35 results about "Kaiser window" patented technology

Disclosed is an electroencephalogram signal processing method and device. Acquired electroencephalogram signals are subjected to amplification preprocessing, Kaiser Window processing is performed on digital electroencephalogram signals including alpha wave, beta wave, theta wave and delta wave, and index parameters of the electroencephalogram signals are obtained through amplitude analysis, time domain analysis and frequency domain analysis. The electroencephalogram signal processing device comprises an electrode sensor, a preprocessing device, an analog / digital (A / D) conversion unit, a digital signal processing unit, an output unit, a display control unit and a storage unit. The electroencephalogram signal processing device is combined with a computer software analyzing and processing device, and human-machine operation is utilized to achieve functions of result display, healthcare advice, voice prompt and the like. The electroencephalogram signal processing device is convenient, easy to use, low in cost, maintenance-free and capable of conveniently displaying the current mental state and electroencephalogram in real time for students, white-collar employees and mental workers.

The invention discloses a method and device for detecting voltage fluctuation and flicker based on an energy operator and spectrum correction. The method comprises the steps of: extracting an envelope signal of a voltage flicker signal by utilizing a Teager-Kaiser energy operator, and speeding up an operational speed to overcome influences from change of parameters such as a signal frequency, a waveform, an amplitude value and a sampled data length during the extraction of the flicker envelope signal and realize rapid and real-time detection of the flicker signal; and performing improved FFT (Fast Fourier Transform) spectrum correction analysis on the voltage flicker signal by adopting a Kaiser window function with a freely selectable proportion of a width of a main lobe to a height of a side lobe, and exactly obtaining the frequency and the amplitude component of the voltage flicker signal when the frequency, the waveform and the amplitude value of the flicker signal are changed excessively. The device based on the method comprises a signal conditioning unit, a data processing unit and a data storage and display unit all of which are connected in order. The detecting method is convenient for rapid and in-time detection process of the signal; and the device has a simple structure and is easy to realize.

The invention discloses a fundamental wave based on Kaiser Window bispectrum line interpolation FFT (Fast Fourier Transform) and a harmonic wave detection method. The method comprises the following steps: analog-to-digital conversion and low-pass filtration treatment is conducted on the signal to be detected; the Kaiser Window with free proportion selection between the attenuation of a main lobe and side lobes, flexible design realization, low side lobe level and quick attenuation speed is adopted to conduct windowing FFT operation on the signal; and bispectrum line interpolation algorithm is used for detecting base wave and harmonic quantities of the detected signal. The following aspects are included: (1) analog-to-digital conversion and low-pass filtration; (2) the FFT operation based on the Kaiser Window; (3) base wave and harmonic wave parameters derived by bispectrum line interpolation and polynomial fitting.

The invention discloses a harmonic analysis method based on the Kaiser window function double-spectral-line interpolation FFT. The method is suitable for analysis and monitoring on voltages, currents and harmonic waves of a power network. The method comprises the steps of firstly, using linear frequency modulation Z conversion for extracting fundamental wave signal parameters (amplitudes, frequencies and phase positions) from electric power signals containing the harmonic waves in a high-precision mode, then adding a Kaiser window function into the analyzed electric power signals to cut off the electric power signals, using the FFT for calculating frequency spectra of remaining signals, and precisely calculating parameters of the electric power harmonic waves according to interpolations of the Kaiser window function by the harmonic frequencies in a frequency domain. The method can effectively overcome fluctuations of fundamental frequencies, and influences of white noise on the harmonic analysis, under the non-integer cycle cut-off condition, the relative error of the frequency calculation of the 21-time harmonic signals is 1.4*10%, the relative error of the amplitude calculation is smaller than or equal to 0.002%, and the relative error of the initial phase position calculation is smaller than or equal to 0.0001%.

A dyadic spatial down sampling filter having tap values configured according to a Kaiser window function a beta factor of approximately 2.5, having approximately 1.5 side lobes, and having a down sampling ratio of approximately 1.9. The dyadic spatial down sampling filter may have tap values [−1, 17, 32, 17, −1] / 64. A dyadic spatial up sampling filter having tap values configured according to a Kaiser window function having a beta factor of approximately 1.5, having approximately 2 side lobes, and having an up sampling ratio of approximately 2. The dyadic spatial up sampling filter may have tap values [−5.44, 0, 20.71, 33.46, 20.71, 0, −5.44] / 64.0, or tap values [−5, 0, 21, 32, 21, 0, −5] / 64, or tap values [−5, 21, 21, −5] / 32.

