44 results about "Nonlinear kinetics" patented technology

The invention discloses a nonlinear dynamics calculation method for a gear pair. The method comprises the steps that the feedback effect of vibration displacement to the dynamic contact condition of agear surface of the gear pair in the actual running process is considered, and the nonlinear excitation of the dynamic meshing rigidity and dynamic comprehensive meshing errors is calculated. Dynamiccontact analysis of the gear pair and a system dynamics solution process are combined, and an excitation-response-feedback loop-locked calculation process of the system is achieved. According to themethod, the nonlinear dynamics phenomenon of the gear pair due to parameters such as gear surface errors and shape correction can be acquired, the dynamics behavior of the system in the dynamic contract process can be more truly simulated, and the calculation accuracy of dynamics is improved.

The invention discloses a cyanobacterial bloom predicting method based on a non-linear kinetic time-series model, which belongs to the water environment predicting field. The method comprises the following steps: using the blue algae growth rate as a time-varying parameter; creating a non-linear kinetic time-series model for the cyanobacteria growth with double nutrient salt cycling; using the combination of the numerical algorithm and the intelligent evolutionary algorithm, optimizing the constant parameters in the non-linear kinetic time-series model for the cyanobacteria growth; through setting the multivariate time-series model to realize the prediction of the time-varying parameter and the cyanobacteria biomass and through using the bifurcation theory and the central manifold theory to make a nonlinear kinetic analysis of the cyanobacteria growth time-varying system, obtaining the outbreak conditions for a cyanobacteria bloom so as to make an early warning of the bloom outbreak. The method proposed by the invention not only determines the conditions for a cyanobacteria bloom outbreak, but also improves the bloom prediction accuracy, providing an effective reference for an environmental protection department and governance decisions for water environment treatment.

The invention discloses a six-degree-of-freedom ultralow frequency vibration isolation device based on a zero stiffness system and a control system thereof, and relates to the fields of multi-degree-of-freedom low frequency, ultralow frequency and even zero-frequency vibration isolation and micro vibration simulation experiments. The six-degree-of-freedom ultralow frequency vibration isolation device based on the zero stiffness system is formed by connecting a supporting platform, a basic platform and a vibration isolation module. The vibration isolation module comprises an upper connecting rod, a lower connecting rod, a columnar shell, a vertical spring, a horizontal spring and a connecting assembly between the springs. The upper end of the upper connecting rod is connected with the supporting platform. The lower end of the upper connecting rod penetrates through an upper end cover of the columnar shell and is connected with the connecting assembly between the springs. The upper end of the lower connecting rod is fixedly connected with a lower end cover of the columnar shell. The lower end of the lower connecting rod is connected with the basic platform. The vibration isolation module meets the characteristic of zero stiffness. In combination with a gravity environment self-adapting control system, an isolated object is in a suspended state. Low frequency, ultralow frequency and even zero-frequency full-band vibration immune and isolation performance can be realized, and the problem of the multicoupling technique of multi-degree-of-freedom ultralow frequency, vibration resonance and non-linear dynamics is solved.

A control system for controlling an operation of a system with continuous- time nonlinear dynamics subject to constraints including equality and inequality constraints on state and control variables of the system, including an estimator to estimate a current state of the system using measurements of the operation of the system and a controller to iteratively solve, at each control time step, an approximation of a constrained nonlinear optimization problem to produce a control solution, wherein the approximation includes a linearization of the nonlinear dynamics of the system discretized by time intervals in the control horizon and represented using an approximation of the constraint Jacobian matrix for each time interval of the control horizon. The iterative solution procedure is based ona block- wise update formula for the approximation of the constraint Jacobian matrix and the intermediate condensing matrices using an evaluation of one or combination of the discretized dynamics of the system and at least one directional derivative of the discretized dynamics of the system. Each block in the constraint Jacobian matrix and in the intermediate condensing matrices represents one time interval in the prediction horizon and can be updated independently, based on a block- wise rank-one update formula without any iterative solution procedure and without any matrix-matrix multiplications or matrix factorizations.

The invention discloses a quasi-static and non-linear kinetic analysis method for the uncertainty of a viscoelastic dielectric elastomer based on an interval method. In the method, a viscoelastic kinetic model of the dielectric elastomer is provided, uncertainty of material parameters, external load and voltage is considered, and creep analysis, relaxation analysis and kinetic response analysis are carried out on the dielectric elastomer with interval uncertainty parameters by introducing an interval perturbation method and a first-order Taylor expansion method. The effectiveness of the interval method provided by the invention is verified by a Monte Carlo simulation method, and the uncertainty prediction method can be used in the design of an active control system taking a dielectric elastomer as a driver or a sensor in the future.

The invention discloses an optimal design method for a heavy-load and unbalanced-load gear transmission system based on motion stability. The method comprises the steps: extracting various internal and external excitation factors which affect the stability and accuracy of gear transmission; the influence of a time-varying center distance caused by factors such as deformation of a transmission shaft and a supporting part due to heavy load on a meshing line and a gear swing effect caused by unbalance loading are mainly introduced, and a bending-torsion-swing coupling nonlinear kinetic equation of a gear transmission system is established and solved; and a parameter interval of stable movement of the system is extracted by means of a nonlinear dynamics theory, so that the system avoids complex nonlinear dynamics behaviors, and the purposes of guiding gear machining design and parameter optimization are achieved.

The invention discloses a nonlinear dynamic modeling method for a harmonic reducer transmission system, and aims to overcome the defect that internal interaction of harmonic gear transmission cannot be reflected as a harmonic gear transmission system is subjected to dynamic modeling processing in a 'black box' mode in a dynamic model of a harmonic gear transmission system in the prior art. According to a harmonic gear transmission principle, a comprehensive dynamic model is established by considering the interaction of all parts in a harmonic gear. The method comprises the following steps: determining physical parameters and operation parameters of the harmonic gear transmission system; simplifying a transmission model of the system according to the harmonic gear transmission principle; calculating meshing rigidity; obtaining a nonlinear dynamic differential equation of the system by adopting the Newton second law, and performing the nonlinear dynamic solution on the system. According to the dynamic model established by applying the method, the internal effect of each part is comprehensively considered, and the precision of the model is ensured.

The invention relates to the field of experimental devices, in particular to a double-mass gap nonlinear dynamics experimental device. The double-plastid gap nonlinear dynamics experiment device comprises an inner plastid, an outer plastid, a shearing motion assembly, a gap nonlinear assembly, a sensor assembly and a supporting assembly. The inner plastid penetrates through the outer plastid, and the inner plastid and the outer plastid are connected through the shearing motion assembly; the inner plastid is connected with one side of the gap nonlinear assembly, and the outer plastid is connected with the other side of the gap nonlinear assembly; the sensor assembly is used for measuring the acceleration time history of the inner plastid and the outer plastid in the horizontal and vertical directions; and the supporting assembly is connected with the inner plastid. The double-plastid gap nonlinear dynamic experiment device provided by the invention can conveniently and effectively perform a double-plastid gap nonlinear dynamic experiment, and can be used for performing experimental verification on an existing nonlinear dynamic theory.