198results about How to "Clear physical meaning" patented technology

An on-orbit geometric calibration method of an optical remote sensing camera aims at a domestic satellite platform and load design characteristics to build a strict imaging model, and uses an internal and external orientation element combination modeling method for geometric calibration treatment. The method is based on the strict imaging model for the geometric calibration treatment, and model parameters have clear physical meanings; 2) simultaneous decoupling of internal and external orientation elements can be realized by internal and external orientation element combination modeling; 3) the model can be used for a multiple linear array camera and multi-camera combination calibration, and has a strong universality; 4) according to the method, various factors causing image distortion in an imaging process can be fully considered, and high precision can be achieved.

The invention discloses a method for comprehensively evaluating the electric energy quality by applying a TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) of a grey correlation coefficient matrix, which comprises the following steps of: taking electric energy quality data at all time intervals and standard data at all grades as an original decision matrix; determining subjective weights through an improved AHP (Analytic Hierarchy Process); determining objective weights through an entropy method; establishing a least square method decision model to obtain a comprehensive weight, so that the deviation of decision results under the subjective weights and the objective weights of all indexes is the least; carrying out standardization and weighted standardization on the decision matrix and obtaining the grey correction coefficient matrix by utilizing the grey theory; taking the grey correction coefficient matrix as a decision matrix of the TOPSIS to obtain the distance between positive ideal solutions and negative ideal solutions of all schemes and the relative closeness of the positive ideal solutions and the negative ideal solutions; and comparing the electric energy quality closeness at all the time intervals with the standard closeness at all the electric energy quality grades to finally obtain the electric energy quality grades at all the time intervals. With the adoption of the method, the electric energy quality evaluation result can be objectively and reasonably obtained under the situation of poor information, so that the practicability and the feasibility are stronger.

The invention provides an impedance network modeling and stability analysis method based on a synchronized reference coordinate system, comprising the following steps of S1: collecting machine network parameters of the target system; S2: calculating the power flow according to the the machine network parameters to obtain the initial value of the state variable for constructing an impedance matrix model of each device in the system; S3:establishing the impedance matrix modeling of each device in the system according to the initial value of the state variable; S4: transforming the impedance matrix model of each device in the system into the coordinate system of the whole network system; S5: constructing the impedance matrix model of the whole system; S6: aggregating the impedance network model into the combined impedance matrix; S7: carrying out the oscillation stability analysis according to the combined impedance matrix. The invention can realize the impedance network modeling of the multi-converter large power grid, and has the advantages of wide application range, clear physical meaning, simplicity, and high efficiency.

The invention discloses a node locating method of a wireless sensor network, comprising the following: step A, a local relative coordinate system of each part of the wireless sensor network is established; step B, the local relative coordinate systems are integrated to obtain an overall relative coordinate of all nodes, and the overall relative coordinate is converted into an overall absolute coordinate by means of a beacon node with known position information; step C, when the overall absolute original coordinate of all nodes is obtained, node locating iteration refinement is carried out. The node locating method, which overcomes the disadvantages in the prior art, provides a high-precision node locating method of a wireless sensor network.

The invention relates to a method for precisely measuring an earth gravitational field, in particular to a satellite gravity inversion method based on a double-satellite spatial three-dimensional interpolation principle. An earth disturbing potential (obtained by computing an inter-satellite speed of a GRACE satellite K wave band measuring instrument, a satellite orbit position and a satellite orbit speed of a global positioning system (GPS) receiver, a satellite nonconservative force of an accelerometer and a satellite three-dimensional attitude data of a fixed star sensitive device) which is positioned on a gravity double-satellite orbit with a relatively irregular spatial position is interpolated three-dimensionally onto a reference spherical surface with a relatively regular spatial position and uniform grid division, so that the earth gravitational field is precisely and quickly inversed. By the method, satellite gravity inversion precision is high, physical meaning in the resolving process is clear, the computing speed is high, requirements on performance of a computer are low, and the method is sensitive to high-frequency signals in the gravitational field, so that the double-satellite spatial three-dimensional interpolation method is an effective method for resolving the earth gravitational field with high precision and high spatial resolution.

