97 results about "Noise measurement" patented technology

The invention relates to the technical field of noise measurement systems, in particular to a noise measurement system for a new energy tire, which comprises a tire positioning and driving unit, a sensor unit, a data acquisition and synchronization unit, a data processing unit, a data analysis unit and a man-machine interaction and display unit, the tire positioning and driving unit simulates different loads, different speeds and different road conditions of a tire by using a rack type tire positioning device, and drives the tire to rotate by using a brushless mute motor, so that a high-speed rotating effect without introducing extra mechanical noise is realized; the sensor unit is arranged on the two sides of the tire and at the position close to the ground through an acoustic sensor free field type condenser microphone array, is fixed to the suspension support through an acceleration sensor and is used for collecting vibration signals; the running states of the tire under different loads, speeds and road conditions are accurately simulated, noise data of the tire under various actual working conditions are obtained, and the measurement result is closer to the real situation.

The invention discloses a self-supervised tomographic SAR (Synthetic Aperture Radar) reconstruction method based on orthogonal subspace decomposition. According to the method, a traditional single original space is reconstructed and expanded into a Range-Null-Raw triple space collaborative learning framework, an R2R and N2N principle-based self-supervised loss function is constructed by using an orthogonal subspace decomposition characteristic of a linear measurement operator, direct mapping learning from noise measurement data to a high-quality reconstruction result is realized, and the real-time performance of a real-time reconstruction system is greatly improved, so that the real-time performance of the real-time performance of the real-time performance of the real-time performance of the real-time performance of the real-time performance of the real-time performance is improved. Observable components are learned through Range space, unobservable components are learned through Null space, a cross constraint strategy of global consistency is ensured through Raw space, and the adaptability of the model to real measurement conditions is enhanced. The performance gap between simulation training and actual deployment in deep learning TomoSAR reconstruction is effectively solved, and a new solution is provided for reliable application of an unsupervised deep reconstruction network in a real TomoSAR imaging task.

The invention relates to the technical field of servo system control, in particular to a noise measurement suppression method and device based on axial angle tracking angular position estimation. The method comprises the following steps: determining a first measurement angle after sine transformation and a second measurement angle after cosine transformation based on the first measurement angle and the second measurement angle; simplifying the first measurement angle after sine transformation and the second measurement angle after cosine transformation to obtain a simplified first measurement angle and a simplified second measurement angle; based on the simplified first measurement angle and the simplified second measurement angle, determining a representation relation between a phase discriminator tracking error of the servo system and a phase-locked loop output angle; determining an input of the servo system based on the representation relationship; determining an estimated angle value based on the input of the servo system and a preset closed-loop transfer function; and controlling the servo system based on the estimated angle value. Therefore, the control precision of the servo system can be improved.

The invention provides a noise acquisition device and a noise measurement device of an operational amplifier. The noise acquisition device comprises a preset resistor matched with a target operational amplifier, a total noise acquisition circuit and a resistance noise acquisition circuit, the total noise acquisition circuit acquires the total noise of the current working environment and amplifies the total noise so as to output the amplified total noise to external preset measurement equipment; the resistance noise acquisition circuit acquires and amplifies first noise correspondingly generated by the preset resistor in the current working environment and carries out amplification processing so as to output the amplified first noise to preset measurement equipment. The total noise and the first noise are collected, the first noise is used for compensating the total noise to obtain the noise of the target operational amplifier, and the defects that measurement cannot be conducted due to the fact that the bottom noise of the spectrum analyzer is too large and the measurement accuracy is reduced due to the first noise are overcome; low-ripple positive and negative direct-current power supply voltage is provided, and the size is small; the spatial noise coupling interference is reduced, and the accuracy is improved.

