438 results about "Band-pass filter" patented technology

The invention relates to a time-varying power high-precision calculation technology of an electric drive system under strong electromagnetic noise interference, and mainly solves the problem of inaccurate power calculation of the electric drive system under strong electromagnetic environment noise and frequency time-varying fluctuation scenes. According to the core technology, a dominant frequency fluctuation curve of a signal is obtained through dynamic tracking of a dominant frequency, and a dynamic band-pass filter changing along with the dominant frequency of the electric drive system is constructed; suppressing pulse noise by combining amplitude self-adaptive filtering of a nonlinear weighting function; a phase demodulation technology fusing zero crossing point correction and Hilbert transform is adopted to eliminate the phase interference problem caused by complex waveforms and weak noise signals; and finally, establishing a time-varying power physical model based on the sliding window. According to the technology, the power calculation accuracy of the electric driving system under the conditions of strong field environmental noise and continuous main frequency conversion is remarkably improved.

The invention discloses a composite fault signal separation method based on adaptive spectral kurtosis deconvolution. The method comprises the following steps: S1, carrying out noise reduction processing on an original composite fault signal; s2, separating the composite fault signal after noise reduction through Hilbert envelope demodulation; s3, optimizing a low-pass filter and a high-pass filter through a Bayesian objective function, and constructing a band-pass filter and a band elimination filter; and S4, carrying out iterative filtering on the composite fault signal after noise reduction through a band-pass filter and a band elimination filter, constructing a frequency-bandwidth fast spectral kurtosis graph according to a fast spectral kurtosis deconvolution method, obtaining a center frequency and bandwidth range corresponding to the maximum spectral kurtosis, and separating out the weak fault signal in the step S2. According to the method, a spectral kurtosis graph is constructed by combining a low-pass filter and a high-pass filter through a fast spectral kurtosis deconvolution method to determine the center frequency and the bandwidth range, targeted separation is carried out on composite fault signals, an initial filtering parameter range is provided for Bayesian optimization, and the fault separation efficiency and accuracy are improved.

The invention provides a vital sign detection method and device based on a millimeter wave radar, electronic equipment and a storage medium. The method comprises the following steps: obtaining a distance frequency domain signal based on a radar echo signal; performing spectral analysis on the distance frequency domain signal, positioning the position of the to-be-detected object, and extracting phase information at the position; filtering through a band-pass filter to obtain a breathing frequency band interval signal and an initial heartbeat frequency band interval signal; performing real-time respiration rate estimation based on the respiration frequency band interval signal to obtain a respiration frequency, and eliminating respiration harmonics in the initial heartbeat frequency band interval signal by using an adaptive wave trap based on the respiration frequency to obtain a heartbeat frequency band interval signal; and with the minimum fuzzy entropy as an optimization target, decomposing the heartbeat frequency band interval signal by using a variational mode decomposition algorithm to obtain a heartbeat signal, and carrying out real-time heart rate estimation based on the heartbeat signal to obtain a real-time heart rate. According to the method, the device, the electronic equipment and the storage medium provided by the invention, the accuracy of heart rate measurement can be improved.

The invention discloses a non-reflection band-pass filter chip based on a novel topological structure, which is characterized by comprising a dielectric substrate, a filter circuit arranged on the dielectric substrate, an input port and an output port, a topological structure of the filter circuit is in bilateral symmetry, a main signal path of the filter circuit is of a five-order band-pass filter structure, and the filter circuit comprises a first series resonator, a third series resonator and another first series resonator which are sequentially connected between an input port and an output port in series; one ends of the two second parallel resonators are respectively connected between the first first series resonator and the third series resonator and between the third series resonator and the second first series resonator, and the other ends of the two second parallel resonators are grounded; the two ends of each first series resonator are connected with an absorption branch in parallel, each absorption branch is formed by sequentially connecting a fourth parallel resonator, a resistor and a fifth parallel resonator in series, and out-of-band energy absorption is achieved through the two branches of the same structure. An absorption circuit and a main filter circuit are organically fused, the problem of out-of-band reflection of a traditional filter is solved, and meanwhile the filter has the advantages of being compact in structure, small in size and high in integration degree.

