19 results about "Noise measurement" patented technology

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).

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.

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.

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 present application relates to a method for measuring a Noise RMS of a periodic signal and a signal-to-noise ratio of a sinusoidal signal. The technical points of the method comprise: respectively executing signal noise measurement on a target periodic digital signal and a target periodic analog signal; obtaining a series of zero-crossing points of electrical signals, performing analog-to-digital conversion once at a relative time determined by means of the series of zero-crossing points; and further calculating the noise of the periodic signals by means of a series of analog-to-digital conversion results. The method further comprises: respectively executing signal-to-noise ratio measurement on a target sinusoidal digital signal and a target sinusoidal analog signal; obtaining a series of zero-crossing points of electrical signals; according to each zero-crossing point, calculating the frequency or period of the electric signal; and then performing calculation to obtain a signal-to-noise ratio of a sinusoidal signal.

This invention relates to the field of ultrasonic water meter testing technology, specifically a low-noise measurement method for ultrasonic water meters. The method includes: controlling an ultrasonic transducer to emit a multi-cycle sinusoidal drive pulse signal with linearly increasing amplitude, stable peak plateau, and linearly decreasing amplitude; injecting this signal into a matched resonant network; generating an ultrasonic signal in the pipe fluid via acoustic coupling; and capturing the signal after propagation in both upstream and downstream directions by a receiving transducer. The received signal undergoes multi-stage analog conditioning including programmable gain amplification, bandpass filtering, and baseline restoration; and is converted into a digital echo sequence at a sampling rate ten times higher than the drive signal frequency. The sliding correlation coefficient is calculated using an adaptive matched filter with an ideal echo as a template, and the phase and frequency response of the matched template are dynamically compensated for with changes in water temperature and pressure. This method can reduce excitation noise, suppress signal interference caused by changes in operating conditions, and improve the quality of the ultrasonic water meter measurement signal.

The application discloses a kind of full digital phase noise measurement methods of millihertz level frequency resolution, belong to phase noise measurement field, the method includes: the signal to be measured is converted into digital signal, and according to the frequency control word of the digital signal generation two-way phase quadrature and no phase truncation spur digital signal, after being mixed with digital signal respectively, carry out multi-section extraction filtering, phase unwrapping, frequency offset elimination, power spectrum estimation and segmented splicing processing.The method can measure the phase noise of signal using only one ADC, the principle is simple, easy to realize the miniaturization of system;By multi-section extraction filtering, while filtering high-frequency components, the data rate after mixing can be reduced, the number of operation points required for power spectrum estimation is reduced, and the phase noise measurement of signal extremely close millihertz level frequency resolution is realized.

This invention discloses a method for determining the sound source level of an underwater moving target based on the characteristics of cross-noise curves measured by dual hydrophones. The method includes the following steps: S1, acquiring the motion noise signal of the underwater target; S2, processing the acquired noise signal and calculating the motion noise curve of the target within a specified frequency band; S3, calculating the difference between the peak values ​​of the cross-noise curves and the time difference between corresponding peak values ​​based on the acquired motion noise curves of the target; S4, calculating the radiated noise frequency band sound source level and radiated noise spectral source level of the target under the corresponding motion condition based on the acquired sound field and noise information. This invention can reduce the influence of distance measurement on noise measurement results, and the simplified measurement system improves the operability of the method.

A housing structure for millimeter wave sleep noise measurement in infants and young children comprises a hard plastic housing (1) in which a first mounting platform (2), a second mounting platform (3) and an area for mounting the radar module (4) are provided in the housing (1); in addition, a wave-matching window (5), a control switching port (6) and a charging port (7) are provided on each of the side walls of the housing (1). The described hard plastic shell (1) has a reduced-surface, box-shaped structure and provides physical protection against external damage. The first mounting platform (2) and the second mounting platform (3) serve to secure and protect the control and power supply board. The mounting zone (4) of the radar module serves to secure the millimeter wave radar module and to determine its mounting orientation. The aforementioned wavelength window (5) is located at the position of the radar module installation area (4) and serves for the normal transmission and reception of millimeter wave signals. The provided connections (6) for the switch and (7) for charging are used for power supply and configuration of the device.

