42 results about "Comb filter" patented technology

The invention discloses a high-order digital decimation filter with a variable decimation multiple, which comprises a cascade comb filter used for downsampling and anti-aliasing filtering, filtering high-frequency components and obtaining low-frequency density signals, and a compensation filter connected to the output end of the cascade comb filter and used for compensating passband attenuation and performing double decimation on the signals, and the output end of the compensation filter is connected with a half-band filter for realizing third-stage signal extraction. The invention further discloses a filtering method of the high-order digital decimation filter with the variable decimation multiple. Aiming at the defects that a traditional single-stage FIR filter is high in hardware requirement, complex in design, high in filter order and not easy to implement and the like, and aiming at the defect that a CIC filter is insufficient in passband flatness, a CFIR compensation filter is used for compensation, and finally a half-band filter is used for frequency reduction.

The invention relates to the technical field of data acquisition, in particular to a data acquisition method and system for a high-low voltage transformer substation. The method comprises the following steps: acquiring an original electrical signal sequence, calculating an initial integer sampling point number based on a zero crossing point interval, determining a fundamental wave period by carrying out autocorrelation operation on the original electrical signal sequence in a preset window taking the fundamental wave period as a center, and obtaining a signal after primary filtering by adopting first comb filtering taking the fundamental wave period as a delay parameter; and performing short-time Fourier transform on the signal after primary filtering, forming a non-integer harmonic frequency point set in a preset non-harmonic frequency band, constructing a second filtering link according to the non-integer harmonic frequency point set, and filtering non-integer harmonics in the signal after primary filtering to obtain collected data. According to the scheme, the fundamental wave period can be accurately determined to deeply suppress the integer harmonics, the non-integer harmonics can be recognized and filtered out in the environment with the low signal-to-noise ratio, and meanwhile original signal damage is avoided.

The invention provides a digital filter, a parameter configuration method and a chip. The digital filter comprises a multi-order sinc filter and a multi-order comb filter which are connected, the order N and the down-sampling rate of the multi-order sinc filter, the order b of the multi-order comb filter and a plurality of corresponding weight coefficients are pre-determined and configured according to the frequency to be filtered; the multi-order sinc filter receives the coded signal, samples the coded signal for N times according to a preset down-sampling rate, and calculates an average value of each sampling result to obtain an average value signal; the multi-order comb filter performs weighting operation on the mean value signal through the first signal processing unit, the second signal processing unit and the corresponding weight coefficients, and sums the mean value signal through the accumulator to obtain an output signal; the output signal is a coded signal after the signal with the frequency to be filtered is filtered. The parameters of the digital filter are flexibly configured based on different application scenes.

The invention provides a tumor in-situ pathology detection system based on an endoscopic multi-mode probe. The tumor in-situ pathology detection system comprises a main controller, an SC laser, a DUV laser, a comb filter, a polarizer, a microarray lens, a multiplexing beam combiner, a conjugate coupling module, an endoscopic optical fiber bundle, a FAST optical fiber bundle, an SC spectrograph and a DUV spectrograph. Aiming at G14-level bronchial navigation surgical robot in-situ pathology detection, the invention provides a detection system based on an endoscopic multi-mode optical probe, FAST hyperspectral image spectrum integrated detection of SC, DUVRS, DUVLIF and mIHC can be realized, a multi-mode hyperspectral fusion image reflecting spatial distribution of histochemical components of a diagnosis point and corresponding spectral feature data are output, and the detection system is used for detecting the in-situ pathology of the G14-level bronchial navigation surgical robot. And real-time, accurate and multi-mode data or information is provided for diagnosis of doctors.

The invention relates to a method for reducing the bias in a periodic signal having a theoretically zero mean value and provided by a sensor associated with a rotary electric machine, in particular by a sensor for determining the angular position of a rotor of a rotary electric machine, the method comprising: - receiving the signal provided by the sensor; - multiplying this signal by a signal proportional to the rotational speed of the rotor of the rotary electric machine in order to obtain a first signal; - at least one integration over half a period of the first signal in order to obtain a second signal; - applying, to the second signal, a finite impulse response filter, in particular a comb filter, so as to add, to the second signal, a delayed version of this second signal in order to obtain a third signal representative of the bias, in particular equal to the bias of the signal provided by the sensor; and - subtracting the third signal from the signal provided by the sensor, so as to reduce the bias in this signal provided by the sensor.