The invention discloses a mobile robot tracking method and device based on a fixed-frequency light source, and the method comprises the following steps: S1, a target person wears a fixed-frequency light source device, so as to emit a fixed-frequency light signal as a target light source; s2, the mobile robot collects an ambient light signal through a carried photoelectric sensor, locks a target light source signal through an adaptive band-pass filter, tracks a phase in real time through a digital phase-locked loop, suppresses non-target frequency noise and interference, and can detect a fixed frequency light signal from strong ambient light interference; and S3, when the fixed-frequency optical signal is successfully identified, the mobile robot starts a tracking mode to ensure that a certain distance and position are kept between the mobile robot and the target person, and a corresponding task is executed. According to the invention, the tracking precision problem in various difficult environments is solved, and the robot can stably and accurately track the specified target.

The invention relates to the technical field of elevator security and protection, in particular to an elevator remote alarm talkback noise reduction method and system.The method comprises the steps that noisy voice signals are processed, 40-dimensional voice features are extracted, the 40-dimensional voice features comprise 20 Mel-frequency cepstral coefficients, and first derivatives and second derivatives of the first 10 Mel-frequency cepstral coefficients are taken in sequence; inputting the 40-dimensional speech features into a pre-trained RNN (Recurrent Neural Network) model, wherein the RNN model outputs 20 gain coefficients; and dynamically adjusting coefficients of 20 first-order IIR band-pass filters based on the 20 gain coefficients, and after the noisy voice signal passes through the 20 first-order IIR band-pass filters in parallel, adding outputs of the first-order IIR band-pass filters to obtain a noise-reduced voice signal. According to the method, the technical problems of poor effect, low efficiency or high cost of an existing elevator remote alarm talkback noise reduction method can be solved in a comprehensive noise reduction mode combining the neural network and traditional signal processing, and efficient noise reduction is achieved on low-cost hardware.

The utility model relates to a micro-fluidic flow cytometry fluorescence detector which comprises an excitation light source optical fiber, a light beam shaping module, a focusing and fluorescence collecting module and a micro-fluidic chip which are sequentially arranged along the excitation light path direction of the excitation light source optical fiber, and a multi-channel silicon photomultiplier tube is arranged above the micro-fluidic chip. A plurality of groups of detection channels for receiving fluorescence signals of different wave bands are arranged in the multichannel silicon photomultiplier tube at intervals up and down, and a dichroscope, a band-pass filter and a lens group are sequentially arranged in each group of detection channel along a light path and are gathered on a receiving chip; the micro-fluidic flow cytometry fluorescence detector can efficiently and accurately complete multi-wavelength fluorescence excitation and signal collection, and is suitable for multi-channel and multi-wavelength fluorescence detection requirements in a micro-fluidic chip.

One example system for detecting an emergency siren comprises a microphone device, a band pass filter operably coupled to the microphone device and configured to filter sound data from the microphone device to produce filtered sound data, a phase lock loop circuit configured to phase filter the filtered sound data to produce phase filtered data, and a processor configured to determine a presence of a siren signal from the phase filtered data.

The invention relates to the cross technical field of elevator fault diagnosis and signal processing, in particular to an elevator shaft breakage early fault detection signal denoising method. The method comprises the following steps: acquiring an original low and medium frequency discrete signal of elevator shaft body vibration, and filtering by adopting a four-order Butterworth band-pass filter to obtain a filtered signal; performing complementary set empirical mode decomposition on the filtering signal to obtain a plurality of IMF components and a residual component, and screening effective IMF components from all the IMF components; the center frequency of each effective IMF component is calculated, and Gaussian weight distribution is carried out on each effective IMF component based on the center frequency of each effective IMF component; performing signal reconstruction on all the effective IMF components and the residual components according to the weight of each effective IMF component to obtain a reconstructed signal; and smoothing residual noise in the reconstructed signal by adopting self-adaptive moving smoothing filtering to obtain a de-noised signal. According to the method, the 30-60Hz low and medium frequency characteristic signals generated in the elevator spindle microcrack propagation stage can be accurately extracted, so that fault judgment is facilitated.

