121 results about "Band-stop filter" patented technology

The invention belongs to the technical field of image processing, and particularly relates to a cable shielding layer weaving density detection system based on image analysis, which comprises an image correction module, a frequency domain analysis module, a self-adaptive filtering module and a density defect detection module, obtaining the maximum peak point of the centralized complex frequency spectrum; constructing a band elimination filter according to the maximum peak point, filtering the centralized complex frequency spectrum through the band elimination filter to obtain a filtered complex frequency spectrum, executing inverse Fourier transform to obtain a filtered space image, and binarizing the filtered space image through a threshold segmentation algorithm to obtain a pore mask; the porosity is obtained according to the ratio of the non-pore pixel points to the total number of the pixel points; and judging the weaving defect of the shielding layer according to the porosity. According to the method, the strong periodic signals of the weaving textures are automatically identified and filtered in the frequency domain, so that non-periodic defects such as pores are effectively highlighted, the technical problem that periodic textures cover defect signals is solved, and the accuracy of defect detection is 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 harmonic reducer fault diagnosis method and system combining SAH with SSET under a time-varying rotating speed, and belongs to the field of harmonic reducer fault diagnosis. The invention aims to solve the problems of large time-frequency ridge line extraction error and inaccurate fault feature order extraction caused by the non-stable and signal modulation characteristics of a harmonic reducer vibration signal under a time-varying rotating speed. According to the SAH construction method based on sub-band rearrangement dual-tree complex wavelet packet transformation, a band elimination filter is designed according to an optimal frequency band, and a resonance frequency band where a fault impact component is located is filtered out; a time-frequency ridge extraction method combining SAH-SSET with a fast path optimization algorithm is provided, a frequency ambiguity phenomenon is improved, order analysis is carried out based on the frequency ambiguity phenomenon, and then the fault type of the harmonic reducer is judged according to an envelope order spectrum.

Wireless devices are commonly carried in fabric-based apparel. Printing metamaterial structures on fabric substrates allows for the ability to create fabric metamaterial layers. A reconfigurable RF based fabric system simply by physically removing or adding different fabric-based metamaterial layers to different regions of the apparel. The fabric-based metamaterial can be used in various filtering applications where the control of phase, reflection angle, refraction angle, polarization, absorption, and transmission of the impinged electromagnetic wave can all be manipulated. Additionally, sophisticated metamaterial systems can be created by combining different metamaterial layers separated above each other. A controllable absorber metamaterial system can be made consisting of two layers. The first layer an electronically controllable that can controllably change between a band-pass and band-reject filter in a relevant frequency band and a second absorptive layer. Vehicles with adjustable metamaterial absorber systems, integrated on the outside or inside of the RF transparent fuselage, have the ability to control their radar cross section dynamically for the purposes of evading detection or spoofing their size by looking larger or similar to vehicles of different radar cross section.

A state monitor system and a state monitor method capable of detecting an AE wave with high accuracy are provided. Accordingly, from a sensing signal SS output detected at an acoustic emission sensor 23, an AE-wave extracting circuit 55 extracts an AE wave AEW taking a structure that is a manufacturing target of three-dimensional printing process as a generation source. An AE-wave analyzing circuit 56 analyzes the AE wave AEW extracted by the AE-wave extracting circuit 55. In this case, the AE-wave extracting circuit 55 includes a noise cutting circuit cutting a first disturbance noise generated in a frequency band of the AE wave AEW while using a band-stop filter.

The invention provides a full-automatic parameter measurement system and method for a micro-cavity optical chip, and the system achieves the automatic measurement of the characteristic parameters of the micro-cavity optical chip through integrating a DFB tunable laser light source, an isolator, an EDFA amplifier, an ASE filter, a fundamental frequency light band elimination filter, a selectable beam splitter, a VOA, a PD, a main control module and other components. The system is connected with a to-be-tested chip through a specific interface, and can automatically obtain a central wavelength change curve, a transmission spectrum characteristic afterglow map and an expected soliton state intensity range of the micro-cavity optical chip at each temperature. The invention aims to automatically test the characteristic parameters of the micro-cavity optical chip so as to assist in reducing the time generated by tuning the optical frequency comb by adopting the chip, and meanwhile, an expected soliton state intensity range is given to reduce the problem of excessive tuning, so that a pre-test process required in chip application is simplified, and great convenience is brought to debugging generation of the integrated optical frequency comb.

