446 results about "Sound power" patented technology

A portable ventilator for providing an air-recipient with compulsory respiration is provided with an outlet manifold and a single-expansion-chamber muffler configured so that airflow through an inhale outlet port of the muffler is pulse-free and a transmission loss, defined as the ratio of sound power generated by the at least one compressor and incident on the muffler to the sound power transmitted by the muffler, is sufficient to deaden the sound power of the compressor.

An apparatus for generating an enhanced downmix signal on the basis of a multi-channel microphone signal has a spatial analyzer configured to compute a set of spatial cue parameters having a direction information describing a direction-of-arrival of a direct sound, a direct sound power information and a diffuse sound power information on the basis of the multi-channel microphone signal. The apparatus also has a filter calculator for calculating enhancement filter parameters in dependence on the direction information describing the direction-of-arrival of the direct sound, in dependence on the direct sound power information and in dependence on the diffuse sound power information. The apparatus also has a filter for filtering the microphone signal, or a signal derived therefrom, using the enhancement filter parameters, to obtain the enhanced downmix signal.

The invention discloses a bent piezoelectric-ceramic low-frequency underwater acoustic transducer comprising a front radiation head, a tail mass block, a front curved beam, a rear curved beam, a front piezoelectric crystal pile, a rear piezoelectric crystal pile, a middle opposite-phase piezoelectric crystal pile, a shell and an output cable, wherein the front curved beam, the rear curved beam, the front radiation head and the tail mass block are respectively stuck on two ends of the piezoelectric crystal piles in a certain mode, and thus the piezoelectric crystal piles are in a 'Z'-shaped bending structure of a zigzag rule shape. The shell is combined with a seal ring to realize underwater sealing. The output cable is characterized in that the leads of the piezoelectric crystal piles are connected to an outer driving source by the tail mass block. In the bent piezoelectric-ceramic low-frequency underwater acoustic transducer, the volume space of the transducer is fully utilized, and the sounding power volume of the transducer is increased; and the longitudinal stretching vibration mode of the piezoelectric crystal piles and the bending vibration mode of the curved beams are fully combined to realize the characteristics of low frequency, light weight and small volume of the underwater acoustic transducer to coexist. The bent piezoelectric-ceramic low-frequency underwater acoustic transducer has the advantages of simple structure, low construction cost and wide application, and is convenient to manufacture and convenient to disassemble.

An autonomous drone integrated with wide bandwidth, high energy acoustic wave generators sent to evict and eradicate agricultural pests within a patrolling area. The drone hovering close to a plant bombards its leaves and fruits with high energy acoustic waves via frequency and tone determined by an onboard synthesizer through acoustic power amplified to drive the sideways and bottom mounted acoustic wave generators. Agricultural pests such as caterpillar, beetle and the like are bombarded with powerful acoustic waves causing their bodies to vigorously vibrate and resonate with synthesizer frequency to dislodge or kill the pests. Other insects such as moths are forced airborne by a propeller's strong downdraft and are electrocuted by integrated high voltage screens. Inside a hotel room, the drone hovers close to a surface of a bedding mattress, bombarding the surfaces with powerful acoustic waves tuned to frequencies that cause bed bugs to resonate and die.

The invention discloses a vehicular Ethernet AVB system. The vehicular Ethernet AVB system comprises vehicular equipment and vehicular network equipment, wherein the vehicular equipment comprises a vehicular circular-view image acquisition unit, a vehicular circular-view image processing unit, a vehicular sound power amplifier unit, a vehicular navigation / entertainment unit, a vehicular instrument unit, a vehicular display unit, a vehicular driving recording unit and a vehicular multimedia antenna unit; and the vehicular network equipment comprises a vehicular Ethernet AVB / CAN network gateway unit and a vehicular CAN bus network transmission unit. AVB protocol transmission based on a vehicular Ethernet is adopted in the invention; compared with the existing various bus transmission schemes, the vehicular Ethernet AVB system disclosed by the invention is obviously improved; and the vehicular Ethernet AVB system is more open in framework, faster in rate and higher in effective load and flexibility.

