CN114674180A

CN114674180A - Video monitoring type directional sound wave dispersing device based on wireless transmission

Info

Publication number: CN114674180A
Application number: CN202210275984.9A
Authority: CN
Inventors: 江山
Original assignee: Beijing Beike Shuopu Technology Co ltd
Current assignee: Beijing Beike Shuopu Technology Co ltd
Priority date: 2022-03-21
Filing date: 2022-03-21
Publication date: 2022-06-28
Anticipated expiration: 2042-03-21
Also published as: CN114674180B

Abstract

The invention relates to a video monitoring type directional sound wave dispeller based on wireless transmission, which comprises a directional sound wave dispel module, a video monitoring module, a wireless transmission module, a data processing module and a control module, wherein the directional sound wave dispel module comprises sound production units and a peak sine wave signal generation module which are arranged according to an array, the peak sine wave signal generation module generates a peak sine wave signal, the peak sine wave signal generates single-stranded sound waves through a single sound production unit, and a sound wave beam is generated after a plurality of groups of single-stranded sound waves are superposed. The directional sound wave dispersing device has the advantages of good dispersing effect, long dispersing distance, low power consumption and the like, and can quickly adjust the sound wave direction; and the intelligent monitoring function is also provided, and the application value is high.

Description

Video monitoring type directional sound wave dispersing device based on wireless transmission

Technical Field

The invention relates to a video monitoring type directional sound wave dispersing device based on wireless transmission, and belongs to the technical field of directional sound wave dispersing equipment.

Background

A directional sound wave diffuser is a device that uses high intensity sound waves to dislodge and alert a target person.

The existing directional sound wave dissipater adjusts the sound wave direction (namely, the main lobe direction of the sound wave) of the sound generating unit by rotating the direction of the front surface of the sound generating unit, and the method comprises manual adjustment, electric adjustment and the like. Such an adjustment requires a corresponding mechanical structure and is relatively slow.

The existing directional sound wave dispersing device does not have a video monitoring function and cannot flexibly master the field situation in real time; even if a conventional video monitoring camera is additionally arranged, the condition that whether a large number of people gather exists is screened and identified by manpower in a large quantity, and the workload is huge.

Because the sound wave beam of the existing directional sound wave dissipater is emitted towards the front of the directional sound wave dissipater, the main sound wave capacity is concentrated in front of the directional sound wave dissipater; however, there is still some noise of intensity behind the directional acoustic wave diffuser; usually, the maximum peak sound pressure level of the directional sound wave diffuser is more than or equal to 70dB +/-1 dB at the position of 100 meters behind the directional sound wave diffuser, and the sound pressure level still exceeds the upper limit of the sound pressure level of a comfortable environment; even if a video monitoring camera is additionally arranged to separate the directional sound wave dispersing device from an office area, the sound insulation effect behind the directional sound wave dispersing device still needs to be improved for some use environments with higher space requirements.

If the corresponding noise reduction mechanism is installed, although the noise behind the directional sound wave dissipater can be reduced to a certain extent, at the same time, the dissipation effect of the directional sound wave dissipater can be influenced to a certain extent.

Therefore, a directional sound wave dispersing device with a video monitoring function, capable of quickly adjusting the main lobe direction of the sound wave and further enhancing the dispersing effect is urgently needed.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a video monitoring type directional sound wave dispersing device based on wireless transmission, and the specific technical scheme is as follows:

video monitoring type directional sound wave dispeller based on wireless transmission, including directional sound wave dispel module, video monitoring module, wireless transmission module, data processing module, control module, directional sound wave dispel the module including sound production unit, the generation module of spike sine wave signal that sets up according to the array, spike sine wave signal generation module generates has spike sine wave signal, and spike sine wave signal passes through single sound production unit and generates the sub-strand sound wave, generates the sound wave after the stack of multiunit sub-strand sound wave and restraints.

As an improvement of the above technical solution, the video monitoring module includes a camera and an electric pan-tilt for driving the camera to horizontally and vertically rotate, the data processing module includes an image processing unit, the camera is used for acquiring a video image of a monitored target and transmitting the video image to the image processing unit through a wireless transmission module; in the image processing unit, feature extraction is carried out on a video image to obtain a feature image, the feature image is identified to generate a motion track vector, the motion track vector is projected to a circular area where the visual field of the camera is located, when the minimum value between the projection of the motion track vector in the circular area where the visual field of the camera is located and the boundary of the circular area where the visual field of the camera is located is smaller than or equal to a first set value, the visual field of the camera is adjusted through the control module and the electric holder, and the adjusting direction of the visual field of the camera and the projection direction of the motion track vector in the circular area where the visual field of the camera is located are arranged in parallel.

As an improvement of the above technical solution, the sine wave signal is generated by a peak sine wave signal generation module to be a peak sine wave signal, and the peak sine wave signal is obtained by superimposing an isosceles right triangle-shaped peak wave on a peak of the sine wave signal.

