized ultrasonic beam from appearing in the range of the path of synthesized ultrasonic beam; further, if the sub-arrays are subdivided, it still cannot be avoided that the target which does not need to receive the path synthesized ultrasonic beam appears in the range of the path synthesized ultrasonic beam, the ultrasonic emission modes of the sub-arrays corresponding to the targets are converted into the focusing mode, so that the target which does not need to receive the ultrasonic beam exists in the range of the ultrasonic beam emission, and the interference to other targets and the leakage of the path synthesized ultrasonic beam are avoided.

In the step 6), if the audio volume obtained by performing nonlinear demodulation on the synthesized ultrasonic waves transmitted by a certain sub-array in the air needs to be increased, if the modulation depth or the power of each transmitter in the sub-array reaches the maximum value and still cannot meet the volume increase requirement, the system adjusts the division of the sub-array, divides the transmitters in other sub-arrays without the requirement for increasing the demodulated audio volume into the sub-arrays with the requirement for increasing the demodulated audio volume, and increases the number of the ultrasonic transmitters in the sub-arrays with the requirement for increasing the demodulated volume, thereby providing the total transmitting power of the sub-arrays.

The specific modules of the phase-control multichannel sound wave directional transmitting system are formed.

1) The man-machine interaction module comprises a virtual target setting submodule and a sound effect setting submodule, wherein the virtual target setting submodule receives information setting of a user on a virtual target, and the information comprises: the type, the number and the position information of each virtual target are transmitted to a target detection module; the sound effect setting submodule receives the setting of the sound effect by the user and transmits the information to the sound effect processing module.

2) An external information receiving module: the module comprises an external virtual target information receiving submodule and an external sound effect setting information receiving submodule, wherein the external virtual target information receiving submodule receives the setting of an external system on the information of a virtual target, and the information comprises: the type and the number of the virtual targets and the position information of the virtual targets; the external sound effect setting information receiving submodule receives the setting of the external system on the sound effect and transmits the information to the sound effect processing module.

3) The target detection module consists of a target detection sensor submodule and a target detection calculation submodule and is used for detecting the type and the number of targets needing to receive ultrasonic waves in the surrounding space and the spatial position of each target relative to the ultrasonic array; and meanwhile, virtual target information transmitted by the human-computer interaction module or the external information receiving module is received.

4) An ultrasonic carrier signal generation module for generating an ultrasonic signal whose frequency can be adjusted within the ultrasonic frequency range as desired.

5) And the sound effect processing module is used for carrying out sound effect processing on the N-channel audio signals according to the sound effect setting transmitted by the man-machine interaction module or the external information receiving module, and transmitting the processed signals to the modulation module.

6) And the modulation module is composed of a replication submodule and a modulation submodule, the replication submodule replicates the ultrasonic carrier signals into N paths of ultrasonic carrier signals, and the modulation submodule modulates the N paths of audio signals to be transmitted to modulate the N paths of ultrasonic carrier signals.

7) The transmitting control module consists of an array partitioning submodule and a transmitting delay control submodule, wherein the array partitioning submodule divides the whole ultrasonic transmitting array into N sub-arrays according to the number N of targets, the position and the number of each array are determined according to the type of the targets and the space position of the targets, and the partitioning of the ultrasonic transmitters of each sub-array and the number of the ultrasonic transmitters contained in the sub-array can be dynamically adjusted in real time according to the change of the space position of the targets and the volume requirement of the target for receiving audio; and the transmitting delay control sub-module performs delay operation on each modulated ultrasonic carrier signal by using an ultrasonic array beam deflection control method according to the space position of the target and then outputs the delayed ultrasonic carrier signal to the transmitting execution module.

8) And the transmitting execution module consists of an ultrasonic transmitter power amplification submodule and an ultrasonic transmitter array, each ultrasonic transmitter is provided with an ultrasonic transmitter power amplification submodule, and the ultrasonic transmitter power amplification submodule transmits signals output to each ultrasonic transmitter in the ultrasonic transmitter array by the transmitting control module to the ultrasonic transmitter after performing power amplification, so that the ultrasonic transmitter is ensured to have enough power to transmit mechanical ultrasonic waves.

The above 3) target detection sensor sub-module adopts an image sensor or a laser radar or a radio millimeter wave radar or an ultrasonic radar, the target detection sensor sub-module performs preprocessing such as filtering on sensor environment detection data and then outputs the preprocessed data to the target detection calculation sub-module, the target detection calculation sub-module uses a target detection algorithm to check whether targets exist in the environment and the number and types of the targets from the environment detection data, and if the targets exist, relative position data of each target relative to the ultrasonic array is further calculated through a space geometric relationship.

Compared with the prior art, the invention has the following advantages:

(1) the audio is intensively emitted in a certain direction by utilizing the strong pointing specificity of the ultrasonic wave, so that the interference to other sounds and the leakage of the audio are avoided;

(2) the ultrasonic transmitting direction can be quickly and accurately changed without mechanically rotating the ultrasonic transmitting array, and the ultrasonic transmitting array is faster than mechanical rotation and is more stable and reliable; the target direction is locked by combining a target detection technology, and the audio sound waves can be ensured to be continuously transmitted to the target under the condition that the target continuously and rapidly moves;

(4) different audio sound waves can be simultaneously transmitted to a plurality of targets, and audio sound waves with a plurality of sound channels and a plurality of sound effects can also be simultaneously transmitted to the same target;

(5) since the virtual target can be set, the function of the spatial virtual speaker can be realized. The user sets the virtual target to be positioned on a specific real object, for example: the wall surface is transmitted by modulated ultrasonic waves, the modulated ultrasonic waves are subjected to nonlinear self-demodulation in the air to generate difference frequency signals, the difference frequency signals are required audio, the audio is transmitted and dispersed to the space through the wall surface, so that a sound source is formed, the effect of simulating the audio transmitted to the surrounding space by a specific entity in the space is achieved, and the function of the space virtual loudspeaker can be realized.