The embodiment of the specification provides a copper foil defect detection system, comprising: a data acquisition module configured to acquire a copper foil surface image through a multi-spectral line-scan digital camera and output original image data; the preprocessing module is configured to perform dynamic denoising and partition contrast enhancement on the original image data to generate a preprocessed image; the frequency domain processing module is configured to perform Fourier transform on the preprocessed image to obtain a frequency domain feature map, separate a low-frequency contour and a high-frequency texture component through a band-pass filter bank, and generate a composite feature map through inverse transformation after frequency domain mask enhancement; the data enhancement module is configured to implement geometric transformation enhancement and frequency domain noise injection on the composite feature map and output an enhanced sample set; and the multi-scale detection network is configured to extract hierarchical features from the enhanced sample set, fuse the hierarchical features through a gating mechanism and output defect positioning and classification results. According to the scheme, the frequency domain image processing technology is combined with the CNN, and the detection effect of the weak contrast defect is improved.

The invention relates to a continuous writing track generation method, system and device based on a brain-computer interface and a medium. The method comprises the following steps: acquiring an electroencephalogram signal and a real writing track when a user imaginates writing through electroencephalogram acquisition equipment; extracting neural activity data related to hand writing movement by using a band-pass filter; extracting writing intention spatio-temporal features based on a preset spatio-temporal deep learning network; mapping an initial handwriting coordinate sequence and a pen state signal through a generator network comprising a full connection layer, a convolution time sequence generation layer and a pen state classification layer; calculating the similarity between the trajectory and a real trajectory by means of a discriminator, and generating handwriting and state signals through adversarial training optimization; and dividing stroke segments according to the pen state and sequentially connecting the stroke segments to generate a continuous writing track. By adopting the method, the brain motion intention can be efficiently and accurately decoded into a coherent writing track, and the practicability of a brain-computer interface in writing and interaction application is improved.

The invention discloses a Coriolis flowmeter signal processing method based on adaptive unscented Kalman filter (UKF) and sliding discrete time Fourier transform (SDTFT), and belongs to the field of Coriolis flowmeter signal processing. The method comprises the following steps: firstly, preprocessing a signal by using a band-pass filter; secondly, extracting a signal frequency by adopting zero-cross detection; furthermore, the frequency obtained by zero-cross detection is taken as the reference frequency, and the phase difference of the two paths of signals is extracted in real time by adopting an SDTFT algorithm considering negative frequency correction; and finally, introducing an adaptive process noise covariance adjustment mechanism based on a phase difference change rate, and constructing an adaptive UKF to carry out error correction on the frequency and the phase difference. According to the invention, the accuracy and real-time performance of signal processing of the Coriolis flowmeter under the conditions of strong interference and sudden phase change can be improved.

The present application relates to a kind of unmanned aerial vehicle signal identification method and system, belong to unmanned aerial vehicle signal identification technical field.It includes: step 1: adaptive noise base estimation;The input unmanned aerial vehicle IQ signal, i.e.unmanned aerial vehicle signal is carried out short-time Fourier transform, and time-frequency matrix is obtained, generates unmanned aerial vehicle time-frequency diagram, estimates noise power spectrum, calculates the power spectral density of each frequency point;Step 2: time-frequency feature enhancement;5 order Butterworth band-pass filter is used to frequency domain filtering to signal;Soft threshold domain denoising of soft short-time Fourier transform result is used;Step 3: multi-feature fusion regression;Energy ratio feature, spectral peak sharpness feature are calculated, and deep learning feature is extracted, feature fusion and regression;Step 4: through the unmanned aerial vehicle signal classification model after training, unmanned aerial vehicle signal identification is realized.The present application method is high in precision in complex environment signal-to-noise ratio estimation, and unmanned aerial vehicle classification precision and generalization are excellent.

The invention relates to a road cavity detection and identification method and system based on multichannel optical fiber sensing. The method comprises the following steps: acquiring and storing Rayleigh scattering light time domain signals which are acquired by a DAS underground sensing system at different positions and different time periods of a detection road section and contain active knocking signals; determining a frequency range of the active knocking signal according to a frequency spectrum obtained after the Rayleigh scattering light time domain signal is subjected to fast Fourier transform processing; carrying out filtering processing on the Rayleigh scattering light time domain signal by adopting a finite impulse response band-pass filter to obtain a filtered signal; the filtered signal is input into a PhaseNetDAS model for seismic phase pickup, and an active source seismic phase is obtained; associating the active source seismic facies with the active source event to obtain a seismic facies report including event latitude and longitude, time and seismic facies arrival time; and inverting the velocity structure of the underground medium by using the seismic phase report by using a tomography method, and determining a road cavity detection and recognition result, thereby improving the accuracy of road cavity detection.