The invention discloses a user clustering and power distribution method and device based on a deep Q network and a medium. The method comprises steps of using a user clustering and power distributionproblem for modeling a joint optimization problem; establishing a BP neural network to realize a power distribution function in the joint optimization problem; training a BP neural network by using the training data set, testing the network and storing a BP neural network model to obtain power distribution results under different channel conditions so as to realize power distribution; modeling theuser clustering problem into a reinforcement learning task; constructing a deep Q network according to the reinforcement learning task; and after the network is trained on line, training a deep Q network according to an input state, and selecting an optimal action as an optimal clustering result to realize user clustering. According to the method, the online calculation complexity can be reduced,the user fairness is ensured to a certain extent, and the spectral efficiency of the system is effectively improved.

The invention discloses an automobile direction intelligent control method based on a driver model. The method includes the steps of firstly, predicting a position where an automobile can reach after a moment T of a preview period according to the current running state of the automobile, comparing the position with a target position after the moment T, obtaining deviation of the two positions, obtaining the ratio of the deviation and T to serve as a predicted automobile transverse velocity, and then comparing the predicted automobile transverse velocity with an actual automobile transverse velocity to obtain a predicted automobile transverse velocity difference; secondly, obtaining a steering wheel turning angle through calculation, and controlling an automobile steering wheel according to the obtained steering wheel turning angle. The invention further discloses an automobile direction intelligent control system based on the drive model. The system comprises a preview module, a prediction module, a comparing module, a calculation module and a control module. Compared with the prior art, parameters of the driver model built in the method are directly obtained through parameters of the whole automobile, the driver module has the advantages of being simple in parameter and clear in physical meaning, and control of the automobile is more accurate and real.

The invention discloses an electric car charging station harmonic wave detection method in a microgrid in the electric engineering microgrid technical field. First, harmonic current in the microgrid are pretreated and is broken down into narrow band frequency signal families S1. Next, continuation treatment is carried out for the narrow band frequency signal families S1 through adoption of a self-adaption step-be-step continuation method to obtain frequency signal families S. Further, empirical mode decomposition is carried out for the frequency signal families S to obtain natural mode components. Hibert conversion is carried out for the natural mode components, and finally instantaneous frequency signals and instantaneous amplitude signals of the components are obtained. The electric car charging station harmonic wave detection method not only is suitable for analyzing nonlinear and nonstationary signals in power quality of the microgrid, but also can better reflect frequency characteristics and amplitude characteristics of the signals by analyzing linear and stationary signals in the power quality of the microgrid than other time-frequency analysis methods, and has more specific physical significance.

The invention discloses a method for positioning low-current grounding fault sections of power distribution networks on the basis of transient energy analysis. The method includes steps of determiningpass frequency band ranges of digital filters and configuring a miniature PMU (power management unit) on each node of the power distribution networks; acquiring zero-sequence voltage phasors and zero-sequence current phasors of the various nodes of the power distribution networks by the aid of the miniature PMUs, judging whether faults of systems occur or not according to the zero-sequence voltage phasors and the zero-sequence current phasors of the various nodes, starting to position the faults if the faults occur, reading three-phase current signals recorded by the various miniature PMUs, computing transient zero-sequence currents of the various nodes by the aid of the three-phase current signals, processing the transient zero-sequence currents, computing transient energy of various sections, and determining the fault sections according to the transient energy of the various sections. The method has the advantages that physical meaning of fault features utilized by the method is clear, the method is high in positioning accuracy and reliability for the fault sections of various branch lines, and input of medium resistors connected with arc suppression coils in parallel or installation of signal injection equipment can be omitted.

The invention relates to a photovoltaic power station equivalent modeling method. The photovoltaic power station equivalent modeling method comprises the steps of building a simulation model of a grid-connected photovoltaic generation unit, including, a transient control module; carrying out a fault simulation experiment for the grid-connected photovoltaic generation unit, obtaining active power response curves in the presence of different voltage drop depths and different time of duration, and storing the active power response curves in the presence of different voltage drop depths and different time of duration into corresponding offline databases; selecting matched offline databases based on the really measured voltage drop depth and time of duration, selecting the active power response curves from the matched offline databases based on the output of the grid-connected photovoltaic generation unit, and clustering and grouping the selected active power response curves based on the active power response similarity when the transient control module is enabled so as to obtain multiple generator set groups; calculating a first equivalent parameter of each generator set group and a second equivalent parameter of a current collection circuit, and building an equivalent model based on the first equivalent parameters and the second equivalent parameter.

