626 results about "Band-pass filter" patented technology

A tracking and adaptive compensation method for power fluctuation of a pulse load of a ship is provided. The method includes: based on a microgrid topology model of the ship, a pulse load model of the pulse load, and an interharmonic power and pulse parameter relationship model, performing power fluctuation tracking, frequency selection and a power spectrum analysis to obtain filtering parameters of a low-pass filter and filtering parameters of a band-pass filter; performing waveform adaptation to eliminate a phase delay caused by the low-pass filter and the band-pass filter, and obtaining a control command for a power compensation strategy; and generating, by a power loop, a pulse width modulation (PWM) signal to control a switching tube in a bidirectional direct current (DC) / DC converter of each of an energy storage battery pack and a supercapacitor of a hybrid energy storage system.

The invention belongs to the technical field of signal acquisition and processing, and discloses a low-noise biopotential signal acquisition system and a low-noise biopotential signal processing method. An original bioelectricity signal of a human body is collected through an electrode array, and analog-to-digital conversion is carried out after the signal is processed by a multi-stage self-adaptive filtering and amplifying circuit. A digital signal is sequentially subjected to adaptive wavelet transform denoising and empirical mode decomposition to obtain a multi-level intrinsic mode function set, an intrinsic mode function of a characteristic frequency band is extracted from the multi-level intrinsic mode function set, and the signal is reconstructed. Introducing a dual noise reduction mechanism combining adaptive wavelet transform and empirical mode decomposition; a signal quality real-time evaluation system is established, and system parameters including the gain of a variable gain amplifier and the bandwidth of a dynamic band-pass filter are dynamically adjusted through closed-loop feedback. The self-adaptive optimization of the whole biopotential signal acquisition process is realized, various interferences are effectively inhibited, the signal characteristics are reserved, and the signal-to-noise ratio is remarkably improved.

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 relates to a system and a method for making a colored low-light image. The system for making the color low-light-level image comprises a high-sensitivity CMOS imaging module which is used for enhancing the photon collection capability and reducing the noise level to complete imaging; the image enhancement processing module adopts a histogram equalization algorithm and comprises the steps of calculating a gray histogram of the original image, calculating a cumulative distribution function according to the gray histogram and performing gray mapping to obtain an enhanced gray value; the image noise reduction processing module is used for carrying out noise reduction on the image after enhancement processing, and filtering is carried out by adopting a night image noise reduction technology, a bilateral filtering method including spatial domain noise reduction and a band-pass filter including frequency domain noise reduction; and the colorful low-light-level image generation module obtains a colorful low-light-level night vision image by adopting an interpolation algorithm and makes a colorful low-light-level image. According to the system and the method for manufacturing the colored low-light-level image, special equipment is not depended on, the imaging quality of the colored low-light-level image can be improved, and the colored low-light-level image can be manufactured.

The invention discloses a permanent magnet motor turn-to-turn short circuit fault diagnosis method considering complex working condition influence, belongs to the technical field of permanent magnet motor fault diagnosis, and aims to solve the problems that a turn-to-turn short circuit diagnosis result of a permanent magnet synchronous motor for an electric vehicle is easily influenced by working conditions and slight faults are difficult to diagnose under complex operation working conditions. The method comprises the following steps: step 1, high-frequency signal injection and information acquisition; injecting the high-frequency rotating voltage signal into a motor control system under a natural coordinate system, and collecting each phase of high-frequency current and each phase of high-frequency voltage of the motor through a band-pass filter; 2, subtracting the high-frequency voltage from the healthy voltage under the condition that the high-frequency signal is injected, and calculating to obtain a high-frequency voltage residual error of each phase; 3, according to the high-frequency voltage residual error of each phase, obtaining two fault characteristic quantities, namely the standard deviation of the high-frequency voltage residual error and the absolute average value of the high-frequency voltage residual error of each phase; and 4, judging whether a turn-to-turn short circuit fault occurs or not according to the fault characteristic quantity, and judging a fault phase.