The application discloses a time difference positioning method based on random robust least square, mainly solves the threshold effect of the existing time difference positioning method when the measurement error increases, and leads to the problem of sharp deterioration of positioning accuracy, and the implementation scheme is as follows: a plurality of observation stations and noise measurement errors are set, the time difference positioning equation is obtained by using the position parameters and the measurement errors, an auxiliary variable is defined, the auxiliary variable is introduced into the time difference positioning equation to establish a constraint equation, the constraint equation is processed by using a random robust least square method to obtain a cost function, the cost function is solved by using a least square method to obtain a target position, a new constraint equation is established according to the internal relation of the auxiliary variable elements, the new constraint equation is solved by using a weighted least square method to obtain a positioning error, the target position is linearly corrected by using the positioning error to obtain a final positioning result, and the target positioning is completed. The application reduces the positioning error, improves the positioning accuracy and the robustness of positioning, and can be used in aerospace, navigation and electronic warfare.

The application provides a kind of transport aircraft cabin top structure noise multi-point measurement method under flight full working condition, and belongs to the technical field of aircraft noise testing.The application uses cargo compartment lifting slide rail as existing installation datum, and forms adjustable measurement point layout structure by telescopic cross bar device and height adjusting lifting rod, so that fast installation, stable fixation and spatial positioning of noise testing sensor in the top area of transport aircraft cabin can be realized without damaging original structure of aircraft body.The application can execute multi-point noise measurement of complex environment in the top area of aircraft cabin without changing original structure of transport aircraft, so that sensor can be stably and reliably installed in flight vibration environment, and effective coverage and accurate identification of key noise area in the top area can be realized.

The present invention relates to a sensor device for attachment to an equipment shell, the device comprising a casing (1) configured for attachment to an equipment shell by means of a fastening system comprising a bushing (4) with a cylindrical part internal to the casing and a flange part (4a) configured to contact the equipment shell when the device is attached to it, the casing (1) housing a plurality of sensors for measuring data related to the operating condition of the equipment, at least one processor configured to receive the data measured by the sensors; and at least one means of wireless communication for communication with a server remote to the device, in which the casing (1) comprises a casing body (2), which receives, at one end, a printed circuit board (11) which receives an acoustic sensor (12) for structural noise measurement, the printed circuit board (11) being in contact with the flange part (4a) of the bushing (4).

A hearing protection device to be worn in ear provides communications of ambient sound to an in-ear speaker. Blast noise is detected and measured using either the in-ear speaker as a microphone or using a separate in-ear microphone.

The utility model relates to the technical field of measuring devices, in particular to a noise measuring device with a telescopic function, which comprises a fixed cylinder, a dustproof cloth bag is sleeved on the outer side of the fixed cylinder, an elastic rubber belt is fixedly connected on the outer side of the dustproof cloth bag, a pair of magnetic blocks is fixedly connected on the outer side of the elastic rubber belt, and the magnetic blocks are fixed on the fixed cylinder. A sliding rod is slidably connected to the side face of the inner wall of the fixing cylinder, a sliding rod is fixedly connected to one end of the sliding rod, and a telescopic assembly is arranged in the fixing cylinder. According to the noise meter, the micro motor, the winding roller, the traction rope, the sliding rod and the spring are arranged in a matched mode, automatic shrinkage of the noise meter body is achieved through take-up and pay-off of the winding roller, and through matched arrangement of the dustproof cloth bag, the magnetic block and the elastic rubber belt, when the noise meter body is shrunk to the position closest to the fixing cylinder, the noise meter body is prevented from falling off. The noise meter body is wrapped and protected through the dustproof cloth bag.

The invention discloses a heat recovery fresh air handling unit noise measurement auxiliary device and a test method thereof.The auxiliary device comprises a noise elimination cover and a noise elimination air pipe, the noise elimination cover is defined by noise elimination walls, an inner groove is formed in the lower face of the noise elimination cover, mounting holes are formed in the two ends of the inner groove respectively, and the mounting holes communicate with the interior and the exterior of the noise elimination cover; a silencing air pipe is arranged corresponding to each mounting hole, one end of each silencing air pipe is located in the corresponding inner groove and used for being connected with a heat recovery fresh air handling unit, the other end of each silencing air pipe penetrates into the silencing cover through the corresponding mounting hole, and a static pressure ring is arranged at the end, connected with the heat recovery fresh air handling unit, of each silencing air pipe and connected with a digital micromanometer. An electric air valve is arranged at the end, penetrating into the silencing cover, of each silencing air pipe. According to the testing method, the heat recovery fresh air handling unit is hoisted in the semi-anechoic chamber through the auxiliary device to be tested. The structure of the original semi-anechoic chamber cannot be damaged through the auxiliary test, and the test cost is reduced.