A method operates a hearing aid, in particular a classic hearing aid. The hearing aid includes an input transducer, a signal processing device, and an output transducer. Wherein an occurrence of a comb filter effect is determined by the signal processing device, and wherein a countermeasure is controlled by the signal processing device as a function of the determined occurrence of the comb filter effect.

The invention relates to the technical field of railway electric traction transmission, in particular to an irregular wheel wear detection method based on stator current analysis, which comprises the following steps of: constructing an electromechanical coupling model of a high-speed train traction transmission system based on a traction variable-current driving model and a train-track coupling power model; secondly, based on an electromechanical coupling model, the influence of irregular wear of the wheel on electrical parameters in an electric driving system is analyzed, and the frequency relation between irregular wear excitation and the electrical parameters (stator harmonic current) is established; and by constructing a comb filter based on variable mode decomposition, accurate capture of wheel wear related harmonic waves in stator current is realized, so that irregular wear of the wheel is detected, additional installation of a sensor is not needed, the cost is low, the method is not liable to be interfered by the external environment, and the method has relatively good engineering applicability.

The application relates to a digital wave trap, a digital low-pass filter and a design method, a medium and an electronic device. The digital wave trap comprises a wave limit boundary anchoring unit and a wave limit zero point modulation unit which are cascaded in sequence, the wave limit boundary anchoring unit adopts a cascaded integral comb filter structure and is used for generating a first attenuation zero point at a boundary frequency of a target wave trap frequency band; the wave limit zero point modulation unit adopts a finite-length unit impulse response filter structure and is used for generating at least one second attenuation zero point in the target wave trap frequency band; and a continuous suppression band for the target wave trap frequency band is formed in the amplitude-frequency response of an output signal of the wave limit zero point modulation unit by the first attenuation zero point and the at least one second attenuation zero point. By using the digital wave trap provided by the application, a digital low-pass filter which can deeply and widely suppress power frequency interference and maintain strict linear phase and excellent low-pass characteristics can be designed without significantly increasing hardware resources and power consumption.

The invention relates to underwater acoustic signal processing, in particular to a low signal-to-noise ratio underwater acoustic line spectrum enhancement system based on deep learning, which comprises a learnable comb filter module, and is characterized in that a series of learnable multi-channel comb filters with fixed frequency are constructed through a convolutional layer to scan input signals, enhance target frequency and attenuate non-target frequency; the channel fusion module is used for carrying out feature extraction and feature fusion on the output signal of the multi-channel comb filter; the frequency estimation module is used for identifying the line spectrum component of the target frequency from the feature map output by the channel fusion module, screening the frequency bin by introducing a learnable threshold parameter, and generating a frequency index of each frame; the mask enhancement module is used for carrying out adaptive filtering on the input signal by utilizing the frequency index sequence output by the frequency estimation module; according to the technical scheme provided by the invention, the defect of insufficient line spectrum enhancement capability in a complex ocean noise environment in the prior art can be effectively overcome.

A method for reducing bias in a periodic signal with a theoretically zero average value provided by a sensor associated with a rotating electrical machine, in particular by a sensor for determining the angular position of a rotating electrical machine rotor, the method comprising: - receiving the signal provided by the sensor - multiplying this signal by a signal proportional to the rotational speed of the rotating electrical machine rotor to obtain a first signal - at least one integration over half a period of the first signal to obtain a second signal - applying a finite impulse response filter to the second signal, in particular a comb filter, to add a delayed version of this second signal to obtain a third signal representative of the bias, in particular equal to the bias of the signal provided by the sensor, and - subtracting the third signal from the signal provided by the sensor.in order to reduce the bias of this signal provided by the sensor. Abbreviated figure: Fig 3,