Drawings

Fig. 1 schematically shows a flow chart of the steps of a method for directional transmission of phase-controlled multichannel sound waves according to the invention.

Fig. 2 schematically shows modules and a correlation diagram of a phase-controlled multi-channel sound wave directional transmitting system according to the present invention.

Fig. 3 schematically shows a monotonous interval in the amplitude-frequency characteristic curve of the selected ultrasonic transmitter.

FIG. 4 schematically illustrates the spatial relationship of the coordinate system of the system object detection sensors to the coordinate system of the central position of the ultrasonic transmit array.

Fig. 5 schematically illustrates the spatial relationship of the coordinate system of the system object detection sensor and the coordinate system of the center position of the ultrasonic transmission array from a top view.

FIG. 6 schematically illustrates the spatial relationship of the coordinate system of the system object detection sensor to the coordinate system of the center position of the ultrasonic transmit array from a side view.

Fig. 7 schematically shows the delay required by each ultrasonic transmitter in the case that the ultrasonic transmitting array is a rectangular plane, the system transmitting mode is in a parallel mode, the target is projected onto the ultrasonic transmitting array plane along the transmitting axis direction of the ultrasonic transmitter, and the target projection is located in the ultrasonic transmitting array area.

Fig. 8 schematically shows that the ultrasonic emission array is a rectangular plane, and in the focusing mode, the target is projected onto the ultrasonic emission array plane along the direction of the emission axis of the ultrasonic emitter, and the target projection is located outside the ultrasonic emission array area, and the delay condition is needed by each ultrasonic emitter.

Fig. 9 schematically shows a situation that the ultrasonic emission array is a rectangular plane, and in the focusing mode, the target is projected onto the ultrasonic emission array plane along the direction of the emission axis of the ultrasonic emitter, and the target projection is located within the ultrasonic emission array area, and the delay is needed by each ultrasonic emitter.

Figure 10 schematically illustrates the system reassigning the transmit correspondence of subarrays to targets in the event that different target movements cause the targets to obscure the composite ultrasound beam from each other.

Fig. 11 schematically shows that when the distance between the projections of different targets in the direction perpendicular to the emission direction of the synthesized ultrasonic parallel beams is smaller than the width of the synthesized ultrasonic parallel beams, that is, when different targets exist within the same synthesized ultrasonic parallel beam width range, the system automatically converts the ultrasonic emission modes corresponding to the targets into the focusing mode to avoid the existence of non-corresponding targets in the ultrasonic parallel beam emission range and avoid the interference with other targets.

Fig. 12 schematically shows an embodiment of a phase-controlled multi-channel sound wave directional transmitting system of the present invention as a desktop directional sound system in a desktop environment, which transmits left and right channel audio to the left and right ears of a plurality of users through an ultrasonic array.

Fig. 13 schematically shows an embodiment of a phase-controlled multi-channel sound wave directional transmitting system according to the present invention, which is respectively disposed on a laptop, a tablet pc, and a mobile phone that are placed on the same desk and are closely spaced, and respectively transmits left and right channel audio to the left and right ears of a plurality of users to avoid mutual interference of audio emitted by different devices.

Fig. 14 schematically shows an embodiment of the present invention in which a phase-controlled multi-channel sound wave directional transmitting system is deployed on the top surface of a room, and the normal of the ultrasonic array surface is vertical downward, so as to transmit left and right channel audio to the left and right ears of a plurality of users respectively.

Fig. 15 schematically shows a phase-controlled multi-channel sound wave directional transmitting system of the present invention deployed in a home theater system, and configured to transmit modulated ultrasonic waves to a set spatial location, so as to generate different difference frequency sound waves at different spatial locations, so as to achieve the effect of simulating different speakers to sound at different spatial locations.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer and clearer, the present invention is further described in detail below with reference to the accompanying drawings and examples, it is to be understood that the specific examples are described herein only for the purpose of explaining the present invention, and are not intended to limit the present invention, and the scope of the present invention as claimed is not limited to the scope of the examples. It is to be noted that the following processes or parameters, if not specified in particular detail, are within the reach of the person skilled in the art and can be realized by reference to the prior art.