The application provides a channel equalization method based on a frequency sampling method, which comprises the following steps: obtaining a frequency domain quotient by taking a frequency response of a channel to be equalized and a reference channel; obtaining a frequency of an ideal equalization filter through a band-pass filter and a frequency domain entropy; performing an IFFT transformation on the ideal equalization filter; and performing several iterations according to channel performance to obtain an ideal equalization filter coefficient. Based on the ideal equalization filter coefficient, an actual equalization filter is constructed through a FIR filter model to complete equalization of the channel to be equalized. The method avoids inverse operation of a matrix of a conventional frequency domain least square method, reduces complexity of the algorithm, and can be realized in real time in engineering. Meanwhile, the method further improves equalization accuracy by using a band-pass filter and an iteration mode.

A light detection device includes: a Fabry-Perot interference filter provided with a light transmission region; a light detector configured to detect light transmitted through the light transmission region; a package having an opening and accommodating the Fabry-Perot interference filter and the light detector; and a light transmitting unit arranged on an inner surface of the package so as to close an opening, the light transmitting unit including a band pass filter configured to transmit light incident on the light transmission region. When viewed from a direction parallel to the line, an outer edge of the Fabry-Perot interference filter is positioned outside an outer edge of the opening, and an outer edge of the light transmitting unit is positioned outside the outer edge of the Fabry-Perot interference filter.

The invention provides an optical feedback resonance enhanced forward Brillouin demodulation structure, which comprises a tunable laser, a first polarization controller, an erbium-doped optical fiber amplifier, an optical coupler, an optical isolator, a forward Brillouin gain optical fiber, a band-pass filter and a photoelectric detector, a second polarization controller; and a spectrum analyzer. The first polarization controller is connected with a port a of the optical coupler, a port b of the optical coupler is connected with an input end of the erbium-doped optical fiber amplifier, an output end of the erbium-doped optical fiber amplifier is connected with the optical isolator, the optical isolator is connected with the band-pass filter, the band-pass filter is connected with the forward Brillouin gain optical fiber, and the optical fiber is fed back to a port c of the coupler through the second polarization controller. The output power of the erbium-doped optical fiber amplifier is controlled, and the polarization states of the pump light and the feedback laser are controlled by the first polarization controller and the second polarization controller, so that the forward Brillouin effect is amplified.

The application provides a learning emotion classification method and system based on electroencephalogram signals, and the method comprises the following steps: acquiring electroencephalogram signals of multiple channels of a learner; different channels correspond to different brain positions; filtering the electroencephalogram signals into multiple different frequency bands through a Butterworth band-pass filter to obtain electroencephalogram signals of multiple frequency bands of multiple channels; inputting the electroencephalogram signals of multiple frequency bands of multiple channels into a trained confusion classification model to obtain a confusion classification result of the learner; if it is judged that the confusion classification result is confusion, the confusion classification result is the learning emotion of the learner; if it is judged that the confusion classification result is not confusion, inputting the electroencephalogram signals of multiple frequency bands of multiple channels into a trained emotion classification model to obtain an emotion classification result of the learner, and the emotion classification result is the learning emotion of the learner. The application can avoid the confusion of the confusion emotion and other emotions, and improve the emotion classification accuracy.

The utility model discloses a Ka wave band frequency source based on a phase-locked loop structure, which comprises a master controller, a crystal oscillator module, a phase-locked loop module and a frequency doubling processing module, and the phase-locked loop module is respectively connected with the master controller, the crystal oscillator module and the frequency doubling processing module. The phase-locked loop module comprises a power supply module, a phase-locked loop main chip, a loop filter module and a locking state indication module, and the phase-locked loop main chip is respectively connected with the power supply module, the loop filter module, the locking state indication module and the main controller; the frequency doubling processing module comprises a low-pass filter, a high-pass filter, a fixed frequency attenuator, a power amplifier, a frequency doubling chip and a band-pass filter which are connected in sequence, and the input end of the low-pass filter is connected with the output end of the voltage-controlled oscillator. The frequency output by the phase-locked loop module is input to the frequency multiplication processing module, and the frequency multiplication processing module carries out harmonic suppression, attenuation, amplification and frequency multiplication processing on the input frequency, so that the output frequency has the advantages of low phase noise, wide frequency band and high stability.

