43 results about "Sound intensity probe" patented technology

The invention discloses a pressure speed method sound field separation method, a measured sound field is provided with a measuring surface S; a sound pressure sensor is adopted to measure the sound pressure on the measuring surface S, and a particle velocity sensor or a sound intensity probe is adopted to measure the particle speed on the measuring surface S; both sides of the measuring surface S are provided with the imaginary source surfaces S1 <*> and S2 <*> which are provided with the equivalent sources; the transfer relationship between the equivalent sources and the sound pressure and the particle speed on the measuring surface S is constructed; the separation of sound source radiation sound pressure and the particle speed of both sides on the measuring surface according to the transfer relationship is realized; the sound field separation is realized by measuring the speed relation of sound pressure and particle on each surface; and the equivalent source method is adopted as the sound field separation arithmetic, the calculation stability is good, the calculation precision is high, and the implement is simple. The method can be widely applicable to the near-field acoustic holography measurement in the environments of internal sound field or noisy sound, the sound intensity method sound source identification in the noisy environment, the material reflection coefficient measurement, and the separation of the scattering sound field.

The invention discloses a system and a method for positioning a noise source. The method comprises the following steps of: adjusting the position and focal length of a camera until a taken image comprises a region to be detected, and storing an image which is taken as a background image into an upper computer; fixing a light source on a sound intensity probe which is connected with a data acquirer; endowing the image which is taken by the camera with the color of a light source by filtering; moving the sound intensity probe, and scanning on the surface of the region to be detected at constant speed; outputting a trigger signal by a pulse signal generator, continuously taking images by the camera, recording a motion image of the light source, recording the trigger signal and an acoustic signal by the data acquirer, and synchronizing the acoustic signal and image taking time; after detection is finished, processing the image, and thus obtaining the position of the light source in a picture; extracting the acoustic signal, and thus obtaining acoustic physical quantity information at a corresponding moment; dividing the region to be detected into triangular units, wherein nodes are the positions of the light source, which are acquired at all moments, and the acquired acoustic physical quantity serves as a cloud picture measuring value; and acquiring a sound field cloud picture, and displaying the sound field cloud picture. The invention has the advantages of quick positioning, accurate measurement and high accuracy.

The present invention relates to a sound intensity and acoustical power measurement method of the high-strength focused ultrasound. The sound intensity and acoustical power measurement method of the present invention is characterized by selecting two mutually parallel first and second planes in a pre-focusing area of the high-strength focused ultrasound to measure, and using a PC to control a hydrophone to scan the sound pressure data on the first plane, and then using a servo motor to control the hydrophone to move along a Z direction accurately, repeating the above control and acquisition processes, and obtaining the sound pressure data on the second plane. The sound intensity and acoustical power measurement method of the high-strength focused ultrasound of the present invention has the remarkable characteristics of being simple and convenient to implement, efficient and accurate to calculate, etc., avoids measuring in a focusing area, can protect a sensor furthest, can obtain a plurality of parameters, such as the sound intensity distribution, etc., while obtaining the acoustical power, facilitates evaluating the performances of a focusing transducer comprehensively, and is suitable for measuring the radiation acoustical powers of various focusing transducers.

Method and apparatus for detecting and locating underwater obstacles in the path of a ship or boat. The apparatus includes a pulsed wide-angle sonar projector (100) controlled by a digital signal processor (400) that emits sound pulses at frequencies of 30 kHz and less that can penetrate sediment-laden water hundreds of meters or more ahead of the ship or boat. The projector generates echoes from submerged objects. A vector sound-intensity probe (200) receives the echoes and transmits them to the digital signal processor. The digital signal processor determines the location of submerged obstacles ahead of the ship or boat from the echoes received by the probe. This information is displayed on an output device (500). The sonar projector and vector sound-intensity probe are contained separately in streamlined housings aimed in the forward direction under the bow of the ship or boat. The processor, output device and other electronics are located on board the ship or boat.

The invention provides a method for evaluating high sound intensity characteristics of a sound intensity measuring instrument. The method is used for evaluating sound intensity level dynamic range upper limit of the sound intensity measuring instrument, and calibrating sound intensity level deviation; a sound intensity probe of the to-be-calibrated sound intensity measuring instrument is provided with two sound intensity probe microphones; the two sound intensity probe microphones are both connected with a sound intensity analysis meter; the intensity probe microphones of the sound intensity measuring instrument and a high sound pressure standard microphone are arranged on a sound intensity level calibration device in axial symmetry. Through the method, the standard sound intensity level is simulated through a standing wave tube sound wave generation technology based on the double resonance sound wave amplitude-phase control principle; the evaluation of sound intensity measuring instrument calibration with measurement range of 100-150dB can be realized.