The invention relates to a noise measurement method and device, electronic equipment and a storage medium, and the method comprises the steps: generating a noise measurement task based on pre-recorded noise data and to-be-measured site information; arranging a plurality of noise measurement recording devices based on the noise measurement task, and collecting audio data by using the plurality of noise measurement recording devices; judging whether target audio data exists in the audio data based on the pre-recorded noise data; and based on a preset storage mode, storing the target audio data while storing the audio data so as to perform noise data analysis by using the audio data and / or the target audio data. Therefore, the technical problems that different noise targets are difficult to distinguish and accurate analysis and comparison are difficult to carry out when the environmental noise is collected in the prior art are solved.

To provide an EMC countermeasure presentation system capable of efficiently extracting and presenting an emission countermeasure case in another field and another model with high similarity (countermeasure effectiveness) in consideration of a device configuration of an electronic apparatus.SOLUTION: A similar configuration extraction unit 3 configured to extract, based on device configuration data 11 at the time of noise measurement, device configuration data at a short distance by configuration learning data 9 obtained by learning a graph model representing a device configuration when the noise countermeasure and reduction amount frequency data is acquired; and a countermeasure estimation unit 4 configured to estimate, from data obtained from the reduction countermeasure extraction unit and the similar configuration extraction unit, a recommended countermeasure content having a high degree of similarity of a device connection configuration and expected to have an excessive noise reduction effect.SELECTED DRAWING: Figure 1

The invention discloses a measuring system with a front transmitting power amplifier and a measuring method, and relates to the technical field of noise measurement. By arranging the noise measurement assembly and the measurement rod assembly, the noise measurement assembly can simulate a profiling measurement motion trail according to the outer contour shape of the transformer through an adjustable profiling rod and guide wheel structure, so that a guide wheel is always in contact with the outer wall of the transformer, and elastic adjustment of a spring is matched; a preset stable detection distance can be kept between the measurement end of the measurement assembly and the outer wall of the transformer, and the adaptive capacity of dynamically adjusting the position of the noise measurement mechanism according to the shape of the outline of the transformer avoids errors caused by large-range fluctuation of a traditional measurement distance, so that the precision of multi-point measurement data is remarkably improved; and the noise measuring mechanism is internally provided with a front transmission power amplifier, so that the acquisition capability of weak noise signals can be enhanced, the method is particularly suitable for fine detection of a low-noise transformer, and the signal acquisition definition is improved.

The present disclosure relates to test and / or measurement system including a base unit with a test ports connectable to a DUT. The base unit includes a port unit connected to one of the test ports. The port unit includes an image-free receiver circuit. An input of the circuit is connected to the one test port. The system includes an ADC unit. An output of the circuit is connected to the ADC unit. A signal source generates a stimulus signal and / or a known noise source to generate a noise signal. If the system operates in an S-parameter measurement mode, the stimulus signal is feedable to a first port of the DUT; and / or, if the system operates in a noise measurement mode, the noise signal is feedable to the first port or to a second port of the DUT. The input connects to the first or second port of the DUT.

The present application relates to a kind of acoustic wind tunnel inside helicopter rotor sound radiation sphere measurement and inversion reconstruction method, it is related to helicopter aerodynamic acoustics wind tunnel test technology and acoustic target characteristic technical field, include: in acoustic wind tunnel using hemispherical far-field noise measuring device measurement helicopter rotor radiated noise, obtain the noise signal of different azimuth of rotor and construct rotor sound radiation sphere model;Based on the sound propagation theory in flow field, construct the propagation model of the surface of sound radiation sphere model to microphone position, and based on the influence of background noise, establish the sound propagation equation of the surface of sound radiation sphere model to microphone in hemispherical far-field noise measuring device;Sound propagation equation is converted to solve least square problem, and the sound source distribution of the surface of sound radiation sphere model is obtained, and the noise of helicopter rotor far field arbitrary position is reconstructed.Can be applied to in acoustic wind tunnel, high background noise and other complex environments reconstruct helicopter rotor sound radiation sphere, carry out practical research and application.

