39 results about "Modal matrix" patented technology

The invention relates to a CAE-based vibration fatigue simulation test method of a new energy vehicle battery pack.The CAE-based vibration fatigue simulation test method comprises the steps that virtual connection parts among a virtual battery pack, a virtual vibration test bench and a virtual battery pack and a virtual vibration test bench areconstructed to obtain a vibration fatigue virtual testdevice; modal calculation is performed on the virtual battery pack within the test vibration frequency range, and the natural frequency and modal matrix of the virtual battery pack are obtained; andactual vibration excitation load is applied to the vibration fatigue virtual test device under the natural frequency and modal matrix of the virtual battery pack; and the vibration fatigue parametersof the virtual battery pack under the actual vibration excitation load are calculated, whether the vibration fatigue parameters meet the vibration fatigue parameter threshold range conditions or not is determined, and if so, the initial parameters of the battery pack are stored to be taken as the design parameters of the battery pack for designing the battery pack. The CAE-based vibration fatiguesimulation test method evaluates whether the virtual battery pack is subjected to vibration fatigue damage or not during the test, and reduces the test cost of the battery pack design.

The invention relates to a natural image classification method and device on basis of multi-modal matrix filling. The method comprises the steps of carrying out feature extraction on natural image data with labels, natural image data without labels and natural image data for testing, and obtaining different feature representations; adopting a matrix filling algorithm to generate estimation labels of all features of the data with the labels; carrying out linear combination on all the estimation labels to be approximate to the corresponding known true labels corresponding to the estimation labels to obtain a combination coefficient; for all features, utilizing the natural image data with the labels and adopting the matrix filling algorithm to predict the labels of the natural image data without the labels and the labels of the natural image data for testing; adopting the combination coefficient to combine the predicted labels of all the features to obtain labels combining multiple features; classifying the natural image data on the basis of the labels combining the multiple features. The natural image classification method and device on the basis of the multi-modal matrix filling are easy to achieve, high classification accuracy can be obtained, meanwhile, the advantages of image classification on the basis of matrix filling are inherited, and the natural image classification method and device on the basis of the multi-modal matrix filling are suitable for the fields of network picture summarizing and classifying, image retrieval and the like.

The invention relates to an engineering testing method of the vibration field of a non-uniform arrangement structure. Based on the condition number of a structural vibration modal matrix, vibration measuring points causing an increase of the condition number of the matrix are removed in the loop iteration process, so that reduction of the number of the measuring points and optimization of the positions of the measuring points are achieved. Then based on a mode superposition method, only measuring data of the optimized measuring points with the number reduced is adopted, and vibration field reconstruction of the whole large structure is achieved. According to the method, a few sensors are optimized for position arrangement, and the vibration response field of the whole structure is reconstructed by means of the measuring data of the sensors, so that space and weight are saved, the testing workload is significantly relieved, and a monitoring position optimization method is provided for avibration monitoring system.

The invention relates to a wind turbine tower stress state calculation method based on a modal superposition method, Firstly, the finite element model of the tower is established, then the truncated modal matrix of the tower is calculated by the finite element method, and the principal vibration coordinates of the tower are calculated according to the real-time vibration values at the monitoring points. Finally, the real-time stress state of the tower is calculated by the modal superposition method. Using this method, the stress states of the whole tower and flange bolts can be calculated quickly according to the real-time vibration values of the finite vibration measuring points of the tower. The method has the characteristics of high calculation accuracy and fast calculation speed, and can meet the requirements of real-time online calculation.