As an improvement of the technical proposal, the amplitude of the sine wave signal is A₀The peak sine wave signal has an amplitude A₁，ΔA=A₁-A₀(ii) a The period of the sine wave signal being T₀The period of the peak wave is T₁；

k₁=ΔA/A₀，0.38≤k₁≤0.72；

k₂=T₁/T₀，0.05≤k₂≤0.25。

As the improvement of the above technical scheme, the periphery cover of directional sound wave dispersion module is equipped with the frame of borduring, the frame of borduring is established the frame of making an uproar that falls as an organic whole, is connected with the frame including the cover in the frame of directional sound wave dispersion module periphery, falls the front end of the frame of making an uproar and is provided with a plurality of arc breachs, is provided with the interval between two adjacent breachs.

As an improvement of the technical scheme, an included angle between the noise reduction frame and the array surface of the sound production unit is alpha, and alpha is more than or equal to 88 degrees and less than 90 degrees.

As an improvement of the above technical solution, the control module includes a phase rotation unit, and the method of changing the acoustic wave direction of the acoustic wave beam includes the steps of:

step S1, establishing a three-dimensional coordinate system by taking the front surface of the sounding unit as a reference, wherein if the length direction of the front surface is an X axis, the width direction of the front surface is a Y axis, the normal direction of the front surface is a Z axis, the X axis and the Y axis form an XY plane, the X axis and the Z axis form an XZ plane, and the Z axis and the Y axis form a YZ plane; establishing an initial sound wave pointing vector in a three-dimensional coordinate system for the sound wave pointing direction of the sound wave beam before adjustment, wherein the initial sound wave pointing vector is a vector a, the projection of the vector a on an XY plane is a component a1, the projection of the vector a on an XZ plane is a component a2, and the projection of the vector a on a YZ plane is a component a 3; establishing a preset sound wave direction vector in a three-dimensional coordinate system for the sound wave direction of the adjusted sound wave beam, wherein the preset sound wave direction vector is a vector b, the projection of the vector b on an XY plane is a component b1, the projection of the vector b on an XZ plane is a component b2, and the projection of the vector b on a YZ plane is a component b 3;

Step S2, calculating the deviation angle between component b1 and component a1 to obtain θ 1, calculating the deviation angle between component b2 and component a2 to obtain θ 2, and calculating the deviation angle between component b3 and component a3 to obtain θ 3;

step S3, θ 1, θ 2, and θ 3 are calculated by an operation module in which Δ isl/d=sinθTheta is theta 1, theta 2 or theta 3, deltalRefers to the phase difference between single-strand sound waves emitted by two adjacent sound emitting units,dis the center-to-center distance between two adjacent sound units;

step S4, converting the peak sine wave signal into a peak sine wave signal with phase deflection through a phase rotation unit, wherein the phase difference between the peak sine wave signal with phase deflection and the peak sine wave signal is deltal；

And step S5, generating deflected single-strand sound waves by the peak sine wave signals with deflected phases through the corresponding sound generating units, and generating sound waves pointing to the deflected sound beams after superposing a plurality of groups of deflected single-strand sound waves.

step P1, establishing a three-dimensional coordinate system with the front surface of the sound generating unit as a reference, wherein if the length direction of the front surface is an X axis, the width direction of the front surface is a Y axis, the normal direction of the front surface is a Z axis, the X axis and the Y axis form an XY plane, the X axis and the Z axis form an XZ plane, and the Z axis and the Y axis form a YZ plane; the plane where the sound wave direction of the sound wave beam before adjustment is located is the plane where the sound wave direction before adjustment is located, the plane where the sound wave direction of the sound wave beam after adjustment is located is the plane where the sound wave direction after adjustment is located, the intersection line between the plane where the sound wave direction after adjustment is located and the plane where the sound wave direction before adjustment is located is a steering intersection line, the included angle between the projection of the sound wave direction of the sound wave beam before adjustment on the XY plane and the projection of the steering intersection line on the XY plane is theta 4, the included angle between the projection of the sound wave direction of the sound wave beam before adjustment on the XZ plane and the projection of the steering intersection line on the XZ plane is theta 5, and the included angle between the projection of the sound wave direction of the sound wave beam before adjustment on the YZ plane and the projection of the steering intersection line on the YZ plane is theta 6;

Step P2, calculating to obtain theta 4, theta 5 and theta 6 through an operation module, wherein in the operation module, deltal/d=sinθTheta is theta 4, theta 5 or theta 6, deltalRefers to the phase difference between single-strand sound waves emitted by two adjacent sound emitting units,dis the center-to-center distance between two adjacent sound units;

step P3, converting the peak sine wave signal into a phase-deflected peak sine wave signal through a phase rotation unit, wherein the phase difference between the phase-deflected peak sine wave signal and the peak sine wave signal is deltal；

And P4, generating deflected single-strand sound waves by the peak sine wave signals with deflected phases through the corresponding sound generating units, and generating sound waves pointing to deflected sound beams after superposing a plurality of groups of deflected single-strand sound waves.

