25 results about "Acoustic radiation" patented technology

This invention relates to the field of dynamic load section stress monitoring and feedforward adaptive intelligent correction technology for coal conveyor belts in thermal power plants. The invention provides an automatic monitoring and correction device for coal conveyor belts, comprising: a control host that extracts speckle decorrelation index and maps the transverse segregation gradient matrix through a data acquisition and detection module; a rheological state analysis module that introduces a fractional-order calculus dynamics model to analyze the creep stress field and outputs a deformation potential energy time series; a spatial feature prediction module that uses the Koopman operator to elevate the nonlinear system to a linear functional space, identifies outbreak nodes by tracking eigenvalue drift trajectories, and issues early warning commands; and an acoustic field adhesion breaking correction module that drives piezoelectric ceramic elements to construct a local acoustic radiation standing wave field, breaking van der Waals forces to release transverse shear potential energy. This invention solves the risk of belt misalignment and tearing caused by material segregation and adhesion under multi-coal blending conditions.

The application claims a MEMS frequency accurate tracking and locking method based on a resonant phase-locked loop (R-PLL). The application relates to the technical field of MEMS (micro-electro-mechanical system) resonator control and frequency tracking, and the method takes the output of a voltage-controlled oscillator as an interference signal, takes the physical response (such as weak electromagnetic leakage or acoustic radiation) of a disturbed MEMS device as a feedback signal, compares the phase difference between the feedback signal and a reference signal through a phase detector, adjusts the interference frequency, and forms a closed-loop locking system. The application adjusts the interference source frequency through a phase detector and a filter, can track the target resonant frequency drift caused by factors such as temperature change in real time, makes the MEMS resonator keep in a phase-locked state with the target resonant frequency, and ensures that the interference energy is always efficiently coupled.

This invention relates to a method for rapid three-dimensional acoustoelastic prediction and line spectrum identification of ship mechanical noise based on online equipment vibration monitoring. The method includes: establishing a refined three-dimensional acoustoelastic calculation model for the overall ship vibration and acoustic radiation calculation of the equipment-vibration isolator-base-shell; applying a unit sweep force at the equipment's center of gravity node to obtain the transfer function from the average vibration acceleration spectrum of each equipment's base surface to the radiated noise; multiplying the average vibration acceleration spectrum monitored online in real time with the transfer function to obtain the ship mechanical noise under real-time excitation of each equipment; performing incoherent superposition of the radiated noise from each equipment to achieve rapid three-dimensional acoustoelastic prediction of ship mechanical noise; extracting the line spectrum peak value, and determining the main source of the line spectrum peak value by calculating the energy contribution of each equipment to the line spectrum peak value. This method achieves high-precision online prediction and automatic identification of the line spectrum source of ship mechanical noise, with high computational efficiency and strong engineering applicability.

This acoustic unit 10 comprises: an acoustic radiator 11 that is formed in a plate shape having a first surface 11a and a second surface 11b facing the opposite side of the first surface, radiates sound to at least the first surface side by vibrating in an intersecting direction Dv intersecting the first surface and the second surface, and includes a first portion 21 and a second portion 22 that vibrate in the intersecting direction in opposite phases to each other; and an acoustic metamaterial 16 that is disposed on the first surface side and suppresses transmission of a second sound generated accompanying the vibration of the second portion to a space S1 on the first surface side of the first portion from which a first sound generated accompanying the vibration of the first portion is radiated.

This invention discloses a sound field modulation device and method based on a multifunctional acoustic metasurface. The acoustic metasurface is installed at the acoustic radiation end of a partitioned piezoelectric transducer for phase modulation of the sound waves excited by the transducer. The partitioned piezoelectric transducer includes partitioned piezoelectric ceramics and a control circuit. The partitioned piezoelectric ceramics are circular and radially divided into an inner circular electrode partition and an outer annular electrode partition. Each electrode partition is electrically connected to the control circuit to independently excite different electrode partitions to generate sound waves. The acoustic metasurface is radially divided into phase modulation regions corresponding one-to-one with the electrode partitions of the partitioned piezoelectric ceramics. Each phase modulation region is equipped with a different phase coding pattern to form sound fields with different functions under different electrode partition excitation states. This invention achieves a multifunctional sound field by switching the partitioned electrodes, which can significantly improve the efficiency of detection and treatment in non-destructive testing and medical ultrasound, and broaden the utilization rate of planar ultrasound transducers.

