40 results about "Fourier analysis" patented technology

The invention relates to the technical field of power grid safety evaluation, in particular to a power system short-circuit parameter prediction method, system and device based on time-space relevance and a storage medium. A multi-dimensional state vector including a node voltage vector, a branch current vector, a short-circuit impedance matrix, spatial position information and a time feature vector is constructed, and a space-time correlation feature vector including a time-dimensional feature, a spatial-dimensional feature, a space-time coupling feature and a state feature is extracted. Wavelet transform, Fourier analysis and graph theory analysis are adopted to identify a parameter change rule and a propagation effect. A multi-level prediction model of a statistical prediction layer, a deep learning layer and a fusion layer is constructed, and comprehensive description of dynamic characteristics of short-circuit parameters is realized through spatio-temporal feature fusion. A staged training strategy is adopted, and comprises the steps of establishing a basic model through offline training, updating parameters in real time through online learning, and quantifying uncertainty through a probability prediction framework. And a prediction correction mechanism and a reliability evaluation system are established, and a complete prediction-evaluation-correction closed loop is formed.

The application provides a method and device for graph data processing, and relates to the technical field of artificial intelligence, and the method comprises: a method for graph data processing, which comprises the following steps: acquiring graph data, extracting the basic structure features of the graph data through a static topology path, adaptively screening the key neighbor features in the graph data based on an attention mechanism and in combination with the basic structure features through a dynamic path, establishing long-distance semantic association between nodes through topology-aware coding based on the basic structure features and the key neighbor features through a linear graph transformer with O ( n ) of linear complexity, and establishing long-distance semantic association between nodes through topology-aware coding; performing frequency domain projection on the node features to generate frequency domain features, explicitly extracting and enhancing the periodic discriminant components in the frequency domain features through a Fourier analysis network to generate graph neural network data. Thus, the graph representation learning capability of the graph neural network is effectively improved.

The invention provides a chronic lumbago surface electromyogram discrimination method and system based on a Fourier analysis neural network and a storage medium, and the method comprises the steps: firstly obtaining a data set which comprises a plurality of surface electromyogram signals and corresponding real labels; preprocessing the surface electromyogram signal to obtain a preprocessed surface electromyogram signal; inputting the preprocessed surface electromyogram signals into a constructed neural network based on Fourier analysis to obtain a prediction label of each surface electromyogram signal; constructing a loss function according to the real label and the predicted label, and training the neural network based on Fourier analysis to obtain a trained neural network based on Fourier analysis; and inputting a surface electromyogram signal to be detected into the trained neural network based on Fourier analysis to obtain a corresponding prediction label. According to the method, the neural network based on Fourier analysis is constructed and trained, the potential periodic features with discrimination are extracted, automatic discrimination of the abnormal modes in the chronic lumbago surface electromyogram signals is achieved, and therefore discrimination with higher robustness, higher generalization and higher efficiency is achieved.

This invention discloses a system and method for psychotherapy that integrates virtual reality scenes, belonging to the interdisciplinary field of psychotherapy and virtual reality. It addresses the problems of fixed scenes, delayed adjustment, weak interactivity, and lack of cultural adaptability in traditional psychotherapy. The method includes using non-contact biosensors to capture facial blood oxygen fluctuations, combining this with a hemodynamic model to remove artifacts, and then quantifying these fluctuations into emotional energy values ​​based on an individual emotional sample set and an incremental learning algorithm to generate scene seeds containing parameters such as color temperature. A virtual physics engine is then driven to reconstruct elements such as light and shadow, and fluids, forming a physically-level dynamic scene. Inertial sensors capture user movements and convert them into virtual pressure gradients, constructing a coupled feedback loop between movement and scene. Psychological trends are predicted through hierarchical Fourier analysis of the seed sequence. This invention achieves real-time adaptation and proactive intervention between psychological states and virtual scenes, enhancing user immersion and cultural and emotional resonance, and improving the accuracy and effectiveness of psychotherapy.