The invention discloses a three-phase meter power flow reversal detection method, which relates to the technical field of electric power, and comprises the following steps of: firstly, acquiring original waveform data in a power grid, identifying a power disturbance frequency point, eliminating a voltage component and a current component on the power disturbance frequency point by using a band elimination filter so as to acquire filtered waveform data; s3, dynamically updating a stability threshold value to judge the consistency of the power structure before and after filtering, triggering an early warning instruction, receiving the early warning instruction, analyzing whether the voltage and current loads of the power system are in a balanced state or not, if so, repeating the step S3 to update a power disturbance frequency point, and if not, executing the step S4; if yes, identifying a power inversion result of the power system through a phase difference compensation mechanism, and the power inversion result is used for reflecting whether the power is inverted or not.

The application belongs to the technical field of image processing, and particularly relates to a cable shielding layer weaving density detection system based on image analysis, which comprises an image correction module, a frequency domain analysis module, an adaptive filtering module and a density defect detection module; a maximum peak point of a centralized complex frequency spectrum is obtained; a band-stop filter is constructed according to the maximum peak point, and the centralized complex frequency spectrum is filtered through the band-stop filter to obtain a filtered complex frequency spectrum and perform inverse Fourier transform to obtain a filtered spatial image, and the filtered spatial image is binarized through a threshold segmentation algorithm to obtain a pore mask; a porosity is obtained according to the ratio of non-pore pixel points to the total number of pixel points; and the shielding layer weaving defect is judged according to the porosity. The application automatically identifies and filters the strong periodicity signal of the weaving texture in the frequency domain, effectively highlights the non-periodic defects such as pores, solves the technical problem that the periodic texture covers the defect signal, and improves the accuracy of defect detection.

The invention discloses a vibration sensor background noise testing method based on a vacuum cavity, and the method comprises the steps: constructing an active-passive composite vibration isolation platform in a sealed vacuum cavity, rigidly fixing a to-be-tested sensor on the vibration isolation platform in a testing process, and guaranteeing that a sensitive axis of the to-be-tested sensor is orthogonal to a cavity reference; and an output signal is recorded for a long time at a sampling rate greater than or equal to 256Hz through a high-precision acquisition system. The data processing comprises polynomial detrending, sliding window de-averaging, multi-band elimination filtering and power spectral density (PSD) analysis so as to extract the equivalent amplitude and frequency domain characteristics of the background noise. In order to ensure the credibility of the result, the test needs to be repeated for three times, the consistency of the PSD curve is compared, and the deviation does not exceed 5%. The method combines the vacuum environment, composite vibration isolation, signal preprocessing and spectrum analysis technologies, can accurately quantify the background noise characteristics of the sensor, and is suitable for research and development verification and performance evaluation of the high-sensitivity sensor.

The invention discloses a tunable band elimination filter based on a quantum well structure photon time crystal and a method. The tunable band elimination filter comprises the quantum well structure photon time crystal; the quantum well structure photon time crystal comprises a first photon time crystal section, a time domain quantum well section and a second photon time crystal section which are connected in sequence; when an electromagnetic signal is propagated, the electromagnetic signal sequentially passes through the first photon time crystal section, the time domain quantum well section and the second photon time crystal section, so that a stable band gap region and a controllable resonance response are formed in a momentum space; a fitting relation between a local state equivalent wave vector and a time structure parameter is established by adjusting a time section proportion parameter and a refractive index contrast ratio in a quantum well structure photon time crystal, so that the local state quantity and momentum position of an electromagnetic signal are regulated and controlled; and frequency spectrum regulation of the electromagnetic signal is realized through a corresponding relation between the momentum space and the frequency domain space. The frequency spectrum regulation and control precision and the system stability are improved.