The invention provides a method for calculating composite index of grid operation based on information source entropy. According to the method, historical data of all indexes are subjected to statistics, the change law of the indexes is analyzed, the orderliness and the degree of stability of the historical data of the indexes are reflected by the information source entropy of the indexes, and then, the weight coefficients of the indexes are obtained. The method for calculating the composite index of the grid operation, provided by the invention, is different from the traditional index weight calculation methods which are based on subjective rating, each index entry serves as an independent information source, and the information source entropy of concerned indexes is calculated and serves as a weight calculation basis of the indexes, so that the fluctuation amplitude and the disorderliness of index values can be reflected objectively, and the contribution rate and the distinction degree of the indexes to the composite index of the grid operation are calculated scientifically. The method is simple in flow, small in calculation amount, low in developing difficulty and distinct in physical meaning and has strong practicability.

The invention discloses a method for building a global gravitational field model by utilizing an inter-satellite distance interpolation. The method disclosed by the invention is as follows: an inter-satellite distance interpolation satellite observation equation is built through introducing the precise inter-satellite distance of a satellite-borne K waveband gauge into a star attachment componentof a double-star opposite rail position vector so as to build a global gravitational field model with high precision and high spatial resolution. The method has high satellite gravity inversion precision, explicit observation equation physical meaning and low computer performance requirement, is easy to sense medium and high frequency gravity field signals, and is favorable for the error analysisof the gravity satellite system.

The invention relates to the field of interleaving techniques such as satellite geodesy, geophysics, space science and the like, and provides a satellite gravity inversion method based on a two-star energy interpolation principle. In the method, the global gravity field is accurately and rapidly inverted by introducing high-accuracy inter-satellite distance interpolation of a satellite-loaded K waveband measuring instrument into two-star relative orbits kinetic energy and further establishing a two-star energy interpolation observation equation. The method has the advantages of high satellitegravity inversion accuracy, definite physical meanings of the observation equation, contribution to error analysis of a gravity satellite system, easiness for sensing high-frequency gravity field signals and low requirement on the computer performance. The sensing accuracy of a 120-step GRACE earth gravity field can be increased substantively, so that the two-star energy interpolation principle method provided by the invention is an effective method for establishing a new generation high-accuracy and high-space-resolution global gravity field model.

The invention discloses a small signal impedance modeling method for a single-phase grid-connected inverter considering a phase-locked loop, which constructs a small signal impedance model of the grid-connected inverter containing a single-phase phase-locked loop by using harmonic linearization, and solves a problem of accurate modeling for broadband impedance of the single-phase grid-connected inverter. Influences imposed on the system stability by power grid impedance and the bandwidth of the phase-locked loop can be analyzed based on the model. When the power grid impedance is small, the influences imposed on the system stability by the phase-locked loop can be neglected; and when the power grid is weak, the phase margin of the system will gradually decrease or even become unstable along the increase in bandwidth of the phase-locked loop. The invention provides a model and method for small disturbance stability analysis for power grid access of the single-phase grid-connected inverter, and facilitates the popularization and application of the single-phase inverter grid-connected system.

The invention discloses a construction method suitable for a rock damage constitutive model under the cyclic load. The method comprises the following steps of solving an elastic-plastic matrix on thebasis of a secondary loading surface theory and a modified CWFS model; and establishing an equation suitable for the rock damage constitutive model under the cyclic load. The method aims to accuratelydescribe the nonlinear mechanical behaviors of a rock material under the cyclic load, comprising a hysteretic ring, the accumulated plastic strain and a damage effect, and the secondary loading surface theory has been successfully applied to the metal, soil and concrete, so that a new path is opened up for establishing the rock damage constitutive model under the cyclic load based on the secondary loading surface theory in combination with a Ducker-Prager yield criterion and by adopting the modified CWFS model.

