Volume 77, Nº 7 (2016)

Analytical expressions for the control functions constructing various families of the optimal trajectories in the linear-quadratic problem and obeying three-point mixed conditions were obtained. Illustrative examples were given.

This paper introduces a new physical considerations-based approach to the development of control algorithms for dynamic plants, which involves a compensation principle as follows. Being external with respect to a controlled plant, control actions (compensating signals) are applied with the opposite sign to the corresponding variables of the inverse mathematical model of the plant. Regularization of the resulting system is performed by incorporating etalon filters in compensation loops. The described method is used to solve a control problem for the linear stable multidimensional plants with additive external influences and compensation of the perturbations affecting the output variables.

For linear systems under bounded control, consideration was given to a pair of methods for approximate solution of the speed problem. Independence of the initial conditions for the switching moments of the quasi-optimal control and their constancy for systems with constant parameters were proved. A domain of initial conditions where the control constraints are not violated was determined. The properties and distinctions of the quasi-optimal control were established. A way to approximate a quasi-optimal control to the optimal one was considered, and the closeness estimate was given.

Consideration was given to the numerical estimation of the maximum likelihood for the parameter vector describing a smooth manifold. Estimation is based on the results of observing motion of a dynamic plant whose trajectory belongs to this manifold and is measured with random errors having normal distribution with certain parameters. Application of the maximum likelihood method to such problems gives rise to the problem of nonlinear highdimensionality programming. Some constructive analytical results obtained enable significant reduction in the problem dimensionality. The problem of identifying the plane of motion of a dynamic plant was examined.

We consider a relaxation of the quadratic assignment problem without the constraint on the number of objects assigned to a specific position. This problem is NP-hard in the general case. To solve the problem, we propose a polynomial algorithm with guaranteed posterior accuracy estimate; we distinguish a class of problems with special assignment cost functions where the algorithm is 2-approximate. We show that if the graph in question contains one simple loop, and the set of assignment positions is a metric space, the proposed algorithm is 2-approximate and guaranteed to be asymptotically exact. We conduct a computational experiment in order to analyze the algorithm’s errors and evaluate its accuracy.

An algorithm to design combinatorial symmetrical block diagrams of the class B(n, s = p + 1, σ = 1), where p is a simple number, was described and illustrated by an example for s = 7 + 1.

We consider an approach to identifying the hydraulic resistance coefficient for a segment of a magistral pipe in transporting hydrocarbon raw material. The considered identification problem reduces to a class of parametric optimal control problems, and we propose to use efficient numerical methods developed for first order finite-dimensional optimization problems to solve it. To this purpose, we derive formulas for components of the objective functional’s gradient in the space of the identified parameters. The resulting values for the vector being optimized can then be used to construct the identified function from some class of functions with interpolation and approximation methods. We also show the results of numerical experiments.

Consideration was given to a special problem of controlling a formation of mobile agents, that of uniform deployment of several identical agents on a segment of the straight line. For the case of agents obeying the first-order dynamic model, this problem seems to be first formulated in 1997 by I.A. Wagner and A.M. Bruckstein as “row straightening.” In the present paper, the straightening algorithm was generalized to a more interesting case where the agent dynamics obeys second-order differential equations or, stated differently, it is the agent’s acceleration (or the force applied to it) that is the control.

Within the stochastic models of mob control, this paper explores the game-theoretic models of informational confrontation when agents are simultaneously controlled by two subjects with noncoinciding interests regarding the number of active agents in an equilibrium state.

This paper describes solution of a topical problem of direct current signal measurement against the background of harmonic interferences. The result is achieved using fissionable sets of measurement signal samples, a method originally developed in ICS RAS. Consideration involves an example of non-coherent harmonic interferences. The efficiency of the obtained results is roughly estimated and their application domains are outlined. And finally, further research directions are identified.

The modern materials and types of the substrates used for the surface acoustic wave (SAW) devices are considered and their special requirements for the SAW sensors are discussed. A classification of the SAWsensors is given, and the factors of SAWsensors design and materials choice criteria are discussed.

The paper presents the electrophysical and electrical models of hydrogen and radiation sensitivities of the integrated sensors with MISFET sensing elements based on the structure Pd–Ta₂O₅–SiO₂–Si. The models take into account the influence of electrical circuits and modes, chip temperatures, surface-state density and radiation parameters on the hydrogen sensitivity of the sensors.