This utility model relates to the field of ship vibration and noise measurement technology, specifically a ship vibration and noise measurement device, including a base plate, a shell on the top of the base plate, an acoustic duct fixed to the left end of the shell, a plurality of neodymium iron boron permanent magnet arrays at the bottom of the base plate, a shell cover on the top of the shell, a vibration damping layer slidably connected inside the shell, an electromagnetic shielding box tightly fitted inside the vibration damping layer, a partition net fixed inside the electromagnetic shielding box, a noise sensor at the left end of the partition net and fastened to the acoustic duct by bolts, a support block slidably connected in a groove at the right end of the partition net, and a vibration sensor tightly fitted inside the support block; this utility model uses an acoustic duct to transmit noise to the noise sensor, thereby ensuring the accuracy of noise measurement, and the angle between the acoustic duct and the shell is 30°, thereby avoiding airflow directly impacting the noise sensor, thus ensuring the safety of the noise sensor.

The application discloses a kind of methods for measuring antenna noise temperature, belong to antenna measurement technical field.The application includes: in antenna field installation antenna to be measured, utilize antenna servo controller to drive antenna points to clear sky, there is no shelter in front of antenna;The state parameter of spectrum analyzer is set, and the noise power density of system output is measured using the noise measurement function of spectrum analyzer;Directly calculate antenna noise temperature from the noise power density of system output measured.The measurement method of the application is simple and easy to operate, and has high popularization and application value.

Disclosed is a monitoring device. More specifically, the present invention relates to a monitoring device including a microphone array for detecting, in consideration of surrounding situations, sources of noise exceeding a threshold that may occur on outdoor roads, factories, and the like, and a noise control system using same. According to an embodiment of the present invention, a conventional CCTV camera, which is installed on a road to monitor vehicles in motion, is provided with a weather observation means and an outdoor noise measurement means, and there is an effect of detecting, by means of same, a sound source that generates noise greater than or equal to a threshold by determining surrounding conditions such as weather.

This application discloses a method and apparatus for transient stability assessment of ultra-high voltage AC transmission systems. The method includes: acquiring process noise, measurement noise, a first parameter, and measurement data; integrating and modeling to obtain a state-space equation; obtaining real-time estimates of state variables through extended Kalman filter dynamic state estimation; determining the specific location of the oscillation center after frequency extraction and linear fitting; obtaining an equivalent system through mirror simplification based on the specific location; calculating the energy function value; and comparing the energy function value with a preset stable energy threshold at the critical moment of system fault clearing to determine the transient stable state of the system. This application improves the accuracy and robustness of assessment under non-Gaussian noise scenarios, adapts to the online assessment needs of ultra-high voltage AC transmission systems, and provides technical support for the safe and stable operation of the power grid.

Methods, systems, and devices for wireless communications are described. The described techniques may enable a user equipment (UE) to allocate bits of a phase quantization based on a relative gain increase of each of a set of amplitude values. For example, the UE may identify a gain matrix that defines a gain associated with allocating quantities of bits to each amplitude value. The UE may accordingly determine, for each bit of the phase quantization, a respective amplitude value to which the UE may allocate the bit. In some examples, the UE may be configured with multiple gain matrices associated with gain increases for multiple respective noise and source distributions. The UE may therefore select the gain matrix from the multiple configured gain matrices based on one or more noise measurements of the channel.