The invention relates to a design response spectrum based floor structure dynamic response testing method under walking loading. The design response spectrum based floor structure dynamic response testing method under the walking loading comprises (1) collecting a large amount of single-people walking load curves and forming into an actual measurement loading database; (2) inputting the actual measurement loading database to a standard excitation system after the actual measurement walking loading data is performed on normalization processing to be performed on time-procedure analysis and calculating to obtain an acceleration response spectrum of the actual measurement walking loading; (3) classifying with testers as objects, performing statics and fitting with an external envelope line of a tester response spectrum serving as a representative curve and constructing a complete piecewise function expression for the design response spectrum; (4) calculating dynamic response of every order vibration mode of the floor structure under the walking loading, combining the dynamic responses of the orders through a square and square root method and finally obtaining the floor dynamic response. Compared with the prior art, the design response spectrum based floor structure dynamic response testing method under the walking loading can accurately estimate the acceleration response of the floor structure under the walking loading.

The invention discloses a method for the network visualization, which belongs to the field of network technology. The method comprises the following steps of: using a buffer read-in mechanism of Java to read large network data and store the large network data into an internal memory; performing hierarchical division of the network by a community dividing method; putting the circle centre of the community of the largest hierarchy in the centre of a visual image according the principle that the radius of each community is equal to the product of the number of the initial nodes contained therein and the radius of the initial node so as to locate the community of each hierarchy by the circular layout which has a hierarchical inclusion structure and draw graphics; providing mouse response on the network graphics, so the user can switch different hierarchies and view the over-all and local structures of the network. In the invention, the modularity index-based community dividing method is adopted, so the physical meaning of the community is clear; the divided community has a multi-level recursive structure, so stacking of a great number of nodes and crossing of edges are avoided and the structure of the network can be viewed more clearly.

The invention discloses a modeling method for a PSP mismatch model of an MOS (metal oxide semiconductor) transistor. The modeling method comprises the steps that a device performance mismatch submodule is added to a standard PSP model and comprises fitting parameters and parametric equations relevant to device performance mismatch; the fitting parameters are influence coefficients of influence degrees of the device performance mismatch on essential parameters, namely toxo, vfbo and wot of the PSP model; the device performance mismatch submodule affects variation characteristics of linear threshold voltage Vtlin, saturation threshold voltage Vtsat, linear drain current Idlin and saturation drain current Idsat of the transistor through the influence coefficients; the effects of the device performance mismatch on the gate-oxide thickness toxo, the size-irrelevant flat-band voltage vfbo and the effective trench width variation wot caused by trench blocking doped transverse diffusion are determined; and the gate-oxide thickness toxo, the size-irrelevant flat-band voltage vfbo and the effective trench width variation wot due to the trench blocking doped transverse diffusion are redefined.

The invention discloses an intelligent ammeter provider multi-target integral evaluation method based on gray correlation degrees; the method comprises the following steps: suggesting an intelligent ammeter provider integral evaluation model so as to fully and objectively evaluate the intelligent ammeter provider; using a vector specification-based method to carry out dimensionless process for an index matrix, thus preventing inconsistent units and large magnitude order difference problems caused by different types of indexes; finally calculating the gray correlation degree, and converting the intelligent ammeter provider multi-target evaluation problem into correlation coefficient comparison. Compared with a conventional simple index weighting method, the intelligent ammeter provider multi-target integral evaluation method is more direct and scientific, can effectively solve the intelligent ammeter provider integral evaluation problem, can carry out multi-target integral quantification evaluation for a to-be-evaluated provider with obvious physics meanings, thus solving the problems that the multi-target evaluation is complex in indexes and strong in subjectivity; the intelligent ammeter provider multi-target integral evaluation method is high in evaluation accuracy, and scientific and objective in evaluations.

The invention discloses a hyper-spectral information extraction method based on main component and cluster analysis. The method comprises the steps of: determining a standardized matrix Z of data of n samples; determining a correlation coefficient matrix R of the standardized matrix Z, calculating the characteristic roots of the correlation coefficient matrix R and characteristic vectors respectively corresponding to each characteristic root, and converting standardized sample data variables into main components, wherein a variable U1 highest in contribution rate is a number 1 main component, a variable U2 the second highest in contribution rate is a number 2 main component, ..., and a variable whose ranking is p is the number p main component; carrying out weighted summation on m main components which are highest in contribution rate to obtain an accumulated contribution rate, and taking the m main components whose accumulated contribution rate exceeds a threshold as cluster analysis main components; and carrying out classification scale calculation on the cluster analysis main components to determine the similarity of the samples, and classifying the samples according to the determined similarity of the samples. According to the invention, the main component analysis method and the cluster analysis method are combined to realize effective extraction of hyper-spectral image information.