As an improvement of the above technical solution, the data processing module further includes a person gathering identification unit, and a working method of the person gathering identification unit includes the steps of:

step Q1, transmitting the video image obtained by the camera to a personnel gathering identification unit through a wireless transmission module, decomposing the video image into video image frames according to frames, carrying out background difference on the video image frames through a background difference method, and carrying out gray scale processing and binarization processing to obtain a binarization image;

Step Q2, dividing pixel points with the same pixel value in the binary image into the same region to obtain an image block set, wherein the same pixel points form image blocks, performing similarity operation on adjacent image blocks in the image block set, and dividing the adjacent image blocks in the image block set which pass through the similarity operation into the same region when the operation result is greater than or equal to a second set value, namely obtaining a screening target; noise filtering is carried out on each screening target in the binary image to obtain a suspected aggregation target;

step Q3, counting the positions of the suspected aggregation targets in the adjacent video image frames to generate movement tracks of the suspected aggregation targets, and performing similarity operation on the two adjacent suspected aggregation target movement tracks, wherein the statistical operation result is greater than or equal to the number of a third set value, and the ratio of the number of the similarity operation result which is greater than or equal to the third set value to the movement tracks of the suspected aggregation targets is the actual probability of the suspected aggregation targets;

step Q4, calculating the aggregation density of the suspected aggregation targets between the aggregation areas, wherein the aggregation density is equal to the ratio of the number of the suspected aggregation targets to the aggregation areas, and the suspected aggregation targets positioned at the outermost periphery are connected in pairs to form the aggregation area with the shape of a polygon;

Step Q5, carrying out assignment calculation on the actual suspected aggregation target probability to obtain a first assignment result, carrying out assignment calculation on the aggregation density to obtain a second assignment result, carrying out weighting calculation on the first assignment result and the second assignment result, and judging as suspected aggregation when the weighting calculation result is greater than or equal to a fourth set value;

and step Q6, the personnel gathering and identifying unit sends alarm information to the suspected gathering information obtained by operation through the wireless transmission module, and judges whether to send a dispersing or warning command or not by manually verifying and verifying the alarm information.

The invention has the beneficial effects that:

1. the video monitoring type directional sound wave dispersing device based on wireless transmission has a video monitoring function, and signals containing a large amount of information are transmitted in real time through a wireless transmission technology, so that the real-time mastering of the field condition is facilitated; a large amount of data processing is carried out through the data processing module of the background, the target can be tracked to a certain degree, whether the situation of personnel gathering exists or not is judged, the workload of follow-up manual examination is reduced, and the working efficiency is remarkably improved.

2. The invention can adjust the phase of the sound wave emitted by different sound generating units, can quickly adjust the direction of the sound wave in a conical range with the geometric center normal of the array surface of the sound generating unit as an axis and the conical vertex angle as 90 degrees; the mechanical rotating structure is reduced, the system complexity is reduced, and the system weight is reduced.

3. The video monitoring type directional sound wave dispersing device based on wireless transmission has the advantages of good dispersing effect, long dispersing distance and low power consumption of the directional sound wave dispersing module.

Drawings

FIG. 1 is a schematic view of changing the acoustic wave directivity of an acoustic wave beam by adjusting a phase difference;

FIG. 2 is a waveform diagram of a conventional sine wave signal;

FIG. 3 is a waveform diagram of a spiking sine wave signal;

FIG. 4 is k₁A plot between values and sound pressure levels;

FIG. 5 is k₁A plot of value versus rate of power consumption reduction;

fig. 6 is a schematic view of the installation of the directional acoustic wave dissipating module 1 and the bag frame;

fig. 7 is a view a-a in fig. 6.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Example 1

Video monitoring type directional sound wave dispeller based on wireless transmission, including directional sound wave dispel module, video monitoring module, wireless transmission module, data processing module, control module, directional sound wave dispel the module including sound production unit, the generation module of spike sine wave signal that sets up according to the array, spike sine wave signal generation module generates has spike sine wave signal, and spike sine wave signal generates the sub-strand sound wave through single sound production unit, generates the sound wave beam that is used for dispelling, warning after the stack of multiunit sub-strand sound wave.

The general sound waveform is generally a sine waveform, the energy consumption of the equipment is relatively high, and the maximum peak sound pressure level is generally represented.

For example: in the existing conventional directional strong sound equipment, the peak sound pressure level at 1 m is 152dB, the dispersion distance is 100 m, and the power is 1000W (peak value).