This application discloses an oil-gas separator, including a cylinder with an inlet end and an outlet end; and at least one reinforcing ring fixedly sleeved on the outer peripheral wall of the cylinder. The reinforcing ring is configured to increase the local stiffness of the cylinder, thereby adjusting the overall modal frequency of the cylinder to above a preset threshold, so that the natural frequency of the cylinder avoids the excitation frequency of the compressor. This application eliminates resonance noise by setting a reinforcing ring on the outer periphery of the cylinder and utilizing the principle of passive structural control. The reinforcing ring significantly increases the local stiffness of the shell, forcing the overall modal frequency of the oil-gas separator to jump above the main excitation frequency band of the compressor, thus cutting off the physical conditions for resonance at its source and overcoming the defect of low absorption efficiency of traditional sound-absorbing cotton for low-frequency vibration. This solution directly modulates the noise radiation source mechanically, effectively suppressing the sound radiation efficiency of the shell. At the same time, the optimized structural parameters eliminate the planar modal resonance of the additional structure itself, achieving substantial improvement in noise across the entire frequency band.

This invention discloses a design method for a multi-layer composite sound-insulating superstructure. The multi-layer composite sound-insulating superstructure is designed as an upper and lower substrate and a rectangular frame. Multiple resonators (Type 1 and Type 2) are respectively disposed on the upper and lower substrates, forming a single-layer superstructure material plate. The rectangular frame is filled with porous sound-absorbing material, with multiple upper and lower holes respectively opened on the upper and lower surfaces of the porous sound-absorbing material. The upper substrate is in contact with the upper surface of the rectangular frame, and the lower substrate is in contact with the lower surface of the rectangular frame. Multiple resonators (Type 1) are inserted into multiple upper holes, and multiple resonators (Type 2) are inserted into multiple lower holes. The two single-layer superstructure material plates are stacked to form a composite superstructure. The composite superstructure utilizes the phase cancellation of sound radiation at the anti-resonance frequency to form a sound insulation peak exceeding the mass law curve, thereby improving the sound insulation performance at mid-to-low frequencies. The internal porous sound-absorbing material further enhances the high-frequency sound insulation performance.

This invention discloses a method for calculating noise through direct coupling between a worm gear structure and its acoustic field, belonging to the field of noise prediction technology for mechanical transmission systems. The method includes: decomposing the time-domain torque into DC and AC components; establishing a structure-acoustic field coupled finite element model with a matching layer (PML); solving for steady-state prestress using the DC component; treating the AC component as a disturbance under prestress, and directly solving the coupled dynamic equations through harmonic response to obtain the full-field sound pressure response in one step; finally, extracting the sound pressure level distribution to achieve noise prediction. This invention overcomes the shortcomings of the traditional "two-step method" (cumbersome process, neglecting the acoustic radiation of the worm gear itself) by linearizing the prestress and using a one-step direct coupling solution, achieving fast and high-fidelity noise prediction under steady-state conditions, significantly improving computational efficiency and accuracy.

This utility model relates to the field of composite panel structure technology, specifically a sound insulation and vibration reduction partition for ship cabins containing acoustic black holes. The partition includes: an acoustic black hole thin plate layer, a damping material layer, and a honeycomb panel layer. Multiple sets of acoustic black hole structures are arranged in an array on the acoustic black hole thin plate layer, and the thickness of the acoustic black hole region satisfies a power law. The damping material layer forms an energy buffer interface, and its two sides are connected to the acoustic black hole thin plate layer and the honeycomb panel layer, respectively. The honeycomb panel layer is used to complete acoustic radiation impedance matching and suppression. This utility model constructs a complete acoustic vibration control chain of "vibration capture - energy dissipation - acoustic impedance matching" through gradient impedance design of each functional layer, improving sound insulation without increasing mass. It is particularly suitable for applications such as ship cabins that are weight-sensitive and require broadband noise reduction.