An interpolation selecting method of image pantograph includes using a weighting sequence to make amplitude be attenuated slowly to be zero near two ends of filter, naming this weighting sequence as window, calculating out cut-off frequency and transition bandwidth of filter according to image character of image to be contracted and enlarged then calculating out beta parameter of Kaiser window and length parameter N of window as well as parameter of Sinc function.

The invention discloses a method and device for configuring the boundary frequency band of an efficient filter rapidly. The method for configuring the boundary frequency band of the efficient filter rapidly comprises the steps that relevant pass band parameters of the filter and the translation parameters are obtained according to the pass band cut-off frequency of the filter and the order of the filter, and the filter coefficient with the length being 2N-1 existing before compensation is obtained according to the relevant pass band parameters of the filter and the translation parameters; a filter coefficient is obtained according to the filter coefficient existing before compensation, the Kaiser window parameter and a compensating filter coefficient analytic expression; the filter coefficient existing before compensation and a compensating filter coefficient are added, so that the final filter coefficient is obtained. The device for configuring the boundary frequency band of the efficient filter rapidly comprises an external RAM, a DSP, an output driver and a display circuit. According to the method and device for configuring the boundary frequency band of the efficient filter rapidly, parameters required for compensating the filter are calculated according to the filter coefficient existing before compensation and a transmission curve and are fed back to be stored in the external RAM, and all the parameters required for designing the filter are input into the DSP through the external RAM, so that the required filter coefficient and the transmission curve are obtained and are displayed through the output driver and the display circuit.

The invention relates to a method for realizing the frequency conversion of multi-sample rate signals by using window function, pertaining to the technical fields of digital transformer substations and wide area measurement of an electric grid. The method comprises the following steps: zero value interpolation of I time is operated on a sampled signal x (n) to obtain an interpolation sequence x1 (1) of I time; Kaiser window FIR low pass filtering, with window length of 10 and Beta value equaling to 7.865, is operated on the signal x1 (1) to obtain a signal y1 (1); Extraction of D time(s) is operated on the signal y1 (1) to obtain a converted signal y (m). The method can complete frequency normalization of different-sample rate signals by using the three-stage-connection of extraction, interpolation and Kaiser window FIR (Finite Impulse Response Filter) low pass filtering, thus totally avoiding the occurrence of aliasing and mirror images of the sampled frequencies.

The invention discloses an electric energy metering method based on Kaiser window FFT four-peak interpolation. The electric energy metering method comprises steps that based on a Kaiser window FFT four-peak interpolation modification formula, FFT frequency shift, and frequency spectrum of a window function Kaiser, amplitudes of symmetrical spectral lines on left sides and right sides of fundamental wave, harmonic wave, and interharmonic wave peak value frequency points are acquired, and by using a polynomial fitting formula, the general amplitude, phase, and frequency interpolation modification formula of the signal fundamental waves, the harmonic waves, and the interharmonic waves is acquired; according to the general amplitude, phase, and frequency interpolation modification formula, the amplitude parameters, the phase parameters, and the frequency parameters of the fundamental waves, the harmonic waves, and the interharmonic waves of measured voltage signals and measured current signals are calculated; fundamental wave electric energy, harmonic wave electric energy, interharmonic wave electric energy, and total electric energy are calculated. The electric energy metering method is advantageous in that according to a four-peak interpolation modulation algorithm, by fully using the symmetrical performance of the left and right four spectral lines of the amplitude frequency points and the main lobe performance and the side lobe performance of the Kaiser window function, high calculation accuracy is provided.

The invention discloses a method of fast phase correction processing of seismic data. The method adopts a Kaiser window Hilbert factor sequence, confirms a Hilbert seismic sequence and directly calculates and confirms a best phase correction factor the through estimation of phase information of residual wavelets, the phase correction processing the is carried out on seismic data records, the fact that influences of the residual wavelet phases are eliminated is achieved, so that the residual wavelet phases reach or are close to a zero phase so as to effectively improve the resolution ratio of the seismic data. The method of the fast phase correction processing of the seismic data only processes the phase of the seismic data wavelets, does not change amplitude spectrum of the data and has the advantages of being little in calculated amount, high in computation speed, good in stability and high in computational accuracy of the correction processing of the phase and has a certain anti-noise property.