Example 1. As shown in figure 12 of the specification. A set of phase-controlled multi-channel sound wave directional transmitting system is arranged on the desktop, and a cylindrical object 201 in the figure is a target detection module; the default transmission mode of the system is a focusing mode; the system detects whether virtual target information exists in the human-computer interaction module or the external information receiving module, and in the embodiment, the virtual target information does not exist; the system detects that 4 targets exist around through a target detection module, wherein the targets are respectively the left ear and the right ear of a user A and the left ear and the right ear of a user B, the system needs to transmit the left channel audio and the right channel audio of the audio A which the user A needs to hear to the left ear and the right ear of the user A respectively, and transmit the left channel audio and the right channel audio of the audio B which the user B needs to hear to the left ear and the right ear of the user B respectively, and the user A and the user B can carry out sound effect processing setting on the system according to own needs so as to finally hear the audio with own needed sound effects, the system emission control module averagely divides the whole emission array into 4 sub-arrays, 202, 203, 204 and 205 in the specification refer to sub-array 1, sub-array 2, sub-array 3 and sub-array 4 respectively, wherein each square represents 1 ultrasonic emitter integrated with a power amplifier, 202, 203, 204, 205 constitute the whole transmission execution module. User a remains stationary and user B moves from position 1 to position 2. The system target detection module detects the left and right ears of the user A and the left and right ears of the user B, calculates the positions of the left and right ears of the user A and the left and right ears of the user B in a target detection module coordinate system X1-Y1-Z1 in real time, the rotation and translation relations of a coordinate system X1-Y1-Z1 and other subarray coordinate systems X2-Y2-Z2, X3-Y3-Z3, X4-Y4-Z4 and X5-Y5-Z5 determined by the spatial structure relation of 201, 202, 203, 204 and 205 in the set of phase-controlled multi-channel sound wave directional transmitting systems are obtained, so that the positions of the left ear of the user A in the coordinate system X2-Y2-Z2, the positions of the right ear of the user A in the coordinate system X3-Y3-Z3, the positions of the left ear of the user B in the coordinate system X4-Y4-Z4 and the positions of the right ear of the user B in the coordinate system X5-Y5-Z5 are obtained; the ultrasonic carrier generation module generates an ultrasonic carrier signal according to the set frequency and transmits the ultrasonic carrier signal to the modulation module, and the modulation module copies the ultrasonic carrier signal for 4 minutes; meanwhile, in the sound effect processing module, according to the settings of the users A and B, the sound effect processing module respectively carries out sound effect processing on the left and right channel audio of the audio A and the left and right channel audio of the audio B which are required to be listened to by the users A and B, and transmits the left and right channel audio of the audio A and the left and right channel audio of the audio B after the sound effect processing to the modulation module; the modulation module modulates the 4 paths of ultrasonic carrier signals by using the left and right channel audio of the audio A and the left and right channel audio of the audio B respectively, and transmits the 4 paths of debugged ultrasonic signals to the emission control module after modulation is finished; the transmitting control module is used for respectively calculating the delay of each ultrasonic transmitter in the subarray 1 relative to the transmitting moment of the first ultrasonic transmitter in the horizontal projection plane and the side projection plane of the subarray 1 according to the position of the left ear of the user A in the coordinate system X2-Y2-Z2, then calculating the delay of the ultrasonic transmitter relative to the earliest ultrasonic transmitting moment of the subarray 1 by using a formula (5), calculating the delay of each ultrasonic transmitter in the subarrays 2, 3 and 4 relative to the earliest transmitting moment of the subarray in the same way, performing delay operation on corresponding ultrasonic signals according to the calculated delay required by each ultrasonic transmitter, and transmitting the delay to the transmitting execution module; the transmitting execution module amplifies the power of the ultrasonic signals and then sends mechanical ultrasonic waves through all the ultrasonic transmitters, the ultrasonic waves transmitted by the subarray 1, the subarray 2, the subarray 3 and the subarray 4 are respectively focused on ultrasonic beams at the space positions of the left ear and the right ear of the user A and the left ear and the right ear of the user B, and the left channel audio and the right channel audio of the audio A and the left channel audio and the right channel audio of the audio B are respectively demodulated in the air by means of nonlinear self-demodulation. The transmit mode may also be user selectable as a parallel mode in which each of the plurality of ultrasonic waves emits from the array with a constant width.

Example 2, as shown in figure 13 of the specification. Under the desktop environment, the left and right sound channel audio is transmitted to the left and right ears of a user through the ultrasonic array, so that the condition that the audio which needs to be heard by the user is diffused to the surrounding space to cause privacy disclosure and noise to other users can be avoided. A notebook computer, a tablet personal computer and a mobile phone are sequentially placed on the same desktop, the notebook computer, the tablet personal computer and the mobile phone are respectively provided with a set of phase-controlled multi-channel sound wave directional transmitting system, and the 3 devices are all provided with a user. In the phase-controlled multi-channel sound wave directional transmitting system of the notebook computer, 301 is a target detection sensor sub-module which is arranged in a target detection module of the notebook computer, the coordinate system of the sub-module is X1-Y1-Z1, and the sub-modules 302 and 303 are ultrasonic sub-arrays which are arranged between a keyboard and a screen of the notebook computer, and other sub-modules of the phase-controlled multi-channel sound wave directional transmitting system are all arranged in the notebook computer. The coordinate system of 302 is X2-Y2-Z2, the coordinate system of 303 is X3-Y3-Z3, the rotational and translational relations between the coordinate system of X1-Y1-Z1 and the coordinate system of X2-Y2-Z2 and the coordinate system of X3-Y3-Z3 can be calculated according to the structure of the notebook computer and the included angle between the screen and the ultrasonic array. In the phase-controlled multi-channel sound wave directional transmitting system of the tablet computer, 304 is a target detection sensor sub-module in a target detection module arranged on the tablet computer, 305 and 306 are two ultrasonic sub-arrays arranged around a screen on the tablet computer respectively, and other sub-modules of the phase-controlled multi-channel sound wave directional transmitting system are arranged inside the tablet computer. 307 is a target detection sensor sub-module in a target detection module deployed on the mobile phone, 308 and 309 are two ultrasonic sub-arrays on the side surface of the mobile phone screen respectively, and other sub-modules of the phase-controlled multi-channel sound wave directional transmitting system are all deployed in the mobile phone. After a phase-controlled multi-channel sound wave directional transmitting system in a notebook computer is started, a default transmitting mode is in a focusing transmitting mode, a user can use a sound effect system required by setting of a man-machine interaction module to firstly detect whether virtual target information exists in the man-machine interaction module or an external information receiving module, and in the embodiment, the virtual target information does not exist. The system acquires the information of the surrounding environment of the notebook computer through a 301 target detection sensor submodule, and detects that a target exists in the surrounding environment through a target detection calculation submodule: the method comprises the steps of calculating the spatial positions of the left ear and the right ear of a user A relative to a target detection sensor submodule simultaneously, calculating the spatial position information of the left ear and the right ear of the user relative to an ultrasonic emission array according to the rotation translation relation of a coordinate system X1-Y1-Z1, X2-Y2-Z2 and X3-Y3-Z3, generating an ultrasonic carrier signal according to a preset ultrasonic carrier frequency after the information of a target around the user is obtained by an ultrasonic carrier generation module, carrying out sound effect processing on 2 channels of audio required by the left ear and the right ear according to the sound effect setting of the user A by an audio effect processing module, transmitting the processed audio signal to a modulation module, firstly duplicating the ultrasonic carrier signal into 2 channels of ultrasonic carriers for the left ear and the right ear, and then modulating the ultrasonic carriers for the left ear and the right ear by using the 2 channels of audio required by the left ear and the right ear respectively, then 2 paths of ultrasonic signals of the modulation number are transmitted to a transmitting control module, the transmitting control module divides an ultrasonic transmitting array into two sub-arrays, namely 302 and 303, according to the 2 paths of ultrasonic modulation signals, each 1 path of ultrasonic modulation signal is transmitted to a transmitting execution module after different time delays, the different time delays are calculated by using the formula according to a transmitting mode and target space position information, and the transmitting execution module receives the ultrasonic modulation signals with different time delays and converts the ultrasonic modulation electrical signals into mechanical ultrasonic waves by using an ultrasonic transmitter to transmit the mechanical ultrasonic waves. Finally, the ultrasonic transmitting sub-arrays 302 and 303 respectively transmit focused ultrasonic beams to the left ear and the right ear of the user A, the ultrasonic beams enter the ears of the user A under the nonlinear demodulation action of air, the audio frequency which needs to be adjusted by the left ear and the right ear of the user A is generated, and the audio frequency which needs to be heard is only sent out by the left ear and the right ear of the user A. Similarly, the