The invention relates to a fusion power supply harmonic suppression method based on an energy storage type STATCOM. The method comprises the following steps: determining a harmonic amplification factor K value; selecting and designing a proper discrete digital band-pass filter, and detecting a target frequency band and filtering characteristic sub-harmonics; the detected harmonic voltage amplitude and phase are used as references, an energy storage type STATCOM is adopted to output same-frequency and same-phase harmonic current, virtual damping is formed at a grid-connected point, a K value is used as a damping coefficient, the output harmonic current reference amplitude is determined, virtual harmonic damping is controlled, and harmonic resonance is suppressed. The virtual harmonic damping method for the energy storage type STATCOM is provided for accurate tracking of low-frequency harmonic and inter-harmonic voltage amplitudes and phases, the chain type STATCOM has the advantages of being high in high-voltage direct-hanging efficiency, high in redundancy fault-tolerant capability and the like and is suitable for high-voltage large-capacity scenes, virtual damping control achieves harmonic suppression by adjusting virtual damping at the harmonic frequency of a control structure, and the energy storage type STATCOM can be applied to high-voltage large-capacity scenes. And the system stability can be effectively improved while harmonic waves are treated.

The invention discloses a track fault identification method and system based on HSROA, and the method comprises the steps: calculating a frequency band entropy value of at least one IMF component signal, and selecting a sensitive IMF component signal from the at least one IMF component signal according to the frequency band entropy value; filtering the sensitive IMF component signal for the second time according to a band-pass filter to obtain a target signal, and performing envelope power spectrum analysis on the target signal to obtain a fault characteristic frequency; fusing the fault feature frequency with a time domain feature, a frequency domain feature and a time-frequency domain feature in the track vibration signal to obtain a fusion feature vector, and constructing a fusion feature matrix according to the fusion feature vector; and inputting the fusion feature matrix into a preset deep belief network for iterative training to obtain a track fault recognition model, inputting the obtained real-time track vibration signal into the track fault recognition model, and outputting the track fault recognition model to obtain a track fault recognition result.

A method and apparatus for converting an input frequency to a voltage signal using a passive band-pass filter. The method includes providing an input signal having a specified frequency and amplitude to a passive band-pass filter. The method also includes obtaining an attenuated signal corresponding to the input signal from the passive band-pass filter. The method also includes providing the attenuated signal to a peak detector to obtain a direct current (DC) signal having an output voltage proportional to the specified frequency. The passive circuitry includes a first circuit to receive an input signal having a specified frequency and amplitude, and output an attenuated signal corresponding to the input signal. The passive circuitry also includes a second circuit to convert the attenuated signal to a DC signal having an output voltage proportional to the specified frequency.

The invention discloses a self-adaptive damping controller and a wind power grid-connected system oscillation suppression method thereof, and the method comprises the steps: building a wind power grid-connected system simulation model, obtaining a system closed-loop transfer function, and connecting the damping controller between a wind power plant side and a power grid side; calculating a logarithmic derivative, analyzing impedance characteristics, judging whether the wind power grid-connected system has an unstable oscillation mode or not, and if so, calculating oscillation frequency; carrying out adaptive parameter setting on the damping controller according to the oscillation frequency, wherein the adaptive parameter setting comprises setting of parameters of a band elimination filter, setting of parameters of a band pass filter, setting of the capacity of the damping controller and setting of parameters of a phase shift link; a current reference signal is generated through the subsynchronous damping calculator and then is converted into a three-phase current through the subsynchronous current generator, the three-phase current is injected into a power grid, the impedance characteristic under the oscillation frequency is adjusted, and system oscillation is restrained. Parameters can be adjusted according to the oscillation frequency, complexity is low, implementation is easy, and high efficiency and accuracy of oscillation suppression are met at the same time.

The invention belongs to the technical field of bridge body monitoring, and discloses a bridge crack propagation evaluation method and system based on acoustic emission signals. The method comprises the following steps: arranging an acoustic emission sensor array at a preset part of a bridge to collect original acoustic emission signals in a preset time period; processing by adopting a band-pass filter to obtain a filtered acoustic emission signal, and separating the filtered acoustic emission signal by using an empirical mode decomposition technology to obtain an effective acoustic emission signal; converting the effective acoustic emission signal by using time-frequency transformation to obtain a signal time-frequency diagram; constructing a crack propagation evaluation model, and obtaining a crack propagation rate and a serious state grade; obtaining a crack space positioning result through crack space positioning; respectively carrying out weighted fusion on the crack propagation rate and the serious state grade of the J sensors, combining with a spatial positioning result and a bridge model, and presenting in a three-dimensional form; according to the invention, more accurate crack positions can be obtained.