The peak sine wave signal is adopted, so that the maximum peak sound pressure level is improved, and meanwhile, the power consumption of equipment is reduced. According to the invention, by modulating the waveform, a needling-shaped sound wave is added on the wave crest of a conventional sine wave, so that the maximum peak sound pressure level can be greatly improved, and meanwhile, the power consumption of the equipment cannot be greatly increased.

Example 2

In an embodiment, the spike sine wave signal generation module generates the spike sine wave signal by the sine wave signal, and the spike sine wave signal is a spike wave in which an isosceles right triangle is superimposed on a peak of the sine wave signal.

The conventional sine wave signal has an amplitude A as shown in FIG. 2₀With a period of T₀。

Those skilled in the art know that: a typical sound waveform is formed by superimposing a series of sinusoidal waves of varying amplitude and frequency. Any waveform can be decomposed into a series of sine waves, as can square waves.

Scheme G1

In this embodiment, the amplitude of the sine wave signal is a as shown in fig. 3₀The peak sine wave signal has an amplitude A₁，ΔA=A₁-A₀(ii) a The period of the sine wave signal being T₀The period of the peak wave is T₁；

k₁=ΔA/A₀，k₂=T₁/T₀. When k is₁The peak sound pressure level at 1 meter, abbreviated sound pressure level, as the value changesThe power consumption of the pressure level and the directional sound wave dispersion module can also change along with the change, and the power consumption reduction rate refers to the ratio of the difference between the power consumption before and after the change to the power consumption before the change. k is a radical of₁The data and curves between values and sound pressure levels are shown in table 1, fig. 4, respectively; k is a radical of₁The data and curves between the values and the power consumption reduction rates are shown in table 2 and fig. 5, respectively. Therefore, preferably, 0.38. ltoreq. k₁≤0.72。

TABLE 1

k₁	Sound pressure level (dB)
		0.08	153
0.18	157
		0.28	162
0.38	165
		0.48	165
0.55	165
		0.58	165
0.68	165
		0.72	164
0.78	165
		0.88	166

TABLE 2

k₁	Rate of decrease in Power consumption (%)
		0.08	5
0.18	12
		0.28	16
0.38	19
		0.48	20
0.55	22
		0.58	21
0.68	20
		0.72	19
0.78	17
		0.88	13

When k is₂If it is too large, the peak sine wave signal will tend to be a triangular wave, resulting in a width of action of the acoustic beam. When k is₂If "= is too small, the power consumption is significantly increased, and therefore, it is possible to obtain, through a plurality of tests: k is more than or equal to 0.05₂Less than or equal to 0.25; when k is₂Optimally = 0.12.

Finally, when k is₁=0.55，k₂When the acoustic wave scattering module is at the position of 0.12, the peak sound pressure level of the acoustic wave beam emitted by the acoustic wave scattering module at the position of 1 meter can reach 165dB, the scattering distance can reach 220 meters, and the action width at the position of 100 meters can reach 36 meters; compared with the conventional directional strong sound equipment with the peak sound pressure level of 152dB at 1 meter, the power consumption of the directional sound wave dispersion module is reduced by 22%, and the power consumption of the directional sound wave dispersion module is low.

Scheme G2

If a sawtooth wave is superimposed, rather than a spike wave, the most immediate consequences are: compared with the spike wave, the power consumption caused by the superposition of the sawtooth wave is larger.

Scheme G3

If a square wave is superimposed, rather than a spike wave, the most immediate consequence is: the sound pressure level enhancement by the superimposed square wave is not as good as the spike wave with respect to the spike wave.

Scheme G4

If the superimposed is a triangular wave with a curve at the waist edge, rather than a sharp peak wave in the shape of an isosceles right triangle, the most direct result is: compared with the isosceles right-angle triangular cusp wave, the triangular wave with the curved waist edge has better sound pressure level improving effect.

Example 3

The control module comprises a phase rotation unit, and the method for changing the sound wave direction of the sound wave beam comprises the following steps:

step S1, establishing a three-dimensional coordinate system with the front surface of the sound generating unit 10 as a reference, wherein if the length direction of the front surface is an X axis, the width direction of the front surface is a Y axis, the normal direction of the front surface is a Z axis, the X axis and the Y axis form an XY plane, the X axis and the Z axis form an XZ plane, and the Z axis and the Y axis form a YZ plane; wherein the acoustic wave direction of the acoustic wave beam is parallel to the main lobe axis of the acoustic wave beam, and the acoustic wave direction is a direction far away from the front surface; establishing an initial sound wave pointing vector in a three-dimensional coordinate system for the sound wave pointing direction of the sound wave beam before adjustment, wherein the initial sound wave pointing vector is a vector a, the projection of the vector a on an XY plane is a component a1, the projection of the vector a on an XZ plane is a component a2, and the projection of the vector a on a YZ plane is a component a 3; and establishing a preset sound wave direction vector in the three-dimensional coordinate system for the sound wave direction of the adjusted sound wave beam, wherein the preset sound wave direction vector is a vector b, the projection of the vector b on an XY plane is a component b1, the projection of the vector b on an XZ plane is a component b2, and the projection of the vector b on a YZ plane is a component b 3.