The invention discloses an MMC impedance prediction method and system of a flexible interconnection system, equipment, a medium and a product, and the method comprises the steps: injecting positive and negative sequence voltage disturbances with different voltage frequencies into a pre-constructed MMC simulation model of a network construction type flexible interconnection system under a plurality of different working condition variables; the method comprises the steps of obtaining output voltage and current time-domain signals of an MMC under disturbance of multiple different voltage frequencies, obtaining output voltage and current frequency-domain data through fast Fourier analysis, determining equivalent impedance of the MMC of the network-forming flexible interconnection system at each frequency according to the output voltage and current frequency-domain data, and determining the equivalent impedance of the MMC of the network-forming flexible interconnection system according to the equivalent impedance. And taking the equivalent impedance and the working condition variable corresponding to each frequency as mapping samples, constructing a training data set, and training the initial fuzzy neural network, thereby enabling the trained MMC equivalent impedance prediction model to output an equivalent impedance prediction value of the MMC at the current calculation moment. Therefore, the impedance characteristics of the network-forming type MMC can be accurately represented in a wide working range.

A quantum computing system includes a classical computer coupled in combination with a quantum computer, wherein the quantum computing system is configurable to execute program instructions to process input data to generate corresponding output data. The program instructions include one or more arithmetic functions to be executed using the quantum computer. The quantum computing system is configured to apply a transformation to transform the one or more arithmetic functions into a series of Fourier components that are executable using the quantum computer by using one or more quantum circuits utilizing rotation gates acting on qubits representing the Fourier components, and to process outputs from the one or more quantum circuits to generate results of the one or more arithmetic functions, wherein the results are used to generate the corresponding output data.

This invention discloses a two-dimensional contour morphology representation method based on current-round Fourier transform, belonging to the field of geometric morphometrics. It solves the technical problems of contour rotation and misalignment caused by elliptical Fourier descriptors. The key point of its technical solution is to complete the reconstruction and normalization of contour shape through current-round Fourier descriptors, achieving contour shape description effect comparable to elliptical Fourier analysis and contour normalization (alignment) effect comparable to the Pu-style method. It can also avoid the graphic pseudo-rotation problem caused by standardization during the extraction of elliptical Fourier descriptors, without the need for prior standardization of contours using other methods, and quantitatively describes contour features based on current-round Fourier descriptors.

The invention discloses a bus bunching prediction method and system based on a time-aware network. The method comprises the following steps: preprocessing bus arrival data, fusing multi-source spatial-temporal characteristics, introducing time period codes, and processing abnormal and missing values; targeted denoising is performed on data with different characteristics based on Fourier analysis, so that the data quality is improved; a time perception neural network is established, local features and long-term dependence are captured through a CNN-LSTM architecture, a time decay factor mechanism is introduced, dynamic modeling of a time sequence information importance decay process is realized, and a long-term rule of data and short-term disturbance after time calibration are effectively integrated; and a dual attention mechanism of time dimension and feature dimension is fused, key features are extracted and integrated, and multi-step prediction of bus bunching is realized. According to the method, the non-linear relation and the space-time dynamic rule of the bus data can be fully captured, and the problem of unequal intervals in a bunching time sequence is effectively solved.

The invention discloses a voltage harmonic suppression method and device for offshore wind power through a hybrid commutation sending-out system, terminal equipment and a storage medium, and belongs to the field of offshore wind power, and the method comprises the steps: collecting a three-phase line voltage waveform of a diode uncontrolled rectification unit in the hybrid commutation sending-out system, carrying out the Fourier analysis, obtaining a line voltage fundamental component, and carrying out the voltage harmonic suppression of the three-phase line voltage waveform; the total harmonic distortion amount is calculated; whether the total harmonic distortion amount exceeds a preset threshold value or not is judged, if yes, the voltage at a PCC point in the hybrid commutation sending-out system is measured, and PCC voltage is obtained through measurement; and according to the PCC voltage, controlling an auxiliary converter in the hybrid commutation sending-out system to inject harmonic current into a diode uncontrolled rectification unit so as to eliminate the harmonic component of the PCC point voltage in the hybrid commutation sending-out system, and if not, maintaining the current operation state of the auxiliary converter unchanged. According to the invention, the problem of voltage harmonic waves existing in the hybrid commutation sending-out system in the prior art can be solved.