The invention discloses a body feeling myoelectricity artificial hand system fusing myoelectricity enhanced decoding and bionic electrical stimulation feedback. The system comprises a myoelectricity bracelet, a main controller, an electrical stimulator and an artificial hand. According to the system, an electromyographic bracelet is used for collecting residual limb side electromyographic signals, a main controller removes electrical stimulation artifacts in the signals in real time through a comb filtering and self-adaptive filtering series algorithm, gesture intentions are recognized online through a self-updating multi-class LDA algorithm, and the prosthetic hand is driven to execute corresponding actions. According to the system, a closed-loop feedback mechanism based on a muscle shuttle sensing model is constructed, the muscle shuttle sensing model simulates neural coding characteristics of a human body muscle shuttle, the real-time stroke of a micro servo electric cylinder of the prosthetic hand and stress information of a torque sensor are mapped into electrical stimulation frequency and voltage parameters respectively, and an electrical stimulator is controlled to apply bionic stimulation to the stump. According to the invention, closed-loop control of myoelectricity intention recognition, artificial limb action execution, state detection and electrical stimulation feedback is realized, the problems of lack of sensory feedback, serious electrical stimulation signal interference and the like of the existing myoelectricity artificial limb are effectively solved, a patient is helped to reconstruct ontology perception, and the accuracy and naturalness of artificial limb control are improved.

The utility model relates to the technical field of optical communication, in particular to an optical filter and optical communication equipment. The optical filter comprises a first polarization output assembly used for converting input light input from a first side into single polarized light and outputting the single polarized light, and the single polarized light has a target polarization direction; the polarizing beam splitter is located on the second side of the first polarization output assembly, the second side is opposite to the first side, and the polarizing beam splitter can transmit light in the target polarization direction and reflect light in other polarization directions; and the two comb filters are respectively positioned in two mutually vertical light emitting directions of the polarizing beam splitter, the filtering wavelength of each comb filter is adjustable, and each comb filter comprises a G-T resonant cavity. The optical filter provided by the utility model is simple in optical path and compact in structure, facilitates reduction of optical loss in an optical system, and is also easy to maintain and adjust.

The application discloses a device for realizing low-frequency wideband sound absorption of a small-space acoustic test box, which comprises a box body, and a composite sound absorption layer is arranged on the inner wall of the box body, characterized in that the composite sound absorption layer comprises multiple air layers for sequentially propagating sound, a micro-slit plate is arranged on the sound input side of each air layer, and a porous sound absorption material and a bottom closed flat plate are arranged on the sound output side of the air layer for finally propagating sound. The size of the small-space acoustic test box is optimized by calculating the normal frequency distribution, the degeneration of low-frequency vibration modes is avoided, and the irregular distribution of low-frequency normal vibration mode frequencies is optimized. The low-frequency sound dyeing and comb filter effect in the small-space acoustic test box are reduced, and a high-fidelity sound test signal acquisition environment is realized.

This application discloses an adaptive cancellation method and system for stator partial discharge signals to eliminate rotating excitation interference, belonging to the field of generator online monitoring technology. The method includes: determining the fundamental frequency and harmonic frequencies of the excitation interference at the current moment based on a synchronization reference signal to construct an interference frequency set; constructing an adaptive comb filter using the interference frequency set to filter the original partial discharge signal, obtaining a comb-filtered signal; performing a time-frequency transformation on the comb-filtered signal to obtain a time-frequency spectrum and identifying the time-frequency region corresponding to the interference frequency set, constructing an adaptive time-frequency masking template based on the time-frequency region, and masking the time-frequency spectrum using the adaptive time-frequency masking template to obtain a masked time-frequency spectrum; and performing an inverse time-frequency transformation on the masked time-frequency spectrum to obtain a partial discharge pulse signal that suppresses excitation interference. This invention can solve the technical problem of strong rotating excitation interference in generator partial discharge monitoring in existing technologies.