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 relates to the technical field of medical signal processing, in particular to a BCG signal processing method combining TimeGAN and a Butterworth filter, which comprises the following steps: carrying out preliminary noise reduction on an input BCG signal by adopting a Butterworth band-pass filter to obtain a filtered signal; performing phase compensation on the filtered signal by adopting a bidirectional filtering mode to obtain a signal without phase distortion; the trained TimeGAN model is adopted to carry out signal optimization on the signal without phase distortion, and an optimized signal is obtained; the TimeGAN model comprises a convolutional neural network which is used for inputting data in the TimeGAN model to carry out feature extraction so as to obtain corresponding local features; the long short-term memory network is used for carrying out time sequence modeling on the local features to obtain corresponding time sequence features; the multi-head attention mechanism is used for calculating weighted features based on the time sequence features; and the generator is used for generating an optimized signal according to the weighted characteristics.

The invention discloses an underground target positioning method based on a rotary permanent magnet type magnetic beacon, and belongs to the field of navigation, guidance and control. According to the invention, the problem of low precision of an existing positioning method caused by attitude errors in an underground positioning scene is solved. The method specifically comprises the following steps of: 1, respectively placing four same rotary permanent magnet type magnetic beacons at four points with known spatial positions, and respectively rotating the four magnetic beacons around a fixed shaft at a set rotating speed; 2, placing a magnetic sensor at an underground target point, and collecting mixed alternating magnetic field data under a sensor coordinate system by using the magnetic sensor; step 3, filtering the acquired mixed alternating magnetic field data by using a designed band-pass filter to obtain an alternating magnetic field vector of each rotating permanent magnet type magnetic beacon at the underground target point; constructing a positioning model according to the alternating magnetic field vector; and 4, obtaining an estimated target point position according to the positioning model. The method can be applied to underground target positioning.

The embodiment of the invention provides a chip atomic clock based on a speed grating spectrum and an implementation method. Comprising a multi-frequency coherent laser source, a quarter-wave plate, an atomic gas chamber, a photoelectric detector, a band-pass filter, a microwave modulation and demodulation module, a crystal oscillator, a phase-locked loop module, a bias-tree module, a DC modulation and demodulation module and a servo control module. The multi-frequency coherent laser source is sequentially connected with the quarter-wave plate, the atomic gas chamber, the photoelectric detector and the band-pass filter, the first output end of the band-pass filter is sequentially connected with the microwave modulation and demodulation module, the crystal oscillator and the phase-locked loop module, and meanwhile the microwave modulation and demodulation module is connected with the phase-locked loop module. And the second output end of the band-pass filter is connected with the DC modulation-demodulation module and the servo control module in sequence. And the bias-tree module is connected with the servo control module and the phase-locked loop module and feeds back a coupled signal to the multi-frequency coherent laser source so as to complete whole clock locking. The atomic clock is used for achieving the effect of improving the spectral line signal-to-noise ratio.

The invention discloses a non-contact heart rate estimation method and system based on multi-modal signal fusion, and relates to the technical field of image processing, and the method comprises the steps: positioning a region of interest in a face video, extracting HSV and Lab color space signals, and fusing the HSV and Lab color space signals; suppressing ambient light interference through background brightness compensation to obtain a color conversion signal and normalizing the color conversion signal; adjusting the bandwidth filtering signal of a band-pass filter by using the historical heart rate to generate an rPPG signal; performing time domain and frequency domain analysis on the rPPG signal, and performing weighted averaging by combining two results to obtain a heart rate estimation value; a historical data smoothing strategy is adopted to correct a heart rate estimation result to ensure accuracy. According to the method, high-precision non-contact heart rate estimation is realized through extraction and fusion of HSV and Lab color space signals, background brightness compensation, signal normalization and processing of human face video signals based on a historical heart rate adjustment band-pass filter.