The present application relates to a distributed power rich area cable insulation partial aging online positioning method and system, the positioning method comprising: establishing a cable distributed parameter model; superimposing f 1±1kHz and f 2±1kHz near wideband signals, the system continuously collects outlet three-phase voltage and current during operation and obtains amplitude-frequency characteristics through Fourier analysis, and the amplitude-frequency characteristics are divided by the amplitude of each phase voltage and current at each frequency point to obtain the wideband impedance spectrum of each phase; the second series resonance frequency measured in the current operating state f 2 is substituted into the cable insulation partial aging distance formula to obtain the cable insulation partial aging distance. The positioning system comprises a first calculation module, a second calculation module and a positioning module; the first calculation module determines the mathematical model of the power station back-end cable and power grid system impedance; the second calculation module obtains the impedance formula of the mathematical model of the power station back-end cable and power grid system impedance after partial aging; and the positioning module determines the position of the partial aging defect of the measured cable. The present application can obtain accurate positioning of partial aging.

The invention provides a control method and device for a magnetic suspension bearing, a medium, a controller and a program product, and the method comprises the steps: collecting the displacement precision data of the magnetic suspension bearing when a magnetic suspension unit is shut down; fourier analysis is carried out on the collected displacement precision data to obtain a corresponding frequency spectrum; determining whether the rotor of the magnetic suspension bearing stops rotating or not according to the obtained frequency spectrum; and if it is determined that the rotor of the magnetic suspension bearing stops rotating, floating stopping operation is executed. According to the scheme provided by the invention, the rotor can stop floating in time after shutdown.

A method of detecting plasma asymmetry in a radio frequency plasma processing system includes providing radio frequency power to a reaction chamber having an approximate chamber axis of symmetry and receiving radio frequency signals from a plurality of broadband electromagnetic sensors. The method also includes processing the radio frequency signals using Fourier analysis and determining that a plasma asymmetry has occurred within the reaction chamber based on the Fourier analysis of the radio frequency signals.

The invention discloses a forward calculation-based gear tooth surface waviness Fourier analysis error interval evaluation method, which comprises the following steps of: firstly, constructing an isomorphic evaluation data set, and statistically analyzing the distribution characteristics of actual sampling intervals to determine a frequency domain credible range; the core of the method is that Monte Carlo forward modeling is introduced, and systematic deviation and random fluctuation caused by sampling interval fluctuation to a frequency spectrum are quantified. Based on this, a heterovariance normal distribution model of the measured amplitude is established, the maximum likelihood estimation is utilized to reversely deduce the true value of the amplitude, and the pivot vector method is adopted to calculate the error interval of the amplitude of the key frequency point under the predetermined confidence level. Furthermore, the optimal sampling length and the resampling interval are optimized and determined through forward modeling calculation. According to the method, the limitation that only a single spectrum result can be given in traditional measurement is broken through, quantitative calibration of errors introduced into a measurement system is achieved, a reliability evaluation result with a confidence interval is provided, and a closed-loop optimization decision basis can be provided for measurement instrument selection and parameter setting.

The application relates to the technical field of ship navigation behavior prediction, and discloses a ship navigation behavior prediction method and system based on an interpretable artificial intelligence. The method comprises the following steps: acquiring ship AIS historical data and historical marine environment data in a target sea area; fusing the ship AIS historical data and the historical marine environment data based on a time scale and a space scale, and constructing a space-time data set; decoupling static variables and time-varying variables of the space-time data set, and determining historical input data, known future input data and static input data; constructing an interpretable space-time fusion neural network model based on a dynamic gate residual neural network, a space-time feature variable selection network, a Fourier analysis gate neural unit and an interpretable multi-head attention mechanism, so as to accurately predict ship navigation behaviors such as a ship trajectory, a ground speed and a ground heading, and output a navigation behavior influence factor weight visualization result, and the method has interpretability.

The application provides a high-stability magnetic modulator excitation demodulation method without correction winding, and relates to the technical fields of precise electromagnetic measurement and signal processing. The application adjusts the turn number difference of the excitation windings of two magnetic cores in a double-magnetic-core differential magnetic modulator, and uses a microcontroller to control the positive and negative duty ratio superposition of a low-frequency component of a square wave excitation source to equivalently inject a low-frequency current signal in the magnetic modulator; in combination with digital acquisition and Fourier analysis, a low-frequency voltage sequence and a second harmonic sequence are constructed, and a low-frequency proportional coefficient and an actual direct current proportional coefficient are calculated, so that the online calibration of a direct current measurement value is realized. The application can eliminate the measurement error caused by time and environmental changes without adding a correction winding or a correction power supply, and significantly improves the long-term measurement precision and stability of the magnetic modulator.