ultrasonic emission subarrays

305, 306 emit focused ultrasonic beams to the left and right ears of the user B, respectively, where the ultrasonic beams undergo nonlinear demodulation at the user's ears to generate audio to be modulated by the left and right ears of the user B. The ultrasonic transmit sub-arrays 308, 309 emit focused ultrasonic beams to the left and right ears of the user C, respectively, which demodulate the audio frequencies to be tuned by the left and right ears of the user C in the air at the ears of the user by means of nonlinear self-demodulation. Since the user A, B, C needs to hear the audio generated by the ultrasonic wave through the air nonlinear demodulation, the audio is attenuated quickly in the air, and it can be ensured that the audio that needs to be heard by other users cannot be heard by each of the users A, B, C, thereby ensuring that the audio that needs to be heard by the user A, B, C is not heard by other users, and ensuring that the audio that needs to be heard by the user A, B, C does not cause noise interference to other users.

Example 3, as shown in figure 14 of the specification. In a multi-user large space scene, a set of phase-controlled multi-channel sound wave directional transmitting system is installed in the top space, a cylinder 401 in the figure represents a target detection sensor sub-module of the system, other modules are integrated into an ultrasonic transmitting sub-array, 402, 403, 404, 405, 406 and 407 are respectively ultrasonic transmitting sub-arrays integrated with power amplifiers, and 402-407 form a transmitting execution module together. Assuming that 3 users exist, after the phase-controlled multi-channel sound wave directional transmitting system is started, the default transmitting mode is in a focusing mode; 3 users can use the man-machine interaction module to set the required sound effects; the system firstly detects whether virtual target information exists in the human-computer interaction module or the external information receiving module, and in the embodiment, the virtual target information does not exist. The system detects that 6 targets exist around through a target detection module of 401, namely the left ear and the right ear of a user A, the left ear and the right ear of a user B and the left ear and the right ear of a user C, the system divides an ultrasonic emission array in an emission execution module into 6 ultrasonic emission sub-arrays of 402, 403, 404, 405, 406 and 407, calculates the position information of the 6 targets in a target sensor sub-module coordinate system X-Y-Z of the target detection module of 401, and calculates the position information of the 6 targets in the 6 ultrasonic emission sub-arrays respectively according to the structural space relationship between each ultrasonic emission sub-array and the target detection sensor sub-module; the ultrasonic carrier generation module generates an ultrasonic carrier signal and transmits the ultrasonic carrier signal to the modulation module; the sound effect processing module performs sound effect processing on 6 paths of audio signals required to be heard by a user according to sound effect setting, and then transmits the 6 paths of audio signals subjected to the sound effect processing to the modulation module; the modulation module is used for multiplexing the ultrasonic carrier signals into 6 paths, modulating the ultrasonic carrier signals by using 6 paths of audio signals subjected to sound effect processing, and transmitting the modulated 6 paths of ultrasonic modulation signals to the transmission control module; the transmitting control module calculates the time of each ultrasonic transmitter in each ultrasonic transmitting subarray needing delay transmitting according to the position information of 6 target positions respectively located in 6 ultrasonic transmitting subarray coordinate systems, corresponding delay is carried out, the time is transmitted to the transmitting execution module, the transmitting execution module transmits each delayed ultrasonic modulation signal to each corresponding ultrasonic transmitter through the power amplification sub-module to complete power amplification operation, and each delayed and power amplified ultrasonic carrier electric signal is converted into mechanical ultrasonic waves through the ultrasonic transmitter to be transmitted. Thus, the ultrasonic transmitting

sub-arrays

402 and 403 respectively transmit the synthesized ultrasonic beams focused on the left and right ears of the user a, and respectively demodulate the sound required by the left and right ears of the user a in the air by means of the nonlinear self-demodulation. Similarly, the sounds required by the left and right ears of user B and user C, and the corresponding ultrasonic beams are always focused on the left and right ears of user A, B, C as user A, B, C moves individually, so that they can hear the respective required sounds without being disturbed by the sounds required by other users. In this embodiment, since A, B, C users are in different moving spatial positions, it may happen that the user a just blocks between the user B and the corresponding ultrasound emission sub-array, which results in that the user a blocks the user B from needing to synthesize an ultrasound beam, when this occurs, the system quickly re-partitions each sub-array size and re-allocates the target corresponding to each sub-array according to the real-time spatial position of the target, further, if the related sub-array is in the parallel emission mode, and re-partitions each sub-array size and re-allocates the target corresponding to each sub-array, the system automatically converts the related sub-array emission mode into the focused emission mode to avoid the blocking; in addition, if a user is too far away from the transmitting sub-array, which causes that all the ultrasonic transmitters of the sub-array transmit at the maximum power, the volume is still too small, and the requirement of the user cannot be met, the system adjusts the size of the sub-array so as to increase the number of the ultrasonic transmitters in the sub-array corresponding to the user, and simultaneously readjusts the transmitting delay of the ultrasonic waves transmitted by each ultrasonic transmitter in the sub-array so as to ensure that the sufficient transmitting power of the sub-array is provided, so that the requirement of the volume of the user is met.