This invention discloses a method for designing an additional stabilizer to suppress low-frequency oscillations in a doubly-fed induction generator (DFIG) wind turbine. The method includes: constructing the input and output terminals of the additional stabilizer and designing the control loop; plotting the Bode plot of the closed-loop transfer function of the original system to determine the dominant oscillation frequency w. d and the phase lag value θ h Perform parameter tuning calculations for the phase compensation stage in the control loop; select the proportional coefficient K of the isolation stage of the additional stabilizer. e The quality coefficient ξ of the second-order bandstop filter with added stabilizer s and resonance coefficient K s Initialize the values; calculate the time δt required to suppress the disturbance and perform iterative calculations; and obtain the optimal parameter K. e ξ s and K s The values ​​are then substituted into the expressions for the isolation stage and the second-order band-stop filter. The additional stabilizer and design method for suppressing low-frequency oscillations in doubly-fed induction generator (DFIG) wind turbines provided by this invention can effectively suppress low-frequency oscillations in DFIG grid-connected systems and significantly enhance the system's stability under small disturbances.

The invention provides an elastic wave CT (Computed Tomography) signal denoising method for improving the inversion precision of karst cave exploration, which belongs to the technical field of engineering exploration and comprises the following steps of: performing normalization preprocessing on a received signal, suppressing random noise by adaptive filtering, converting a time domain signal into an F-K domain and identifying a surface wave, filtering a surface wave signal by a Gaussian band elimination filter, and converting the F-K domain signal back to the time domain. The method comprises the following steps of: highlighting a take-off characteristic of a weak P wave covered by a strong surface wave through normalization; using a minimum mean square error adaptive filter to accurately filter random noise; subsequently converting to an F-K domain, and smoothly attenuating the surface wave through a Gaussian band elimination filter by utilizing the frequency wave number distribution difference of the surface wave and the P wave; the method realizes layered removal of random noise and surface waves, finally outputs high-purity direct P-wave signals, greatly improves P-wave travel time pickup and wave velocity calculation precision, and remarkably improves inversion precision of an elastic wave CT exploration method in detection of geologic bodies such as karst caves and fracture zones.

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.

Methods, systems, and devices for wireless communications are described. Generally, the described techniques may enable a user equipment (UE) to disable a sleep mode or awake from sleep earlier for channels or bandwidths that have a frequency spur compared to channels or bandwidths without a frequency spur. Awaking from sleep earlier may enable a band stop filter of the UE to receive more samples to suppress the frequency spur and reduce sensitivity degradation of the UE for decoding control messages. The UE may disable the sleep mode or wake earlier based on a signal-to-noise ratio (SNR) of received signal, a magnitude of the frequency spur, a coding rate of the control message, a bandwidth of the control message, or any combination thereof.

The invention relates to a robot, a control method of the robot, and a recording medium. The robot system includes: an arm; one or more motors that move the arm in accordance with a drive signal; a control unit that controls the motor; and an input unit. The control unit has one or more groups including: a filter processing unit that performs filter processing on the position command and generates a filter completion command; and a drive signal generation unit that generates a drive signal using the filter completion command. The filter processing unit is provided with: a band elimination filter; and a low pass filter capable of changing a cut-off frequency. When an instruction that the content of the operation speed should be prioritized is received, the cut-off frequency is set to a first frequency, and when an instruction that the vibration suppression of the arm and the content of the vibration suppression in the operation speed of the arm should be prioritized is received, the cut-off frequency is set to a second frequency lower than the first frequency.