The invention discloses an image fusing method based on Kaiser window FFT single-peak interpolation and modification. The method includes the steps of obtaining the universal amplitude, phase and frequency interpolation and modification formula of signal fundamental waves, harmonic waves and inter-harmonic waves through a polynomial fitting formula on the basis of a Kaiser window FFT single-peak interpolation and modification formula, the frequency shift property of an FFT and the amplitude of the maximum spectral lines and secondary spectral lines of a window function Kaiser frequency spectrum on the left side and the right side of a fundamental wave, harmonic wave and inter-harmonic wave peak frequency point, calculating to-be-tested image signals according to the universal amplitude, phase and frequency interpolation and modification formula, and calculating fusing efficiency. By means of a single-peak interpolation and modification algorithm, through the flexibility of Kaiser window function shape parameters, the interpolation and modification of high-precision harmonic wave parameters of dynamic signals are achieved, and the high image fusing degree is achieved.

The present invention relates to a projector trapezium correction system. On the output end of picture current of projector the invented projector trapezium correction system can be adopted to make image processing. Said processing method includes the following steps: firstly, making the picture current be passed through A / D converter circuit to obtain digital signal, after having been processed making the digital signal be passed through D / A converter circuit to obtain analog signal and output it; using FPGA chip as image processing core chip, the FPGA chip is connected with data and control port of microprocessor, utilizing microprocessor to control FPGA to execute operation, said microprocessor has memory, clock and power supply module, image processing software is used for processing video signal, in which pretreatment adopts Kaiser window and Sinc function filter to make filtration, the correction adopts line interpolation algorithm and ZEROPAD edge sawtooth correction technique and signal communication between chips adopts I2C bus connection.

The present invention discloses an estimation method based on broadband OFDM system frequency-dependent Doppler shift. Signals are transmitted by the wireless channels, when a reception end and a transmission end exist the relative movement, frequency deviation is generated between a reception signal and a sending signal, namely a Doppler effect occurs, and the more drastic is the relative movement, the severer is the Doppler effect. In a broadband OFDM system, the Doppler shift of the system changes along with the change of the frequency. In order to estimate the frequency-dependent Doppler shift of the broadband OFDM system, the method of the present invention firstly adopts two pilot frequency clusters to estimate the Doppler shift on two different subcarriers of the system respectively, and then adopts a linear fitting mode in a frequency domain to estimate to obtain the Doppler shift of the whole frequency domain, namely, the Doppler shift of all subcarriers. In addition, in order to improve a Doppler shift estimation effect, the present invention also adopts a method of adding a Kaiser window in a time domain to improve. The estimation method of the present invention has the advantage of good error performance.

A measurement method for subsynchronous and supersynchronous phasors of a power system voltage harmonic wave comprises the following steps of (1) collecting power grid voltage signals and performing data preprocessing, and performing time domain Kaiser window processing on the obtained voltage sampling data; (2) sequentially performing local discrete Fourier transform in frequency bands on the windowed data, and calculating spectral line amplitude values in each frequency band; (3) counting and arranging the spectral line amplitude values in each frequency band except a fundamental frequency to obtain a spectral line having a specific amplitude value; (4) performing double-spectral-line interpolation calculation between the two adjacent maximum amplitude values for the obtained spectral line amplitude values to obtain a frequency correction coefficient, thereby determining frequencies of sub-synchronous and super-synchronous components; and (5) calculating by using the frequency correction coefficient to solve a corrected formula of the amplitude values and phases, and obtaining the amplitude values and phases of the subsynchronous and supersynchronous components. According to themeasurement method for the subsynchronous and supersynchronous phasors of the power system voltage harmonic wave, Kaiser window function processing is performed on the sampled data in equal intervalfrequency bands, and the obtained specific spectral lines are subjected to correction processing to obtain the subsynchronous and supersynchronous frequencies, amplitude values and phases.

The invention discloses a flexibly-configured low cost fiber disturbance event end point detection method and a flexibly-configured low cost fiber disturbance event end point detector. The method comprises steps that a frequency shift filter coefficient is acquired through stop band width, frequency translation amount and filter frequency vector length, Fourier transform for the frequency shift filter coefficient is carried out, a compensation filter coefficient is further acquired through a Kaiser window and a rectangular window; a frequency shift compensation low pass filter coefficient is acquired through the frequency shift filter coefficient and the compensation filter coefficient; the frequency shift compensation low pass filter coefficient is processed, and a high pass filter is acquired; a signal after downsampling is inputted to the high pass filter, and a filtering output sequence is acquired; the first position of the filtering output sequence having an energy value greater than the energy threshold is searched, and the position is the disturbance start point. The detector comprises an analog-digital converter, an FFT analyzer and a DSP device. Through the method and the device, parameter adjustment can be realized, various environment background demands can be satisfied, and quite high timeliness and relatively low cost are realized.