The invention relates to a linear type double-acting refrigeration system. The linear type double-acting refrigeration system consists of N pulse tube refrigerators and N-1 linear type double-acting compressors, which are serially connected between a linear type compressor and a linear type electric generator in sequence and arranged at intervals, wherein the linear type compressor is positioned at the beginning end of the system, and the linear type electric generator is positioned at the tail end of the system; each of the linear type compressor and the linear type electric generator works in a single-piston manner; two pistons of each linear type double-acting compressor work at the same time; N is a positive integer of 2-20. According to the system, inertial tubes and air reservoirs or two-way air inlet equal phase-modulation structures in a traditional pulse tube refrigerator are omitted, so that the structure is compact; required phase can be realized by adjusting the frequency characteristics of linear motors at both ends of each pulse tube refrigerator and motion phases of compression pistons and expansion pistons; the flow-out sound power of the refrigerators is free of dissipation, and is absorbed by the expansion pistons of the linear motors, so that high efficiency and large refrigerating capacity can be obtained; the linear type double-acting refrigeration system has good application prospect in occasions requiring the refrigerators to obtain large refrigerating capacity, high efficiency and long service life.

Method and apparatus for locating and quantifying sound sources using an array of acoustic vector probes (200). Signals received at the probes are converted to digital form and fed into a digital signal processor (400) which computes the sound pressure and the sound-intensity vector at each probe. The set of sound-intensity vectors measured by the array provides a set of directions to a sound source (100) whose approximate spatial coordinates are determined using a least-squares triangulation formula. The sound-intensity vectors also determine sound-power flow from the source. In addition sound pressure measured by the probes can be phased to form a sensitivity beam (250) for scanning a source. Sound-intensity measurements made concurrently can be used to determine the spatial coordinates of the part being scanned and the sound power radiated by that part. Results are displayed on a computer screen or other device (500) permitting an operator to interact with and control the apparatus. Additional related features and methods are disclosed.

The invention relates to an emergency anti-collision prewarning system when a driver runs a red light, which comprises a machine case (11) and a case body back panel (17), wherein a computer information processor (3) with an input end and an output end is arranged in the machine case (11), and a monitoring camera (1), a microwave radar speedometer (2) and an integrated meteorological sensor (4) are connected with the input end, and the output end is connected with a prewarning sound power module (5), a prewarning laser emitting controller (6) and a prewarning signal wireless sharing distributor (8). The emergency anti-collision prewarning system is characterized in that a prewarning speaker (9) is connected with an output end of the prewarning sound power module (5) and a laser (7) is connected with an output end of the prewarning laser emitting controller (6). The invention can be used for timely sending out an anti-collision prewarning signal when a driver runs a red light to the pedestrian and vehicles crossing the green light so that the pedestrian and the vehicles can be more vigilant to quickly take protective measures in order to reduce and prevent traffic accidents and protect lives and vehicle property of people.

The invention relates to an ultra-large power electromagnetic suction push-pull driving sound source, comprising a base, an upper coil and a lower coil which are arranged inside the base, a vibration part which is arranged at the clearance between the upper coil and the lower coil, and an acoustic radiator which is arranged at the upper side of the base; the upper coil and the lower coil are arranged in the same axle; furthermore, the upper coil and the lower coil have the same winding direction; the sound source also comprises a control signal processing circuit which comprises a half-wave rectifier circuit that respectively provides the positive signal part and the negative signal part of the control signal to the upper coil and the lower coil. The ultra-large power electromagnetic suction push-pull driving sound source has the remarkable advantages that the ultra-large sound power output can be generated, the energy conversion efficiency is high and the nonlinear distortion can be inhibited.

The invention discloses a noise power estimation method. The method comprises the steps of first sampling input noisy voices to obtain input noisy voice signal sampling points, framing the sampling points chronologically and obtaining a series of analysis frames; then based on noisy voice signal sampling points in a current analysis frame, calculating a maximum normalized autocorrelation value of the current analysis frame, noisy voice power and a posteriori signal to noise ratio of each frequency point in the current analysis frame, and a voice presence probability of each frequency point in the current analysis frame; and finally, based on a noise power estimated value of each frequency point in a previous analysis frame, and the noisy voice power and the voice presence probability of each frequency point in the current analysis frame, calculating a noise power estimated value of each frequency point in the current analysis frame. The noise power estimation method is simple in operation and small in storage resource occupation, and is capable of quickly estimating the power of all kinds of noise.

