1590 results about "Phase modulation" patented technology

The invention discloses a machine vision-based intelligent detection method for steel galvanized surface defects, which comprises the following steps: S1, acquiring and preprocessing a steel galvanized surface image to obtain a standardized image; s2, constructing a specular reflection probability graph according to the brightness distribution and the gradient magnitude, and calculating a reflection intensity value; s3, calculating a structure tensor matrix, determining a main direction angle and an anisotropic consistency coefficient, and generating a direction feature matrix; s4, establishing a multi-scale direction adaptive phase kernel function, and performing phase modulation in a frequency domain by adopting an improved phase stretching transformation algorithm; s5, inverse Fourier transform is executed, and a phase response matrix is extracted; s6, performing weighted fusion to obtain a comprehensive phase response diagram; and S7, setting a threshold value according to the noise variance and the statistical characteristics, executing binarization and morphological processing, and outputting a defect region and boundary coordinates. According to the invention, high-precision identification and boundary positioning of steel galvanized surface defects are realized.

The invention relates to the technical field of quantum communication security, and discloses a quantum key distribution secure communication system based on a quantum mechanics principle. The system comprises a quantum state preparation unit which controls a quantum emission device to output a quantum state sequence containing a preset polarization angle and a phase modulation photon group; a quantum channel feature extraction unit captures channel environment interference parameters and constructs a photon polarization distribution matrix; a quantum communication security evaluation unit receives the matrix, and calculates a channel security coefficient threshold through a quantum bit error rate analyzer; the quantum key dynamic optimization unit generates an optimized key segmentation strategy in combination with a security coefficient threshold and a historical key negotiation record; the quantum key rotation control unit switches quantum state modulation parameters according to a segmentation strategy and a time window; and the quantum node synchronization management unit monitors node clock offset and injects a calibration signal to realize key distribution time slot alignment. The system can dynamically cope with environmental interference, and improves the security and adaptability of quantum key distribution.

The invention provides an OTFS radar communication integrated signal processing method and system based on time-frequency-space domain joint optimization. According to the method, pilot symbol positions and densities are configured in an OTFS time-frequency grid according to channel time-varying characteristics and bandwidths, and a Doppler index range is set to optimize channel information acquisition; deploying a controllable reflecting surface, constructing a phase modulation matrix based on a target position and communication channel parameters, dynamically adjusting a phase gradient direction, and separating energy of a target echo and a communication signal; within a set Doppler index range, calculating frequency offset estimation, correcting a time domain sampling point of a received signal, and generating a phase correction vector; and positioning a spatial aliasing main interference area, and inhibiting symbol interference and spatial aliasing caused by a high-speed target through frequency domain beam forming weighting and phase rotation compensation in combination with a phase correction vector and a sub-Doppler parameter in the area. According to the invention, time-frequency-space domain cooperative efficient processing of OTFS radar communication integrated signals is realized.

The invention relates to the technical field of detection, in particular to a complex shell detection method and system based on structured light scanning. The method comprises the following steps: calculating a wrapped phase value and a phase modulation amplitude of each pixel point under each frequency, calculating discrete probability distribution containing candidate stripe series and a corresponding probability for each pixel point based on a multi-frequency wrapped phase difference, generating an initial pixel confidence map, and constructing an energy function; the penalty weight of the smooth item is determined according to the phase modulation amplitude and the wrapped phase gradient local variance, obtaining an initial fringe order distribution diagram, updating discrete probability distribution by using an initial pixel confidence map, re-minimizing an energy function to obtain a corrected fringe order distribution diagram, and reconstructing a final three-dimensional shape. And iteratively optimizing a projector principal point and a radial distortion coefficient in system calibration parameters. According to the scheme, the geometric details of the surface can be reserved, and the processing effect and the measurement precision of the complex curved surface and the high-curvature area are improved.

