


Vol 78, No 2 (2017)
- Year: 2017
- Articles: 15
- URL: https://ogarev-online.ru/0005-1179/issue/view/9000
Linear Systems
Pareto suboptimal controllers against coalitions of disturbances
Abstract
We consider a multi-criteria problem of suppressing disturbances with linear feedback with respect to the state or output measured with noise. We assume that the system has N potentially possible inputs for disturbances from given classes, and the criteria are induced norms of operators generated by the system from the corresponding input to the common target output. We obtain necessary Pareto optimality conditions. We show that based on scalar optimization of the suppression level for the disturbances that act on all inputs we can synthesize Pareto suboptimal controllers whose relative losses compared to Pareto optimal controllers do not exceed 1 − \(\sqrt N /N\). Our results generalize to the case when disturbances from different classes may form coalitions.



Nonlinear Systems
Designing a stable cycle in weakly coupled identical systems
Abstract
Consideration was given to a dynamic model containing weakly coupled identical subsystems. The subsystem was assumed to admit a family of periodic solutions where the period is a monotonic function of one parameter. Requirements on the coupling under which the model has an asymptotic orbital stable cycle were established. The problem of stabilization of the model oscillations by a small smooth autonomous coupling control was solved using the results obtained. The system of two coupled conservative systems with one degree of freedom was considered individually.



Stochastic Systems, Queueing Systems
Stochastic online optimization. Single-point and multi-point non-linear multi-armed bandits. Convex and strongly-convex case
Abstract
In this paper the gradient-free modification of the mirror descent method for convex stochastic online optimization problems is proposed. The crucial assumption in the problem setting is that function realizations are observed with minor noises. The aim of this paper is to derive the convergence rate of the proposed methods and to determine a noise level which does not significantly affect the convergence rate.



System Analysis and Operations Research
Traffic modeling flows in a developing urban infrastructure with a software suite for creating interactive virtual environments
Abstract
We present a design paradigm for a cloud-based service for interactive modeling of traffic flows in a developing urban infrastructure. The mathematical forecasting model for the load of a transportation network is constructed as a result of synthesizing a gravitational model that describes origin-destination trips and a multimodal traffic equilibrium problem with elastic demand. The search for traffic equilibrium reduces to solving a variational inequality. Three-dimensional visualization of the transportation network and adjacent infrastructure is implemented with the virtual environment’s declarative model.



Comparative analysis of the performance of selective and group repeat transmission modes in a transport protocol
Abstract
We propose a model of a virtual connection controlled by a transport protocol in the selective and group failure modes as a Markov chain with discrete time that accounts for the influence of protocol parameters of window size and timeout duration for waiting for acknowledgements, probabilities of distorting segments in individual links of the data transmission path on the throughput of a transport connection. We have analyzed how the throughput of the control procedure depends on protocol parameters, level of errors in communication channels, and round-trip delay. We have proposed a method for choosing protocol parameters.



Iterative MC-algorithm to solve the global optimization problems
Abstract
A new method was proposed to solve the global minimization problems of the Hölder functions on compact sets obeying continuous functions. The method relies on the Monte Carlo batch processing intended for constructing the sequences of values of the “quasi-global” minima and their decrements. A numerical procedure was proposed to generate a probabilistic stopping rule whose operability was corroborated by numerous tests and benchmarks with algorithmically defined functions.



Control in Social Economic Systems, Medicine, and Biology
Control for a system of linear agents based on a high order adaptation algorithm
Abstract
We solve the problem of synchronizing a network of linear agents with unknown parameters and unknown network topology given that the Laplacian that defines it has no complex eigenvalues. To solve this problem, we use a modified high order adaptation algorithm. We obtain conditions for reaching consensus with the proposed algorithm. We show modeling results that demonstrate the efficiency of the proposed approach.



Safety, Viability, Reliability, Technical Diagnostics
Self-testing of multiprocessor systems with regular diagnostic connections
Abstract
We propose an approach to organizing self-testing in a multiprocessor system under certain constraints; in particular, we use special diagnostic graphs, and the number of failures does not exceed a certain value T. We show that a test experiment where each of n processors is tested by two others lets one determine the state of all except possibly two processors for T = 4 and except one for T = 3. The total number of tests does not exceed 2n + 2.



New structures of the concurrent error detection systems for logic circuits
Abstract
Proposed were new structures for concurrent error detection systems of the combinatorial logic circuits based on the codes with summation of the weighted transitions and their modifications. They were compared with the traditional systems of duplication and check by the Berger code. The structure based on the code with summation of the weighted transitions allowed one to improve the index of realization complexity as compared with the duplication system by 4 % on the average. The structure obtained by modifying the code with summation of the weighted transitions into the optimal code enables one to improve this index almost twice as much as compared with the system of checking by the Berger code. At that, this system has a better index of error detection. In certain cases, the structure of the concurrent error detection system on the basis of the optimal code is superior in complexity to the system of parity check.



Navigation and Control of Moving Systems
Finding analytic solutions on active arcs of the optimal trajectory in a gravitational field and their applications
Abstract
We consider a method for finding partial solutions for the optimal motion problem of a space vehicle in a central Newtonian field on intermediate thrust arcs. This is the Lehmann-Filhés method based on knowing an incomplete integral of the Hamilton–Jacobi equations. With this method, we obtain a number of partial solutions that can be applied to solving practical problems of space flight mechanics. As an example, we solve the problem of rotating the axis of an elliptical orbit. We compare characteristic velocities necessary to rotate the axis of an elliptical orbit.



Control Sciences
Structural modeling of oligopoly market under the nonlinear functions of demand and agents’ costs
Abstract
In this paper, we consider the structural modeling problem of an oligopoly market for an arbitrary number of agents, the linear and nonlinear models of market demand, and the nonlinear models of agents’ costs. The equilibrium behavior of the agents is described on the basis of conjectural variations in the Cournot or Stackelberg reaction models (in the cases of one or several leaders). The adequacy of the Cournot reaction model is demonstrated using the equilibrium modeling of the Volga region telecommunication market, where the price functions and agents’ cost functions for the voice and Internet services are defined by statistical analysis methods.



Automation in Industry
Distributed predictive process control in metallurgy
Abstract
The advantages and basic concepts of model-based predictive control (MPC) are discussed. Possible MPC application in metallurgy is outlined. An example of an MPC system for billet cooling developed for a continuous casting machine is adduced.



Advanced process control system for a crude distillation unit. A case study
Abstract
Development, implementation, and operation of an advanced control system for a crude distillation unit are described. The system is based on Honeywell Profit® Controller software. The paper outlines the CDU/VDU-4 plant of Gasprom Neftekhim Salavat JSC (Bashkortostan Republic, Russia) as a control object, discusses project implementation phases, mentions APC maintenance issues, and summarizes key success factors.



Sensors and Systems
Operation of a pseudorandom sequence synchronization system under noise errors
Abstract
This paper analyzes the operation of a pseudorandom sequence synchronization system in an error control system for digital communication channels with noises. It is demonstrated that the arbitrary-level error coefficient can be measured.



Mathematical Game Theory and Applications
Strategic stability in linear-quadratic differential games with nontransferable payoffs
Abstract
We address the problem of strategically supported cooperation for linear-quadratic differential games with nontransferable payoffs. As an optimality principle, we study Pareto-optimal solutions. It is assumed that players use a payoff distribution procedure guaranteeing individual rationality of a cooperative solution over the entire game horizon. We prove that under these conditions a Pareto-optimal solution can be strategically supported by an ε-Nash equilibrium. An example is considered.