To reduce comb filtering in the ipsilateral when rendering binaural audio from plural virtual speakers on, for example, headphones, the ipsilateral delays of the ITDs of the respective speakers can be reduced to zero and the contralateral delays increased to maintain the same temporal length of the ITDs, shifting the delays to the less important contralateral ear.

The application provides a communication antenna steering control system and method, and relates to the technical field of antenna control, and comprises the following: a parameter configuration module, which is used for acquiring the initial state of a communication antenna and collecting hardware state information in real time; a signal capture and tracking module, which is used for configuring the initial frequency of a digital control oscillator, starting a parallel correlator group to scan the carrier frequency, and calculating frequency domain power spectrum data; and an angle calculation module, which maps the resampling phase difference and baseline parameters to an azimuth angle based on quaternion solution, and superimposes IMU angular velocity data for dynamic compensation. The application realizes high sensitivity capture of signals in a wide frequency band by adopting a multi-stage phase-locked loop architecture, a dynamic threshold adaptive algorithm, a cascaded frequency division coefficient compensation and a FIR comb filter; greatly reduces the phase lag of a steering engine system by fusing extended Kalman filtering and mechanical hysteresis compensation algorithms; and makes the system still maintain high pointing accuracy in a dynamic scene by combining real-time fusion of IMU angular velocity.

The embodiment of the invention provides an interpolation filter circuit, a circuit module and a chip, the interpolation filter circuit comprises a compensation filter and an integrator comb filter, the compensation filter is used for carrying out first interpolation processing on an input signal of the interpolation filter circuit, and the integrator comb filter is used for carrying out second interpolation processing on the input signal of the interpolation filter circuit; a first interpolation result is obtained and input to the integrator comb filter; and the integrator comb filter is used for performing second interpolation processing on the first interpolation result to obtain a second interpolation result, and taking the second interpolation result as an output signal of the interpolation filter circuit. Therefore, the circuit complexity and the cost can be reduced.

The application discloses a combustion fault alarm method of a gas turbine, and belongs to the technical field of gas turbine fault detection. The method comprises the following steps: obtaining combustion pressure data of the gas turbine; inputting the combustion pressure data of the gas turbine into a pre-constructed pressure feature monitoring model to output a pressure feature monitoring result; inputting the pressure feature monitoring result into a pre-constructed combustion state prediction model, comparing the pressure feature monitoring result with a pre-set health threshold, and outputting a combustion fault result; and generating a fault alarm result according to the combustion fault result; wherein the construction of the pressure feature monitoring model comprises the following steps: obtaining a comb filter; adding an adaptive notch filter after a band-pass filter in the comb filter to obtain the pressure feature monitoring model; and the band-pass filter is an empirical guide multi-band band-pass filter. The application can improve the feature monitoring precision and reliability of the combustion process of the gas turbine, and ensure the stable operation of the combustion system.

The application discloses a heart rate extraction method based on an adaptive comb filter. The method comprises the following steps: 1, obtaining a life signal by processing a radar echo; 2, extracting a breathing rate and other features therefrom, and initializing parameters of the filter; 3, designing an ALE module for evaluating a filtering effect, and initializing parameters of the module; 4, passing the life signal through the adaptive comb filter, and iterating until the parameters to be optimized are basically converged; and 5, selecting a heartbeat frequency from a spectrum of an output signal of the life signal through the filter. The heart rate extraction method based on the adaptive comb filter considers the intermodulation characteristics of breathing and heart rate components of the life signal in a Doppler radar system, and effectively reduces the interference of breathing and higher harmonics on the selection of the heart rate. The experimental results show that when the higher harmonics of breathing in the life signal affect the measurement of the heart rate, the adaptive comb filter can accurately measure the heart rate of a person to be measured.

This invention provides an on-board quantitative diagnostic method for wheel polygons based on frequency response functions, belonging to the field of rail transit technology. This method first utilizes comb filtering to remove the influence of rail roughness, leaving a "purer" wheel polygon response component. Then, it uses the frequency response function to consider and correct the influence of the structure's inherent modes, thereby quantitatively diagnosing the polygon order and roughness level from the axle box vibration signal. This invention solves the problem of wheel and rail roughness vibration components being mixed in the axle box vibration response, leading to misjudgments between the wheel and rail during diagnosis, and the difficulty in quantitatively assessing wheel roughness in on-board wheel polygon detection methods.