Whistling / wheezing detection device (1) for detecting whistling / wheezing based on a sound measured from a living body while the whistling / wheezing detection device (1) is in contact with a body surface (S) of the living body, wherein the whistling / wheezing detection device (1) comprises the following: a noise measuring element (M1, M2); a space-forming element (30, 33, 34, 35, 350) that forms a recording space (SP1) which accommodates the noise measurement element (M1, M2); and a cover element (36) that forms a pressure receiving unit (3a) which closes the receiving chamber (SP1) and receives pressure from the body surface (S), wherein the space-forming element (30, 33, 34, 35, 350) has a hole section (40) that is connected to an atmosphere, the recording chamber (SP1) is connected to the atmosphere via the hole section (40), and the hole section (40) includes a branching section (BR1 to BR3) between an inlet (41) on one side of the receiving space (SP1) and an outlet (49) on one side of the atmosphere and two branched hole sections (44, 46) that branch off from one side of the inlet at the branching section (BR1 to BR3), one branched hole section (46) of the two branched hole sections (44, 46) is connected to the outlet (49) and the other branched hole section (44) of the two branched hole sections is closed.

The invention discloses a system and a method for measuring celestial body radiation noise based on an idle channel of a GNSS (Global Navigation Satellite System) receiver, relates to the crossing field of satellite navigation and radio astronomy detection, fully utilizes the idle channel in the receiver, realizes function expansion through firmware and algorithm upgrading, and does not need to add radio frequency hardware. This means that the idle channel and the navigation channel share the same radio frequency link in the links of the antenna, the feeder line, the low noise amplifier, the down-conversion and the like, so that the noise measurement result is consistent with the real observation condition. The deep fusion of navigation and scientific detection is realized, the baseband output is converted into a real-time radio radiation detector through statistical analysis, and the time sequence data of the equivalent noise temperature of the antenna can be continuously acquired. The data can be directly used for tasks such as sun storm monitoring, moon brightness temperature measurement, space background radiation change analysis and the like, and a real-time data source is provided for radio astronomy, space weather monitoring and planetary scientific detection.

The invention discloses a phase noise measurement method and system based on a frequency spectrograph, and relates to the technical field of communication measurement instruments and meters, and the method comprises the steps: obtaining ADC data, carrying out the digital down-conversion and decimation filtering of the ADC data, obtaining IQ baseband data, carrying out the digital phase demodulation of the IQ baseband data, and obtaining phase change data; performing frequency difference estimation on the phase change data to obtain a frequency difference estimation result, and performing frequency difference compensation on the phase change data to obtain compensated phase change data; extracting the compensated phase change data to obtain phase fluctuation data, and performing FFT (Fast Fourier Transform) operation to obtain phase noise original data; carrying out self frequency mixing operation on the IQ baseband data to obtain amplitude modulation noise original data; and performing spectrum estimation processing on the phase noise original data and the amplitude modulation noise original data, and then performing stray elimination and smoothing processing to obtain a final phase noise measurement value and an amplitude modulation noise measurement value.

The application discloses a ship radiation noise measuring system and a double-layer cylindrical array measuring device, wherein the cylindrical array measuring device comprises a circular bottom support plate, a circular top support plate, a support pipe, a group of hydrophone oscillators, a ranging transducer, a support base and an electronic cabin; opposite ends of the support pipe are respectively installed in the middle of the bottom support plate and the middle of the top support plate; opposite ends of the hydrophone oscillators are respectively installed in the circumferences of the bottom support plate and the top support plate; the ranging transducer is installed on the top support plate; the support base is installed below the bottom support plate; the electronic cabin is installed below the bottom support plate and is surrounded by the support base; and each hydrophone oscillator is connected to the electronic cabin.

In order to facilitate the disposition of multiple noise measuring points in a distributed manner, this underwater noise monitoring device is provide with: a processing unit in which, by using data which was acquired using optical fibers installed underwater or on a bottom of water and which indicates noise or vibration at the position of each of the optical fibers, a statistical value of the amount of noise or vibration is derived at the time and the place when / where the data was acquired; and an output unit that outputs the statistical value.