The invention discloses a superconducting microwave resonant cavity, a band elimination filter and a frequency control method, and relates to the technical field of superconducting microwave resonant cavities. The superconducting microwave resonant cavity comprises a thin film layer, a first superconducting electrode, a second superconducting electrode, a third superconducting electrode, a first port and a second port. The first superconducting electrode is arranged on the first surface of the thin film layer; the second superconducting electrode is arranged on one side of the second surface of the thin film layer, a gap exists between the second superconducting electrode and the second surface, and the first end of the second superconducting electrode is connected with the first end of the first superconducting electrode; the third superconducting electrode is arranged on the first surface; the first port is coupled with the first end of the first superconducting electrode and is coupled with the first end of the second superconducting electrode, and the first port receives an external input signal and outputs a target signal; and the second port is connected with the third superconducting electrode and receives an external direct current control signal. The resonant frequency of the microwave resonant cavity is adjustable.

The invention provides an electronic wire harness anti-interference optimization method and system, and the method comprises the steps: S2, blocking a DC component and low-frequency interference through employing a band elimination filter according to the initial spectrum distribution, and extracting a core frequency band of high-frequency signal transmission from a filtered signal; s4, acquiring demand data of voltage grade separation from the signal output, designing an electrical isolation layer through a multi-layer shielding structure, and determining isolation boundaries among different voltage grades; s5, according to the isolation boundary, a space optimization algorithm is adopted to adjust wire harness arrangement in the compact layout, and structural parameters considering isolation and coupling balance are obtained; and S8, according to the final scheme, a time domain reflection method is adopted to detect the distortion rate in signal transmission, the actual effect of improving the anti-interference capability is judged from the detection result, and optimized operation parameters are obtained. The anti-interference capability and the signal transmission quality of the electronic wire harness in a complex electromagnetic environment are effectively improved.

The present disclosure provides a method and device for determining filters in a superconducting quantum chip, and related equipment, relating to the technical field of quantum computing, and particularly to the technical field of superconducting quantum chips. The specific implementation scheme is as follows: determining the center frequencies of two band-stop filters based on the center frequency of a quantum bit of the superconducting quantum chip; determining the lengths of the two band-stop filters based on the center frequencies of the two band-stop filters; and determining the line segment length of a target line segment of a readout line between the two band-stop filters as the distance between the two band-stop filters based on the operating frequency range of the quantum bit; wherein the two band-stop filters are connected to the readout line, and the readout line between the two band-stop filters is coupled to a readout cavity so that the two band-stop filters are distributed on both sides of the readout cavity. In the present disclosure, based on the center frequency of the quantum bit, the key parameters of the band-stop filter can be designed to improve the decoherence time of the quantum bit, and the entire process design is simple and easy to implement.

The application discloses a microwave generation method and device, a microwave generator and a storage medium. The method comprises the following steps: acquiring an optical signal output by an adjustable laser and inputting the optical signal to a preset modulator through a polarization controller; loading a driving signal on the preset modulator and adjusting the power size, and outputting first positive and negative second-order sidebands and second positive and negative second-order sidebands; inputting the first positive and negative second-order sidebands and the second positive and negative second-order sidebands into a polarization maintaining Bragg grating through a circulator, making the sidebands orthogonal to each other through a band-stop filter, and obtaining the first positive and negative second-order sidebands and the second positive and negative second-order sidebands after the orthogonalization; respectively performing modulation processing on the sidebands after the orthogonalization, and obtaining a target signal; and performing spread spectrum on the target signal, and generating a microwave signal. The application acquires two pairs of sidebands through an optical signal and performs modulation, generates a microwave signal after spread spectrum on the target signal obtained, solves the problem of a small adjustable frequency range, and generates an arbitrary waveform phase microwave signal with a large adjustable frequency range and low noise.

The invention relates to the technical field of band elimination filters, and discloses a V-band H-plane rectangular waveguide TE20 mode band elimination filter which comprises a body and a cover plate installed on the body. A main waveguide cavity is arranged on the body, a plurality of TE20 mode rectangular resonant cavities are symmetrically distributed on two sides of the main waveguide cavity, and each TE20 mode rectangular resonant cavity is communicated with the main waveguide cavity through an H-surface capacitance coupling window; a tuning screw is arranged on the cover plate, the tuning screw comprises a threaded part and a light pillar part, the light pillar part extends into the TE20 mode rectangular resonant cavity, and the threaded part is matched and fixed with a threaded hole in the cover plate; the band elimination filter solves the problems that an existing band elimination filter is wide in transition band and large in loss.