The application belongs to the technical field of underwater acoustic detection, and discloses an equivalent source method for predicting underwater acoustic cross-medium propagation in a channel space. For an underwater structure in an actual project, a group of equivalent sources are arranged in the interior of the structure to describe the vibration-acoustic response of the structure. The vibration speed of the structure surface is obtained through simulation calculation or arrangement of an acceleration sensor measurement, so that the equivalent source intensity can be determined, and then an underwater structure acoustic radiation model is constructed. The equivalent source is analytically expressed by using a free field space Green function, which does not meet the boundary conditions and the sound velocity gradient characteristics of the ocean channel, and is not applicable to the calculation of channel underwater acoustic and cross-medium propagation. The equivalent source is constructed by using a displacement potential Green function to be unconditionally stable in the channel space, so as to meet the requirements of the channel boundary, the sound velocity gradient and the like, and to establish the underwater acoustic cross-medium propagation. The application arranges a group of equivalent sources in the interior of the structure, uses the vibration speed of the structure surface to solve the equivalent source intensity, describes the vibration-acoustic response of the structure, and establishes a transfer function equivalent source model of vibration-acoustic radiation.

This utility model relates to the field of chip packaging technology, and more particularly to a packaging structure for reducing the total harmonic distortion (THD) of MEMS piezoacoustic devices. The structure includes: a substrate having a hollowed-out cavity, a limiting device, and multiple vent holes at the bottom; and a MEMS sound-emitting chip, inverted and soldered onto the substrate, with its edge region bonded to the substrate via a connection point to form a first acoustic cavity. This utility model provides a packaging structure for reducing the THD of MEMS piezoacoustic devices. The inverted soldering of the MEMS sound-emitting chip effectively reduces the volume while ensuring packaging stability. The diaphragm of the MEMS sound-emitting chip and the substrate form the first acoustic cavity, while the chip, substrate, and shell together form a second acoustic cavity. Through dual-cavity air pressure balance, mechanical limiting, and acoustic path optimization, nonlinear vibration is reduced, significantly lowering the total harmonic distortion (THD) of the MEMS piezoacoustic device and improving sound radiation efficiency.

The application provides a device and method for measuring the ultrahigh frequency ultrasonic acoustic radiation force on an object, wherein the device comprises an elastic force receiving component, an ultrahigh frequency ultrasonic transducer and a displacement measuring device, the elastic force receiving component comprises a glass capillary and an object, the lower end of the glass capillary is a fixed end, the upper end of the glass capillary is a free end, and the object is fixed to the upper end of the glass capillary; the ultrahigh frequency ultrasonic transducer is located on the side of the object, the ultrahigh frequency ultrasonic transducer is used to generate ultrahigh frequency ultrasonic waves according to an excitation signal, and the object moves axially and laterally under the action of axial and lateral ultrasonic acoustic radiation forces; and the displacement measuring device is arranged above the object and is used to measure the axial and lateral displacements of the object under the action of the axial and lateral ultrasonic acoustic radiation forces. The device can be used to simultaneously measure the axial and lateral ultrasonic acoustic radiation forces on the object.

The present application belongs to the technical field of helicopter fault diagnosis, and relates to a helicopter rotor potential fault intelligent diagnosis method and system based on acoustic signals. The method comprises: implanting typical fault characteristics into characteristic parameters to generate rotor models of multiple fault states; solving flow field parameters to obtain dynamic pressure loads on the surface of rotor blades; collecting time-varying sequence signals of acoustic pressure through a virtual acoustic sensor array; extracting fault characteristics; constructing a fault classification and discrimination model based on machine learning; and outputting the fault state and fault type of the rotor. The present application can comprehensively reflect the influence of rotor faults on acoustic radiation characteristics, effectively solve the problem of difficult acquisition of helicopter rotor fault samples through high-fidelity geometric modeling, fault implantation and CFD and CSD coupling strategies, and realize automatic identification and type positioning of faults through extraction of multi-dimensional fault characteristics and construction of a fault diagnosis model based on machine learning algorithms.