Disclosed is a geophone and hydrophone seismic data matching method. The land geophone and hydrophone seismic data matching method comprises collecting and preprocessing seismic data of a land geophone and a hydrophone; computing a Kaiser window Hilbert factor sequence; according to a land geophone seismic data sequence and the Kaiser window Hilbert factor sequence, computing a land geophone data Hilbert seismic channel sequence; according to the land geophone data Hilbert seismic channel sequence, computing land geophone and hydrophone data correlated sequences; according to the land geophone and hydrophone data correlated sequences, computing the characteristic coefficient of a phase matching factor characteristic equation; computing the correlated sequence of phase matching data of the hydrophone and the land geophone; according to the correlated sequence, structuring and solving an amplitude matching factor characteristic equation; according to the amplitude matching factor characteristic equation, performing data amplitude matching of the geophone.

The invention discloses a timing tracking method and apparatus used in a DMR (Digital Mobile Radio) system and is directed to the field of wireless communication technology. The timing tracking apparatus comprises a base-band orthogonal signal difference extractor, a timing deviation extractor, a weight average arithmetic unit and an interpolation corrector. The base-band orthogonal signal difference extractor carries out a digit down conversion processing towards DMR physical layer modulation signals to obtain base-band orthogonal signals I (k) and Q (k). A difference operation and an arc tangent operation are carried out towards the base-band orthogonal signals I (k) and Q (k) to obtain a difference [fai] (k). The timing deviation extractor extracts a timing discrepancy based on [fai] (k) signal characteristics to obtain the timing discrepancy value e (k) of the present signal. The weight average arithmetic unit utilizes a weight value [omega] to carry out a weight average operation towards the extracted timing discrepancy value e (k) and outputs an average value f (k). The interpolation corrector utilizes Kaiser Window and the average value f (k) to carry out an interpolation correction towards the different [fai] (k) to obtain a correction value y (k). According to the timing tracking method and apparatus in the invention, the timing deviation can be accurately estimated and compensated. The invention is suited for the 4CPFSK signal demodulation in the DMR system.

The present invention relates to a low-pass digital filter method suitable for DC line protection. Its technical features include the following steps: Step 1. Research and select a low-pass filter designed with a Kaiser window as a low-pass digital filter for DC line protection. Step 2, get β=7.865 in the Kaiser window function, N=21, calculate the coefficient of the Kaiser window low-pass digital filter; Step 3, multiply successively with the sampling value array x (n) of DC line protection Add the series of ω(n) to calculate the output series after filtering by the Kaiser window low-pass digital filter; step 4, send the series y(n) obtained by filtering into the program of DC line protection to perform protection judgment According to the calculation. The invention can accurately extract the DC components in the voltage and current from the sampling signals containing the DC components, transient high-frequency oscillation components and noise, provide correct measurement quantities for the backup protection of the DC line, and ensure the backup of the DC transmission line Selectivity of protective actions.

The invention discloses an image fusion method based on Kaiser window FFT four-peak interpolation modification. The method comprises the steps that based on a Kaiser window FFT four-peak interpolationmodification formula, FFT frequency shift and amplitude values of the frequency spectrum of a window function Kaiser at four symmetrical spectral lines at the left side and right of fundamental wave,harmonic wave and inter-harmonic wave peak value frequency points, a general amplitude, phase and frequency interpolation modification formula of the signal fundamental waves, the harmonic waves andthe inter-harmonic waves is acquired by using a polynomial fitting formula; amplitude parameters, phase parameters and frequency parameters of the fundamental waves, the harmonic waves and the inter-harmonic waves of measured image signals are calculated according to the general amplitude, phase and frequency interpolation modification formula; and thus the fundamental waves, the harmonic waves and the inter-harmonic waves are calculated. The image fusion method utilizes a four-peak interpolation modification algorithm, makes full use of the symmetrical performance of the four spectral lines at the left and right of the amplitude frequency points and excellent main lobe and sidelobe performance of the Kaiser window function and has high calculation accuracy.

The invention discloses a measuring method of the strain dynamic coefficient. The measuring method comprises the following steps that step (10): dynamic strain sample collection is carried out, wherein a grating strain meter is matched to a strain acquisition system, then the grating strain meter acquires dynamic strain of a measuring point, and a dynamic strain sample is formed; step (20): the FIR Kaiser window filter parameters are designed, an ideal filter mode is set to be the ideal low pass filtering mode, and the cut-off frequency, the transition band and the ripple of the FIR Kaiser window filter are determined; step (30): the FIR Kaiser window filter is generated, and the dynamic strain sample is filtered; step (40): the dynamic coefficient of the structure local strain is measured. The measuring method can accurately measure the dynamic coefficient of the structure local strain.