Example 4, as shown in figure 15 of the specification. In a cinema environment, a set of phase-controlled multi-channel sound wave directional transmitting system is arranged on a short cabinet in front of a user and is used for providing a multi-channel sound effect environment for the user. After the system is started, the default transmission mode of the system is the focusing mode by default. The user sets the types and the position information of 4 virtual targets and the sound effect required by each target by using a human-computer interaction system; 508, 509, 510 and 511 in the figure represent the 4 virtual targets, wherein 508 is of the type "right horn", 509 is of the type "right rear horn", 510 is the position "left rear horn" and 511 is the position "left horn"; the system firstly detects whether virtual target information exists in the human-computer interaction module or the external information receiving module, in the embodiment, if no virtual target exists in the external information receiving module, the system transmits the virtual target information in the human-computer interaction module to the target detection module, and if the system detects that 2 actual targets exist through the target detection module, the total number of the targets exists is 6; the system divides the ultrasonic wave transmitting array in the transmitting execution module into 6 ultrasonic wave transmitting sub-arrays 502, 503, 504, 505, 506 and 507 which are the left ear and the right ear of the user respectively; the target detection module calculates the position information of the left ear and the right ear of the user and 6 targets, namely the virtual targets 508, 509, 510 and 511, in a coordinate system X-Y-Z, and calculates the position information of the 6 targets respectively positioned in 6 ultrasonic emission subarray coordinate systems according to the structural space position relation of the 6 ultrasonic emission subarrays of the system 502, 503, 504, 505, 506 and 507 and the target detection module; the ultrasonic carrier generation module generates an ultrasonic carrier signal and transmits the ultrasonic carrier signal to the modulation module; the sound effect processing module performs sound effect processing on 6 paths of audio signals required to be heard by a user according to sound effect setting, and then transmits the 6 paths of audio signals subjected to the sound effect processing to the modulation module; the modulation module is used for multiplexing the ultrasonic carrier signals into 6 paths, modulating the ultrasonic carrier signals by using 6 paths of audio signals subjected to sound effect processing, and transmitting the modulated 6 paths of ultrasonic modulation signals to the transmission control module; the transmitting control module calculates the time of delayed transmission required by each ultrasonic transmitter in each ultrasonic transmitting subarray according to the position information of 6 target positions respectively located in 6 ultrasonic transmitting subarray coordinate systems, and transmits the time to the transmitting execution module after corresponding time delay, the transmitting execution module transmits each delayed ultrasonic modulation signal to each corresponding ultrasonic transmitter through the power amplification sub-module to finish the power amplification operation, and each delayed and power amplified ultrasonic carrier electric signal is converted into mechanical ultrasonic waves through the ultrasonic transmitter to be transmitted; 502. 503 ultrasonic beams emitted by the user A are focused on the left ear and the right ear of the user A, and the sound required by the left ear and the right ear of the user A is demodulated by means of nonlinear self-demodulation action in the air respectively; 505 focuses on 508 the "right horn" and demodulates the sound of the "right horn" required by the user in the air at 508 by means of nonlinear self-demodulation; similarly, the ultrasonic beam emitted by 504 is focused on 509 'right rear horn', and the sound of the 'right rear horn' required by the user is demodulated in the air at 509 by means of the nonlinear self-demodulation function; 507, the ultrasonic beam emitted by the ultrasonic microphone is focused at 511 'left horn', and the sound of the 'left horn' required by the user is demodulated in the air at 511 by means of nonlinear self-demodulation; 506 is focused at 510 "left rear horn" and demodulates the user's desired "left rear horn" sound in the air at 510 by means of non-linear self-demodulation. The user is thus immersed in the surround sound effect, and further, the user can set the position of the virtual object to be mobile, for example: however, virtual object 508 "right horn" is set to move up at a certain speed or at a certain speed according to a certain spatial path, thereby simulating a moving sound source.

It should be understood that the above embodiments are only for illustrating the technical solutions of the present invention, not for limiting the same, and those skilled in the art can modify the technical solutions described in the above embodiments or substitute some technical features thereof; and all such modifications and alterations are intended to fall within the scope of the appended claims.

Claims

1. A method and a system for directional emission of phase-controlled multi-channel sound waves are characterized in that the system comprises:

1) the man-machine interaction module comprises a virtual target setting submodule and a sound effect setting submodule, wherein the virtual target setting submodule receives information setting of a user on a virtual target, and the information comprises: the type, the number and the position information of each virtual target are transmitted to a target detection module; the sound effect setting submodule receives the setting of a user on sound effects and transmits information to the sound effect processing module;

2) an external information receiving module: the module comprises an external virtual target information receiving submodule and an external sound effect setting information receiving submodule, wherein the external virtual target information receiving submodule receives the setting of an external system on the information of a virtual target, and the information comprises: the type and the number of the virtual targets and the position information of the virtual targets; the external sound effect setting information receiving submodule receives the setting of an external system on sound effects and transmits information to the sound effect processing module;

3) the target detection module consists of a target detection sensor submodule and a target detection calculation submodule and is used for detecting the type and the number of targets needing to receive ultrasonic waves in the surrounding space and the spatial position of each target relative to the ultrasonic array; meanwhile, virtual target information transmitted by the human-computer interaction module or the external information receiving module is received;

4) an ultrasonic carrier signal generation module, which is used for adjusting the frequency of the generated ultrasonic signal within an ultrasonic frequency range according to the requirement;