The invention discloses a multi-source data-based selling point generation method for AI intelligent marketing, and relates to the technical field of big data analysis and application, and the method comprises the following steps: obtaining a unified time scale matrix in a multi-source data access stage, building an extreme value inhibition prior based on the unified time scale matrix, and building an acquisition synchronization baseline; full-link time alignment is realized by collecting a synchronous base line; and acquiring an extreme value diagnosis fingerprint under the constraint of full-link time alignment, generating a threshold track based on a quantile residual spectrum and kurtosis skewness, and capturing and calibrating a burst extreme value by taking the threshold track as a dynamic reference. According to the method, a time sequence consistency basis is constructed, a data extreme value is accurately identified and corrected, the content is ensured to be true and credible in combination with causal correction and semantic screening, dynamic closed-loop optimization of content generation and delivery is realized through closed-loop feedback and phase regulation and control, and the authenticity, stability and compliance of AI marketing content are effectively improved.

The present disclosure relates to the technical field of electromagnetic wave sensors, in particular to a signal transmitting, calibration, compensation and transceiving links, an integrated circuit, an electromagnetic wave sensor and a device, wherein the transmitting link includes an analog signal source and a digital phase shifter, the analog signal source may be configured to provide an initial analog signal, and the digital phase shifter may be configured to provide a phase shift signal in a digital domain and to perform phase shifting on the initial analog signal based on the phase shift signal, so as to perform a preset phase shifting operation on the initial analog signal, thereby effectively improving the phase modulation resolution and phase modulation accuracy.

The invention provides a preparation method of a barrier type antimonide infrared detector. The preparation method comprises the following steps: selecting a gallium antimonide substrate; a gallium antimonide buffer layer, an indium arsenide heavily-doped layer, a class II superlattice absorption layer and an aluminum-arsenic-antimony barrier layer are sequentially grown on the substrate in an epitaxial mode through a molecular beam epitaxy method; mechanically stripping the hexagonal boron nitride two-dimensional material, and transferring the stripped hexagonal boron nitride to the aluminum-arsenic-antimony barrier layer to form a Van der Waals heterojunction and composite barrier layer structure; depositing electrodes by using an ultraviolet lithography technology and a thermal evaporation mode to form one electrode arranged on the gallium antimonide buffer layer and the other electrode arranged on the boron nitride; a large-numerical-aperture micro-lens array is processed on a substrate, and the micro-lens array is composed of gallium antimonide cylinders with a phase modulation function; therefore, the antimonide medium-wave infrared detector with the composite barrier layer can be formed, the quantum efficiency is improved, the order of magnitude of dark current is reduced, and room-temperature medium-wave infrared detection can be realized.

The invention discloses a non-contact local curvature measurement method and system based on a computational metasurface, and the method comprises the steps: S1, phase modulation: carrying out the phase modulation of an incident light field carrying the information of a to-be-measured object through an optical computational metasurface, so as to generate transverse displacement light field distribution related to the contour of the to-be-measured object; s2, signal extraction: separating and extracting a first-order differential signal carrying the edge information of the object to be measured by using a biorthogonal polarization filtering system; s3, reconstructing a three-dimensional shape: reconstructing the three-dimensional shape of the object to be measured according to the first-order differential signal; and S4, curvature calculation: calculating the curvature radius of any local part of the object to be measured according to the three-dimensional shape. The optical calculation metasurface is combined with a biorthogonal polarization filtering system, differential operation of a light field is achieved, the edge contour of an intensity object and the three-dimensional shape of a phase object can be obtained without difference, and therefore non-contact and high-precision measurement of the curvature of the object is achieved, the problem of physical damage of traditional contact type measurement is solved, and the measurement accuracy is improved. And the detection efficiency and adaptability are improved.

Disclosed in the present invention are a dual electro-optic frequency comb-based laser tracking interferometric spatial coordinate measurement system and method. Multiple target mirrors are identified by means of a vision module, to guide a rotating mirror to direct laser light toward each target mirror individually. A laser tracking interferometric ranging module obtains a tracking error of the laser beam deviating from the center of the target mirror to be used for closed-loop tracking control. A light source module outputs single-frequency laser light traceable to a gas absorption peak. By controlling a light source modulation module to enable or disable an electro-optic phase modulation drive signal, dual electro-optic frequency combs or dual-frequency continuous-wave laser light is outputted. In a tracking state, the laser tracking interferometric ranging module respectively uses the two light sources to measure the absolute distance and the relative displacement of a target mirror, and the real-time distance between the target mirror and an original point is computed by means of distance fusion; the elevation angle and the azimuth angle of the target mirror are obtained in real time by means of an azimuth angle and elevation angle measurement module; tracking control and coordinate computation are carried out by means of a tracking control and signal processing module and a computer, and finally three-dimensional spatial coordinates of all the target mirrors are measured.