The application provides an electromagnetic wave compact time domain fine integration method based on an artificial anisotropy parameter, which comprises the following steps: obtaining a waveguide with a long straight constant structure, and performing mesh division through a rectangular mesh; introducing an artificial anisotropy parameter to obtain a control equation of an electromagnetic wave in a rectangular mesh area; obtaining a numerical dispersion equation through Fourier analysis to obtain a numerical dispersion equation of the electromagnetic wave in the rectangular mesh area; defining a normalized numerical phase velocity value, and preliminarily selecting the artificial anisotropy parameter to obtain a preliminary value of the artificial anisotropy parameter; calculating an optimal value of the artificial anisotropy parameter according to the preliminary value and the numerical dispersion equation of the electromagnetic wave in the rectangular mesh area; and obtaining an electromagnetic field quantity iterative solving formula according to the optimal value and the control equation to perform iterative solving, so as to obtain the electromagnetic field quantity of the electromagnetic wave in the rectangular mesh area. The application can reduce the number of mesh divisions and the memory requirement, and can improve the calculation efficiency and the calculation precision.

The present application belongs to the field of integrated circuit manufacturing online measurement, and discloses a snapshot overlay error measurement method and system, which comprises the following steps: measuring a measured object, obtaining two measurement spectra with positive and negative preset deviations respectively, coherently demodulating the measurement spectra, and shifting the specific frequency channel to the zero frequency channel; processing the spectrum data after frequency shifting by using a linear operator to obtain the coefficients corresponding to the positive and negative preset deviations; constructing a characteristic quantity according to the linear combination of the real part and the imaginary part of the coefficients, then calculating the corresponding characteristic quantity according to the coefficients corresponding to the positive and negative preset deviations; and calculating the overlay error according to the characteristic quantity based on the linear relationship between the characteristic quantity and the overlay error. The present application can solve the overlay error with multi-wavelength coupling without using traditional Fourier analysis and truncation operation, has high precision and robustness to noise, and can be used for data processing of snapshot overlay error measurement in multiple scenes.

The application discloses a method for magnetic field padding of a full superconducting cyclotron based on a target first harmonic, and comprises the following steps: determining distribution requirements of the target first harmonic; determining superconducting coil groups for generating the target first harmonic; forming the superconducting coil groups by a group of coils; obtaining an adjustment scheme of each superconducting coil group and a total adjustment scheme number m; determining positions and numbers of radial measurement points and a total harmonic component number n; based on Fourier analysis, establishing a padding matrix A of the first harmonic based on a unit current adjustment amount, the total harmonic component n and the total adjustment scheme number m; based on Fourier analysis, establishing a target first harmonic amplitude matrix B based on the total harmonic component n; listing a padding equation B=AX, and solving X, wherein X is a matrix of superposition coefficients of the adjustment schemes; and the method can perform the magnetic field padding by a coil group as a unit, and a first harmonic formed by a group of coils can better express a distribution shape of the magnetic field, and can better replace a conventional strip padding method.

To provide a method for digital demodulation of all even harmonics of a magnetic modulator based on full phase analysis.SOLUTION: According to the digital demodulation method for all even-order harmonics of a magnetic modulator based on full-phase analysis, when the magnetic modulator is calibrated, standard voltage time sequence data output by the magnetic modulator when a direct current calibration current of a set value flows through the magnetic modulator is obtained, an output voltage sequence of full-phase Fourier analysis is established and pre-processed according to the standard voltage time sequence data, and the pre-processed output voltage sequence of full-phase Fourier analysis is comprehensively analyzed to obtain standard even-order harmonic signals and current conversion coefficients of each order. The present invention uses the full-phase Fourier analysis technology to perform comprehensive pre-processing and comprehensive analysis on the output voltage signal of the air modulator, which greatly reduces the problems of spectrum leakage and phase disturbance, so that the data sampled at different time points are fully utilized, and the signal processing is more accurate.SELECTED DRAWING: Figure 1

The invention relates to the technical field of electronic measurement and circuit analysis, in particular to a circuit model rapid identification and reproduction device and method based on impulse response, and the device comprises a microcontroller, a field programmable gate array, a signal generation module, a signal collection module, a data processing module and a signal reproduction module. Circuit modeling is realized through a technical route of impulse signal excitation-response acquisition-Fourier analysis, and the core method is as follows: a microcontroller outputs an approximate impulse signal with the width of 1 microsecond to an unknown circuit through a digital-to-analog converter, and the impulse response of the circuit is acquired by using the analog-to-digital converter and is discretized; the discrete data is transmitted to a field programmable gate array, frequency characteristics are obtained through fast Fourier transform operation, amplitude-frequency characteristics are analyzed to identify filtering types, and key parameters are extracted to construct a transfer function model; a finite impulse response filter coefficient is generated based on the model, and undistorted reproduction of an output signal of an unknown circuit is achieved.