In step S2, the deviation angle between component b1 and component a1 is calculated to obtain θ 1, the deviation angle between component b2 and component a2 is calculated to obtain θ 2, and the deviation angle between component b3 and component a3 is calculated to obtain θ 3.

Step S3, calculating theta 1, theta 2 and theta 3 through an operation module, wherein in the operation module, deltal/d=sinθTheta is theta 1, theta 2 or theta 3, deltalRefers to the phase difference between the single sound waves emitted by two adjacent sound units 10,dis the center-to-center distance between two adjacent sound emitting units 10.

Step S4, the peak sine wave signal is converted by the phase rotation unitConverting into peak sine wave signal of phase deflection, wherein the phase difference between the peak sine wave signal of phase deflection and the peak sine wave signal is deltal。

Step S5, the peak sine wave signals with phase deflection are used to generate deflected single-strand sound waves through the corresponding sound generating units 10, and multiple groups of deflected single-strand sound waves are superimposed to generate sound waves pointing to the deflected sound wave beam.

As shown in fig. 1, when the phase difference of the single-strand sound wave emitted from the sound emitting unit 10 located on the left side in fig. 1 is adjusted with respect to the sound emitting unit 10 located on the middle, the single-strand sound wave emitted from the sound emitting unit 10 on the left side in fig. 1 and the single-strand sound wave emitted from the sound emitting unit 10 located on the middle side in fig. 1 are superimposed, and then the sound wave directivity of the superimposed sound wave beam is deflected. The phase difference may be converted into a phase difference by corresponding to the wavelength deviation. Delta l、d、Theta are all as shown in figure 1.

Compared with embodiment 4, the present embodiment has the disadvantage of large calculation amount, and has the advantage of small error, and the adjustment error of the final sound wave beam is within +/-0.1 degree.

Example 4

step P1, establishing a three-dimensional coordinate system with the front surface of the sounding unit 10 as a reference, wherein, if the length direction of the front surface is an X axis, the width direction of the front surface is a Y axis, the normal direction of the front surface is a Z axis, the X axis and the Y axis form an XY plane, the X axis and the Z axis form an XZ plane, and the Z axis and the Y axis form a YZ plane; the acoustic wave direction of the acoustic wave beam is parallel to the axis of a main lobe of the acoustic wave beam, and the acoustic wave direction is far away from the array surface; the plane where the sound wave direction of the sound wave beam before adjustment is located is the plane where the sound wave direction before adjustment is located, the plane where the sound wave direction of the sound wave beam after adjustment is located is the plane where the sound wave direction after adjustment is located, the intersecting line between the plane where the sound wave direction after adjustment is located and the plane where the sound wave direction before adjustment is located is a steering intersecting line, the included angle between the projection of the sound wave direction of the sound wave beam before adjustment on the XY plane and the projection of the steering intersecting line on the XY plane is theta 4, the included angle between the projection of the sound wave direction of the sound wave beam before adjustment on the XZ plane and the projection of the steering intersecting line on the XZ plane is theta 5, and the included angle between the projection of the sound wave direction of the sound wave beam before adjustment on the YZ plane and the projection of the steering intersecting line on the YZ plane is theta 6.

Step P2, calculating theta 4, theta 5 and theta 6 through an operation module, wherein in the operation module, deltal/d=sinθTheta is theta 4, theta 5 or theta 6, deltalRefers to the phase difference between the single sound waves emitted by two adjacent sound emitting units 10,dis the center-to-center distance between two adjacent sound emitting units 10.

Step P3, converting the peak sine wave signal into a phase-deflected peak sine wave signal through a phase rotation unit, wherein the phase difference between the phase-deflected peak sine wave signal and the peak sine wave signal is deltal。

And P4, generating deflected single-strand sound waves by the peak sine wave signals with deflected phases through the corresponding sound generating units 10, and generating sound waves pointing to the deflected sound beams after superposing a plurality of groups of deflected single-strand sound waves.

Similarly, as shown in fig. 1, when the phase difference of the single-strand sound wave emitted from the sound emitting unit 10 located on the left side in fig. 1 is adjusted with respect to the sound emitting unit 10 located on the middle, the single-strand sound wave emitted from the sound emitting unit 10 on the left side in fig. 1 and the single-strand sound wave emitted from the sound emitting unit 10 located on the middle in fig. 1 are superimposed, and then the sound wave directivity of the superimposed sound wave beam is deflected. The phase difference may be converted into a phase difference by corresponding to the wavelength deviation. Deltal、d、Theta are all as shown in figure 1.

Compared with embodiment 3, this embodiment has the advantages of small calculation amount and relatively large error, and the final adjustment error of the sonic beam is +/-0.5 degrees.

