A new algorithm for the least squares (LS) solutions within the Vector Fitting (VF) method is proposed in the paper. The algorithm is based on QR-factorization, which exploits the specific structure of the VF matrix. Numerical experiments confirmed an essential reduction of the computational efforts. Besides, the new algorithm ensures a better accuracy and requires considerably less memory than the standard Matlab sparse solver. The special form of LS matrix (left part of the matrix is block-diagonal with identical blocks) in VF problem allowed us to propose a more effective linear solver, than the standard one. The efficiency of the new algorithm is achieved due to replacement of the full matrix QR factorization by the following sequence of operations: QR factorization of the block; orthogonalization of the right part of the matrix with respect to the obtained block of Q matrix; QR factorization of the orthogonalized right part of the matrix. It was experimentally demonstrated that in order to ensure sufficient accuracy of the solver it was necessary to perform reorthogonalization of Q matrix of the right part of LS matrix and to perform QR factorizations with column permutation. Testing of the developed solver and its comparison with the standard solver was done for two data sets. The testing results showed that the new solver allowed us to reduce CPU time by the factor up to 50 for sufficiently large sizes of LS system. In most cases the new solver ensures less value of the residual norm than the standard solver and a better accuracy. The advantages of the new solver become even more impressive with an increase of the size of the system.

This paper is devoted to the distributed control system with the network architecture consisting of a multitude of objects united by a communication channel and participating in implementation of the flow of the incoming consumer tasks. At that, it is assumed that each consumer task consists of a set of interconnected operations, presented as an acyclic graph, and can appear any moment. In the paper the authors show that a centralized management solution with a single control unit in such a distributed system with a large number of objects is very complicated. Therefore, they propose a method for a decentralized management of the distributed systems using multiple management devices for the individual objects. They propose new algorithms for individual management of the objects of a distributed system for four versions of the original statement: the objects can perform the same set of operations at the same time; the objects perform the same set of operations, but the times of execution of the identical operations in various objects are different; the objects perform different sets of operations, but the times of execution of the identical operations are equal; the objects perform different sets of operations and the times of execution of the identical operations in different objects are different. In conclusion the authors present the results of the experimental researches of the proposed algorithms achieved due to application of the program model of the distributed system.

The article is devoted to development of algorithms for the onboard indication equipment of the modern anthropocentric objects (manned aircraft, manned submersibles, various vehicles and technical systems with operators) using mathematical and hardware-in-the-loop (HIL) scaled-down simulation involving professional operators. The paper demonstrates feasibility of creation of mathematical models (MM) of operator's work in typical combat situations (TC-s) of anthropocentric objects' operating cycle. For each TC its own MM is developed. It consists of two blocks: the onboard algorithm simulation unit (SOA), supplying the determined TC-s information to the information and control field (ICF) of the anthropocentric object cabin and situational control unit (SCU), simulating operator's activity algorithms using only the available current TCS information on ICF and the controls available on it. Anthropocentric object includes such physical systems as onboard measuring systems, onboard executive systems, crewmembers and ICF. The crew is the main element of such a system, and for it SCU is developing. The work describes the joint development procedures in TC: a) operator decision graph (ODG) and onboard algorithms scheme (OAS); b) SOA and SCU based on ODG and OAS. Performance of the proposed approach is demonstrated on the example of the anthropocentric object of F-I6M3 Fighter.

The subject of the article is the situation when a side in a conflict, defending itself from the enemy attacks, is a hardware-redundant technical system, containing the main and standby units, which can be involved for recovery of its functionality in the process of a conflict in accordance with the chosen protection strategy instead of the main unites, which failed under the impact of the enemy attacks. During a conflict the attacking side with its attack resources tries to weaken the targeted technical system by focusing its attacks on the functional units, increasing their failure rate during the period of the conflict and thus reducing the faultless operation and average uptime of the targeted technical system. Given the probabilistic character of the process, the behavior of the considered technical system involved in a conflict situation is approximated by Markov process and is described by Kolmogorov system of differential equations with variable coefficients. For solving of these equations the method of discretization and integer programming is used. The essence of this method, applied to the considered problem, is that the system of differential equations describing the behavior of a technical system in a conflict situation, the coefficients of which are functions of time, should be replaced by a system of discrete analogues, the coefficients of which can be considered constant with a predetermined degree of accuracy at discrete time intervals during the conflict. In order to optimize the reliability function and average time before a failure of the defender hardware-redundant technical systems in the process of the conflict, the author in this work proposes mathematical models for solving of these problems under different strategies for the use of the reserve units instead of the faulty ones. These strategies boil down to a targeted redundant power distribution between the main units of the technical system prior to the beginning of a conflict and dynamic reallocation of them in the process of conflict for achievement of the tasks, set before the technical system in a confrontation with the enemy. For implementation of these strategies the author proposes a method for computing of the corresponding vectors of redundancy and sequence of moments of redistribution of the reserve units between the main ones in the process of a conflict. Numerical algorithms were developed for solving of four problems of optimization of reliability of the considered technical system in the process of the conflict by selection of an appropriate backup strategy, convenient for implementation with the help of modern personal computers.