The present application relates to the field of sequence recommendation, and particularly relates to a recommendation method and device, electronic equipment and storage medium, the method generates a more robust user behavior sequence representation through signal reconstruction by a reverse denoising network which fuses a bidirectional Mamba to capture long-range ordered dependencies of sequences and a bidirectional self-attention mechanism to capture global context association. The denoised sequence representation is sent to a parallel double analysis structure, wherein a Fourier analysis module adaptively decouples and aggregates multi-scale periodic patterns through a learnable band attention mechanism, and a time domain Transformer encoder is used to model dependencies in the sequence at the same time. The outputs of the two are finally fused to generate a user preference representation. The DCFRec is optimized through joint training to improve the robustness and recommendation accuracy of the model.

A method for digitally demodulating all even-order harmonics of a magnetic modulator based on full phase analysis is provided. [Solution] A digital demodulation method for all even-order harmonics of a magnetic modulator based on full-phase analysis involves calibrating a magnetic modulator by obtaining standard voltage time series data output by the magnetic modulator when a set DC calibration current is passed through the magnetic modulator, establishing and preprocessing an output voltage sequence through full-phase Fourier analysis based on the standard voltage time series data, and comprehensively analyzing the preprocessed output voltage sequence through full-phase Fourier analysis to obtain standard even-order harmonic signals and current conversion coefficients for each order. By using full-phase Fourier analysis technology, the present invention performs comprehensive preprocessing and comprehensive analysis of the output voltage signal of the magnetic modulator, significantly reducing the problems of spectral leakage and phase disturbance, making full use of data sampled at different times and making signal processing more accurate.

A method for measuring at least one parameter indicative of the optical transmission quality of an eye (30), such as information about absorbing or scattering structures affecting the light propagation between the cornea and the retina and / or information about the imaging quality, e.g. the point spread function (PSF) of the eye, is described. The method comprises recording a plurality of optical coherence tomography A-scans of different corneal positions xi,yi of the eye (30) by means of an optical coherence tomography device (10-18) and a scanner (24a, 24b). For each A-scan, a reflection value at the retina of the eye is determined. The reflection values can then be combined, e.g. for displaying an image of the transmission quality of the eye as a function of xi,yi, or for determining the point spread function (PSF) of the eye by means of Fourier analysis.

The invention provides a cluster type magnetic modulator sharing demodulation, and relates to the technical field of electrical measurement and signal processing. The device consists of a plurality of closed annular magnetic modulators, and is sleeved on a monitoring line to realize non-contact measurement; the voltage excitation unit provides square wave excitation with different fundamental wave frequencies for each magnetic modulator; the signal output unit combines multiple paths of analog outputs, converts the analog outputs into digital signals through the acquisition module, extracts amplitudes at corresponding double frequencies through windowing Fourier analysis, and converts the amplitudes into measurement results of all channels in combination with proportionality coefficients, so that centralized demodulation of multiple channels is realized, the number of hardware is reduced, the cost and the wiring complexity are reduced, and the measurement accuracy is improved. The precision and the sensitivity are ensured; and the system integration degree and the adaptability are improved.

The application discloses a self-calibration method for an angle encoder and belongs to the technical field of precision measurement. The method mainly comprises the following steps: optimizing arrangement positions of a plurality of reading heads, and constructing three groups of reading head combinations; rotating the angle encoder and collecting angle data of the three groups of reading heads to obtain three groups of measurement data; establishing error compensation functions of the three groups of reading heads through the three groups of measurement data; and finally, completing cross compensation of error harmonic components through Fourier analysis on the three groups of error compensation functions, so that the self-calibration of the angle encoder is realized. While using fewer reading heads, the application can effectively improve the calibration order of harmonic errors, and realizes high-precision in-situ calibration of the angle encoder at a lower cost.

