scholarly journals ALGORITHMS OF SYSTEM SYNTHESIS FOR STABILIZING UNCERTAIN DYNAMIC OBJECTS

2020 ◽  
Vol 2021 (1) ◽  
pp. 75-80
Author(s):  
Uktam Mamirov ◽  

The article deals with the formation of stable algorithms for the system synthesis for the stabilizing uncertain dynamic objects based on the method of local optimization in the presence of approximate mathematical models. The article analyzes the issues of building adaptive control systems using the concept of roughness, taking into account the assessment of the maximum allowable discrepancy between the object and its model. Some of the most constructive algorithms for determining pseudo-inverse matrices are given. When calculating the pseudo-inverse matrix of the control object, modified QR decomposition algorithms are used, obtained by deleting or assigning a column. The obtained algorithms allow us to conclude that the stabilization systems can be built on the basis of the local optimization method in the presence of approximate mathematical models. At the same time, it turns out that the asymptotic stability, i.e., the limited output with a limited input, can be achieved with sufficiently rough estimates of the object parameters and external perturbations using regular methods.

2021 ◽  
Vol 4 ◽  
pp. 105-116
Author(s):  
Valeriy Severyn ◽  
◽  
Elena Nikulina ◽  
◽  

Mathematical models of the WWER-1000 nuclear power reactor have been developed with division into zones along the vertical axis in the form of nonlinear systems of differential equations with dimensionless relative state variables. Models in a given number of zones along the vertical axis represent neutron kinetics, gradual heat release, thermal processes in fuel, cladding and coolant, changes in the concentration of iodine, xenon and boron. The parameters of mathematical models have been calculated based on the design and technological parameters of the V-320 series nuclear reactor. A general model of the reactor as a control object with division into zones along the vertical axis, as well as models with control of absorbing rods and boric acid, are obtained. Integration of the obtained systems of differential equations for given initial conditions allows one to obtain changes in all state variables in the reactor zones along the vertical axis. In particular, from the change in power in the zones along the vertical axis, the axial offset is calculated as the relative value of the difference between the powers of the upper and lower halves of the reactor core. The developed reactor models with dimensionless relative state variables use a minimum number of calculations, allow calculating the change in the axial offset, and are included in the information technology for controlling the power units of nuclear power plants to optimize the maneuvering modes of the WWER-1000 V-320 series reactor.


2013 ◽  
Vol 385-386 ◽  
pp. 999-1006
Author(s):  
Wei Wang ◽  
Ting Yu ◽  
Tian Jiao Pu ◽  
Ai Zhong Tian ◽  
Ji Keng Lin

Controlled partitioning strategy is one of the effective measures taken for the situation when system out-of-step occurs. The complete splitting model, mostly solved by approximate decomposition algorithms, is a large-scale nonlinear mixed integer programming problem. A new alternate optimization method based on master-slave problem to search for optimal splitting strategy is proposed hereby. The complete model was converted into master-slave problems based on CGKP (Connected Graph Constrained Knapsack Problem). The coupling between master problem and slave problem is achieved through load adjustment. A better splitting strategy can be obtained through the alternating iteration between the master problem and the salve problem. The results of the examples show that the method can obtain better splitting strategy with less shed load than other approximate algorithms, which verifies the feasibility and effectiveness of the new approach presented.


