15 results about "Transfer matrix" patented technology

This invention discloses a dynamic load identification method and apparatus based on a physically guided convolutional long short-term memory network, relating to the field of data processing. The method includes: constructing and training a dynamic load identification model based on a convolutional long short-term memory network to obtain a trained dynamic load identification model; the loss functions used in the training process of the dynamic load identification model include a data-driven loss function and a physically guided loss function. The physically guided loss function is constructed based on the dynamic equations transformed from the motion equations of a linear system under dynamic action, and uses an overall transfer matrix; acquiring the time-domain signals of acceleration and / or strain responses of each test point collected within each time window when the dynamic load to be identified is applied to one or more points on the structure, and inputting these signals into the trained dynamic load identification model to obtain the predicted dynamic load corresponding to one or more points. This invention solves the problem of the current load identification method's strong dependence on data.

The invention provides a Hermite-Newton formula milling stability domain prediction method based on prediction correction, and the method comprises the steps: converting a time delay differential equation considering regenerative flutter milling dynamics into a space state form, and obtaining a space state equation; the cutter tooth cutting period is divided into a free vibration time period and a forced vibration time period; equally dividing a forced vibration time period into a plurality of small intervals, and performing integral calculation on the space state equation in any small interval to obtain a relation equation between a state item and a time delay item; using Hermite and Newton formulas to approach a state item and a time delay item to obtain state quantities which are respectively used as a predicted value and a corrected value; calculating a mapping relation between cutter tooth responses of adjacent periods through simultaneous prediction value and correction value equations; constructing a transfer matrix according to the mapping relation; according to the method, the defect that calculation precision and calculation efficiency cannot be considered at the same time in a traditional numerical solution method is overcome, and the milling stability domain is estimated more accurately and efficiently.

This application discloses a method and related device for identifying the stiffness and resistance parameters of pipeline hangers, relating to the field of pipeline system dynamics analysis technology. The method includes acquiring the geometric and material parameters of the pipeline system and establishing a transfer matrix dynamic model; constructing a frequency response function based on vibration response and extracting experimental frequency response data; constructing a forward calculation model of the frequency response function, calculating theoretical frequency response data, and extracting characteristic parameters; comparing experimental and theoretical frequency response characteristic parameters to obtain frequency response error data; searching for Pareto optimal solutions within the feasible search range of stiffness and damping based on the frequency response error data and the NSGA-II algorithm, and selecting optimal stiffness and damping parameters from the Pareto optimal solution set based on the normalized weighted Euclidean distance criterion. This application eliminates the need for direct contact measurement of the hangers; parameter identification can be achieved simply by collecting the vibration response on the pipeline, solving the technical problem of accurately measuring the dynamic parameters of hangers under complex working conditions.

The application discloses a MoM-PO electromagnetic scattering hybrid method based on matrix dimension reduction, according to the region division of a target into an original region and a dimension reduction region, impedance matrices in a method of moments (MoM) are divided into blocks, and then two transfer matrices are constructed to establish an expression of unknowns between the two regions; through simple operation of the matrix blocks, the high-dimensional impedance matrix is changed into a low-dimensional impedance matrix, so that the complexity of matrix element filling and subsequent equation solving and calculation can be effectively reduced; and through the introduction of an electric dipole model, the calculation process of matrix element filling is further simplified.

The invention discloses an optimal loading time domain signal acquisition method and system suitable for finite element analysis, and the method comprises the steps: building a finite element model of a product structure, and constructing a transfer matrix relation in a time domain range; constructing a compatibility matrix in combination with response data of a plurality of measuring points and the transfer matrix relationship; acquiring a row with the maximum average compatibility index in the compatibility matrix, and taking a measuring point corresponding to the row as an optimal response point; based on the optimal response point, performing inversion through the transfer matrix relation to obtain an optimal time domain loading load signal; and applying the optimal time domain loading load signal to a loading surface of the finite element model to obtain other mechanical response data of the product structure. The time domain load obtained by inversion of the optimal response point is accurate and reliable so as to more accurately support numerical simulation analysis of a product.