Systems and methods for GNSS interference monitoring are provided. In certain embodiments, a system includes at least one GNSS receiver configured to receive a plurality of signals from a plurality of satellites and provide measurements from the plurality of satellites; and a processor coupled to the at least one GNSS receiver. Further, the processor is configured to calculate a detection parameter that comprises at least one of a composite detection parameter based on a short-term average and a long-term average of carrier-to-noise measurements for the plurality of signals; and a transient detection parameter based on an average difference for the plurality of satellites between the short-term average and long-term average of the carrier-to-noise measurements for each satellite in the plurality of satellites. The processor is also configured to determine a state of the plurality of signals based on a comparison of the composite detection parameter against a comparison threshold.

The invention discloses a system for obtaining the annual statistical value of the corona effect of a high-altitude AC power transmission line through quarterly observation, and the system comprises an audible noise measurement device which comprises at least one outdoor microphone disposed at a preset position, and an analyzer; the radio interference measuring device comprises an antenna and a receiver which are arranged at preset positions of the power transmission line; the meteorological equipment is used for measuring and distinguishing weather and rainy days; the computer is in communication connection with the audible noise measuring device, the radio interference measuring device and the meteorological equipment, and is used for synchronously controlling the start and stop of the equipment and collecting and storing data; wherein the audible noise measurement device, the radio interference measurement device and the meteorological equipment form an all-weather synchronous measurement system which is configured to acquire data through synchronous observation of three consecutive months in autumn, and the data are classified and counted by the computer according to weather conditions; and obtaining a rainy day audible noise L50 value capable of representing a year-round statistical result, and a radio interference average value in rainy days and good weather.

This invention provides an experimental system and method for synchronously measuring the flow field and noise inside a pipe by eliminating optical distortion. The system includes: an optical distortion elimination loop, which includes a first one-way valve, a NaI solution calibration device, a heat exchange module, and a circulating water pump; an experimental pipe section, which is equipped with a second one-way valve, a flow meter, and a flow control valve; a PIV flow field measurement module, which includes a laser and two high-speed cameras; a noise measurement module, which is used to acquire noise data of the pipe components under test; a synchronizer, which is connected to the laser, high-speed cameras, and noise measurement module; and a computer, which is connected to the PIV flow field measurement module, the noise measurement module, and the synchronizer via a signal transmission line. By eliminating optical distortion inside the pipe through the distortion elimination loop, accurate identification of the flow mechanism is achieved, and a high degree of synchronization between flow behavior and sound pressure fluctuations on both temporal and spatial scales is realized.

The application discloses a ship radiated noise power spectrum measurement method based on frequency difference beam forming, comprising the following steps: obtaining a to-be-measured radiated noise signal received by a base array; constructing a difference frequency signal through the conjugate product of the to-be-measured radiated noise signal and a reference frequency signal; performing beam forming on the constructed difference frequency signal based on the difference frequency, and calculating the amplitude of the beam output signal of the difference frequency signal; correcting the amplitude of the beam output signal of the difference frequency signal by using the amplitude of the reference frequency signal to obtain the amplitude of the to-be-measured radiated noise signal, and calculating the power spectrum of the to-be-measured radiated noise signal. The application converts the signal outside the design frequency band of the base array to the inside of the design frequency band to perform beam forming, improves the array gain, better suppresses the environmental noise, improves the measurement performance of the base array on the radiated noise outside the design frequency band, greatly expands the frequency band width of the ship radiated noise measurement, and can realize the measurement of the radiated noise with a larger bandwidth by using a smaller aperture array.

A noise evaluation facility (100) is provided with a winding unit (12), a noise measurement device (20), and a vibration measurement device (30). The winding unit (12) is attached to a magnetic core (11) as a target to be evaluated. The noise measurement device (20) includes a microphone (21). The microphone (21) is disposed at a position facing a measurement surface (13) of a measurement object (10) including the magnetic core (11) and the winding unit (12). The noise measurement device (20) is configured to measure noise generated from the object (10) to be measured. The vibration measurement device (30) is configured to measure the vibration of the measurement surface (13) in a direction intersecting the measurement surface (13).