The application discloses a power grid voltage sag detection method based on improved discrete Fourier transform and belongs to the field of power quality detection. f (z), a resonator and an adjustment factor G a (z), so as to obtain a phase signal of a positive sequence fundamental component; S3: the module length of the phase signal of the positive sequence fundamental component is calculated, so as to obtain the amplitude of the positive sequence fundamental voltage; after the amplitude is compared with a power grid voltage sag detection threshold, whether the power grid voltage is sagged can be judged. The algorithm can realize accurate detection of the power grid voltage sag event under the non-ideal power grid condition of harmonic distortion and three-phase voltage imbalance.

This invention discloses a planar waveguide speaker with controllable directivity, comprising a speaker body. The speaker body is characterized by having a waveguide horn containing at least one sound outlet cavity. The inner surface of the sound outlet cavity includes two opposing parabolic arc surfaces and two opposing planes. By eliminating excessive transmission paths, sound pressure loss is reduced. Simultaneously, by modifying a portion of the waveguide horn's internal shape to a parabolic shape, the waveguide horn can generate cylindrical waves, improving harmful sound interference within the horn and between horns, and avoiding comb filtering in the audience's listening area.

The present application relates to underwater acoustic signal processing, and in particular to a low signal-to-noise ratio underwater acoustic spectrum enhancement system based on deep learning, a learnable comb filter module, a series of frequency-fixed learnable multi-channel comb filters are constructed through a convolution layer to scan the input signal, enhance the target frequency and attenuate the non-target frequency; a channel fusion module, feature extraction and feature fusion are performed on the output signal of the multi-channel comb filter; a frequency estimation module, the line spectrum component of the target frequency is identified from the feature map output by the channel fusion module, a learnable threshold parameter is introduced to screen the frequency bin, and the frequency index of each frame is generated; a mask enhancement module, the input signal is adaptively filtered using the frequency index sequence output by the frequency estimation module; the technical scheme provided by the present application can effectively overcome the defects of the prior art, such as insufficient line spectrum enhancement capability in a complex marine noise environment.

An optoelectronic device includes a first reflector and a second reflector, which define an optical path on a substrate. A gain medium is disposed on the optical path between the first and second reflectors and configured to amplify laser radiation within a given gain band. A comb filter is disposed on the optical path between the first and second reflectors and configured to pass a set of distinct wavelength sub-bands within the gain band, the set of distinct wavelength sub-bands defining a comb. A bandpass filter is disposed on the optical path between the first and second reflectors in series with the comb filter. The bandpass filter has a passband encompassing a subset of the wavelength sub-bands in the comb.

The present application relates to the technical field of grid voltage phase signal detection and extraction, in particular to a synchronous phase-locked loop with a combined filter structure. In view of the technical problem that the conventional phase-locked loop is easily affected by voltage distortion and cannot realize accurate phase locking under severe grid conditions, the present application proposes a synchronous phase-locked loop solution based on a combined filter architecture. In order to improve the anti-interference stability of the phase-locked loop, the present application first designs an enhanced fourth-order generalized integrator with a direct current offset voltage elimination function, and builds a double-enhanced fourth-order generalized integrator structure based on it. At the same time, a first-order comb filter capable of effectively suppressing grid harmonic disturbance is introduced, and the two are cascaded to form a combined filter and integrated into a three-phase grid-connected phase-locked loop system, finally realizing the rapid and accurate extraction of grid phase information under severe grid conditions. The present application is mainly applied to the synchronous control process of grid-connected converters in complex grid environments.