The invention provides a self-adaptive underwater buried object detection method and device, and relates to the technical field of underwater detection. The method comprises the following steps: establishing a wave number integral model of a non-uniform medium, and correcting a traditional Helmholtz equation to represent sound wave propagation characteristics between a sedimentary layer and a buried target; constructing a coupling perturbation scattering model, expanding the coupling perturbation scattering model to a second order through Taylor expansion, and realizing joint modeling of coherent scattering and diffuse scattering in combination with a correction integral equation; carrying out global modeling on the multi-interface layered medium by adopting a transfer matrix method, and deducing a total reflection coefficient; establishing a constitutive relation model of the viscoelastic material based on the fractional derivative, and realizing acoustic response prediction of multi-physics coupling in combination with a random equivalent medium theory; and training detection signal data by using a long short-term memory auto-encoder network, and judging the existence of a target by calculating a reconstruction error. Through the method and the device provided by the invention, accurate detection in a complex underwater environment is realized, the problems of poor environmental adaptability, insufficient data and the like of a traditional method are avoided, and the detection accuracy and reliability are improved.

The application discloses a kind of based on finite difference reduction multibody system transfer matrix method of rotating beam system dynamic characteristic analysis method and system.Method includes: the physical parameter model of rotating beam system is established, and the structural parameter of rotating beam is acquired;Rotating beam system dynamics control differential equation is established;Rotating beam system is discretized using finite difference method;The transfer matrix of the discretized multibody system model is constructed, and the transfer matrix is processed using reduction equation, and the reduced difference point reduction transfer matrix recursive relationship is obtained;The reduced state vector recursive equation is established, and the dynamic characteristic parameter of rotating beam system is calculated and output.The application is combined with finite difference method by multibody system transfer matrix method, and rotating beam element is discretized difference, and the differential term of rotating beam differential equation is differentially approximated to deduce transfer matrix, retains the characteristics of low matrix order involved in transfer matrix method, reduces the calculation scale, improves the success rate of numerical calculation result, and can effectively solve rotating beam and other dynamics problems.

The invention discloses an elastic element-containing pipeline frequency domain TMM calculation method, and relates to the technical field of pipeline system dynamics analysis. The method comprises the following steps: firstly, establishing a straight pipe local coordinate system and dividing system units, and constructing a pipeline element 14 equation model based on a Timoshenko beam theory; constructing a field transfer matrix and a point transfer matrix of the elastic element and the elastic support by referring to a four-end parameter method and combining impedance parameters, and integrating the field transfer matrix and the point transfer matrix into a system overall transfer matrix; and finally, establishing a complete frequency domain TMM calculation logic, and solving a pipeline frequency domain response through a node force balance condition, a continuous condition and a boundary condition. The method solves the problems that a traditional method is difficult to consider both precision and efficiency and poor in universality, can accurately reflect the dynamic characteristics of the elastic element, greatly improves the calculation efficiency, is adaptive to various elastic elements, and can provide reliable support for low-vibration design of pipelines in the fields of ocean engineering, shipbuilding and the like.

The invention relates to the technical field of model optimization, in particular to an aggregation Markov model dimension reduction method and device for dynamic system monitoring, and the method comprises the steps: firstly obtaining a probability transfer matrix Q, an observation probability matrix O and an initial distribution vector p of a target model; generating a diagonal matrix based on O, and constructing an intermediate matrix M fusing dynamic and initial information of the model; calculating the maximum matching number E of the bipartite graph constructed by the M, and comparing the maximum matching number E with the model dimension n to judge whether the dimension of the model can be reduced or not; if the dimension can be reduced, for each observation category, constructing a conversion sub-matrix based on a bipartite graph matching result of the sub-matrix blocks, and combining to form a conversion matrix T; and finally, constructing a dimensionality reduction aggregation Markov model with lower dimensionality by utilizing T and a left inverse matrix thereof. The invention provides a determinable automatic dimension reduction mechanism, which can obviously reduce the calculation complexity on the premise of ensuring the function equivalence of the model, and is particularly suitable for edge calculation scenes with limited resources.

The application discloses a kind of shipboard aircraft dynamics fast calculation method.Method includes following process: establishing shipboard aircraft catapult take-off multi-flexible body system dynamics model, establishes shipboard aircraft catapult take-off multi-flexible body system topology, utilize finite element method to establish main tire refinement finite element model, then tire flexible body dynamics characteristic parameter is exported and deduces the dynamics equation of tire flexible element, based on multi-body system transfer matrix method (MSTMM) and finite element modal synthesis method deduce shipboard aircraft catapult take-off multi-flexible body system total transfer equation and total transfer matrix, solve the inherent frequency of shipboard aircraft multi-flexible body system considering inflatable flexible tire and the dynamic response of catapult take-off;The method proposed in the application overcomes the defects of high matrix order and large amount of calculation of traditional methods when dealing with complex coupling system of shipboard aircraft containing inflatable flexible tire, has the advantages of fast calculation speed, high degree of programming and strong universality, provides an efficient calculation method for the dynamic analysis of complex shipboard aircraft multi-flexible body system.