This utility model discloses a noise measurement trolley for exhaust pipes, relating to the field of vehicle measurement technology. The exhaust pipe noise measurement trolley includes a moving platform and two positioning mechanisms. Each positioning mechanism includes a guide rail, a bracket, and a mounting assembly. The guide rail is horizontally mounted on the moving platform, the bracket is connected to the guide rail and can slide horizontally along it, and the mounting assembly is mounted on the bracket and can slide vertically along it. The mounting assembly has a mounting platform on which a noise measuring instrument for measuring exhaust pipe noise is mounted. In the two positioning mechanisms, the extension directions of the two guide rails are perpendicular to each other, and the intersection of the extension lines of the two guide rails is located outside the moving platform. The two noise measuring instruments can simultaneously measure the noise of the exhaust pipe from 45° directions on both sides, effectively avoiding errors caused by single-point measurement and improving measurement accuracy. The position adjustment process of the noise measuring instruments is simple and efficient, significantly improving measurement efficiency.

This application relates to the field of semiconductor device parameter testing technology, and discloses a semiconductor low-frequency noise measurement system adaptable to multiple types of devices, comprising a hardware measurement and software analysis subsystem. The hardware measurement subsystem includes a low-noise power supply and bias module, a dual-path device adapter, a multi-channel synchronous acquisition module, and a hierarchical adaptive preamplifier. The system superimposes a high-frequency perturbation sensing signal onto the measurement link, extracts feedback parameters to calculate the equivalent input impedance, quantizes the physical pole frequency, drives a controlled analog switch matrix to generate controlled physical zeros, and cancels additional low-pass poles caused by impedance mismatch. The dual-path device adapter synchronously extracts the mixed signal of the test channel and the common-mode leakage signal of the reference channel; the software analysis and control module reconstructs the transfer function, uses coherence coefficients to dynamically weight and fuse the physical prior and data-driven model, performs coherent subtraction and full-link inversion compensation in the complex frequency domain, and outputs a clean equivalent noise voltage spectral density sequence.

The application provides a noise measurement method and a noise measurement system, wherein the noise measurement method comprises the following steps: presetting n groups of read-out voltage signals to be read out with different amplitudes in an open-loop mode, adjusting the size of the bias current signal of an n-time direct-current superconducting quantum interference device, and obtaining corresponding read-out voltage signals; reading out the voltage noise corresponding to the n-time bias current signal in the previous step in a closed-loop locking mode, and recording the voltage noise as n groups of voltage noise signals; converting each voltage noise signal to obtain corresponding magnetic flux noise signals, and performing a preset fitting algorithm to obtain the device magnetic flux noise of the direct-current superconducting quantum interference device and the introduced noise of the magnetic flux locking read-out circuit. The application distinguishes the device magnetic flux noise of the direct-current superconducting quantum interference device and the introduced noise of the magnetic flux locking read-out circuit through the preset algorithm, thereby avoiding the problem of inaccuracy caused by regarding all the voltage noise as the device magnetic flux noise of the direct-current superconducting quantum interference device.

Biological noise measuring device which features: a principal body (1; 1A; 1B) comprising: a first noise measuring instrument (M1) configured to measure a biological noise, a housing (31) which accommodates the first noise measuring instrument (M1) and which has an opening (31h) which, in a state in which the housing (31) is pressed against the body surface (S), is closed by a body surface (S) of a living body, a second noise measuring instrument (M2) provided outside the enclosure (31) and configured to measure ambient noise of the enclosure (31), and a control (4) which causes a noise generator (8) to produce a noise in a state in which the opening (31h) in the housing (31) is not closed, which determines, based on an intensity of the noise measured by the first noise measuring instrument (M1) and an intensity of the noise measured by the second noise measuring instrument (M2), whether a relationship between a measurement sensitivity of the first noise measuring instrument (M1) and a measurement sensitivity of the second noise measuring instrument (M2) satisfies a predetermined condition or not, and which, if it is determined that the relationship does not satisfy the condition, indicates that it is unable to ensure the measurement accuracy of the biological noise, or adjusts the measurement sensitivity of the first noise measuring instrument (M1) and / or the second noise measuring instrument (M2).