A forward focused bipolar loudspeaker system includes a front-facing driver array and a rear facing driver array with substantially identical front-facing and rear-facing midrange or mid-bass drivers voiced and driven so that the measured SPL curves of each of the arrays, when measured individually, are tonally balanced. The front array and rear array have substantially identical on-axis and off axis frequency response and the rear array's output power (SPL) is reduced by, preferably, about 6 dB with respect to the output power produced by the front-facing array, while retaining a flat tonal balance for both the front and rear speakers, to produce a sound power ratio of about 2:1 as measured by comparing the front and back SPL levels of the speakers. This bipolar speaker system and method for voicing was discovered to provide greater clarity and improved localization while retaining the spacious envelopment of the bipolar sound field.

The invention relates to a method for measuring sound source radiation sound power and particularly relates to a method for measuring underwater sound source low frequency radiation sound power in a rectangular reverberation water tank arranged in the air. The method comprises steps that, a sound source is fixed at a position of a reverberation water tank for emission, and a hydrophone is fixed at another position to measure a sound pressure amplitude of the reception position; a reverberation water tank normal frequency calculation algorithm taking consideration of influence of a water tank wall structure on a sound field is employed, each-order normal frequency of the measurement water tank sound field is determined; the sound pressure amplitude measured in the step (1) and the water tank sound field normal frequency determined in the step (2) are taken as input parameters, the algorithm calculating the free field sound power in the reverberation water tank is employed, and the sound power of a to-be-measured sound source in the free field is determined. The method does not need to utilize a known sound source to carry out correction on the reverberation water tank sound field. When the sound field normal frequency in the water tank and the speed potential function are determined, influence of the water tank wall structure on the sound field is considered, so the sound field calculation result in the water tank is more accurate.

This invention is a kind of somesthetic vibration sounding power amplification circuit. It mainly concludes audio signal input part, audio signal output power amplifier part, remote controller part and power supply part. It also concludes a low-frequency circuit which can output low-frequency signals. This circuit is consisted with two-stage low-pass filter circuit, protection circuit and low-frequency signals amplifier. The high-frequency part of inputted audio signals is filtered by two-stage low-pass filter circuit. The low-frequency signals are amplified by low-frequency signals amplifier and outputted. The outputted signals make the energy transformer generate mechanical vibration effect. The vibration strength is controlled by remote controller.

The invention provides a method for predicting noise in a wind power plant. The method comprises the steps that 1, an apparent sound power level database and a meteorological data database of a wind turbine generator in the wind power plant are established; 2, an equivalent discharging sound power level of the wind turbine generator is obtained; 3, a wind power plant sound pressure level, relative to a sound source measuring receiving point, of the wind power plant is obtained. Compared with the prior art, the method for predicting noise in the wind power plant can conduct real-time and long-period noise prediction on the wind power plant based on the geographical characteristics of the wind power plant.

The invention provides a power transformer DC magnetic bias state detection method based on a noise method. The state detection method comprises transformer noise sound pressure level and sound power level measurement and noise spectrum analysis method. According to the method, magnetic bias condition of the DC invaded into a transformer and the magnetic bias state of the transformer are determined according to the transformer noise sound pressure level and sound power level added values and change of the noise spectrum. The detection method is simple, practical, energy saving and highly-efficient, can be jointly used with other electric performance test methods being combined, can also be used alone, and can carry out detection and analysis on the DC magnetic bias state of the transformer to guarantee the transformer to run safely and reliably in the DC magnetic bias state. The detection method is suitable for three-phase five-column, single-phase three-column and single-phase four-column iron core type transformers, and is not suitable for a three-phase three-column iron core type transformer.

A system is provided for attenuating tonal acoustic noise associated with a single positive displacement compressor, or multiple positive displacement compressors proximately located from each other. A controller selectably controls the rotational speed and the frequency of operation of each of the compressors. The controller controls the rotational speed of the compressors about a predetermined rotational speed, in a random manner, within the pre-selected speed band to reduce the magnitude of the central tonal acoustic frequency of the pressure pulsations and disperse the sound power over a wider acoustic bandwidth.