Author(s):  
N. Koshevoy ◽  
E. Kostenko ◽  
V. Muratov

he planning of the experiment allows us to solve the problem of obtaining a mathematical model with minimal cost and time costs. The cost of implementing an experiment is significantly affected by the order of alternating levels of change in factors. Thus, it is required to find a procedure for the implementation of experiments that provides the minimum cost (time) for conducting a multivariate experiment. This task becomes especially relevant when studying long and expensive processes. The purpose of this article is the further development of the methodology of optimal planning of the experiment in terms of cost (time), which includes a set of methods for optimizing the plans of the experiment and hardware and software for their implementation. Object of study: optimization processes for the cost of three-level plans for multivariate experiments. Subject of research: optimization method for cost and time costs of experimental designs based on the use of the jumping frog method. Experimental research methods are widely used to optimize production processes. One of the main goals of the experiment is to obtain the maximum amount of information about the influence of the studied factors on the production process. Next, a mathematical model of the object under study is built. Moreover, it is necessary to obtain these models at the minimum cost and time costs. The design of the experiment allows you to get mathematical models with minimal cost and time costs. For this, a method and software were developed for optimizing three-level plans using the jumping frog method. Three-level plans are used in the construction of mathematical models of the studied objects and systems. An analysis is made of the known methods for the synthesis of three-level plans that are optimal in cost and time costs. The operability of the algorithm was tested when studying the roughness of the silicon surface during deep plasma-chemical etching of MEMS elements. Its effectiveness is shown in comparison with the following methods: swarm of particles, taboo search, branches and borders. Using the developed method and software for optimizing three-level plans using the jumping frog method, one can achieve high winnings compared to the initial experimental plan, optimal or close to optimal results compared to particle swarm, taboo search, branches and borders methods, and also high speed of solving the optimization problem in comparison with previously developed optimization methods for three-level experimental designs.


Vestnik MEI ◽  
2021 ◽  
pp. 122-131
Author(s):  
Vladimir P. Zver′kov ◽  
◽  
Viktor F. Kuzishchin ◽  
Vladimir R. Sabanin ◽  
◽  
...  

Matters concerned with development of a fully variable nonlinear simulation model of a double-loop system for automatically controlling the steam pressure in the main steam header (MSH) of a VVER type reactor based NPP power unit’s secondary circuit are considered. A two-stage procedure for optimizing the control system dynamic tuning is described, which uses the linear system frequency analysis method at the first stage and a numerical simulation and optimization method at the second stage, which takes into account the nonlinearities of the control equipment and control object. An evolutionary algorithm of multiparametric optimization with respect to a complex optimality indicator than takes into account the specific requirements for the system is used. The system performance efficiency in a wide range of the power unit outputs has been studied.


2019 ◽  
Vol 20 (6) ◽  
pp. 341-351 ◽  
Author(s):  
B. V. Sukhinin ◽  
V. V. Surkov

This work is proposed to continue the discussion of the problems, theoretical foundations and practical features of the construction and synthesis of robust control systems with high gain, allowing us to control multidimensional nonlinear dynamic objects of high dimensional with functional uncertainties. If problems could not be solved at the level where they appeared, it is necessary to rise the level of understanding of the laws of nature, or in the words of master Lui-Shi Chun Qiu (China, 3rd century BC): "The boy of five chi growth leads the bull by the bridle and the bull obeys him in everything. This is because the person in this case follows naturalness" (the laws of nature). The judo philosophy ("soft way") is based on the principles of using the power and energy of the opponent to achieve victory. The purpose of this work is to demonstrate the theoretical aspects and practical features of the methods of synthesis of optimal control systems by the criterion of maximum reproduction accuracy using the example of robust systems, which allow to control dynamic objects with functional uncertainties, including unstable objects, no minimal-phase objects, neutral objects and objects with differentiation properties. The simplicity (at the level of the engineer) and universality, mathematical rigor and physical validity of this approach is based on the judo philosophy: suppressing the dynamics of a functionally uncertain object and external disturbances by the infinitely large gain with the finite control signal and at the same time maintaining sustainability. Theoretically exhaustive solution of the problem of robust control is given by the idea of constructing systems that are stable with an unlimited increase of the gain coefficient. The sustainability properties are valid for optimal systems that were synthesized using quadratic quality functionals that do not explicitly depend on the control signal, and using a restriction on the control signal. It is significant that in contrast to continuous systems with un-measurable disturbances and not well known control object (in which the conditions of invariance imply the use of infinitely large gain), in relay (discontinuous) systems the equivalent effect is achieved with the help of finite control signal. A nice bonus is the highest accuracy which leads to mathematically zero error of regulation, thus all error coefficients (of position, speed, acceleration, acceleration derivative, etc.) is also equal to zero in the presence of external and internal interferences. In fact, the optimal accuracy control system is equivalent to a system with astatism of the n-th order: the regulator contains n serial connected integrators.


2011 ◽  
Vol 2011 (0) ◽  
pp. _1A1-M13_1-_1A1-M13_2
Author(s):  
Shota INABA ◽  
Masashi FURUKAWA ◽  
Keiko YUKAWA ◽  
Masahiro KINOSHITA ◽  
Takashi KAWAKAMI

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