The invention discloses a regional electric network failure diagnosis method based on five-layer and three-region cause and effect rule network, which can perform backward reasoning for the protection and on-off action information in an SCADA (supervisory control and data acquisition) system for tracing back failure causes, so as to determine the failure element. And forwarding reasoning is performed for the failure causes to detect the protection of false operation and failed operation and on-off aggregation. The five-layer and three-region cause and effect rule network built in the invention has the characteristics of clear structure and explicit physical meaning and can perform graphical expression, so as to have strong intuitionism and to be convenient to easily understand. The judgment of the protection of false operation and failed operation and on-off is simple and fast by the operations of a plurality of aggregations. In the invention, various candidate reasons are mutually restrained by constructing an action condition layer; and the influences of various failure symptoms at the opposite side of a circuit to the side are reflected by constructing a middle diagnosis auxiliary area, so that the accuracy of failure diagnosis at the side is strengthened.

The invention relates to a method for accurately detecting the earth gravity field, in particular to a method which includes: based on the load error analysis theory, accurately building the distance error between satellites of a K wave band distance meter, the satellite orbit position error and the orbital velocity error of a global positioning system (GPS) receiver and an error model in which accumulative geoid accuracy is affected by the nonconservative force error coalition of a satellite-bone accelerometer, and further accurately and rapidly inversing the earth gravity field. The method is high in inversion accuracy of the earth gravity field, simple in satellite gravity inversion process, low in performance requirements of a computer and definite in physical meanings of a satellite observation equation, and effectively improves inversion speed on the premise of ensuring calculation accuracy. The satellite gravity inversion method based on the load error analysis theory is an effective method for calculating the earth gravity field which is high in accuracy and spatial resolution.

The invention discloses a subspace identification based forecasting method for superheated steam output of a boiler of a firepower power station, which comprises the following steps: firstly, acquiring production data from plant-level DCS (Distributed Control System) configuration software at regular time; secondly, correcting bad points, filtering and denoising; thirdly, calculating input and output variables required by model identification; fourthly, constructing an Hankel matrix by utilizing continuous acquired and processed data and rolling to update; fifthly, approximating the boiler process to a linear state space model; sixthly, using a subspace theory to identify a matrix of the state space model [A, B, C and D]; seventhly, utilizing the latest input energy information as the obtained input variables of the state space model after the identification and calculating output energy of future moments; eighthly, calculating the mean value at the same time by utilizing a historical forecast value and a current forecast result and correcting by utilizing the past forecast deviation; and ninthly, rolling to update the data of identification of the model. The forecasting method is applicable to online forecast of superheated steam output energy in the boiler production process and provides guidance and reference for the optimization control of boiler combustion.

The invention relates to an object-oriented programming method for reading and writing a PSD-BPA data file. The method comprises the following specific steps: (1) analyzing the types and data formats of all cards in a BPA data file, and performing data abstraction; (2) defining a service primitive according to the result of data abstraction, designing a class structure framework; (3) completing the definitions of derived classes in the class structure framework in sequence from top to bottom; (4) implementing the class structure framework by adopting an object-oriented programming language; (5) determining the specific use way of the class structure framework according to an application requirement, and implementing and deploying an interface program; (6) verifying the correctness of the deployed interface program in different computation environments. Compared with the prior art, the object-oriented programming method has the advantages that the design of a BPA data interface ha a consistent hierarchical relation with a BPA program user manual, so that the extensibility, portability and maintainability of a data interface program are ensured, and the difficulty in developing and maintaining a BPA bilateral data conversion interface is lowered.