Aspects of this disclosure relate to a parallel hybrid acoustic passive filter. The parallel hybrid acoustic passive filter includes a first sub-filter and a second sub-filter. The first sub-filter includes a first acoustic resonator and a first non-acoustic passive component. The second sub-filter includes a second acoustic resonator and second first non-acoustic passive component. The first sub-filter and the second sub-filter are together arranged to filter a radio frequency signal. The parallel hybrid acoustic filter can be a band pass filter or a band stop filter, for example. Related multiplexers, wireless communication devices, and methods are disclosed.

The present application relates to the technical field of electric power metering, and especially relates to a kind of electric energy meter state in network monitoring method, device, terminal and storage medium, the electric energy meter state in network monitoring method disclosed by the present application is loaded harmonic through trunk line, harmonic and the waveform of the current of trunk line and branch line line have obvious difference, by opening the band-stop filter in each branch line line, so that the harmonic current of trunk line only passes through the electric energy meter for detection, then by comparing the data of the electric energy meter to be detected with the data of total meter, whether the electric energy meter to be detected meets the precision requirement can be obtained, therefore, after applying the method of the present application, the electric energy meter can be completed online detection without disassembly, equipment resources and human resources are saved, and the reliable operation and measurement accuracy of the electric energy meter are also guaranteed.

A radio frequency front-end circuit includes a first diplexer, an extractor, and a second diplexer. First diplexer is coupled to an antenna for receiving a radio frequency signal and configured to separate radio frequency signal into a first signal within low, mid and high bands of a wireless wide area network and a second signal within an ultra-high band of WWAN. Extractor is coupled to first diplexer. Extractor includes two band pass filters and a band rejection filter. Two band pass filters are configured to extract two global navigation system signals within two global navigation system bands from first signal. Band rejection filter is configured to allow a third signal within the mid and high bands of WWAN in first signal to pass. Second diplexer is coupled to first diplexer and extractor and configured to combine second and third signals into a WWAN signal.

This invention discloses an IPMSM position estimation method and system based on rotating high-frequency injection, comprising: (1) injecting a high-frequency voltage signal into the stationary α-β coordinate axis of the motor; (2) sampling the three-phase current and obtaining the two-phase stationary coordinate system through Clark transformation; (3) obtaining the fundamental current through a notch filter; (4) obtaining the high-frequency response current of the stationary α-β coordinate axis; (5) rotating the transformation and obtaining the high-frequency response negative sequence current through low-pass filtering; (6) designing and modulating the compensation phase; (7) cross-multiplying the compensation phase vector with the modulated compensation phase vector to obtain the estimated angular velocity and rotor position of the motor. This invention uses a notch filter to process the signal, eliminating the band-stop filter in the d-axis and q-axis current feedback loop in the control loop, thus simplifying the system complexity; by compensating for the rotor position lag angle, it increases the system stability and improves the rotor position identification accuracy.

The invention relates to a device (1) for adjusting a steering position (X) of a motor vehicle, wherein the device (1) comprises at least a steering position control (2), an actuator (3), and a steering mechanism (4), wherein at least one steering position (X) is supplied to the steering mechanism (4) as a feedback variable to the steering position control (2), wherein at least one disturbance source exerts a vibration signal on at least one steering variable, which is fed back to the steering position control (2) as a feedback variable, wherein a unit (6) is provided in a feedback path (9) for at least one feedback variable, which has a phase-controlled loop and amplitude control for compensating the vibration signal, the output signal (V) of which k ) is subtracted from the feedback variable and / or a low-pass filter (10) or a band-stop filter is arranged in a feedback path (9) of at least one feedback variable, as well as a method.