The invention discloses an unbalanced load compensation method for a three-phase four-wire three-level converter. According to the method, a three-phase four-wire system three-level converter bridge arm voltage mathematical model is established based on sine carrier in-phase laminated modulation, and harmonic content analysis is completed; an SOGI-pro module is established (an error integration link is added at the input front end of a D axis of an SOGI filter, and D and Q axis second-order band-pass filters are transformed into third-order band-pass filters), so that the positive and negative sequence separation precision of three-phase unbalanced load voltage is improved. According to the method, the order of the SOGI filter is improved by reasonably designing a closed-loop transfer function, and the filtering effect of the SOGI filter in high and low frequency bands is enhanced. And a sequence-dividing imbalance compensation control loop is designed based on the three-sequence dq0 coordinate system, so that zero-static-error tracking of a positive-sequence fundamental component and powerful suppression of negative-sequence and zero-sequence imbalance components are realized. According to the invention, the accuracy of traditional positive and negative sequence separation is improved, so that the unbalanced load compensation effect under sequence separation control can be improved.

The invention discloses a correlation analysis-based magnetic suspension rotor system on-line time-lag identification method, which comprises the following steps of: generating a sine excitation signal through an excitation signal generator to excite a magnetic suspension rotor system, collecting a control voltage and a displacement signal, and introducing the control voltage and the displacement signal into a cross-correlation time-lag identifier to carry out time-lag identification. The time-delay identifier is composed of a band-pass filter, a conversion transfer function, a data storage module and a cross-correlation time-delay identification operation module. Voltage and displacement signals which are introduced into the cross-correlation time-lag identifier are firstly filtered through a band-pass filter and then converted into homologous signals through a conversion transfer function, then data storage and iteration are carried out by utilizing a data storage module, and finally the required time-lag amount is identified by utilizing a cross-correlation operation module. According to the method, the advantage that the magnetic suspension rotor system is active and controllable is utilized, extra testing equipment does not need to be used, the structure is simple, few computing resources are occupied, time delay information in the system can be obtained online, and time delay identification of the magnetic suspension rotor system is achieved.

The invention provides a multi-antenna switching system and a control method. The system comprises a radio frequency interface module, a single-pole double-throw switch module, a single-pole three-throw switch module, a coupler, a band-pass filter, a power amplification module, a power detection module and a control module. The method comprises the following steps: controlling a current working antenna, and collecting a real-time performance data set of each group of antennas; evaluating and comparing all the antenna groups, and screening out a target antenna group; and judging whether the current working antenna and the target antenna group are the same group or not to perform antenna switching to obtain a new antenna group, and continuously monitoring the performance change of the new antenna group. According to the invention, the automatic selection and adaptive switching of the optimal antenna of the communication equipment under the multi-antenna condition are realized, the signal quality and stability are greatly improved, manual intervention is avoided, the self-healing and adaptive capabilities of the equipment are improved, the dynamic complex change of a network environment is supported, and the method can be widely applied to scenes such as 5G, Internet of Things, wireless communication and mobile terminals.

A radio frequency communication filter based on voltage tuning comprises an LC low-pass filter composed of a first set of parallel variable capacitance diode units, a second set of parallel variable capacitance diode units and an inductor L2, and an RC high-pass filter which is adjusted along with a tuning voltage control end VT and composed of a capacitor C2, a variable capacitance diode V17, a variable capacitance diode V18, a capacitor C4 and a resistor R2. A third group of parallel variable capacitance diode units, a fourth group of parallel variable capacitance diode units and an inductor L3 form an LC low-pass filter, and a capacitor C3, a variable capacitance diode V20, a variable capacitance diode V19, a capacitor C5 and a resistor R2 form another RC high-pass filter which is adjusted along with a tuning voltage control end VT. And the two band-pass filters are connected to form a high-selectivity and low-insertion-loss adjustable band-pass filter driven by the same controllable tuning voltage control end.

The invention discloses an automatic parameter compensation device for an intelligent fusion terminal and a concentrator. The automatic parameter compensation device comprises an aging prediction model training module used for generating a communication unit aging prediction model; the current data acquisition module is used for acquiring current data of the communication unit; the aging coefficient obtaining module is used for obtaining a first aging coefficient of the communication unit according to the current data; the input module is used for inputting current data into a communication unit aging prediction model to obtain initial aging degree data; the aging degree obtaining module is used for obtaining actual aging degree data according to the first aging coefficient and the initial aging degree data; and the automatic compensation module is used for controlling the low-noise amplifier and the band-pass filter to perform corresponding compensation according to the actual aging degree data. According to the invention, parameter compensation can be carried out on signal decline and bit error rate increase caused by aging of the communication unit, and the accuracy and reliability of data transmission are improved.

