Autors: S. Sherbakov, Y. Bychkov
The Infinity
software system is based on the analytical numerical method of calculating
the nonlinear dynamic systems. Only some of the features of the analytical
numerical method are realized in this software.
The features of the analytical
numerical method of analysis and parametrical synthesis of the nonlinear
nonautonomous determined system with lumped parameters of the dynamic
system models are described below. The consistent procedure of model
generation, specialized calculation algorithms together with the
existing software, the method makes up a unique problem-adapted
modeling complex.
The progress in the information technologies field
as well as in the theory of nonlinear phenomena, system analysis
and applied mathematics has increased the role of mathematical modeling
in engineering development and scientific investigations, thus turning
this universal methodology into the basis of mathematization of
the scientific-and-engineering progress. Judging by the means used
and the results received mathematical modeling proved to be a factor
which unites traditional research methods and new methodology; thus
enabling you to receive the necessary information about the character
and specific features of the processes in the dynamic systems quickly
and easily, to do the right prognosis and to make up recommendations
which will be able to guarantee reaching your purpose.
One of the main components of the complex dynamic
system modeling is the generated model calculation method, its possibilities
and unique features influencing to a great extent the validity level
of the received results as well as the complicity and the volume
of the calculations made. The essential nonlinearity and nonstationarity
of the complex dynamic systems models, their objective stiffness
and poor conditionality together with ambiguity and instability
of the coordinates’ behavior cause a number of special and
obligatory requirements to the analysis and synthesis method used
for such models. Taking into consideration the last achievements
in the development of the qualitative nonlinear phenomena theory
and the basic directions of improving the calculus mathematics methods,
the single-step variable order analysis and parametrical synthesis
method of nonlinear nonautonomus dynamic system models, named as
analytical numerical method, has been developed. The calculus algorithm
of the method imposes only two restrictions on the modeling system
properties description, demanding determinated and lumped parameters
of the generated model, including accountable external influences.
The computational model of the analytical part of the method is
based on the generalized functions set, generalized Laplace transformation
and functional power series. The numerical part of the method is
realized according to the principle of analytic continuation of
the regular component of the required solution of the model dynamics
equation. The calculation step choice procedure provides the solution
of all problems concerning the existence and uniqueness of the required
solution analysis, the opportunity to majorize the absolute local
and full calculation inaccuracy of the approximate solution, the
coordination of the step length and the change rate of the regular
component of the required solution, and also the observance of the
numerical stability conditions. The method order is the function
of the interaction result of the model dynamic properties of their
own and the specified level of the limited absolute local inaccuracy
of its analytical numerical calculation. If necessary, the method
order can be arbitrary high, constantly providing the coordination
and convergence of the method.
The main difference and the advantage of the developed method is
the possibility to receive not only the approximate solutions of
the analyzed model dynamics equation in the time optimum grid, as
well as the solutions with the specified level of the limited absolute
local and full inaccuracy of areas calculation, containing unknown
exact values of the desired solutions of this equation. Taking into
account the conversion of cause and effect relationship the method
can be effectively used for the solution of the parametrical synthesis
problem within the framework of the generated system model.
Having in mind to extend the possibilities of
the method on the basis of its analytical model the problem-oriented
research algorithms of poorly conditioned models, models with non-distinguished
linear part and with discontinuous differentiated coordinates; rigid
model calculation and the models with complex functional nonlinearity;
analysis of limited coordinates states of the selected class of
nonautonomous non-stationary models and spectral structure of the
distinguished linear part of the model dynamics equations have been
generated.
To sum it all up,
it is possible to say that the analytical numerical method which
makes up the basis of the complex modeling approach of complex dynamic
system modeling has the necessary analytical models and calculus
algorithms, so that its functional features enable you to carry
out the all-round and full research analysis of the properties and
peculiarities of the modeling object of its own.
All the procedures and transformations accompanying
the dynamic systems modeling process including the generation of
their models of a various complexity degree, directed enumeration,
the addition and the analytical numerical calculation of these models
under the condition of optimization of the calculations volume on
the interval unit of the Taylor series convergence for the regular
components of the desired solutions are well formalized and correctly
coordinated, thus representing together with the developed software
the uniform problem-adapted modeling complex.
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