The invention discloses an electric performance-oriented space mesh antenna key dynamical modal selection method. The method comprises the following steps of: inputting geometric parameters, material parameters, electric parameters of modal guillotine factors; calculating an ideal antenna far electric field; establishing an antenna structure finite element model; extracting node, unit and shape function information; calculating a unit electric performance first-order coefficient matrix; grouping an overall electric performance first-order coefficient matrix; carrying out antenna structure modal analysis; outputting a modal matrix; calculating a first-order sensitivity, for the modal, of the electric performance; outputting a modal shape equivalent mass fraction; calculating significance factors, for the modal, of the electric performance; judging whether the significance factors are greater than the modal guillotine factors or not; if the judging result is positive, selecting the significance factors; and otherwise, abandoning the significance factors. According to the method disclosed by the invention, the deficiencies of the traditional dynamical modal selection method are overcome, the influences, on the electric performance of antennas, of modals in different orders are integrally considered in the modal selection process, and the problem of electric performance-oriented space mesh antenna key dynamical modal selection is solved.

The invention discloses a patent text retrieval method and device based on multi-modal matrix vector representation, a word vector set of all words is obtained through training according to an existing patent data set, so that word vectors can contain information of all keywords, an image vectorization representation model is obtained through training of the existing patent data set, and the retrieval efficiency is improved. According to the method, the attached drawings in the patent are extracted, the graph vectors corresponding to the attached drawings are obtained, the graph vectors and the word vectors are combined, when the patent is retrieved, a large amount of useful information contained in the attached drawings in the patent is fully utilized, and meanwhile, some retrieval requirements of searching for a text through a graph, searching for a graph through a text and searching for a graph through a graph in the current market are met; and the patent retrieval result is more accurate.

The present invention relates to an image classification method and device based on multimodal matrix filling. The method includes: performing feature extraction on labeled, unlabeled and tested natural image data to obtain different feature representations; using a matrix filling algorithm to generate The estimated label of each feature of the labeled data; the estimated label is linearly combined to approximate its corresponding known real label, and the combination coefficient is obtained; for various features, the matrix filling algorithm is used to predict the unidentified The label of the label and the label of the tested natural image data; using the combination coefficient to combine the labels of all the features predicted to obtain the label of the fusion of multiple features; classifying the natural image data based on the label of the fusion of multiple features. The invention is easy to realize, can obtain higher classification accuracy rate, and at the same time inherits the advantages of image classification based on matrix filling, and is suitable for the fields of network picture summarization and classification, image retrieval and the like.

The invention discloses a rolling bearing fault diagnosis method based on improved variational mode decomposition and extreme learning machine, which is characterized in that: the vibration signals of rolling bearings under different types of faults are collected, and the maximum correlation kurtosis deconvolution is used to filter the vibration signals, Using the particle swarm algorithm to optimize the parameters of the maximum correlation kurtosis deconvolution method, the envelope energy entropy after signal deconvolution is proposed as the fitness function; the energy threshold is proposed to improve the number of modes in the variational mode decomposition , realize the improved variational mode decomposition of the filtered vibration signal, and obtain the modal matrix of the corresponding vibration signal; perform singular value decomposition on the modal matrix, obtain a singular value vector and construct a rolling bearing fault feature set; use extreme learning The computer trains the fault feature set to establish a rolling bearing fault diagnosis model. The invention realizes the stable feature extraction of the complex vibration signal of the rolling bearing, thereby improving the diagnostic accuracy.

The invention provides a spatial six-degree-of-freedom motion platform modal control method. In the invention, a spatial six-degree-of-freedom motion platform modal matrix is used to convert a strong-coupling physical space system into a decoupled modal space system, a modal control concept is introduced on the basis of the conventional spatial six-degree-of-freedom hydraulic motion platform control, the modal conversion matrix is used to decouple a strong dynamic coupling six-degree-of-freedom hydraulic motion platform, an expected physical input signal and a motion platform actual output signal are converted into modal signals to perform independent modal control regulation, the drive and control of the spatial six-degree-of-freedom hydraulic motion platform are realized, the coupling influences among the actuators and degrees of freedom in a spatial six-degree-of-freedom hydraulic motion are weakened effectively, indexes such as the single degree of freedom motion and multiple degree of freedom motion reproduction of the six-degree-of-freedom hydraulic motion platform are improved, and the bandwidths of degrees of freedoms besides the close degree of freedom of a first order modal are improved.