The present application aims at solving the problem of providing a photoelectric conversion element with improved durability. To solve the problem, the present application provides a photoelectric conversion element including a first electrode, a second electrode, and a photoelectric conversion layer disposed between the first electrode and the second electrode, the photoelectric conversion layer containing a crystal of perovskite structure. The photoelectric conversion element is characterized in that it has a charge transport layer between the photoelectric conversion layer and the first electrode, and has the following features: the charge transport layer contains a charge transport substance and an insulating resin that are phase-separated; the ratio of the volume of the region of the charge transport substance to the volume of the region of the insulating resin is 5 or more and 30 or less; and in a binary image of the two-dimensional spatial distribution of the regions A and B obtained by measuring the charge transport layer with an optical microscope, when a value obtained by Fourier analysis of the binary image, that is, a value determined by a calculation method of D, is represented by D [μm], the D [μm] satisfies 4 ≤ D ≤ 12.

The present application relates to the technical field of control board signal processing, and provides a method for improving the anti-interference capability of a control board, frequency characteristics of each motor control signal in the control board are collected, a frequency spectrum is obtained by performing Fourier analysis on the frequency characteristics, and the control signals are divided into a high-frequency signal group and a low-frequency signal group according to the frequency spectrum; time slot allocation is performed on the control signals in the high-frequency signal group, the transmission cycle of the high-frequency signal group is divided into N time slots, and each control signal occupies one time slot; based on the frequency characteristics of the low-frequency signal group, an orthogonal modulation base vector is constructed, and the control signals of the low-frequency signal group are mapped onto the orthogonal modulation base vector; and according to the time slot allocation scheme and the orthogonal modulation base vector, the signal transmission timing of the control board is reconstructed, so that the control signals of the high-frequency signal group and the low-frequency signal group do not interfere with each other. The technical problem that the control precision is reduced due to mutual interference of the control signals when the control board is in operation with multiple motors is solved.

The invention discloses a power control method and device suitable for conventional direct current networking transformation, which are applied to the technical field of power control, and the method comprises the steps: obtaining output current data and direct current side voltage data, and obtaining grid-connected voltage data and grid-connected phase angle data; extracting a frequency oscillation component from the instantaneous power data; performing adaptive frequency tracking processing on the frequency oscillation component by using a fast Fourier analysis technology to obtain dominant oscillation frequency data; inputting the direct current side voltage data into a cross coupling damping matrix for processing to obtain gain compensation data; acquiring impedance data of the target power grid in real time, and generating an anti-oscillation power signal based on the gain compensation data and the impedance data; and performing power control on the target power grid by using the anti-oscillation power signal. According to the method provided by the invention, the problem of broadband oscillation generated in the process of replacing the reactive power compensation equipment of the direct current application with the network construction type SVG can be solved, so that the safe operation of the power grid is ensured.

The present application relates to the technical field of grounding resistance detection, in particular to a single-core cable grounding resistance detection method with strong power frequency interference resistance. The present application uses a coupling capacitor clamp to non-contact inject high-frequency signals, first collects background voltage and current signals, selects an injection frequency far from power frequency and harmonics through Fourier analysis; adopts a normalized least mean square adaptive filter to cancel background noise and generate an enhanced signal; then down-converts the signal to a baseband through digital quadrature demodulation, estimates the amplitude and phase in real time through a Kalman filter, and periodically calibrates the state and noise parameters through a compressed sensing algorithm; finally calculates the loop impedance according to the voltage, current amplitude and phase difference to obtain the grounding resistance. The method has the advantages of non-contact, high safety, strong anti-interference ability, high measurement accuracy, etc., and is suitable for cable grounding state monitoring in complex electromagnetic environments.

This invention belongs to the field of three-dimensional dynamic topography measurement, specifically a multi-frequency structured light time-domain least squares fitting three-dimensional dynamic measurement method. It includes multi-frequency structured light projection, capturing images of stripes at different frequencies and performing Fourier analysis to extract the Fourier phase corresponding to each stripe image; obtaining the corresponding difference phase sequence centered on each frame of the multi-frequency stripe sequence; performing time-domain least squares fitting analysis on the extracted difference phase sequence to solve the wrapping phase of each frame of sampled stripes; and expanding the wrapping phase using the multi-frequency information in the sampling sequence to obtain the three-dimensional topography corresponding to each frame of sampled stripes. This invention integrates information from multiple frames of stripes at different frequencies to perform time-domain least squares fitting to solve the wrapping phase of each frame of stripes in the sampling sequence. Compared with the traditional single-frame Fourier transform method, the solution information is richer, which helps to improve measurement accuracy.