The invention belongs to the technical field of microwave circuits, and particularly provides a Z-shaped four-order small band-pass filter based on a quarter mode, so as to realize the performance characteristics of small size, light weight and high out-of-band rejection of the band-pass filter. The invention comprises a port coupling structure, namely an input coaxial port and an output coaxial port; the embedded tuning structure comprises a first tuning blind hole, a second tuning blind hole, a third tuning blind hole and a fourth tuning blind hole; a U-shaped windowing coupling structure; the through holes are positive symmetric short windowing through holes and oblique symmetric long windowing through holes; the Z-shaped filter cavity structure is a cavity with a silver-plated surface. According to the four-order band-pass filter, the high-dielectric-constant material is combined with partial surface silver plating of the cavity, so that a virtual magnetic wall is formed on the non-silver-plated surface to realize a quarter-mode working mode, and tuning and windowing coupling structures are combined to form the four-order band-pass filter. Due to the novel design thought, compared with a traditional full-mode band-pass filter, the full-mode band-pass filter has the advantages that the size and the weight are reduced by about 75%. The invention can be used in communication systems and millimeter wave related applications.

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 provides a heart sound classification method based on sample amplification and a noise attention network, which relates to the technical field of medical signal processing and artificial intelligence and comprises four steps of data set construction, data processing, heart sound classification model construction and classification result output. Noise outside the heart sound frequency range is filtered out through a band-pass filter and then input into a generative adversarial network to generate heart sound data, then a channel and space attention mechanism is introduced to facilitate extraction of meaningful features by a model, the model is enabled to converge more quickly, and then Gaussian noise with proper standard deviation is injected to obtain heart sound data. The robustness and generalization ability of the noise attention network with the channel and space attention mechanism are improved; along with gradual convergence of training, indexes such as accuracy, specificity and precision of the output cardiovascular disease types gradually tend to be stable, so that auxiliary diagnosis is provided during heart sound auscultation, the cardiovascular disease types are output, and a reliable basis is provided for heart sound auscultation results.

The invention discloses a high-frequency residual error-feature correlation type permanent magnet motor turn-to-turn short circuit fault diagnosis method, belongs to the technical field of permanent magnet motor fault diagnosis, and aims to solve the problems that fault features are easily interfered by working conditions and slight faults are difficult to diagnose when turn-to-turn short circuit diagnosis is carried out on an existing motor. The method comprises the following steps: step 1, high-frequency signal injection and information acquisition; injecting the high-frequency rotating voltage signal into a motor control system under a natural coordinate system; collecting each phase high-frequency current and each phase high-frequency voltage of the motor through a band-pass filter; 2, subtracting the high-frequency voltage from the healthy voltage, and calculating to obtain a high-frequency voltage residual error of each phase; step 3, obtaining fault characteristic quantity FIn of each phase according to the motor parameters, the high-frequency voltage of each phase and the high-frequency voltage residual error; and 4, judging whether a turn-to-turn short circuit fault and a fault phase occur or not according to the fault characteristic quantity of each phase.

A 4 frequency-shift keying (4FSK) transceiver is provided. The 4FSK transceiver includes both a 4FSK transmitter and a 4FSK receiver. The 4FSK transmitter includes a voltage-controlled oscillator (VCO) and two data links coupled to the VCO for delivering two parallel streams of input data bits to the VCO. For each pair of parallel input data bits received from the two data links, the VCO outputs a modulated signal having one of four operating frequencies via 4FSK modulation. Separately, the 4FSK receiver includes a power divider, for dividing the multi-frequency modulated signal into two paths of two binary bit streams, and a pair of low-noise amplifiers (LNAs) separately coupled to the two paths and configured as a pair of band-pass filters for filtering two different subsets of the four operating frequencies from the two binary bit streams into two filtered binary bit streams.