5) the sound effect processing module is used for carrying out sound effect processing on the N-channel audio signals according to sound effect setting transmitted by the man-machine interaction module or the external information receiving module, and transmitting the processed signals to the modulation module;

6) the modulation module is composed of a replication submodule and a modulation submodule, the replication submodule replicates the ultrasonic carrier signals into N paths of ultrasonic carrier signals, and the modulation submodule modulates the N paths of audio signals to be transmitted to modulate the N paths of ultrasonic carrier signals;

7) the transmitting control module consists of an array partitioning submodule and a transmitting delay control submodule, wherein the array partitioning submodule divides the whole ultrasonic transmitting array into N sub-arrays according to the number N of targets, the position and the number of each array are determined according to the type of the targets and the space position of the targets, and the partitioning of the ultrasonic transmitters of each sub-array and the number of the ultrasonic transmitters contained in the sub-array can be dynamically adjusted in real time according to the change of the space position of the targets and the volume requirement of the target for receiving audio; the transmission delay control submodule carries out delay operation on each modulated ultrasonic carrier signal by using an ultrasonic array beam deflection control method according to the space position of a target and then outputs the delayed ultrasonic carrier signal to the transmission execution module;

2. A phase-controlled multi-channel sound wave directional transmitting method and a system are characterized in that the method comprises the following steps:

step 1) firstly, detecting whether virtual target information exists in a human-computer interaction module or an external information receiving module, and then transmitting the virtual target information into a target detection module, wherein the information comprises: the type of the virtual target, the number of the virtual targets and the spatial position of each virtual target;

step 2) the target detection module receives the virtual target information, then uses a sensor in the target detection module to detect the surrounding environment, and detects whether a target exists around according to the surrounding environment detection data by combining a target detection algorithm, if so, the target information is further detected, and the target information comprises: target type, number of targets N and respective target spatial position (P)₁~P_N)，(P₁~P_N) Representing the spatial positions of the N actual targets; finally, the virtual target information and the actual target information are sent to a transmission control module;

step 3) when the target detection module detects a received virtual target or an actual target, an ultrasonic carrier generation module is used for generating an ultrasonic carrier signal with adjustable frequency;

step 4) receiving sound effect setting information in a human-computer interaction module or an external information receiving module, processing audio signals needing to be transmitted to N-path targets by using a sound effect processing module according to different requirements of N targets (including virtual targets and actual targets) on sound effects in sound effect setting, independently adjusting and changing the frequency, amplitude and phase of different frequency signal components forming the audio signals in each path of audio signals of the N-path targets in the sound effect processing module, and transmitting the adjusted N-path audio signals to a modulation module;

step 5) after the ultrasonic carrier signal is generated, modulating the ultrasonic carrier signal by using N paths of audio signals which need to be transmitted to N targets and are subjected to sound effect processing to obtain N paths of ultrasonic modulation signals;

step 6) transmitting the N ultrasonic modulation signals to a transmitting control module, dividing the ultrasonic transmitting array into N sub-arrays by the transmitting control module according to the number of targets and the space position of each target, calculating the phase of each ultrasonic transmitter in each sub-array required to be shifted according to an ultrasonic array synthetic sound beam phase control method, and calculating the transmitting delay (according to the relation of the phase wavelength sound velocity of the ultrasonic in the air), (^t ₁₁，^t ₁₂，……），……（^t _N1，^t _N2，……）；

Step 7) delaying the N paths of ultrasonic modulation signals obtained in the step 5) according to the transmission delay needed by each ultrasonic transmitter calculated in the step 6), sending the delayed signals to an ultrasonic transmitter power amplifier, and finally transmitting the delayed signals through the ultrasonic transmitters, wherein N paths of modulated synthesized ultrasonic beams are transmitted to N targets;

3. Furthermore, the target detection sensor sub-module adopts an image sensor or a laser radar or a radio millimeter wave radar or an ultrasonic radar, the target detection sensor sub-module carries out preprocessing such as filtering on the environment detection data of the sensor and then outputs the preprocessed data to the target detection calculation sub-module, the target detection calculation sub-module uses a target detection algorithm to check whether targets exist in the environment and the number and the types of the targets from the environment detection data, and if the targets exist, the relative position data of each target relative to the ultrasonic array is further calculated through the space geometric relationship; in the step 2), if no target exists, the target detection module does not send data to the emission control module, and the system does not start the subsequent steps 3) -6) to work, so that the energy is saved and the energy consumption of the system is reduced.

4. Further, in the step 5), two different modulation methods may be adopted, and the first method is: if the amplitude of the mechanical ultrasonic waves is controlled by using the amplitude of the input voltage or current of the ultrasonic transmitter, carrying out amplitude modulation on the ultrasonic carrier by using the audio frequency to be transmitted to a target to obtain amplitude modulated waves; the second method is as follows: if the amplitude-frequency characteristic of the ultrasonic transmitter is utilized, the frequency modulation method can be used to modulate the audio frequency to be transmitted to a target by combining the amplitude-frequency characteristic of the ultrasonic transmitter to obtain frequency-modulated wave, and the frequency-modulated wave is influenced by the amplitude-frequency characteristic of the ultrasonic transmitter when being transmitted by the ultrasonic transmitter, so that the mechanical ultrasonic wave transmitted by the ultrasonic transmitter becomes amplitude-modulated wave; the frequency amplitude characteristic of the ultrasonic transmitter means that under the condition that the input voltage or current is not changed, the amplitude of the mechanical ultrasonic wave emitted by the ultrasonic transmitter has a functional relationship with the ultrasonic frequency, and under different ultrasonic frequencies, the amplitude of the mechanical ultrasonic wave output by the ultrasonic transmitter is different, namely:

A=g(f) (1)

if f (t) represents the function of the ultrasonic carrier electric signal frequency at the time t, f (t) is substituted into the formula (1) to obtain:

g[f(t)] (2)

obtaining the amplitude function of the mechanical ultrasonic wave output by the ultrasonic transmitter at the moment t;

assuming that the ith audio waveform function to be transmitted is h (t), the ultrasonic carrier signal needs to be frequency-modulated, so that the amplitude a of the transmitted mechanical ultrasonic wave is linearly related to h (t), that is:

A=a×h(t)+b (3)

f(t)=g^-1[a×h(t)+b] (4)

selecting a section of monotonic interval of the function g (f), assuming that the abscissa corresponding to the minimum value point of the monotonic curve is Xp _ min, the ordinate is A _ min, the abscissa corresponding to the maximum value point is Xp _ max, and the ordinate is A _ max, obtaining the frequency f (t) of the ultrasonic carrier needing to be modulated at the moment t through a formula (4), and then carrying out frequency modulation operation on the ultrasonic carrier signal through a frequency modulation technical method to obtain the required frequency-modulated ultrasonic carrier signal; in order to fully utilize the transmitting capability of the ultrasonic transmitter, the method for selecting g (f) the monotonous interval comprises the following steps: the section closest to the linear function needs to be selected, and the section with the largest frequency bandwidth is preferentially selected under the condition that the degree of the proximity to the linear function is the same.

5. The ultrasonic wave transmitting direction phase control algorithm in the step 6) is determined according to the target space position, the distance d + l/2 of each transmitter in the transmitting array, the sound velocity v of the ultrasonic wave in the air and the shape of the ultrasonic wave transmitting array, according to the spatial geometrical relationship, respectively projecting the geometrical relationship to two mutually vertical projection surfaces, wherein one projection surface selects a horizontal plane and looks from top to bottom, the other projection surface selects the side surface of the ultrasonic emission array as the projection surface, the delay or the advance emission time of each ultrasonic emitter on one projection surface is calculated first, then the delay or the advance emission time of each ultrasonic emitter on the other projection surface is calculated, and finally the calculation results of the two projection surfaces are synthesized, wherein the formula is (5), so that the delay or the advance emission time required by each ultrasonic emitter can be obtained finally;

（5）

in the formula (5), T_{Combination of Chinese herbs}Representing the delay, T, of the transmission instant at which the ultrasonic transmitter transmits the ultrasonic wave earliest with respect to the ultrasonic array in which it is located_{Level of}Representing the calculated delay, T, in horizontal projection of the ultrasonic transmitter with respect to the transmission instant at which the ultrasonic array at which it is located transmits the ultrasonic wave earliest_{Side surface}The time delay calculated on the side projection is represented relative to the transmitting moment of the ultrasonic wave which is transmitted by the ultrasonic transmitter at the earliest in the ultrasonic array;

further, in the ultrasonic wave transmitting direction phase control algorithm in step 6), when one side of the ultrasonic wave array is selected as the projection plane, and the ultrasonic wave transmitting array is in the parallel transmitting mode, that is: when the ultrasonic synthesized beam is not required to be focused or diverged, the transmitting time delta t required to be spaced by any two adjacent ultrasonic transmitters can be calculated by the formula (6):

△t=p/v=(d+l/2)×sin(θ)/v（6）

(6) in the method, d is the distance between the outer surfaces of the ultrasonic transmitters, l is the distance between the outer surfaces of the ultrasonic transmitters and a central axis, (d + l/2) the distance between the central axes of the ultrasonic transmitters, p is the projection length of the distance between the central axes of the ultrasonic transmitters in the transmitting direction of an ultrasonic synthesized beam, and v is the sound velocity of ultrasonic waves in air, and because of a parallel mode, the included angle between a connecting line from a target to the center of each ultrasonic transmitter and the transmitting axis of the ultrasonic transmitter is equal to theta; in this ultrasonic wave emission array, supposing there are k total ultrasonic transmitters, the ultrasonic transmitter farthest from the target is recorded as the ultrasonic transmitter # 1, the ultrasonic transmitter # 1 transmits first, and numbers the ultrasonic transmitter closest to the target in turn, the ultrasonic transmitter closest to the target is recorded as the ultrasonic transmitter # k, the ultrasonic transmitter # k transmits last, and the ultrasonic transmitter # i transmits for the total transmission delay of the ultrasonic transmitter # 1 at the transmission time:

（i-1）×△t，i∈(1,2,…k)（7）。

6. further, in the ultrasonic wave transmitting direction phase control algorithm in step 6), when one side of the ultrasonic wave array is selected as the projection plane, and the ultrasonic wave transmitting array is in the focused transmitting mode, that is: when the ultrasonic synthesized beam is required to be focused on a target, in the ultrasonic transmitting array, assuming that k ultrasonic transmitters are total, the ultrasonic transmitter farthest from the target is recorded as the No. 1 ultrasonic transmitter, the No. 1 ultrasonic transmitter transmits firstly, the ultrasonic transmitter closest to the target is numbered sequentially, the ultrasonic transmitter closest to the target is recorded as the No. k ultrasonic transmitter, the No. k ultrasonic transmitter transmits finally, and when the target is along the transmitting axis of the ultrasonic transmitterWhen the direction is projected onto an ultrasonic emission array plane and the target projection is positioned outside an ultrasonic emission array area, the emission moment of the No. i ultrasonic emitter needs to be delayed by delta t relative to the No. i-1 ultrasonic emitter_i-1，i∈(1,2,…k)，△t_i-1Calculated using equation (8):