The invention provides a distributed feedback laser with a double-layer grating structure, and relates to the technical field of lasers, the laser forms an InGaAlAs multi-quantum well active region, an upper sampling grating layer and a lower phase shift grating layer on an n-type InP substrate in sequence, the upper grating layer is designed based on a reconstruction equivalent chirp technology, and the lower phase shift grating layer is designed based on a reconstruction equivalent chirp technology. Two sections of asymmetric modulation areas with sampling periods linearly gradually changing in opposite directions are arranged in the axial direction of the resonant cavity, and the lower grating layer is a quarter-wave phase shift grating matched with the period of the upper seed grating. Through the synergistic effect of equivalent phase modulation and phase shift generated by the double-layer grating, the photon density distribution in the cavity can be improved, the longitudinal space hole burning effect can be weakened, the sensitivity to end face phase fluctuation can be reduced, high single-mode power and large modulation bandwidth can be realized in a wide temperature range, and the double-layer grating is suitable for a high-speed optical communication and coarse wavelength division multiplexing transmission system.

The invention discloses a laser frequency stabilization system based on Faraday anomalous dispersion atomic filtering, which is used for carrying out frequency stabilization on phase modulation multi-sideband laser, and comprises a frequency doubling laser unit which is configured to comprise a fundamental frequency seed light source, an electro-optical modulator, a fundamental frequency amplifier and a frequency doubling crystal; the light splitting module unit is configured to split the frequency doubling light into a main output light path and a monitoring light path; the atomic optical rotation filter is located on the monitoring light path and is configured to maintain the purity of the frequency-stabilized laser spectrum through purification treatment under the control of the axial magnetic field and the temperature; the frequency stabilization unit is configured to be a frequency stabilization light path and a servo system, and the frequency stabilization light path is used for obtaining laser frequency information and generating an error signal; the servo system is used for controlling the frequency of the fundamental frequency seed light source according to the error signal feedback. According to the laser frequency stabilization system provided by the invention, the spectrum purification and frequency stabilization precision can be improved, so that high-frequency stability locking is realized.

The invention is applicable to the technical field of concrete deformation measurement, and particularly relates to a non-contact concrete deformation testing system and method based on a laser ranging technology, and the system comprises a laser ranging unit which is provided with a double-frequency phase modulation laser, an optical transceiver antenna and a phase detection circuit; the environmental parameter acquisition unit comprises a temperature sensor, a humidity sensor and an air pressure sensor; and the data processing unit carries an atmospheric refractive index calculation module, a Kalman filtering algorithm and a three-level early warning module, and supports wired / wireless data transmission. The distance measurement precision is high, and the concrete micro-deformation monitoring requirement is met; non-contact characteristic: non-damage monitoring on the concrete surface is realized through a diffuse reflection target; intelligent data processing: structural deformation and environmental noise are effectively distinguished, and the early warning reliability is improved; automatic monitoring is achieved, and the manual inspection cost is greatly reduced.

The invention discloses an on-chip time-frequency transmission system and method based on an octave optical comb and an electro-optical modulation optical comb, and the method comprises the steps: constructing a chip-based optical reference cavity through the technologies of vacuum optical cement, photoresist backflow and the like, and achieving an on-chip ultra-stable laser through a phase modulator and a reflection separation optical path; an on-chip laser source pumping micro-ring resonant cavity is utilized to generate an octave optical frequency comb, frequency multiplication is carried out on the on-chip laser source pumping micro-ring resonant cavity and an additional laser source to realize detection and locking of carrier envelope offset frequency (fceo), frequency beating is carried out on the on-chip laser source pumping micro-ring resonant cavity and the on-chip ultra-stable laser device to realize frequency beating (fbeam) locking, and the laser source is utilized to generate an electro-optical modulation optical frequency comb through a circulating phase modulator to realize frequency beating and locking of the on-chip ultra-stable laser device. And the optical time frequency is locked with the locked octave optical comb, is sent to a far end after polarization control and light amplification, and simultaneously receives an electro-optical modulation optical comb at the far end and performs linear light sampling, so that the transmission of the optical time frequency is realized. The optical fiber or space optical link time-frequency transmission device can realize optical fiber or space optical link time-frequency transmission, and has the advantages of low overall noise, high transmission precision, compact structure, small size, low power consumption and the like.