The invention relates to the technical field of vehicle-mounted health monitoring, and provides a directional noise reduction method for vehicle-mounted capacitive physiological signal monitoring. The method comprises the following steps: acquiring an original physiological signal of a driver and vehicle state data including an engine rotating speed and a vehicle speed in real time; calculating the main characteristic frequency of the current vehicle vibration based on the vehicle state data and generating a corresponding noise reference signal; taking the characteristic frequency as a center, and adopting a programmable comb filter to carry out preliminary noise reduction on the original physiological signal; and based on the noise reference signal, carrying out fine processing on the preliminary noise reduction signal through adaptive filtering, and outputting a final noise-reduced physiological signal. According to the method, through noise source modeling and two-stage collaborative filtering, directional and efficient suppression of vehicle vibration noise is achieved, the signal-to-noise ratio and heart rate detection accuracy are effectively improved, meanwhile, the requirement for computing resources is remarkably reduced, and the self-adaptability and reliability in a complex vehicle-mounted environment are enhanced.

The present disclosure provides systems and methods for wirelessly charging an implantable medical device. An external charging device includes a coil, signal generating circuitry to drive current through the coil at a charging frequency to induce current in a second coil in the implantable medical device, monitoring circuitry to generate an output signal to monitor charging operations, and a comb filter. The comb filter is configured to apply filtering to the output signal to remove noise from the output signal, wherein the filtering is applied based on the charging frequency. The external charging device is configured to process the filtered output signal to detect a circuit state of charging circuitry of the implantable medical device during charging operations, and the external charging device is configured to vary the charging frequency based, in part, on detection of the circuit state of the charging circuitry of the implantable medical device.

The invention belongs to the technical field of underwater communication, and particularly relates to a high-temperature metal underwater detection method and system based on an FPGA, and the method comprises the steps: capturing an underwater sound wave signal through an underwater sensor, and converting the underwater sound wave signal into an analog electric signal; amplifying the analog electric signal by using a variable gain amplifier; converting the amplified analog signal into a digital signal through an analog-to-digital converter; the frequency spectrum of the digital signal is shifted to a base band by adopting a digital orthogonal down-conversion technology so as to reduce the signal processing complexity; a cascaded integrator comb filter is used for filtering baseband signals, so that the consumption of hardware resources is reduced, and the operation rate is improved; underwater target detection of high-temperature metal is realized based on a CFAR threshold adjustable method, and a detection result is displayed through a graphical user interface. The method effectively overcomes noise interference in a complex underwater sound environment, improves the detection efficiency and adaptability, and is suitable for safety production scenes such as high-temperature metal underwater leakage detection.

Removal of motion artifacts from photoplethysmography (PPG) signals from a PPG sensor by applying a harmonic notch filter to a PPG signal where positions of the filter notches are based on a period of an accelerometer signal received from an accelerometer sensor in a vicinity of the PPG sensor to yield a first filtered signal; determining a signal quality index (SQI) associated with the PPG signal based on the accelerometer signal; determining an estimated heart rate based on the PPG signal; and applying a harmonic comb filter to the first filtered signal to where the filter peaks are based on the estimated heart rate. The estimated heart rate may be determined according to a confidence level based on SQI. A wearable device may implement the system for removing motion artifacts from PPG signals.

The utility model provides a rotor noise filtering device for a digital interphone system of a helicopter. The rotor noise filtering device comprises a filter main body; the filter main body comprises a noise reduction equipment main body, a voice acquisition filter circuit equipment main body and an amplification circuit equipment main body. The utility model provides a rotor noise filtering device for a communication system in a digital machine of a helicopter, and the device carries out the preliminary filtering of a part of engine noise and rotor noise which are collected by a microphone and appear in the flight process of the helicopter through a noise reduction module of an internal operation spectral subtraction method, an MMSE algorithm, a Wiener filtering algorithm and a VAD algorithm. And a comb-shaped filtering algorithm which is operated in the ARM processor and aims at a specific model is used, so that the defects of a single filtering algorithm are comprehensively overcome, the problem of whistling caused by the fact that part of rotor noise still leaks into the earphone after noise reduction is solved, the voice quality is improved, the voice state is clear and no whistling is caused when the whole machine is in a flying state, and the safety of the whole machine is ensured. And the effects of suppressing whistling and comb-shaped filtering are achieved.