The paper presents the results of research and model tests a modular switched reluctance machine (MSRM) and shows the construction implemented in a prototype and tested in static mode, with a detailed explanation of the construction of an electromagnetic modules. It emphasized a number of positive aspects of the practical implementation of this construction, in particular the principle of increasing the overall capacity and distinctive features of its mathematical description. An algorithm for calculating the parameters of the electromagnetic module of the machine in the FEA software package Ansys Maxwell is shown too. On the basis of the calculation results presented in the analytical and graphical form, developed a mathematical description MSRM and created a computer model of the MSRM and a computer model of an electric drive on its basis in the software package MATLAB-Simulink, which confirmed the limit characteristics of the machine specified in the design. Electric drive with the considered machine built by principle of subordination control with the internal current loop, which use the relay s in each phase, i.e. sliding mode, and the outer loop speed, which use the PI regulator.

The problem of synthesis of control system for once-through boiler is discussed in the paper. The simplified linear model of the boiler heater is considered here. It is proposed to use cascade control approach to control the plant as it is possible to measure the intermediate variable. Different dynamics of the inner and outer circuits simplifies the designing process. It is shown that the inner loop can be controlled by using typical P controller. Parameters of the external heater circuit are non-stationary and depend on the boiler load so it is suggested to use the robust PID controller to control it. The coefficients of this controller are suggested to bet calculated on the basis of the localization method. The main advantage of the method is using the derivative vector for manipulated variable calculations, which allows us to deal with the pending type of control object. This paper includes numerical experiments with a set of linearized model of the super-heater. The results show that the obtained control system has good enough quality of transient processes. The designed set of controllers was applied to the great non-linear model of the once-through boiler, which provides more realistic transient processes. The simulation results of this application are almost the same as in case of the linear model. Therefore it can be said that the designed control system fully perform all the requirements.

Efficiency of the asymptotic approach to the problem of determination of the components of the vector of absolute angular velocity of an object by the data from a twofold unit of three gyroscopes was experimentally confirmed. Cinematic diagram of the gyroscopic block, algebraic algorithms, methods and results of the experiments were provided. At the first stage six measurement channels were calibrated, at the second stage the measurement accuracy of the constant components of the angular velocities within the range of 1...7 deg/s was evaluated. At the third stage the effectiveness of the error compensation block in the dynamic mode was investigated experimentally. The components of the angular velocity presented realization of the stationary random processes with a constant of 1...6 deg/s, random components with amplitudes up to 0,8 deg/s and frequency of 15 Hz. Therefore, methods of correlation analysis of the random processes were applied for the analysis of the experimental data. Application of the algorithms based on simplified equations of the inverse task for a block of three gyro angular velocity meters, allows us to significantly reduce the dc component and instantaneous values of the errors in estimation of the parameters of an object's motion.

A system of hypersonic drag mitigation is proposed. It is based on injection of light and/or hot gas in a new, isobaric mode, in order to form a "gaseous fore body" and to protect the frontal part of the surface of a hypersonic vehicle from formation of the hypersonic boundary layer. The effectivity of application of the proposed system depends on whether the advantages of the drag mitigation outweigh the drawbacks of storing of the additional gas. The question was studied with help of complex (integral) modeling of the hypersonic flying vehicles. There were compared two designs of hypersonic vehicles, which were able to implement the same mission. One of the designs included a solid propellant rocket engine to compensate the hypersonic aerodynamic drag, the other one applied the system of hypersonic drag mitigation with a continuous injection of helium. The complex models took into account the internal (engine) and external gas dynamics with the shock wave drag and surface friction, flight dynamics in the exponential atmosphere, mass change, flight control, etc. Computations have demonstrated that the start mass of the first vehicle was approximately twice as big as that of the second one. An additional advantage of the system of hypersonic drag mitigation is a considerable growth of the available coolant, which can provide comfortable thermal onboard conditions. Thus, there are cases, for which it is advantageous to apply the proposed system of hypersonic drag mitigation.