The invention is suitable for the technical field of communication, and particularly relates to a method for detecting mismatched harmonic waves of a power amplifier. The method comprises the steps that a first power detection unit is connected with a coupler through a control unit, the standing-wave ratio of a to-be-detected power amplifier chip is adjusted to be 1: 1 through a tuner, and the power of an input signal of a vector signal generator is adjusted till the target power of the to-be-detected power amplifier chip is reached; the second power detection unit is connected with the coupler through the control unit, the output standing-wave ratio of the to-be-detected power amplifier chip is adjusted to a preset specific value through the tuner, and when the tuner modulates phases at intervals of preset degrees, the harmonic power of the to-be-detected power amplifier chip in each phase is recorded through the second power detection unit. Compared with the prior art, the method can accurately test and evaluate the harmonic wave of the to-be-tested power amplifier chip under the mismatched standing wave condition, thereby evaluating the harmonic wave index of the to-be-tested power amplifier chip.

The invention belongs to the technical field of power system operation and motors, and particularly relates to an energy storage type phase modifier control method which comprises the steps that a rotating shaft of a double-fed motor is connected with a flywheel to serve as an energy storage type phase modifier; the rotor winding is connected to a power grid through an excitation system and a transformer in sequence, and the excitation system is electrically connected by a reactor, a back-to-back converter and a filter in sequence; the stator winding is directly connected to a power grid; the control system decouples reactive power and active power, vector control is carried out on exciting current to absorb or release power, and reactive power-voltage support and active power-frequency support of the power grid are completed. The method overcomes the defects that a traditional direct-current excitation phase modulation mode can only modulate phase and cannot modulate frequency, or is cumbersome and slow in response. The system can meet the requirement of wide-range variable-speed operation, quickly store / release a large amount of rotor kinetic energy, inhibit the voltage and frequency fluctuation of a power grid, and is especially suitable for stations with high new energy occupation ratio. The invention also provides a non-transitory readable recording medium storing the program of the method and a system comprising the medium, and the program can be called through a processing circuit to execute the method.

The invention relates to the technical field of self-synchronizing voltage source control, and discloses a balance current controlled self-synchronizing voltage source control method and system. The method comprises the following steps: acquiring and preprocessing operation data of a grid-connected inverter to obtain active / reactive components of voltage and current of a filter element; generating a three-phase terminal voltage instruction of the self-synchronizing voltage source based on the components, and determining a current instruction signal in combination with the grid-connected voltage; a three-phase modulation signal is generated through adjustment of a PIR controller and coordinate inverse transformation, then a filter inductance value is calculated according to the ripple characteristic of the modulation signal and a switching period, a filter capacitance value is determined by combining resonant frequency, and finally accurate control of the self-synchronizing voltage source is realized according to a filter parameter. By dynamically calculating the matching parameters of the filter inductance and the filter capacitance, the active regulation and control capability of the output impedance characteristic of the inverter is enhanced, and the resonance risk during the impedance change of the power grid is effectively inhibited. The technical problem that the stability is limited due to insufficient impedance regulation and control in the prior art is solved.

The invention provides a spatial light modulator, a self-checking device thereof and a light computing device, and relates to the technical field of optical modulation.The spatial light modulator comprises an incident waveguide structure, a covering plate, a liquid crystal layer, a substrate and an emergent waveguide structure; the incident waveguide structure is optically coupled with the cover plate and is used for guiding externally incident laser into the cover plate at a preset angle; the covering plate is used for enabling laser to be propagated in the covering plate in a total reflection form; the substrate bears the liquid crystal layer, integrates the driving circuit and is used for applying regulation and control voltage to the liquid crystal layer; the liquid crystal layer is arranged on the lower side of the covering plate and used for conducting phase modulation on the laser transmitted to the liquid crystal layer in a total reflection mode in response to the regulation voltage. And the emergent waveguide structure is optically coupled with the covering plate and is used for guiding the laser modulated by the liquid crystal layer out of the covering plate to a free space. According to the spatial light modulator, efficient spatial modulation and accurate control of the light field are realized, so that the integration and function accuracy of the spatial light modulator in self-inspection and light calculation are improved.