The invention discloses a sound insulation measurement system based on a hand-held sound intensity probe suite. The sound insulation measurement system based on the hand-held sound intensity probe suite comprises a complete elimination chamber and a reverberation room which are separated through a wall surface, the center of the wall surface is provided with a window which divides the complete elimination chamber and the reverberation room completely through sealing installation of a sample piece to be tested, and the reverberation room is internally and uniformly provided with a plurality oflow-frequency loudspeakers, high-frequency loudspeakers and microphones. The complete elimination chamber is provided with the hand-held sound intensity probe suite, a data acquisition system and hardware and a test computer. The data acquisition system and hardware is in circuit connection with the low-frequency loudspeakers and the high-frequency loudspeakers through an audio control unit to constitute an original signal output module. The hand-held sound intensity probe suite and the microphones are separately connected with the data acquisition system and hardware, and the data acquisitionsystem and hardware is connected with the test computer. According to the sound insulation measurement system based on the hand-held sound intensity probe suite, the structure is simple, the test process is easy to adjust, the sound insulation measurement system is convenient to move, meanwhile, sound insulation measurement results are reliable, and the cost is low.

A system for normalizing and calibrating the microphones of a sound-intensity probe or a composite of such probes, with respect to a stable comparison microphone with known acoustical characteristics. Normalizing and calibrating are performed using an apparatus 57 consisting of a tube with a loudspeaker inserted in one end and a fixture for holding the microphones of the probe together with the comparison microphone in the other end. The comparison microphone has known acoustical characteristics supplied by the manufacturer. Two banks of quarter-wave resonators 83 and 84 are attached to the side of the tube to absorb standing waves. The sound-intensity probe can be either a two-microphone probe used for measuring a single component of the sound-intensity vector or a probe with four microphones in the regular tetrahedral arrangement used for measuring the full sound-intensity vector. The microphones in the probe are made to have a substantially identical response with the comparison microphone by determining the transfer functions between the microphones and the comparison microphone. The transfer functions and known acoustical characteristics of the comparison microphone are then used to correct the pressure measurements by the microphones, when they are used to measure sound intensity. This ensures that the sound-intensity measurements are accurate and that there is essentially no bias in determining the direction to a sound source from the direction of the sound-intensity vector.

The invention relates to a sound intensity testing bracket, which comprises a bracket base, a vertical rail, a horizontal rail and a sound intensity probe, wherein the vertical rail is vertically arranged on the bracket base; the horizontal rail is vertically arranged on the vertical rail and is arranged horizontally; and the sound intensity probe is movably arranged on the horizontal rail.

The invention discloses a sound source positioning method and system. Through the arrangement of a sound intensity sensor group in advance, specific sound sources are arranged in various testing directions with fixed intervals by taking the sound intensity sensor group as the center in sequence, and direction feature data corresponding to the specific sound sources in the various testing directions is collected; sound intensity feature data corresponding to the specific sound sources at different distances is collected to establish the attenuation characteristic of sound intensity and transmission distance; sound intensity data corresponding to a sound source to be tested is collected, the sound intensity data and the direction feature data corresponding to the testing directions are respectively subjected to correlation analysis, and the testing direction corresponding to the maximum value of correlation results is determined as the direction of the sound source to be tested; according to the sound intensity data and the attenuation characteristic, the distance between the sound source to be tested and the sound intensity sensor group is determined. The sound source positioning is realized by adoption of methods of feature matching of the sound source direction and the attenuation characteristic of the sound source distance, the implementation difficulty of sound source positioning is reduced, and meanwhile the positioning accuracy and the stability are improved.

The invention discloses a system and a method for positioning a noise source. The method comprises the following steps of: adjusting the position and focal length of a camera until a taken image comprises a region to be detected, and storing an image which is taken as a background image into an upper computer; fixing a light source on a sound intensity probe which is connected with a data acquirer; endowing the image which is taken by the camera with the color of a light source by filtering; moving the sound intensity probe, and scanning on the surface of the region to be detected at constant speed; outputting a trigger signal by a pulse signal generator, continuously taking images by the camera, recording a motion image of the light source, recording the trigger signal and an acoustic signal by the data acquirer, and synchronizing the acoustic signal and image taking time; after detection is finished, processing the image, and thus obtaining the position of the light source in a picture; extracting the acoustic signal, and thus obtaining acoustic physical quantity information at a corresponding moment; dividing the region to be detected into triangular units, wherein nodes are the positions of the light source, which are acquired at all moments, and the acquired acoustic physical quantity serves as a cloud picture measuring value; and acquiring a sound field cloud picture, and displaying the sound field cloud picture. The invention has the advantages of quick positioning, accurate measurement and high accuracy.