The invention discloses a corrosion residual life prediction method of transmission line towers in coastal regions. The method comprises the following steps: 1) measuring average thickness of tower material's residual zinc coating of a predicted tower; 2) measuring the minimal residual thickness of tower material's severely corroded regions of the predicted tower, and subtracting the minimal residual thickness from tower material's original thickness of the predicted tower so as to obtain the tower material's maximum corrosion depth of the predicted tower; 3) determining iron corrosion rate and zinc corrosion rate of the coastal region where the predicted tower resides; 4) obtaining the tower material's maximum allowable corrosion depth of the coastal region where the predicted tower resides; and 5) calculating corrosion residual safe life of the predicted tower. According to the invention, residual safe life of corroded transmission line towers in coastal regions can be predicted rapidly and accurately. Thus, measures can be taken timely so as to control and prevent accidents such as off-line, power failure, trip-out, etc. of transmission lines due to corrosion. The method of the invention has advantages of high accuracy and strong practicality.

The invention relates to a satellite-borne accelerometer nonconservative force data accurate calibrating method based on a novel dual-satellite adjacent energy difference principle in the technical field of crossing of satellite geodesy, geophysics, space science and the like. The satellite-borne accelerometer nonconservative force data accurate calibrating method comprises the steps of: on the basis of establishing a reference disturbing potential-free dual-satellite disturbing potential difference observation equation, by using priori information of a global gravitational field model, establishing a novel dual-satellite adjacent energy difference observation equation on the basis of the dual-satellite adjacent energy difference principle, and fitting a scale factor and an offset factor of calibration parameters so that satellite-borne accelerometer nonconservative force data is accurately calibrated. The method has high calibration precision and is suitable for rapid calibration of single-satellite and dual-satellite accelerometer data, thus earth gravitational field inversion precision can be effectively enhanced.

The invention relates to a spectral unmixing method based on core prototype sample analysis. The method includes the steps of collecting hyperspectral data to be processed, determining the parameters of the whole process, preprocessing input image data and achieving spectral unmixing on the preprocessed data through a core prototype sample analysis method. The spectral unmixing method is easy to implement, the spectral unmixing process does not need to be independently factorized into an end member extraction process and an unmixing process, the unmixing problem of the inexistence of pure end members can be solved, and the optimal end member selecting and unmixing problem of data at different mixing degrees can be solved as well. In addition, the physical meanings of an ultimate extraction result are definite, and data deciphering capacity is higher. Meanwhile, the result obtained in the method is more stable compared with a non-negative matrix factorization spectral unmixing result, and the precision is better.

The invention discloses a communication signal classification and recognition method based on multi-feature association and a Bayesian network, and belongs to the technical field of communication signal processing. According to the method, based on characteristics of large fluctuation range of the signal-to-noise ratio and insufficient training samples, features of the time domain, the frequency domain and the space domain of signals are associated, a Bayesian network model is designed, a Bayesian network classifier is obtained through structure learning and parameter learning, and a user cognition result is obtained. According to the method, cognitive classification is performed by employing the Bayesian network classifier, the dependence relations between the features of dimensions can be fully mined, the physical meaning is clear, and the method is applicable to a small-sample condition and an incomplete data set; performing a discretization pre-processing method by employing combination of priori and clustering, and original data information can be reserved to the maximum; and parameter learning is performed on the Bayesian network model by employing random sampling so that good classification accuracy can still be obtained in the conditions of large fluctuation range of the signal-to-noise ratio and insufficient quantity of the training samples.

The present invention discloses method of measuring atomic force microscope needle tip radius with single-wall carbon nanotube. The measurement includes the following steps: depositing single-wall carbon nanotube of 1-5 nm diameter on the surface of mica chip; measuring with atomic force microscope with the needle tip to be measured the measurement width w and height h of single-wall carbon nanotube; and calculating the radius of the needle tip to be measured based on w and h. The present invention uses the single-wall carbon nanotube as standard measuring sample for measuring the radius of the needle tip of atomic force microscope, and has the advantages of simple and intuitive mathematics mold clear physical meaning, precise, efficient and real-time measurement, etc. and may be used in measuring needle tip radius over 1 nm.

The invention discloses a loop current inhibition method suitable for a modular multilevel converter. The loop current inhibition method includes that loop current inside the modular multilevel converter (MMC) is separated from detected bridge arm current through frequency-doubled negative sequence rotation coordinate conversion, and a cross coupling novel control mode is adopted to realize quick inhibition of frequency-doubled loop current inside the MMC, so that capacitor voltage fluctuation of an MMC submodule can be effectively reduced, and stability and overall running performance of an MMC system can be improved.