The invention relates to the technical field of dynamic modeling of precise optical instruments and mechatronics systems, in particular to a rapid reflector system modeling and performance prediction method based on a transfer matrix method. The FSM system is modularly decomposed into basic elements such as a flexible hinge and a rigid connecting rod; respectively establishing a transfer matrix of each element to describe an input-output mechanical relationship; assembling the matrixes into a total model according to a system topological structure, and solving by introducing a boundary condition, so as to quickly and accurately calculate a mapping relation from the driving displacement to the mirror plane directional angle; according to the method, the calculation error is relatively small, the single analysis time is greatly shortened, and the order of magnitude of efficiency is improved.

This invention belongs to the field of flow field super-resolution prediction technology, specifically involving a time-based super-resolution flow field prediction method, program, device, and storage medium based on a combination of DMD and Schur-Pade methods. This invention is based on the fundamental idea of ​​treating the evolution of complex flow fields as a linear dynamic system using the DMD method. It combines this with the Schur-Pade method for solving real powers of a square matrix, employing four techniques—Schur decomposition, square root matrix decomposition, Pade approximation, and explicit correction of diagonal elements—to perform real-power operations on the flow field transfer matrix. Then, based on the flow field prediction formula obtained from the DMD method, it achieves super-resolution prediction of the flow field at any given time. This invention, through the combination of the DMD and Schur-Pade methods, forms a stable, efficient, and high-precision time-based super-resolution flow field prediction method, avoiding the problems of high randomness, long training time, and difficult parameter tuning associated with machine learning-based flow field prediction methods.

The application relates to a high-order rotationally symmetric target heterogeneous parallel electromagnetic simulation method and system based on a moment method and an equivalent principle method, high-order line basis functions are introduced into a rotationally symmetric body algorithm based on the equivalent principle method, adaptive high-order matrix filling, loop reduction and boundary division are completed based on a deep calculation unit architecture, and an LU matrix inversion operator under the architecture is proposed; first, a rotationally symmetric target is geometrically modeled and equivalent surface modeled, an EPA-BoR equation set is constructed, a high-order U matrix and a transfer matrix are derived; then, each matrix of the high-order EPA-BoR equation set is generated based on a heterogeneous parallel calculation strategy; after each MPI process generates corresponding scattering operators and translation operators, electromagnetic scattering solving is completed through inter-process transmission calculation; and finally, the radar scattering cross section of the rotationally symmetric target is calculated according to current solving results. The application has high calculation precision, low memory occupation and greatly improved solving efficiency.

The invention provides a transmission system dynamics analysis method based on a finite element transfer matrix method, relates to the technical field of finite element analysis, and solves the technical problem that in the prior art, an energy method, a finite element method and the like are difficult to model for transmission assemblies with various types and complex structures. According to the scheme, the method comprises the steps of modeling based on transmission system component multi-physics field coupling, modeling of a component dynamic model based on a finite element-transfer matrix method, modeling of a transmission system dynamic model, quoting boundary conditions to a transmission system total dynamic transfer equation to obtain a characteristic frequency equation of a transmission system, and solving to obtain an analysis result. On the premise that the precision equivalent to that of a traditional FEM is kept, the calculation efficiency is improved by nearly 8000 times, and the method is more suitable for real-time simulation and system-level optimization of transmission system engineering.

The invention discloses a magnetocardiogram forward model construction method based on a Block Toeplitz matrix, relates to the field of biomedical engineering, and comprises epicardial potential simulation, body surface heart magnetic field data simulation, heart magnetic field data structured expansion transformation and an expansion transfer matrix construction method. According to the construction method of the magnetocardiogram forward model, simulated body surface heart magnetic field data is obtained through calculation by combining the Biot-Savart law on the basis of a personalized heart geometric model obtained through CT segmentation and reconstruction and an improved FHN model simulation epicardial potential. For the ill-conditioned problem existing in inverse problem solution, heart magnetic field data is expanded to construct a Block Toeplitz matrix, and an expansion transfer matrix capable of solving inverse operation ill-conditioned is deduced and calculated. According to the method, ill-conditioned discomfort is inhibited under the condition that regularization constraint is not added in the inverse problem solving process, and an existing magnetocardiogram forward model building and inverse problem solving method is expected to be supplemented.