The application provides an engine noise active synthesis and optimization system and method, relates to the technical field of internal combustion engine noise, vibration and sound roughness control, and comprises the following modules: a path inversion modeling module based on working condition sensing, which obtains component structure sound transfer functions and air sound transfer functions; an engine noise measurement module, which obtains target point measured noise; a path joint mapping identification module, which inversely calculates component structure sound contribution and air sound contribution; a noise active synthesis module, which vector superimposes the contribution to obtain synthesized noise; and a synthesized noise judgment module, which compares and verifies the synthesized noise and the measured noise, and corrects the transfer function through regularization processing until the accuracy requirement is met when the deviation is greater than the threshold. Through double-path synchronous inversion modeling and regularization correction, the application realizes noise contribution quantization and active synthesis, quickly screens and optimizes the scheme in combination with the virtual path breaking technology, and solves the problems of insufficient noise recognition accuracy, long development cycle and poor optimization effect.

The utility model provides a height-adjustable noise measuring instrument, which relates to the technical field of noise measurement, and comprises a bottom plate, the top of the bottom plate is fixedly connected with a mounting rack, the inner side of the mounting rack is rotatably connected with a lifting assembly, and the outer side of the lifting assembly is fixedly connected with a clamping assembly; according to the height-adjustable noise measuring instrument, the pull rod is pulled to drive the clamping tooth block to move, so that limitation on the circular gear is relieved, the rack is pushed to enable the sliding block to drive the rack to move in the sliding groove, the rack is attached to the measuring instrument body to clamp the measuring instrument body, and the height of the measuring instrument is adjusted. The pull rod is loosened, so that the spring drives the pull rod to reset, the clamping tooth block limits the gear, the rack is prevented from deviating due to the influence of external force, shaking caused by the influence of wind power at a high position can be prevented, shaking can be prevented by clamping the measuring instrument body during height adjustment, and the safety is improved.

The application discloses a line noise measurement method and device, and belongs to the technical field of noise measurement. In the line noise measurement method, a bridge circuit is formed by using a first adjustable resistor, a second adjustable resistor, a first fixed resistor and a second fixed resistor, the first fixed resistor and / or the second fixed resistor is connected with a line to be measured, a bridge signal output by the bridge circuit is detected through a reference signal, a first noise spectrum containing thermal noise of the first fixed resistor and the second fixed resistor is obtained, and then the first noise spectrum is processed according to a theoretical value of the thermal noise of the first fixed resistor and the second fixed resistor, so that the line noise of the line to be measured is determined. The measurement method can accurately measure the line noise, and is beneficial to accurate evaluation of line performance.

The application discloses a noise power level determination method and device, a storage medium and a computer device. The method comprises the following steps: controlling the joint movement of a robot, and recording corresponding robot noise audio; determining the noise energy corresponding to each joint when the joints move respectively according to the robot noise audio; and determining the overall noise power level of the robot according to the noise energy. The application solves the technical problem of low overall noise measurement efficiency of the robot.

The invention discloses a high-orbit SAR on-orbit noise measurement method. The method comprises the following steps: 1, adjusting the beam direction of a satellite antenna to enable the beam direction of the satellite antenna to point to cold air; 2, a lower computer of an SAR load subsystem radar receives an SAR work instruction packet sent by a satellite data management subsystem and injects the SAR work instruction packet into a central control processor; 3, the central control processor sets working parameters of the SAR load receiving single machine according to the SAR working instruction packet; the central control processor does not output a transmitted waveform; and 4, after a cold air noise signal received by the satellite antenna is amplified, AD acquisition and processing are carried out by a central control processor of the SAR load subsystem radar, the processed calibration data are combined and packaged according to a preset format, a data stream is formed and then transmitted to a data transmission system, and the data transmission system transmits the data stream to the satellite antenna. And after the data transmission system issues the data to the ground, a high-orbit SAR on-orbit noise measurement result is obtained. According to the method, the measurement precision of the on-orbit noise of the SAR system can be greatly improved.