The application discloses a harmonic compensation and stability improvement method, system, medium and equipment, filters components of a grid voltage in a two-phase static coordinate system to obtain corresponding fundamental components; subtracts the fundamental components of the grid voltage from the components of the grid voltage in the two-phase static coordinate system to obtain total harmonic components of the grid voltage; filters the total harmonic components of the grid voltage by using multiple band-pass filters to obtain multiple harmonic components corresponding to frequencies; subtracts reference current instructions of an active power filter from the multiple harmonic components, and inputs the result as a new current reference instruction into a current controller; and based on a virtual harmonic admittance method, outputs harmonic compensation currents through current inner loop control in the two-phase static coordinate system to realize harmonic compensation on a nonlinear load with frequency coupling characteristics and suppression of harmonic compensation oscillation. The application can adapt to various complex grid environments and has relatively practical engineering application value.

The invention discloses a band-pass filter based on an artificial surface plasmon polariton structure and a design method thereof, a metal structure of the band-pass filter comprises an polariton structure region, the polariton structure region is provided with a plurality of plasmon polariton grooves, and the plurality of plasmon polariton grooves are arranged at intervals along a first direction; the depth direction of the plasmon polariton grooves is perpendicular to the first direction, the lengths and the widths of the plasmon polariton grooves are the same, and the multiple plasmon polariton grooves are formed in the same side of the polariton structure; the split resonant rings are arranged on the dielectric substrate, and the multiple split resonant rings are arranged close to the metal structure. Due to the fact that the multiple plasmon polariton grooves formed in the polariton structure and arranged at intervals in the first direction can form the artificial surface plasmon polariton structure, the band-pass filter based on the artificial surface plasmon polariton structure has the high inhibition capacity for harmonic waves of the band-pass frequency, and the band-pass filter based on the artificial surface plasmon polariton structure has the good inhibition capacity for the harmonic waves of the band-pass frequency.

The application provides a device for adopting multi-channel transmitting signals, and belongs to the technical field of signal processing. The device comprises multiple signal transmitting branches, each of which comprises a directional antenna and a radio frequency channel connected with the directional antenna; a baseband module connected with the multiple signal transmitting branches; the radio frequency channel comprises a first band-pass filter, a second band-pass filter, a first radio frequency switch and a gain adjusting module; the first radio frequency switch is used for selecting the first band-pass filter or the second band-pass filter to be communicated with the gain adjusting module according to the working mode of the device for adopting multi-channel transmitting signals, so as to output the filtered target bandwidth signal through the directional antenna, output the filtered target bandwidth signal through the directional antenna in each signal transmitting branch, and further provide a test scene for a to-be-tested wearable device, so that the performance verification of the to-be-tested wearable device does not need to be carried out in an actual scene, the verification cost is reduced, and the verification efficiency is improved.

The application relates to an acoustic device and a wireless communication device. The acoustic device comprises an external terminal, a band-stop terminal and a band-pass terminal; a band-pass filter, one end of which is electrically connected to the band-pass terminal, and the other end of which is electrically connected to the external terminal; a band-stop filter, one end of which is electrically connected to the band-stop terminal, and the other end of which is electrically connected to the external terminal; and a filter capacitor, which is connected in parallel to the band-stop filter between the external terminal and the band-stop terminal. The application can effectively improve the insertion loss deterioration problem of the high-frequency band-pass part of the band-stop filter.

The LTCC band-pass filter comprises an LTCC porcelain body, a first inductor and a second inductor of the LTCC band-pass filter are arranged on the upper portion and the lower portion in the left side of the LTCC porcelain body respectively, the two inductors in the right side and the two inductors on the left side are symmetrically arranged, and other capacitors are correspondingly arranged. According to the utility model, the four inductors are arranged up and down and in bilateral symmetry, and the distance between the inductors at the input end and the output end can be flexibly adjusted, so that the coupling coefficient is adjusted, another two zero points are obtained by adjusting the coupling coefficient of the two inductors, the near-end suppression of the filter is optimized, and the selectivity of the filter is improved.

