38 results about "Transfer-matrix method (optics)" patented technology

A dynamic coupling time varying failure rate analysis method of a on-orbit space flexible gear mechanism comprises the seven steps that firstly, according to the fact that a shaft in the on-orbit space flexible gear mechanism is an elastic body, a kinetic equation of the flexible shaft is built, and the finite element method is adopted for analysis; secondly, a gear kinetic equation is built; thirdly, a nonlinear kinetics equation of coupling of the flexible shaft and a gear in the on-orbit space flexible gear mechanism is built; fourthly, transmission stimulation analysis is performed on the space flexible gear mechanism; fifthly, the Newmark algorithm is adopted to calculate a dynamic load coefficient; sixthly, a gear bending stress reliability limit state function is built in the on-orbit space flexible gear mechanism; seventhly, dynamic reliability and failure rate analysis are performed on the space flexible gear mechanism. The method solves the problem that reliability calculating accuracy is low because of nonlinear factors of a traditional transfer matrix method and mode superposition method, and has engineering practical value for improving reliability of the on-orbit space flexible gear mechanism and other spacecrafts. The method is also suitable for other flexible gear mechanisms.

The invention provides a dynamics forecasting method of a random branch structure. The dynamics forecasting method comprises the following steps of: (1) selecting a main transmission path, i.e. for a system which comprises the random branch structure, firstly, selecting one chain-type main transmission path from one boundary end to the other boundary end; (2) establishing each branch point model, i.e. by the influence of adsorbing each sub branch, establishing the model between state vectors of both front and rear ends of each branch point on the main transmission path; (3) establishing an integral model, i.e. establishing the integral model between state vectors of both initial and tail ends by an arrangement sequence of transfer elements and point elements of each field on the main transmission path; and (4) forecasting a structural dynamics problem, i.e. introducing a boundary condition and an external acting force which serve as definite conditions and applying a transfer matrix method to forecast the dynamics problem of a chain system. The dynamics forecasting method has wide application range, has simple and convenient implementing process, is very beneficial to programming calculating and has high forecasting accuracy; the integral solving process cannot cause the increase of a variable freedom degree value; and the forecasting efficiency is ensured high.

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 belongs to the field of diesel engine air distribution system researches and relates to a diesel engine air distribution system dynamic calculation method based on a multi-body system transfer matrix. The diesel engine air distribution system dynamic calculation method based on the multi-body system transfer matrix comprises the following steps of: building a cam profile Nth harmonic fitting function, selecting a state vector, a boundary condition, an initial input quantity and the like required by a multi-body system transfer matrix method, analyzing the mechanical properties of all components of an air distribution system, deducing a transfer matrix which reflects the mechanical properties, integrating all parameters to obtain a total transfer equation, solving the total transfer equation to obtain the dynamic response situation of each part, drawing the dynamic characteristic curve of each part and the like. The diesel engine air distribution system dynamic calculation method based on the multi-body system transfer matrix has the advantages that the mechanical response situations of all parts during the movement of the air distribution system can be intuitively reflected through the dynamic characteristic curves, the dynamic response results and the like of all parts, the method is suitable for air distribution systems of diesel engines with different speed types, the measuring and modeling time needed for building a three-dimensional model is greatly saved, and the obtained results are more effective than the results obtained through solution by using the traditional multi-rigid-body differential equation set.

A critical load calculation method of parallel-shaft tooth-typed compressor belongs to the field of rotating mechanical rotor dynamics and particularly includes following steps: (1) obtaining required parameters of critical loads of the parallel-shaft tooth-typed compressor; (2) calculating dynamic characteristic parameters of each gear output shaft under different powers according to the obtained parameters; (3) inputting the dynamic characteristic parameters into a dynamic equation and calculating a first-stage critical rotating speed, a second-stage critical rotating speed and a third-stage critical rotating speed of each gear output shaft under different powers through a transfer matrix method; (4) fitting the first-stage critical rotating speed, the second-stage critical rotating speed and the third-stage critical rotating speed of each gear output shaft under different powers through a polynomial to obtain fitting functions of each critical rotating speed; and (5) according to an operation rotating speed and the critical rotating speed fitting function of each gear output shaft, determining whether a critical rotating speed of each gear output shaft exists or not in design and calculating the particular critical rotating speed. The method is used for determining whether the critical load of each gear output shaft exists or not during design of the parallel-shaft tooth-typed compressor, thereby guiding a designer to optimize design of the compressor.

The invention discloses a method and system for quantitatively calculating the vibration response of a complex combined shell structure in a fluid medium, wherein the method includes the following steps: obtaining structural parameters and excitation parameters of the combined shell system in the fluid medium; according to the obtained structural parameters and excitation parameters, Collocate points on the surface of the combined shell along the direction of the generatrix, use the fine integration method to calculate the field transfer matrix and point transfer matrix between the collocated points of the combined shell system, and calculate the external force vector; according to the boundary conditions at both ends of the combined shell system and the structural continuity conditions, establish The dynamic model of the fluid medium-combined shell system; the vibration response of the fluid medium-combined shell system is obtained by solving the Moore-Penrose generalized inverse matrix. Based on fine integration and transfer matrix method, the invention can quantitatively calculate the vibration response of the complex combination shell in the fluid medium which is generated by external excitation, and provides reference and basis for the analysis of the vibration characteristics of the underwater vehicle.

The invention discloses a method for establishing and solving a manipulator model based on an improved multi-body system transfer matrix. According to the structural characteristics, motion transmission and force transmission relationship of the planar manipulator, the present invention improves the discrete-time transfer matrix method of the multi-rigid body system, establishes a unified model of n-degree-of-freedom serial manipulators, and aims at the relationship between the joint space and the operation space of the manipulator. Based on the two known motion conditions between the two, by setting the boundary conditions, the kinematics and dynamics solution method and process of the system model are proposed. The research object of the present invention is a planar serial robot system. The mathematical model established by using the improved method of the multi-body system discrete time transfer matrix not only has the characteristics of flexible modeling and small calculation scale, but also can cover the kinematics and dynamics characteristics of the system at the same time. , which is more effective than the traditional robot modeling method, embodies the superiority of the new method, and achieves the goals of clear thinking, simple programming and easy realization.