△t_i-1=p_i-1/v=(d+l/2)×sin(θ_i-1)/v（8）；

7. Further, in the ultrasonic wave transmitting direction phase control algorithm in step 6), when one side of the ultrasonic wave array is selected as the projection plane, and the ultrasonic wave transmitting array is in the focused transmitting mode, that is: when the ultrasonic synthesized beam is required to be focused to a target, on the side projection of the target and the ultrasonic emission array, when the target is projected onto the ultrasonic emission array plane along the emission axis direction of the ultrasonic emitters and the target projection is positioned in the ultrasonic emission array area, assuming that the array has a total of k ultrasonic emitters, and m ultrasonic emitters exist on the left side of the target projection₁An ultrasonic transmitter with m on the right₂An ultrasonic transmitter (m)₁+m₂= k), the array is divided into two parts, namely a left part and a right part, and the left part and the right part are respectively equivalent to a left sub-array and a right sub-array;

in the left subarray part, the leftmost ultrasonic transmitter is farthest from the target and is marked as the left No. 1 ultrasonic transmitter, and the ultrasonic transmitters closest to the target are numbered sequentially, so that the ultrasonic transmitter closest to the target is marked as the left m₁Number ultrasonic emitter, m th left₁The ultrasonic transmitter emits the ultrasonic signal finally, and the time delay of the ultrasonic transmitter j on the left side relative to the ultrasonic transmitter j-1 on the left side is recorded as left delta t_j-1，j∈(1,2,…m₁) Left Δ t_j-1Calculated using equation (8), then:

left delta t_j-1=p_j-1/v=(d+l/2)×sin(θ_j-1)/v （9）；

In the right subarray portion, the leftmost ultrasound transmitter is closest to the target, denoted as the m-th right subarray portion₂The number of the ultrasonic transmitters is sequentially numbered to the ultrasonic transmitter farthest from the target, the ultrasonic transmitter farthest from the target on the rightmost side is recorded as the No. 1 ultrasonic transmitter on the right side, and in the subarray part on the right side, the No. m ultrasonic transmitter on the right side₂The ultrasonic transmitter on the right transmits last, the ultrasonic transmitter No. 1 on the right transmits first, and the delay of the ultrasonic transmitter No. j on the right relative to the ultrasonic transmitter No. j-1 on the right is recorded as right delta t_j-1，j∈(1,2,…m₂) Right delta t_j-1Calculated using the formula (8) to obtain,

right delta t_j-1=p_j-1/v=(d+l/2)×sin(θ_j-1)/v （10）

In the projection position of the target, the target is reached to the nearest, and here, a virtual ultrasonic transmitter is assumed to exist and is recorded as the No. X virtual ultrasonic transmitter, and obviously, the No. X virtual ultrasonic transmitter needs to transmit finally in the whole array (including the left sub-array part and the right sub-array part);

no. X virtual ultrasonic transmitter is m relative to the left₁The delay required for ultrasonic transmitter is:

T_m1=p_m1/v=X_off×sin(θ_m1)/v （11）；

T_m2=p_m2/v=(d+l/2-X_off)×sin(θ_m2)/v （12）；

the needed delay of the No. X virtual ultrasonic transmitter relative to the No. 1 left is obtained by the formulas (9) and (10) and is recorded as a left T, and the left T is calculated by the formula (11):

left T = left Δ T₁+ left Δ t₂+ … + left Δ t_m1-1+T_m1（13）；

Similarly, the needed delay of the No. X virtual ultrasonic transmitter relative to the No. 1 right virtual ultrasonic transmitter obtained by the formulas (9) and (10) is recorded as right T, and the right T is calculated by the formula (11):

right T = right Δ T₁+ right delta t₂+ … + right Δ t_m2-1+T_m2（14）；

t_right+ right T = T_left+ left T (15);

t_rightleft T-right T (16);

the emitting time of each ultrasonic emitter in the array on one projection surface when the ultrasonic emitting array is in the focusing emitting mode can be calculated by the formulas (8) to (16); in the same way, the transmitting delay of each ultrasonic transmitter in the array on the other projection plane perpendicular to the projection plane can be obtained, and the transmitting delays required by each ultrasonic transmitter calculated by the two projection planes are superposed to obtain the final transmitting delay of each ultrasonic transmitter, so that the ultrasonic array can transmit the synthesized ultrasonic parallel beam in any direction in the three-dimensional space or transmit the synthesized ultrasonic focusing beam to any point in the three-dimensional space.

8. Further, in the step 6), since each target may move the spatial position, a situation that the targets that need to receive different audio frequencies are shielded from each other on the transmission path of the synthesized ultrasonic beam may occur, and when the situation occurs, the system may quickly re-partition the size of each sub-array and re-allocate the targets corresponding to each sub-array according to the real-time spatial position of the target, so as to avoid that no target that does not correspond to the synthesized ultrasonic beam exists in the synthesized ultrasonic beam range of each sub-array, and at the same time, the target does not feel the interruption of the audio frequency.

9. Further, in the step 6), in the parallel transmission mode, when different targets exist in the range of the synthesized ultrasonic beam transmitted by one sub-array, the system will automatically re-partition the sub-array, so as to avoid the target which does not need to receive the path synthesized ultrasonic beam from appearing in the range of the path synthesized ultrasonic beam; further, if the sub-arrays are subdivided, it still cannot be avoided that the target which does not need to receive the path synthesized ultrasonic beam appears in the range of the path synthesized ultrasonic beam, the ultrasonic emission modes of the sub-arrays corresponding to the targets are converted into the focusing mode, so that the target which does not need to receive the ultrasonic beam exists in the range of the ultrasonic beam emission, and the interference to other targets and the leakage of the path synthesized ultrasonic beam are avoided.

10. Further, in step 6), if it is necessary to increase the audio volume obtained by performing nonlinear demodulation on the synthesized ultrasonic waves transmitted by one of the sub-arrays in the air, if the modulation depth or the power of each transmitter in the sub-array reaches the maximum and still cannot meet the volume increase requirement, the system adjusts the division of the sub-arrays, divides the transmitters in other sub-arrays which do not increase the demodulated audio volume requirement into sub-arrays which have the requirement for increasing the demodulated audio volume, and increases the number of ultrasonic transmitters in the sub-arrays which have the requirement for increasing the demodulated volume, thereby providing the total transmission power of the sub-arrays.