The application discloses an LC band-pass filter based on LTCC technology and relates to the microwave technical field, and at least comprises nine conductor layers; the first conductor layer is a grounding layer, the second conductor layer is an inductance circuit layer, the third conductor layer, the fourth conductor layer, the fifth conductor layer, the sixth conductor layer, the seventh conductor layer, the eighth conductor layer and the ninth conductor layer are all capacitance circuit layers, and the conductor layers are connected through metal through holes. The third conductor layer and the ninth conductor layer are input and output layers of the capacitance circuit and are electrically coupled with the fourth conductor layer and the eighth conductor layer; the second conductor layer and the fourth conductor layer to the eighth conductor layer form a resonator. The application solves the technical problem that the LC band-pass filter occupies a large space, and reduces the volume of the LC band-pass filter.

The present application relates to a kind of passage attention residual network emotional electroencephalogram identification method, belong to brain information decoding technical field.The present application uses Butterworth band-pass filter to obtain the target frequency band of original electroencephalogram, combines differential entropy algorithm, respectively to target frequency band obtains feature and it is converted into 4D representation according to electrode channel position.Extracted multi-band differential entropy feature is used as the input of model, using passage attention residual network to learn feature, channel attention mechanism can be well simulated electrode channel information and enhance convolution feature learning, and can significantly improve emotional classification accuracy.The present application can be used as a kind of combination of time, frequency and spatial information emotional electroencephalogram decoding strategy, the proposed passage attention residual network model provides new ideas for building better emotional recognition framework in the future.

The invention discloses a phase coding optoelectronic oscillator with an adjustable duty ratio and an implementation method thereof, and relates to the technical field of photoelectricity. The optoelectronic oscillator comprises a laser, a Mach-Zehnder modulator, a single-mode fiber, a photoelectric detector, an electric amplifier, an electric band-pass filter and an electric power divider which are connected in sequence; a direct current port of the intensity modulator is connected with the function generator, one path of the electric power divider serves as output, and the other path is connected with a radio frequency port of the intensity modulator; the output voltage of the preset function generator jumps between the two linear bias points and the minimum bias point of the Mach-Zehnder modulator, so that the direct output of the phase-coded microwave signal with the adjustable duty ratio is realized. According to the invention, the coherence of the phase coding microwave signal is good, the phase noise is low, the duty ratio is adjustable, the coding flexibility is high, the structure is simple, and the equipment cost is low.

The utility model provides a high-suppression ceramic dielectric band-pass filter, and relates to the technical field of filters. The ceramic dielectric band-pass filter is composed of a ceramic dielectric main body and a metal shielding cover. The ceramic dielectric main body is provided with an open surface and a short-circuit surface, and is provided with five third resonance through holes, two second resonance through holes (located on the two sides of the five third resonance through holes) and two first resonance through holes (located on the two sides of the second resonance through holes). And the metal shielding cover covers part of the open surface. The surface of the main body is covered with a metal covering layer, and one side of the open surface of the metal covering layer is provided with a first isolation groove (surrounding the first and second resonance through holes) and first and second capacitance grooves (located between the first and second resonance through holes) to form a first metal loading layer, a second metal loading layer and an output electrode. And a second isolation groove is additionally arranged to surround the third resonance through hole and the third metal loading layer. And an inductance line layer is formed between the two isolation grooves. The output electrode extends from the open surface to the side surface.

The invention discloses an anti-interference wake-up receiver which comprises an antenna, a first band-pass filter, an impedance matching circuit, a low-noise amplification circuit, a first envelope detection circuit, a second band-pass filter, a second envelope detection circuit, a low-pass filter, an operation amplification circuit, a mean value circuit, a matching filter and a decoder which are connected in sequence. According to the invention, through multi-stage filtering and amplification processing, the anti-interference capability and the signal identification accuracy of the wake-up receiver in a complex electromagnetic environment can be effectively improved.

An RF device may include an RF antenna, and an ASIC downstream from the RF antenna. The ASIC may include ADCs configured to generate replica digitized input signals, a DSP core downstream from the ADCs and having first complex coefficient multipliers, first band pass filters respectively coupled to the first complex coefficient multipliers, and a summer downstream from the first band pass filters. The ASIC may also include DACs configured to generate analog output signals, and a feedback loop coupled between the DACs and the ADCs. The RF device may further include a processor configured to control the first complex coefficient multipliers and associated delay circuits.