An amplifier includes: a high-frequency input terminal; a high-frequency output terminal; a multistage circuit provided between the high-frequency input terminal and the high-frequency output terminal and including two or more amplifiers and connected in series, each amplifier including an input matching circuit, a transistor, and an output matching circuit; a stabilizing circuit provided in at least two of the amplifiers and including a bandpass filter and a resistor connected in parallel; and a band-rejection filter provided between the at least two of amplifiers and eliminating a frequency lower than an operation frequency of the amplifier. The stabilizing circuit and the band-rejection filter are provided between an output terminal of the transistor of the amplifier and the output matching circuit or provided in the output matching circuit. The closer to the high-frequency input terminal the bandpass filter is, the lower a resonance frequency of the bandpass filter is.

Enhancing spurious rejection in an acoustic filter circuit is provided. Specifically, the filter circuit includes an acoustic bandpass filter circuit and an acoustic bandstop filter circuit. In embodiments disclosed herein, the acoustic bandpass filter circuit and the acoustic bandstop filter circuit can be integrated into either a single semiconductor die or a single system-in-package (SiP). By integrating the acoustic bandstop filter circuit with the acoustic bandpass filter circuit, it is possible to enhance spurious rejection with minimum impact on insertion loss and passband performance to thereby improve overall performance of the acoustic filter circuit. Moreover, it is possible to reduce fabrication variation and cost of the acoustic filter circuit as well.

The invention discloses a large-range coupling adjustable structure of a band elimination filter, and belongs to the field of band elimination filters. A large-range coupling adjustable structure of a band elimination filter comprises a cavity and further comprises an input connector and an output connector which are arranged on the outer walls of the two sides of the cavity respectively. The cover plate is arranged on the cavity, and a plurality of groups of frequency tuning screws are arranged on the cover plate; the plurality of groups of resonant columns are fixedly connected in the cavity, and the plurality of groups of resonant columns are respectively matched with the plurality of groups of frequency tuning screws; the copper sheet is arranged in the cavity, and the two ends of the copper sheet are matched with the input connector and the output connector respectively; the auxiliary tuning screw is arranged on the cover plate, and the bottom of the auxiliary tuning screw penetrates through the cover plate and is arranged in the cavity; according to the invention, the problems of difficult design and debugging, long debugging time span and the like of the band elimination filter in the design, assembly and debugging process are solved, and the characteristics of stability, consistency, reliability, operability, low cost and the like are improved.

A high-frequency tunable bandstop filter based on a YIG substrate belongs to the field of microwave magnetic device technology. It includes a YIG substrate, functional metal layers and ground metal layers formed on the front and back sides of the YIG substrate; the functional metal layers include a microstrip line structure penetrating the YIG substrate, and a square open-loop resonant ring structure disposed on one side of the microstrip line structure. This invention utilizes the tunable permeability of the YIG substrate as a tuning source, overcoming the limitations of traditional fixed resonant structures and methods using semiconductor varactor diodes, ferroelectric materials, or piezoelectric materials, which cannot meet the poor adaptability to high-frequency scenarios and environments. It achieves precise suppression of dynamic electromagnetic interference frequencies at their source; by employing a composite structure of a square open-loop resonant ring and a microstrip line, and YIG substrate-compatible semiconductor wafer technology, it achieves real-time high-frequency signal tuning processing, meeting the current low-cost and high-integration industrial application value.

The invention provides a double-frequency cavity band-stop filter based on a defect ridge waveguide, relates to the technical field of wireless communication, and solves the problems that a waveguide band-stop filter in the prior art is usually formed by loading stub resonators on a main waveguide transmission line at an interval of odd number times of 1 / 4 waveguide wavelength, and although the performance is good, the band-stop filter cannot be used normally. However, the additional resonant cavity causes the technical problems of large structure size and complex processing. According to the technical scheme, through grooves with step widths are etched in a metal ridge in the transmission direction to construct defect ridge waveguide band elimination units, and the double-frequency band elimination filter based on the defect ridge waveguide structure is provided. According to the invention, an extra resonant cavity is avoided, the size of the device is reduced, the passband insertion loss is relatively low, the stopband suppression level is good, and excellent performance is shown.