The present application provides a kind of warning device for vehicle, it is configured according to the detection signal from the object detection device for detecting the object existing in the surrounding of vehicle, the door opening operation of vehicle is warned for passenger, with: sound radiation pressure generating part, it emits ultrasonic waves, and generates the sound radiation pressure that makes people feel tactile in the surrounding space of door lock release operation part in vehicle room;And warning control part, according to the reception of detection signal, makes sound radiation pressure generating part generate sound radiation pressure.

A kind of suspension vibration isolation device of modular periodic structure, at least one suspension unit is composed of;The suspension unit includes, outgoing end main plate;Adapter plate group is set on the outgoing end main plate, and the adapter plate group at least includes inner adapter plate and outer adapter plate;Compression-torsion coupling structure is connected between the inner adapter plate and outer adapter plate.This structure has obvious band gap characteristics, can more effectively prevent the propagation of vibration and the inhibition of sound radiation, reduce the deformation in circumferential direction due to breathing vibration and axial vibration in the involved propulsion system, in addition, hard core and soft material wrapped in the outside are filled in compression-torsion coupling structure to enhance its damping effect, and different damping effects can be achieved by changing the soft material outside.

The present invention provides a composite loudspeaker, comprising a basket, and a vibration system and a magnetic circuit system which are separately fixed to the basket, the magnetic circuit system driving the vibration system to vibrate to produce sound. The vibration system comprises a first woofer and a tweeter which are arranged on a first side of the magnetic circuit system, and a second woofer arranged on a second side of the magnetic circuit system. The first woofer and the tweeter are coaxially arranged, and the first woofer is arranged around the outer side of the tweeter. The magnetic circuit system comprises a central magnetic steel and an edge magnetic steel arranged on the outer periphery of the central magnetic steel. The central magnetic steel and the edge magnetic steel are oppositely magnetized. The composite loudspeaker of the present invention can produce sound on both sides, thereby improving an effective sound radiation area, improving frequency response, reducing structural nonlinearity, reducing distortion, and improving sound quality of the loudspeaker. The vibration system comprises both the woofers and the tweeter, thereby compensating for a lack of high-frequency response of the loudspeaker.

The application discloses a granular damping noise suppression superstructure device based on mode conversion function, which comprises an outer shell, an inner shell, a noise reduction ring and a connecting device. A plurality of noise reduction rings are periodically arranged along the shell in the axial direction, and the outer shell and the inner shell are assembled and connected through the connecting device, so that a double-layer shell structure with periodic characteristics is formed, a band gap characteristic is introduced, and low-frequency sound radiation suppression is realized. The noise reduction ring comprises an inner hexagonal screw, a cover plate, a granular damping group and an integrated annular frame, the inside of the integrated annular frame is composed of a plurality of unit structures, each unit structure is formed by rotating the granular damping group and a cavity, the unit structures are arranged in a non-mirror-symmetrical manner, and the propagation of structural vibration and elastic waves is effectively suppressed, the granular damping group is composed of double-radius solid spheres arranged closely, and the noise reduction frequency band is widened through the synergistic effect of different radius particles. The device can be used for the outer shell structure of an underwater vehicle to realize low-frequency broadband noise suppression effect.

This application provides an underwater target classification method and apparatus, relating to the field of sonar target recognition technology. The method includes: processing a target signal using an underwater acoustic signal beat extraction model to obtain propeller beat information and blade beat information of the target signal; the target signal is the beam signal of acoustic radiation from a target object received by sonar; based on the propeller beat information and blade beat information of the target signal, obtaining mask sequences corresponding to the propeller beat information and blade beat information respectively; fusing the mask sequences of the propeller beat information and blade beat information; and performing feature enhancement on the time-spectrum map of the target signal based on the fused mask sequence to complete the classification of the target signal. Thus, by strengthening the target's rhythm perception ability at the feature input stage, the robustness of underwater target classification is effectively improved.