The invention discloses a robust adaptive beamforming method based on shrinkage estimation covariance matrix reconstruction. The method comprises the following steps: performing linear shrinkage estimation on a sampling covariance matrix; performing feature decomposition on the sampling covariance matrix obtained by linear shrinkage estimation to obtain a noise subspace; calculating average noisepower in an expected small-angle interval according to the MUSIC spectrum, and removing the average noise power in the process of reconstructing an accurate expected signal covariance matrix; carryingout feature decomposition on the reconstructed expected signal covariance matrix, taking a feature vector corresponding to a maximum feature value as an initially estimated expected signal steering vector, and combining a modulus constraint and a noise power constraint of the preliminarily estimated expected signal steering vector into a Laplace constraint to obtain a corrected expected signal steering vector; and forming a robust adaptive wave beam by utilizing the sampling covariance matrix obtained by linear contraction and the expected signal steering vector. The main lobe wave beam and the output signal to interference plus noise ratio of the wave beam formed by the method are closer to ideal values, and the method has higher anti-interference capability.

A material flow sensor for a harvesting machine comprising an acoustic chamber comprising an impact plate and a housing, microphone, a pneumatic impulse line connecting the housing and the microphone, and an electronics module, wherein the housing is shaped so as to direct sound waves created by crop matter striking the impact plate into the pneumatic impulse line, wherein the sound waves move through the pneumatic impulse line into the microphone, which detects the sound waves and converts them into an electrical signal that is a representation of the sound power derived from the sound waves, which in turn is a representation of the mass of the crop matter striking the material flow sensor.

A method implemented using at least one processor module includes receiving a plurality of operational parameters corresponding to a plurality of wind turbines and obtaining a plurality of source sound power values corresponding to the plurality of wind turbines. The method further includes obtaining a receptor sound pressure value corresponding to a receptor location and estimating an attenuation model based on the plurality of source sound power values, and the receptor sound pressure value. The attenuation model disclosed herein comprises a plurality of attenuation coefficients. The method also includes determining at least one turbine set-point corresponding to at least one wind turbine among the plurality of wind turbines based on the plurality of attenuation coefficients, and the plurality of turbine operational parameters.

Method, user device and computer program product for suppressing echo. An audio signal is outputted from a speaker. A microphone receives an audio signal which includes echo resulting from said outputted audio signal. An echo path of the echo is modelled using a plurality of models. A first of the models is a FIR based model and a second of the models is different to the first model. The first model is used to determine a first model estimate of the echo power of a first component of the echo. The second model is used to determine a second model estimate of the echo power of a second component of the echo. The first and second model estimates of the echo power are combined. The combined estimate of the echo power is used to apply echo suppression to the received audio signal, thereby suppressing the echo.

The invention relates to a method for predicting far-field noises of a converter transformer. The method comprises the steps of 1) according to a factory sound power level and a noise spectrum of theconverter transformer, building a Cadna / A prediction software-based model; 2) measuring a near-field noise value of the converter transformer and a spectrum of a sound receiving point; 3) converting sound pressure levels into sound pressures, and calculating respective contribution value proportions eta, wherein the sound pressure levels include sound pressure levels LPi, contributed by a converter transformer body and a fan of the converter transformer body, of the sound receiving point and a total sound pressure level LP of the sound receiving point; 4) by applying an inversion method of Cadna / A software, according to a contribution value proportion, adjusting sound power levels of the converter transformer body and the fan to make a predicted value of the sound receiving point basicallyconsistent with an error of an actually measured value; and 5) according to the adjusted model, performing far-field noise prediction of the converter transformer. According to the method, through Cadna / A software modeling, the model is adjusted to be matched with noise distribution around the converter transformer according to the percentage of the contribution values of the noise spectrums of the converter transformer body and the fan, thereby realizing accurate prediction of the far-field noises of the converter transformer.

The invention provides an engine noise testing method based on an outfield airplane. The method comprises the following steps of: 1) selecting requirements of a noise measuring condition; 2) arranging measuring points; 3) preparing a measuring field and establishing a noise testing system; 4) measuring and recording the frequency spectrum (A-weighted) of sound pressure level frequency multiplication of airplane engine noises, then calculating a total sound pressure level of all the measuring points; 5) measuring the sound pressure level of each measuring point in the step 4); 6) measuring a surface average sound pressure level; 7) measuring a sound power level of the engine noises; and 8) analyzing the measured noises. Compared with the prior art, the method provided by the invention is capable of accurately measuring the noises of the outfield airplane engine, and a basis is provided for the research of outfield airplane engine noise inhibition.