The invention provides a modal modeling method of a kinematic system with spatial six degrees of freedom, which comprises the following steps: scattering a parallel kinematic system with complex spatial six degrees of freedom into a plurality of substructures; computing the modalities of the previous orders of the substructures by adopting a substructure transfer matrix method to acquire low-order modality characteristics of the substructures; constructing a modal matrix; converting physical coordinates into modal coordinates by modal coordinate conversion; establishing a modal kinematic second order differential equation for each substructure; removing the redundant degree of freedom; carrying out modal synthesis on each substructure, thereby establishing an integral modal kinematic equation of the parallel kinematic system with spatial six degrees of freedom to acquire a modal model of the parallel kinematic system with spatial butted six degrees of freedom; and finally, converting the modal model into physical coordinates through coordinate conversion to acquire a physical spatial dynamic equation. The modal modeling method of the kinematic system, which is provided by the invention, has overlarge working space, overlong kinematic routes of supporting legs and high bandwidth and accuracy requirements of the system, and overcomes the limitation of multi-rigid body modeling of a spatial butted overlarge kinematic system.

The invention provides a method for detecting nonlinear features of a spacecraft structure driven by free vibration displacement response. The measured position movement response under the state; (2) The dynamic mode decomposition of the structure free vibration displacement response under the first initial displacement is carried out to obtain the dynamic mode matrix of the structure and its corresponding eigenvalues; (3) The decomposition obtained The dynamic mode matrix and its corresponding eigenvalues ​​reconstruct the position movement response under the second enlarged initial displacement condition, and analyze the difference between the measured position movement response under the second enlarged initial condition, and detect The existence of structural nonlinearity. For the detection problem of nonlinear features in the spacecraft structure containing hinges, directly using the displacement response of the structure in the free vibration state can effectively judge whether there are nonlinear features in the spacecraft structure.

The invention discloses a complex mode random eigenvalue direct variance calculation method based on the matrix perturbation theory. According to the method, first, the complex mode eigenvalue of structure vibration and the first-order perturbation quantity of corresponding eigenvectors generated when the rigidity, the damping, the mass and other parameters of a structure are changed are derived according to the matrix perturbation theory; then, a direct variance calculation algorithm for calculating the change range of the structure complex mode eigenvalue is established based on the eigenvalue of the complex mode structure and the first-order perturbation quantity of the eigenvectors according to the probability theory. When complex eigenvalue analysis of an asymmetric structure system is performed, the change range of the complex mode eigenvalue of the structure system can be rapidly and accurately acquired without knowing or supposing correlation coefficient matrixes of structure parameters, and therefore engineering application of the method to large structures is greatly facilitated.

The invention belongs to the technical field of aeroelastic analysis of an aircraft and relates to an aeroelastic analysis method in consideration of dynamic characteristics of an engine. The method comprises the steps of I, extracting engine reference points; II, establishing following matrixes according to extracted engine reference point positions and the dynamic characteristics of the engine: an engine thrust rigidity correction matrix as shown in the description, wherein j is engine number, F is a thrust vector of the engine reference point positions, and M is a moment vector caused by engine thrust, and a gyroscopic moment damping correction matrix as shown in the description, wherein omega is an angular velocity of the engine reference point positions, and theta is a turn angle vector of the engine reference point positions; III, correcting an aeroelastic motion equation without considering the dynamic characteristics of the engine according to the correction matrix established in step II, wherein the aeroelastic motion equation is as shown in the description, deltaM*= phiTdeltaMphi, deltaD*= phiTdeltaDphi, deltaK*= phiTdeltaKphi, deltaM* is a mass correction matrix, and phi is a modal matrix; and IV, calculating aeroelastic stability or dynamic response according to the corrected aeroelastic motion equation.