The hybrid sound radiation device according to the invention is used for vibrating a heavy-weight rigid plate at audio frequencies. The device comprises two voice coils arranged concentrically, the external voice coil being coupled to a fluid reservoir comprising a three-fluid medium having a substantially constant viscosity as a function of frequency. A third coil is arranged around the side wall of the fluid reservoir and two electrodes of opposite polarity are provided in the fluid reservoir for providing a substantially constant electric field inside the fluid reservoir. The device further comprises a vibrating element in the form of a heavy-weight, rigid, planar plate rigidly connected to the fluid reservoir; and control circuits connected to the first, second and third coils and the electrodes.

This invention belongs to the technical field of embedded piezoelectric sensor devices and cement-based functional composite materials, specifically relating to a cement-based embedded high-pressure resistant bidirectional bending-tension piezoelectric smart aggregate. The smart aggregate includes: a shell assembly comprising a first shell and a second shell that snap together to form a sealed cavity; both the first and second shells include a force-radiating structure, a vibration-conducting structure, and a force-transmitting component connecting them; two piezoelectric driving elements symmetrically arranged on the inner surfaces of the vibration-conducting structures of the first and second shells; a circuit board disposed within the sealed cavity; an elastic electrical connection structure abutting the circuit board against the electrodes of the piezoelectric driving elements; and a grounding structure that suspends and fixes the circuit board within the sealed cavity, forming a grounding loop. This invention utilizes an arc-shaped dome to achieve high-pressure to pre-tightening force conversion, dual piezoelectric driving elements to optimize low-frequency sound radiation, and a weld-free elastic connection and suspended grounding structure for vibration and impact resistance, making it suitable for structural health monitoring in deep underwater high-pressure conditions.

This disclosure provides a superstructure, a loudspeaker unit, and a design method for the superstructure, relating to the field of audio technology. The method specifically involves defining an objective function and a loss function based on the sound pressure amplitude directivity and the change in sound radiation power level. Iterative optimization combining finite element simulation and a genetic algorithm is used to obtain the design parameters of the superstructure, which is then fabricated. The superstructure designed by this disclosure includes j conical rings, a first connecting structure, and a second connecting structure, deployed on the sound output side of the loudspeaker unit. It can effectively broaden the radiation directivity of the loudspeaker unit in all three-dimensional space, achieving relatively uniform sound wave radiation in all directions.

The application discloses a kind of supercharged low-frequency pressure hydrophone, and the hydrophone includes: front shell, back cover, supercharged component and sensitive element, supercharged component is connected with sensitive element and is contained in the inside of front shell, and the cooperation realizes the monitoring of underwater sound pressure fluctuation;Back cover is assembled in front shell by threaded connection;Supercharged component is equipped with the first pressure surface, second pressure surface and third pressure surface with conical surface;Third pressure surface is connected with second pressure surface by first connecting shaft, and second pressure surface is connected with first pressure surface by second connecting shaft, and pressure surface is used to receive the pressure of pipeline sound radiation wave;First pressure surface, second pressure surface and third pressure surface all have conical surface;Connecting mode is selected from bonding or welding;The outer diameter of three pressure surfaces is same, and the taper angle of conical surface is consistent.The application is arranged array type pressure surface in the extension direction of hydrophone, and the effective pressure area of disc type hydrophone is increased, so as to break through size constraint and improve sensitivity.

A method for predicting the sound radiation of a flexible layer laid water flow structure, the sound radiation calculation model of the flexible layer laid water flow structure is divided into model one and model two, the four-terminal acoustic impedance parameters are used to describe the relationship between the sound pressure and the vibration velocity of the inner and outer surfaces of the flexible layer, and the non-coherent wall plane wave superposition method is used to process the fluctuating pressure excitation of the turbulent boundary layer. Model one solves the vibration response of the outer surface and the excitation force transmitted to the inner surface under the assumption that the inner surface of the flexible layer is fixed; model two establishes a coupling equation to solve the vibration response by taking the excitation force as the structure input and considering the sound radiation reaction of the outer surface; and the complete sound radiation power is obtained by linearly superimposing the results of the two models. The present application can accurately describe the physical process of the flow-induced load transmitted to the surface of the structure through the flexible layer, realize the unified vibration-sound coupling solution of the flexible layer laid structure under the action of the outer surface flow-induced load, and provide an efficient and accurate new method for predicting the sound radiation of the flexible layer laid water flow structure in engineering.