The invention provides a statistical energy analysis-based ship cabin noise forecasting method. The method comprises the steps of 1, preliminarily building a statistical energy analysis-based ship cabin noise forecasting model by utilizing ship drawing data; 2, performing local detail optimization on an emphatically assessed cabin and load region in the built model, and constructing an external auxiliary sound cavity; 3, determining a vibration acceleration load and a sound power load of equipment by utilizing an experimental test; 4, performing calculation by utilizing the experimental test or a formula to determine loss factors in a steel plate and the sound cavity; 5, building a microacoustic analysis model of an outfitting material structure by utilizing a transfer matrix method, and obtaining acoustic parameters of an outfitting material through sound absorption and insulation analysis; 6, setting frequency response analysis as a 1 / 3 octave frequency, and setting a calculation frequency to be 31.5Hz-8kHz; and 7, performing ship cabin noise forecasting analysis by applying statistical energy analysis. The efficiency and precision of ship cabin noise forecasting can be effectively improved; and the method can be applied to ocean platform and ship cabin noise forecasting and control.

The invention relates to a method and an arrangement for detecting acoustic and optical information as well as a corresponding computer program and a corresponding computer-readable storage medium, which can in particular be used to generate three-dimensional sound maps. The sound maps can be visualized and provided with information about acoustic sources, sound power and emitter characteristics. For this purpose, it is proposed to use for the detection of acoustic and optical information at least one microphone array and at least one device for detecting optical geometry data, wherein the at least one microphone array and the at least one device for detecting optical geometry data are arranged in a defined positional relationship. Acoustic information emitted from an object and the geometry of the object are detected by moving the at least one microphone array, the at least one device for detecting optical geometry data and the object relative to each other.

The invention discloses a spacecraft damping vibration isolation micro-vibration test chamber which is divided into a test chamber body and a control chamber body. The test chamber body comprises a room body, vibration isolation platforms, a test device and an auxiliary facility. The room body of the test chamber body is a semi-damping chamber, the floor is a gravity-leveled floor, and a roof and surrounding walls of the test chamber body are provided with wedge absorbers respectively. The center of the floor of the test chamber body is provided with three vibration isolation platforms. The first vibration isolation platform is a single-machine micro-vibration source surrounding test station and is provided with two spacecraft single-machine interference source test platforms. The second vibration isolation platform is a special multi-freedom-degree source surrounding simulation station and is provided with a six-freedom-degree source surrounding simulation system. The third vibration isolation platform is a station for a manned spacecraft single-machine noise source device sound power test and a large-part and small satellite whole micro-vibration test and is provided with a product and micro-vibration test tool and the like. The side face of the test chamber body is provided with a sound isolation door beneficial to going in and going out of tested devices or products. The control chamber body is a conventional spacecraft environmental test chamber.

The invention provides a structure optimization design method for an automobile damping board. The structure optimization design method has the advantages that through strain energy overlay analysis and parallel coupling mode design of sound power losses of the damping board and based on light weight option design of cost, performance and the process, the material, the thickness and the arrangement of the damping board are designed, overall shape optimization is conducted on a metal plate and the damping board, and the light weight design of the damping board is achieved on the premise that the NVH performance is achieved.

The invention provides a flow guide device used for measuring underwater jet flow noises by a reverberation method. The flow guide device comprises a water inlet pipe, a flow guide pipe, a flow stabilizing box, a height adjuster and a water outlet pipe, wherein one end of the water inlet pipe is inserted into a non-noise-eliminating water pool or water tank; the other end of the water inlet pipe is connected with the flow guide pipe; one end of the flow guide pipe is connected with the water inlet pipe and the other end of the flow guide pipe is connected with the flow stabilizing box; the flow stabilizing box is fixedly provided with the flow guide pipe; the flow stabilizing box is arranged on the height adjuster; the height adjuster can be used for freely adjusting the height in the vertical direction; and the water outlet pipe is located on the side face of the flow stabilizing box. According to the flow guide device used for measuring the underwater jet flow noises by the reverberation method, when the reverberation method is used for measuring radiation sound power of the underwater jet flow noises, the volume of water in the non-noise-eliminating water pool or water tank is not increased by jet flow and the jet flow radiation noises are not transmitted to the outer side, and the noises of the outer side are not transmitted into the non-noise-eliminating water pool or water tank, so that the measurement of the radiation sound power of the underwater jet flow noises is not influenced.