Disclosed in the present invention are a control method and system capable of providing frequency support for a flexible interconnected power distribution network. The method comprises: using a permanent-magnet direct-drive wind turbine connected to a flexible interconnected power distribution network to provide frequency support, measuring a direct-current voltage of a grid-side converter of the wind turbine, calculating a per-unit value and the phase of the direct-current voltage, and calculating the amplitude of a modulation voltage; generating a trigger pulse signal; monitoring the rotation speed of a wind turbine rotor and the rotor position angle of a synchronous generator, and acquiring a per-unit value of optimal power; calculating an active power reference value; on the basis of active power control and current control, outputting a d-axis component and a q-axis component of a modulation voltage of a generator-side converter, and by means of rotating coordinate transformation, generating a three-phase modulation voltage in a stationary coordinate system; and generating a trigger pulse signal by means of a pulse width modulation stage. The present invention enables wind turbines to provide quick response for power distribution networks in a frequency support stage, and prevent rotation speed stalling and suppress secondary frequency drop in a rotation speed recovery stage, thereby improving the support capability of the wind turbines for power grids.

A transparent antenna unit, comprising: a phase modulation layer, wherein the phase modulation layer comprises a first dielectric plate, a tunable dielectric layer and a second dielectric plate which are stacked in sequence, a first functional electrode located between the first dielectric plate and the tunable dielectric layer, and a second functional electrode located between the tunable dielectric layer and the second dielectric plate, and the orthographic projections of the first functional electrode and the second functional electrode on the first dielectric plate overlap with each other; and a transparent feed layer located on the layer of the first dielectric plate away from the first functional electrode, and connected to the first functional electrode or the second functional electrode.

An inertia cooperative control method of an integrated optical storage alternating current and direct current hybrid micro-grid comprises the steps that firstly, according to static and dynamic power capacities of energy storage units in direct current sub-grids and allowed direct current voltage deviation, sub-grid equivalent virtual resistance and virtual capacitance are calculated; secondly, RC + R type parallel virtual impedance parameters are distributed according to the power proportion of each energy storage unit, and multi-energy-storage cooperative response power disturbance according to the capacity is achieved; then, a phase angle is generated based on the mapping relation between direct-current side voltage and frequency, an alternating-current voltage amplitude instruction is determined in combination with reactive power droop control and feeder impedance voltage drop compensation, and a dq-axis voltage instruction is generated through virtual impedance compensation; normalized three-phase modulation waves are obtained through voltage-current double closed-loop control and dq / abc coordinate transformation, and six paths of PWM signals are generated to drive an interconnection converter after the normalized three-phase modulation waves are compared with triangular carrier waves. The method does not need to depend on external communication, has the capabilities of autonomous inertia support, voltage and frequency coordinated regulation and reasonable multi-source power distribution, and improves the stability and dynamic response performance of the system under island operation.

The invention discloses a switch cabinet electric arc light detection method and system based on multispectral fusion, and relates to the technical field of electric power system intelligent detection, and the method comprises the following steps: S1, building a cross-spectrum unified time reference, and carrying out the synchronous comparison of an infrared light signal, a visible light signal and an ultraviolet light signal, extracting a temperature transition trigger feature and a strong light disturbance spectrum feature, and generating a time synchronization deviation vector; and S2, constructing an anti-fact spectrum playback model based on the time synchronization deviation vector, generating a shadow spectrum sequence, positioning an infrared response threshold lifting reason through energy difference analysis, calculating a spectrum overlapping risk interval and duration, and outputting a threshold disturbance distribution diagram. According to the method, infrared anomalies are identified through cross-spectrum time alignment, anti-fact playback and differential analysis, channel recovery is guided in combination with springback prediction and time sequence correction, and a spectrum broken chain window is constructed through dislocation sampling and phase regulation and control, so that the accuracy and the anti-interference capability of arc identification are effectively improved.