Example 5

The video monitoring module comprises a camera and an electric cradle head used for driving the camera to horizontally and vertically rotate, the data processing module comprises an image processing unit, and the camera is used for acquiring a video image of a monitored target and transmitting the video image to the image processing unit through a wireless transmission module; in the image processing unit, feature extraction is carried out on a video image to obtain a feature image, the feature image is identified to generate a motion track vector, the motion track vector is projected to a circular area where the visual field of the camera is located, when the minimum value between the projection of the motion track vector in the circular area where the visual field of the camera is located and the boundary of the circular area where the visual field of the camera is located is smaller than or equal to a first set value, the visual field of the camera is adjusted through the control module and the electric holder, and the adjusting direction of the visual field of the camera and the projection direction of the motion track vector in the circular area where the visual field of the camera is located are arranged in parallel.

The image processing unit can be used for analyzing the video image, extracting corresponding information in the image, obtaining a motion track (motion track vector) of a target (characteristic image) through data operation, and obtaining a motion trend of the target through calculation according to the motion track vector.

Example 6

The data processing module further comprises a personnel gathering identification unit, and the working method of the personnel gathering identification unit comprises the following steps:

and step Q1, transmitting the video image acquired by the camera to a personnel gathering identification unit through a wireless transmission module, decomposing the video image into video image frames according to frames, carrying out background difference on the video image frames through a background difference method, judging and removing shadows in the video image frames, and carrying out gray level processing and binarization processing to obtain a binarization image. The video image frames are subjected to preliminary processing for subsequent operation.

Step Q2, dividing pixel points with the same pixel value in the binary image into the same region to obtain an image block set, wherein the same pixel points form image blocks, performing similarity operation on adjacent image blocks in the image block set, and dividing the adjacent image blocks which pass the similarity operation in the image block set into the same region when the operation result is greater than or equal to a second set value, namely obtaining a screening target; and carrying out noise filtering on each screening target in the binary image to obtain a suspected aggregation target. Key indicators of suspected aggregation targets, such as hair; in order to improve the fault tolerance, the data are collected by a similarity algorithm.

And step Q3, counting the positions of the suspected aggregation targets in the adjacent video image frames to generate movement tracks of the suspected aggregation targets, and performing similarity calculation on the two adjacent suspected aggregation target movement tracks, wherein the statistical calculation result is greater than or equal to the number of a third set value, and the ratio of the number of the similarity calculation result which is greater than or equal to the third set value to the movement tracks of the suspected aggregation targets is the actual probability of the suspected aggregation targets. And calculating to obtain a third set value by analyzing the motion trail of the existing aggregation personnel, and then calculating by utilizing statistics to obtain the actual suspected aggregation target probability.

And step Q4, calculating the aggregation density of the suspected aggregation targets among the aggregation areas, wherein the aggregation density is equal to the ratio of the number of the suspected aggregation targets to the aggregation areas, and the suspected aggregation targets at the outermost periphery are connected in pairs to form the aggregation areas with the polygonal shapes.

And step Q5, carrying out assignment calculation on the actual suspected aggregation target probability to obtain a first assignment result, carrying out assignment calculation on the aggregation density to obtain a second assignment result, carrying out weighting calculation on the first assignment result and the second assignment result, and judging suspected aggregation when the weighting calculation result is greater than or equal to a fourth set value. The fault tolerance is further improved by carrying out weighted calculation on the two targets of the actual suspected aggregation target probability and the aggregation density.

And step Q6, the personnel gathering and identifying unit sends alarm information to the suspected gathering information obtained by operation through a wireless transmission module, and judges whether to send a dispersing or warning command or not by manually verifying and verifying the alarm information.

Whether gathering through personnel gathering identification element can carry out preliminary identification to personnel, can save a large amount of manpowers, only need audit alone and report an emergency and ask for help or increased vigilance information, simultaneously, still need report usually to the order of whether sending and starting directional sound wave module of dispelling. The main function of the people group identification unit is to avoid 24-hour staring monitoring of the auditor.

Test for validation of effectiveness

Selecting 3723 videos with aggregation behaviors from a database, and auditing the commands which are judged to be suspected of aggregation after the steps Q1-Q5, wherein the accuracy rate of the detection is 78.51%; the effectiveness of the method is verified; the manual workload can be saved by more than 75% at least, and the implementation effect is good.

Example 7

As shown in fig. 6 and 7, the periphery cover of the directional sound wave dispersion module 1 is provided with a covering frame 20, the covering frame 20 includes a frame 21 which is arranged at the periphery of the directional sound wave dispersion module 1 and a noise reduction frame 22 which is connected with the frame 21 into a whole, the front end of the noise reduction frame 22 is provided with a plurality of arc-shaped notches 221, and an interval is arranged between two adjacent notches 221.