The invention provides a transformer calibrator verification method and a transformer calibrator verification system based on Kaiser window FFT filtering. The transformer calibrator verification method and the transformer calibrator verification system adopt automatic verification software of an upper computer and mainly achieve the functions of automatically verifying a transformer calibrator according to national metrological verification regulations, automatically recording test data, being capable of printing all records and a verification certificate required by the regulations, calculating a ratio difference value and an angular difference value according to a set measuring point output signal, and comparing calculation results, thereby ensuring the verification precision and verification efficiency; a Kaiser window FFT filtering algorithm is adopted for extracting fundamental waves, a main influencing factor for extracting differential value signal fundamental wave components ischannel leakage caused by frequency fluctuations, and leakage is reduced by increasing data sampling points, namely, reducing the width of a main lobe of a rectangular window; and since the filteringalgorithm based on fundamental wave has good adaptability to frequency fluctuations, real-time tracking of frequency can be realized, and the precision of fundamental wave extraction can be greatly improved.

The application discloses a method for measuring the repeatability of time-lapse seismic data, which belongs to the technical field of oil field exploration. The method includes: firstly making a difference between the start data and the monitoring data to obtain the difference data, and then using the Kaiser window Hilbert operator to respectively obtain the Kaiser window Hilbert channel data corresponding to the start data, the monitoring data and the difference data, Then the envelope data of the seismic data is obtained, the envelope sum is calculated by using the envelope data, and the repeatability factor of the envelope feature is obtained, and the truncation threshold is finally determined, and the repeatability factor of the envelope feature is converted into an envelope by using the truncation threshold In this way, according to the envelope feature repeatability indicator factor with a value of 0 or 1, it is possible to intuitively measure whether the seismic data is repeatable.

The invention provides a scanning nondestructive testing system and method based on a weak magnetic sensor and belongs to the field of nondestructive testing. The method comprises the following steps:carrying out excitation on a test system by utilizing a magnetic field with a fixed frequency of 4Hz; controlling two sliding blocks to move on synchronous guide rails by utilizing two stepper motorsto form a transmission apparatus, so that the weak magnetic sensor fixed on the sliding block is allowed to scan the entire sample surface; collecting measurement data and position information of theweak magnetic sensor in real time by utilizing a data acquisition module; and carrying out band-pass filtering and pseudo image processing on the data collected by the data acquisition module by utilizing a data processing and pseudo-imaging system, thereby realizing detection and location of internal defects of material. The method can detect the internal defects of the composite material; and due to existence of excitation of an external stable magnetic field and band-pass filtering realized by utilizing a Kaiser window during data processing, the method can be used when the experimental environment has great interference.

The invention discloses a method for extracting time-frequency parameters of power quality disturbance signals on the basis of fast K-S (Kaiser-S) transformation. The method includes steps of (1), sampling the tested samples; (2), performing the fast K-S transformation on the tested signals; (3), repeating executing the step (2) until amplitudes, phases and start-stop and sudden-change moments of all the disturbance signals are analyzed, and extracting the time-frequency parameters of the power quality disturbance signals. Compared with the prior art, the method has the advantages that Kaiser windows replace Gauss windows for traditional S transformation, widths and heights of Kaiser window functions can be adaptively adjusted along with change of frequencies, and the energy accumulation and frequency adaptive adjustment capacity of time-frequency analysis of the traditional S transformation can be improved; the computational complexity can be reduced by means of judging characteristic frequencies; the method is wide in application range, and the fast K-S transformation and the method for extracting the time-frequency parameters of the power quality disturbance signals have a wide application prospect in fields of vibration signal analysis, fault diagnosis, pattern recognition, noise measurement and biomedical examination.

The invention discloses a dynamic phasor estimation method and system based on Kaiser windows. The method comprises the following steps: firstly, building a phasor estimation model of a power oscillation signal, obtaining the amplitude-frequency response of the oscillation signal under different side lobe attenuation conditions through adjusting a Bessel parameter beta of the Kaiser windows, and building a Taylor derivative estimation equation set based on a plurality of Kaiser windows in order to improve phasor estimation precision under power oscillation; and secondly, solving a Taylor derivative to be solved in an equation set by using a least square estimation method to obtain a fundamental component of the electric power oscillation fundamental frequency signal. In practical application, phase shift operation is adopted to correct deviation between reference time and report time of a satellite time service system, and a final accurate result of phasor estimation is output. Accurate phasor measurement under the power oscillation condition is achieved, and the test results of standard dynamic modulation and RTDS signal generation show that when power oscillation happens to a power system, the method has high dynamic estimation precision and meets various indexes of the measurement standard.