The invention discloses a broadband and high-efficiency true time delay reflective array antenna, and belongs to the technical field of antenna engineering. Through the design of the broadband horn feed antenna, the broadband butterfly-shaped dipole antenna and the real-time-delay coaxial transmission line, high-efficiency directional radiation is realized. The gain bandwidth of the multi-layer patch type reflective array antenna is much larger than that of a traditional multi-layer patch type reflective array antenna; compared with a traditional transmission line phase modulation type reflective array antenna, due to stable time delay and shielding and no resonant structure, the antenna has better gain stability, and an in-band gain curve is increased approximately linearly. Finally, the antenna is simple in structure and can be realized only by a single-layer patch structure and a common coaxial transmission cable, and high-cost laminated patch processing is not needed.

The invention belongs to the technical field of optical calculation, and discloses an error-adaptive optical diffraction neural network in-situ training method, which comprises the following steps: based on the phase of each phase modulation layer, calculating the light field complex amplitude Uk of the input sample complex amplitude on the rear surface of each phase modulation layer and the light field complex amplitude Uo of the input sample complex amplitude on an output plane after forward propagation; calculating an error light field P based on Uo, carrying out three-dimensional central symmetry on a back propagation light path of the error light field P without changing the phase distribution of each phase modulation layer, and calculating the light field complex amplitude of the complex amplitude of the symmetrical error light field on the front surface of each phase modulation layer after forward propagation; the method comprises the steps of obtaining the light field complex amplitude Un + 1-k'of P back propagation to the rear surface of each phase modulation layer, calculating the gradient related to a loss function based on Uk and Un + 1-k 'so as to carry out updating, and carrying out the next round of training until a preset training round or loss convergence is reached. The method can adapt to errors existing in an optical system.

The invention discloses an automatic wavelength tuning method and system for a tunable laser based on particle swarm optimization, and is applied to the technical field of wavelength tuning of semiconductor tunable lasers. According to the method, a particle swarm optimization (PSO) algorithm is taken as a core, multi-target iterative search optimization is carried out on initial current-wavelength data, and in a tuning initialization stage, a system firstly carries out coarse scanning on three paths of current of a left reflecting grating region, a right reflecting grating region and a phase modulation region of a sampling grating distributed Bragg reflection laser; manual intervention is not needed, the system can complete efficient configuration screening in a given target wavelength range, the intelligent level of the tuning system is remarkably improved, good automation capacity and expansibility are achieved, scanning of a large number of invalid data and tedious operation procedures in the traditional tuning process are avoided, and the tuning efficiency is improved. And meanwhile, a high-quality current-wavelength lookup table can be quickly constructed, and the method has wide engineering application prospects in optical communication, sensing and other scenes.

The invention belongs to the technical field of grid-connected inverter harmonic analysis, and particularly discloses a grid-connected inverter harmonic closed-loop transmission analysis method and system considering broadband coupling. The method comprises the following steps: respectively establishing a harmonic component transfer function of each module; based on the harmonic component transfer function of the sampling module, calculating to obtain harmonic active power and harmonic reactive power input to the power outer loop control module; based on a harmonic component transfer function of the power outer loop control module, calculating to obtain a harmonic current component in a reference current signal output by a power outer loop; based on a harmonic component transfer function of a current inner loop control module, obtaining a three-phase modulation voltage harmonic component and an inverter port voltage harmonic component through coordinate inverse transformation; on the basis of the inverter port voltage harmonic component, a main circuit harmonic transfer equation is combined, and a grid-connected point harmonic current component is obtained through calculation; the method overcomes the defects that a traditional analysis method cannot consider the control of a whole loop by a closed loop, and the broadband coupling is insufficiently considered.