First, the hemming frame 20 is generally made of rubber or plastic, and thus, in order to improve stability, the reinforcing ribs 23 are integrally formed between the noise reduction frame 22 and the bezel 21, so that the angle between the noise reduction frame 22 and the bezel 21 can be stabilized.

Those skilled in the art can understand that if the sound wave is diffracted to the rear of the frame 21, the sound wave first passes through the noise reduction frame 22, due to the existence of the notch 221, the front end of the noise reduction frame 22 forms a flat-top wavy structure (a structure formed by the arc notch 221+ the top plane), when the sound wave reaches the front end of the noise reduction frame 22, a large amount of sound waves are scattered by the front end of the noise reduction frame 22 with the special structure, the propagation direction of the sound waves is scattered to all directions, the sound wave energy is scattered, and the sound pressure level of the sound wave propagated to the rear of the directional sound wave scattering module 1 is significantly reduced, so that the physiological discomfort caused to the personnel behind the directional sound wave scattering module 1 is effectively reduced, and the practicability and the safety of the sound wave are improved.

The included angle between the noise reduction frame 22 and the front surface of the sound generating unit 10 is alpha.

Testing the back sound pressure level of the directional sound wave dispersion module 1 under the test condition that the test is carried out at a position 1 meter away from the back of the directional sound wave dispersion module 1; the sound insulation amount is the difference in sound pressure level (1 meter behind) between before the package frame 20 is mounted and after the package frame 20 is mounted.

Scheme W1

The action width at 100 m and the sound insulation at the back 1 m were measured by varying the α value, and the results are shown in table 3:

TABLE 3

α	Action width (rice)	Sound insulation quantity (dB)
			＞90°	37	4~5
90°	36.6	5
			89.6°	36.1	7
89.2°	36	10
			88.8°	35.5	10
88.4°	34	10
			88°	32.2	11
87.6°	30	11

When α > 90 °, this is a common design, mainly that the noise reduction frame 22 is in an expanded configuration, not affecting the emission of the acoustic beam from there to a distance, with very low acoustic beam losses; but it also has limited effectiveness in breaking up the rearward sound waves.

Therefore, it is preferred that 88. ltoreq. alpha.be less than 90 degrees. Most preferably, the action width at 100 meters can reach 36 meters when α =89.2 °. The sound insulation quantity measured at the position 1 m behind the sound insulation board is 10 dB; the maximum peak sound pressure level is less than or equal to 60dB +/-1 dB at the position of 100 meters on the back of the directional sound wave dispersion module.

In the above embodiment, the main frequency of the sound wave of the present invention is 2000Hz, the propagation speed of the sound wave is 340 m/s, and the wavelength is 0.17 m.

As is well known in the art, the frequency and phase of the sound waves emitted from all the sound emitting units are generally the same. After the array where the sound generating unit is located emits sound waves which are superposed, the sound waves point to the position right in front of the sound generating unit array surface, and the main lobe axis of the sound waves is parallel to the normal line of the sound generating unit array surface.

The invention can adjust the sound wave phase of each sound generating unit 10, so that the main lobe of the sound wave after the sound waves are superposed points to a specific angle, which is equivalent to that the front surface of the sound generating unit 10 is physically rotated.

The invention can quickly (millisecond-level) adjust the sound wave direction (namely the sound wave main lobe direction) in a conical range taking the geometric central normal of the array surface of the sounding unit as an axis and the conical vertex angle (the geometric central point of the array surface of the sounding unit is the conical vertex) as 90 degrees in the adjusting range based on adjusting the phases of the sound waves emitted by different sounding units.

The method has high speed of adjusting the main lobe direction of the sound wave, and meets the application requirement of a quick response scene. Mechanical rotating structures are reduced, the complexity of the system is reduced, and the weight of the system is reduced.

The video monitoring type directional sound wave dispersing device based on wireless transmission has good dispersing effect, the peak sound pressure level can reach 165dB at the position of 1 m, the dispersing distance is 200-220 m, the action width at the position of 100 m reaches 36 m, the power consumption of a directional sound wave dispersing module is low, and the broadcasting distance is 2500 m; moreover, due to the arrangement of the spike wave, sound can be clearly transmitted within 1500 meters under the condition that the background noise is 88 dB; the adjustment range of the sound wave beam is in a cone range with the cone vertex angle of 90 degrees, and the sound wave direction can be rapidly adjusted.

The invention also has a video monitoring function, and signals containing a large amount of information are transmitted in real time through a wireless transmission technology, so that the real-time mastering of the field situation is facilitated; a large amount of data processing is carried out through the data processing module of the background, the target can be tracked to a certain degree, whether the situation of personnel gathering exists or not is judged, the workload of follow-up manual examination is reduced, and the working efficiency is remarkably improved.