The invention relates to the technical field of classification and recognition, and provides a radar rotor target classification and recognition method, device and equipment and a medium, and the method comprises the steps: carrying out the digital processing of a radar rotor signal, uploading the radar rotor signal after pulse compression to a digital signal processing unit, extracting signal features and track features corresponding to the radar rotor signals in the digital signal processing unit, and identifying a first classification result of the rotor unmanned aerial vehicle according to the signal features and the track features; extracting a micro-motion feature of the radar rotor signal, and extracting a frequency band corresponding to the micro-motion feature through a band-pass filter; extracting a time-frequency graph corresponding to the frequency band uploaded to the radar terminal storage device, and identifying the time-frequency graph to obtain a second classification result of the rotor unmanned aerial vehicle; and fusing the first classification result and the second classification result to obtain a target classification recognition result corresponding to the rotor unmanned aerial vehicle. According to the invention, the accuracy of rotor unmanned aerial vehicle classification and identification can be improved.

The invention provides a same-time same-frequency-band full duplex communication device with rapid and agile frequency. Comprising a duplexer, a first frequency hopping wave trap, a first radio frequency amplifier, a first frequency hopping filter, a second frequency hopping wave trap, a second radio frequency amplifier, a second frequency hopping filter, a third radio frequency amplifier, a band-pass filter, an analog-to-digital converter, a standard frequency, a channel controller, a baseband processor, a digital-to-analog converter, a fourth radio frequency amplifier and a third frequency hopping filter. A fifth radio frequency amplifier; and a fourth frequency hopping filter. According to the simultaneous same-frequency-band full-duplex communication device with the fast and agile frequency, the working frequency of the full-duplex communication device covers 100 MHz to 1 GHz, the frequency range is wide, the communication efficiency is high, time delay is small, self-interference generated by a local transmitter is effectively restrained, application of a full-duplex communication system in the wide-frequency-band simultaneous same-frequency-band high-speed frequency hopping process can be met, and the full-duplex communication device is suitable for wide-frequency-band simultaneous same-frequency-band high-speed frequency hopping. The transceiving isolation of the system duplexer is greater than 30dBc, and the notch suppression capability of the receiving path is greater than 65dBc.

The invention provides a BOTDR system Brillouin gain spectrum correction method and system based on a symmetric kernel, and belongs to the technical field of optical fiber sensing. The method comprises the following steps: acquiring Brillouin gain spectrum information along a sensing optical fiber; acquiring amplitude-frequency responses of the balanced photoelectric detector and the band-pass filter in a full frequency band by using a vector network analyzer; performing convolution processing on the obtained Brillouin gain spectrum information along the sensing optical fiber and the amplitude-frequency response of the balanced photoelectric detector and the band-pass filter in the full frequency band to obtain a corrected Brillouin gain spectrum; lorentz fitting is carried out on the corrected Brillouin gain spectrum to extract Brillouin frequency shift, and the Brillouin frequency shift is converted into temperature and strain information. The spectral line symmetry and the signal-to-noise ratio are improved, the symmetry of the corrected Brillouin gain spectrum is remarkably enhanced, the phenomena of peak offset and asymmetric broadening caused by system bandwidth limitation are eliminated, and the extraction precision of the Brillouin gain spectrum is remarkably improved.

The invention relates to an electromagnetic coil excitation signal modulation device and method. A control module outputs a PWM signal of a target frequency to a signal adjustment module, and sends a control voltage corresponding to the target frequency to a voltage-controlled adjustable center frequency point band-pass filter; the signal adjusting module receives the output voltage sent by the control module, performs feedback adjustment according to the output voltage and a sampling signal output by the feedback sampling module, and outputs an amplified PWM signal with the same frequency as the PWM signal to the voltage-controlled adjustable center frequency point band-pass filter; the voltage-controlled adjustable center frequency point band-pass filter modulates the amplified PWM signal into a same-frequency sine wave signal according to the control voltage sent by the control module and sends the same-frequency sine wave signal to the power amplification module; and the power amplification module performs power amplification on the same-frequency sine wave signal and outputs an excitation signal to the electromagnetic coil. On-line continuous adjustment of a center frequency point is supported, signal modulation is more accurate, and the use reliability in a complex electromagnetic environment is improved.