The invention belongs to the technical field of radar data processing, and particularly relates to a GPGPU-based time-varying target echo simulation method and device. Each thread in each Block in each Grid of the GPGPU is responsible for echo calculation of a target in a channel at each moment, and each echo calculation step comprises the following steps: S1, calculating an inherent frequency domain scattering coefficient of the target according to an incident angle of a radar to the target; s2, obtaining an inherent time domain scattering coefficient of the target through inverse Fourier transform; s3, carrying out amplitude-phase modulation on the inherent time domain scattering coefficient of the target; s4, calculating a target response signal based on the modulated time domain scattering coefficient; and S5, determining a time-varying target echo signal according to the target echo frequency, the time delay, the target Doppler frequency and the calculated target response signal. Important support is provided for testing and verification of a radar detection system, and the simulation effect is closer to a real scene.

The invention discloses an LCoS device and a phase modulation method of the LCoS device. The LCoS device comprises a transparent electrode, a liquid crystal layer, a metasurface layer and a back plate which are sequentially arranged from the incident end to the reflecting end. A projection included angle is formed between the long axis of the metasurface layer and the liquid crystal molecule director of the liquid crystal layer on a propagation plane; the liquid crystal layer is used for performing phase modulation on a parallel first polarization component of incident light, and the conversion metasurface is used for performing polarization state exchange on the parallel first polarization component and an orthogonal second polarization component of the incident light; the back plate is used for reflecting incident light; and the liquid crystal layer is used for performing phase modulation on the exchanged second polarization component, so that the emergent first polarization component and the emergent second polarization component are subjected to phase modulation. The metasurface layer is introduced, a polarization-dependent modulator is converted into a polarization-independent modulator through two times of liquid crystal layer passing and one time of polarization conversion, and the fundamental limitation of a traditional LCoS device is solved.

This invention relates to the field of short-term meteorological forecasting technology, specifically to a forecasting model architecture based on point cloud data and a spatiotemporal frequency domain joint attention mechanism. This forecasting model architecture includes a Z-coordinate system three-dimensional point cloud visualization data model and a P-coordinate system four-dimensional spatiotemporal frequency domain joint attention model. The three-dimensional point cloud visualization data model directly represents the three-dimensional distribution of meteorological elements. Combined with the DEM trust propagation completion algorithm, the observation coverage of a 1km resolution area is increased by 40%, significantly improving the forecast accuracy in complex terrain areas (such as mountainous regions). Then, a decision tree model and satellite observation data are used to fuse precipitation data, filling in the gaps in precipitation observation data for areas without monitoring stations. Finally, based on the Earth's rotation period and P-coordinate system four-dimensional spatiotemporal time domain data, a Fourier transform + phase modulation module enhances the frequency domain capture capability of precipitation cycle signals, significantly improving the TS score for severe convective weather.

The invention provides a compensation method for asymmetric errors of a double-path weak measurement system and the double-path weak measurement system, which can be applied to the technical field of quantum measurement. The compensation method comprises the following steps: under the condition that wide-spectrum light passes through a double-path weak measurement system and the size of a signal which is weakly coupled with a weak coupling module is within a preset range, applying a square wave signal with a preset amplitude to a push-pull phase modulator, and performing binary detection by using an acquisition module to obtain four first detection signals; under the condition that the preset amplitude is not 0, determining a first error introduced by asymmetric loss of the double-path weak measurement system according to the corresponding four first detection signals; according to the four first detection signals corresponding to the square wave signal with the preset amplitude of 0 and the first error, determining a second error introduced by filter asymmetry of the double-path weak measurement system; according to the first error and the second error, asymmetric error compensation is carried out on the response formula, and it is ensured that the double-path weak measurement system has high sensitivity and stability.

The invention provides a unified carrier reverse lamination modulation method based on a three-level converter. The method comprises the following steps: acquiring the current three-phase reference voltage of the three-level converter; calculating a zero-sequence component of a current modulation strategy according to the three-phase reference voltage and the current modulation strategy; determining a three-phase modulation wave according to the three-phase reference voltage and the zero-sequence component; and generating a switching tube driving signal of each bridge arm in the three-level converter according to the three-phase modulation wave. According to the invention, through a unified zero-sequence component calculation mode, on the basis of carrier reverse-phase laminated modulation, compatibility with different modulation strategies is realized, a zero-sequence vector calculation process is omitted, a space vector region does not need to be judged, occupation of calculation resources when the modulation strategies are realized is effectively reduced, and the implementation efficiency of the modulation strategies is improved. And transient oscillation during strategy switching is suppressed.