The above description is intended to be illustrative of the preferred embodiment of the present invention and should not be taken as limiting the invention, but rather, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

Claims

1. Video monitoring type directional sound wave dispersing device based on wireless transmission, its characterized in that: including directional sound wave module, video monitoring module, wireless transmission module, data processing module, control module of dispelling, directional sound wave module of dispelling includes sound production unit, the spike sine wave signal generation module that sets up according to the array, spike sine wave signal generation module generates has spike sine wave signal, and spike sine wave signal passes through single sound production unit and generates the sub-strand sound wave, and the sound wave is restrainted after the stack of multiunit sub-strand sound wave.

2. The wireless transmission based video surveillance type directional acoustic wave diffuser of claim 1, characterized in that: the video monitoring module comprises a camera and an electric cradle head used for driving the camera to horizontally and vertically rotate, the data processing module comprises an image processing unit, and the camera is used for acquiring a video image of a monitored target and transmitting the video image to the image processing unit through a wireless transmission module; in the image processing unit, feature extraction is carried out on a video image to obtain a feature image, the feature image is identified to generate a motion track vector, the motion track vector is projected to a circular area where the visual field of the camera is located, when the minimum value between the projection of the motion track vector in the circular area where the visual field of the camera is located and the boundary of the circular area where the visual field of the camera is located is smaller than or equal to a first set value, the visual field of the camera is adjusted through the control module and the electric holder, and the adjusting direction of the visual field of the camera and the projection direction of the motion track vector in the circular area where the visual field of the camera is located are arranged in parallel.

3. The wireless transmission based video surveillance type directional acoustic wave diffuser of claim 1, characterized in that: the sine wave signal is generated into a peak sine wave signal through a peak sine wave signal generating module, and the peak sine wave signal is formed by superposing isosceles right triangle-shaped peak waves at the wave crests of the sine wave signal.

4. The wireless transmission based video surveillance type directional acoustic wave diffuser of claim 3, characterized in that: amplitude of the sine wave signal being A₀The peak sine wave signal has an amplitude A₁，ΔA=A₁-A₀(ii) a The period of the sine wave signal being T₀The period of the peak wave is T₁；

k₁=ΔA/A₀，0.38≤k₁≤0.72；

k₂=T₁/T₀，0.05≤k₂≤0.25。

5. The wireless transmission based video surveillance type directional acoustic wave diffuser of claim 1, characterized in that: the periphery cover of directional sound wave dispersion module is equipped with a frame of borduring, the frame of borduring is established the frame of making an uproar as an organic whole, is connected the frame of making an uproar that falls as the frame including the cover in the periphery of directional sound wave dispersion module, falls the front end of the frame of making an uproar and is provided with a plurality of arc breachs, is provided with the interval between two adjacent breachs.

6. The wireless transmission based video surveillance type directional acoustic wave diffuser of claim 5, characterized in that: the included angle between the noise reduction frame and the array surface of the sound production unit is alpha, and alpha is more than or equal to 88 degrees and less than 90 degrees.

7. The wireless transmission based video surveillance type directional acoustic wave diffuser of claim 2, wherein the control module comprises a phase rotation unit, and the method of changing the acoustic wave directivity of the acoustic wave beam comprises the steps of:

Step S3, calculating theta 1, theta 2 and theta 3 through an operation module, wherein in the operation module, deltal/d=sinθTheta is theta 1, theta 2 or theta 3, deltalMeans two adjacent to each otherThe phase difference between the single sound waves emitted by the sound emitting unit,dis the center-to-center distance between two adjacent sound units;

8. The wireless transmission based video surveillance type directional acoustic wave diffuser in accordance with claim 2, wherein the control module includes a phase rotation unit, and the method of changing the acoustic wave directivity of the acoustic wave beam comprises the steps of:

Step P2, calculating theta 4, theta 5 and theta 6 through an operation module, wherein in the operation module, deltal/d=sinθTheta is theta 4, theta 5 or theta 6, deltalRefers to the phase difference between single-strand sound waves emitted by two adjacent sound emitting units,dis the center-to-center distance between two adjacent sound units;

9. The wireless transmission based video monitoring type directional acoustic wave diffuser of claim 2, wherein the data processing module further comprises a people gathering identification unit, and the working method of the people gathering identification unit comprises the following steps:

step Q4, calculating the aggregation density of the suspected aggregation targets among the aggregation areas, wherein the aggregation density is equal to the ratio of the number of the suspected aggregation targets to the aggregation areas, and the suspected aggregation targets at the outermost periphery are connected in pairs to form the aggregation areas with the polygonal shapes;

Step Q5, carrying out assignment calculation on the actual suspected aggregation target probability to obtain a first assignment result, carrying out assignment calculation on the aggregation density to obtain a second assignment result, carrying out weighting calculation on the first assignment result and the second assignment result, and judging suspected aggregation when the weighting calculation result is greater than or equal to a fourth set value;