Home – Home – Jornals – Avtometriya 2017 number 4

A problem of control of trajectory motion of a quadrotor vehicle is considered. The choice of the form of required differential equations in the previously proposed method of tracking of a moving target is justified. The workability of the control system in the presence of measurement noise and external perturbations is confirmed by results of experiments with the AR.Drone quadrotor.

A structural technology of multicriterial optimization of control of technical objects with distributed parameters is proposed. The technology is based on a single-criterion version in the form of the minmax convolution of normalized performance criteria. The approach under development is based on the transition to an equivalent form of the variational problem with constraints, with the problem solution being a priori Pareto-effective. Further procedures of preliminary parametrization of control actions and subsequent reduction to a special problem of semi-infinite programming make it possible to find the sought extremals with the use of their Chebyshev properties and fundamental laws of the subject domain. An example of multicriterial optimization of operation modes of an engineering thermophysics object is presented, which is of independent interest.

The problem of asymptotic estimation of a linear combination of variables of the state of a bilinear dynamical system using a minimum-order observer is considered. An algorithm for calculating the matrix coefficients of a functional observer using the technology of canonization of matrices is proposed, and conditions for the solvability of the synthesis problem are formulated.

The problem of dynamic decoupling of control channels for multidimensional objects is aimed at autonomization of control of output variables of the object, which is ensured by means of including special correcting links into the control system. A new method of solving this problem is proposed, where decoupling is provided by a block of dynamic correction. The desired result of decoupling is represented by a standard model with separate control channels. The mathematical apparatus applied for calculating the correction block is based on the formalism of linear-quadratic optimization, where the optimized integral quadratic criteria serve as a measure of deviation of the transient characteristics of the corrected object from their desired (standard) values.

A hardware-software platform is presented, which is designed for the development and half-sized simulation of flying vehicle control systems. This platform ensures the construction of the mathematical model of the object, development of algorithms and software for onboard radioelectronic equipment and on-ground control station, and visualization of the three-dimensional model of the vehicle and external environment of the cockpit in the simulator training mode.

The problem of designing a control system for a stand for strength tests of aircraft structures is considered. A method for calculating the parameters of a proportional-integral controller (control algorithm) using the motion separation method for the test stand taking into account the delay effect in the control channel is presented. A structure of the adaptive algorithm is proposed that limits the amplitude of high-frequency oscillations in the control system with a change in the direction of motion of the rod of the hydraulic cylinders and provides the specified accuracy and quality of transients at all stages of the loading cyclogram of structures. The results of tests of the developed control system with the adaptive control algorithm on an experimental strength test stand for aircraft structures are given.

A method of formation of test signals is proposed for studying the aerodynamic characteristics of flying vehicles with the use of the technology of freely flying dynamically similar models. Simultaneous excitation of all input channels in a prescribed frequency band by a set of mutually orthogonal signals is applied to increase the efficiency. A modified method of calculating the set of mutually orthogonal sinusoidal signals with a small normalized peak factor is presented. Results of simulating the motion of a flying vehicle in the MATLAB/Simulink environment with the use of the developed method of test signal formation are reported.

A joint phase-locked loop for tuning the angular shifts (velocity) and Euclidean norm of three-phase voltages of an autonomous inverter to the same network parameters is designed, which can be used, in particular, to equalize the potentials of two parallel-connected power sources at the fundamental harmonic at the moments of switching the stator windings of an asynchronous AC motor from a converter to a centralized power-supply system and back. Technical implementation of the developed synchronization algorithm will significantly reduce the inductance of the equalization reactor and exclude emergency operation modes in power circuits of the electric drive.

A new approach to the synthesis of an automated control system for the process of applying a porous insulation on a conductive cable core is considered, which is based on using structurally and parametrically optimized digital controllers of an arbitrary order instead of calculating typical PID controllers using known methods. The digital controller is clocked by signals of a clock length sensor from a measuring wheel, instead of a timer signal, which provides the robust properties of the system with respect to the changing rate of insulation. Settings of digital controllers according to the criterion based on the need to ensure the achievement of operational characteristics of the manufactured cable are determined on a simulation model of stochastic extrusion and are minimized by moving a regular simplex in the parameter space of the tuned controller.

A method for designing Takagi-Sugeno fuzzy systems is proposed in which the structure of the systems is generated using a piecewise linear initialization algorithm, and parameters are optimized using a meta-heuristic algorithm. The obtained systems are tested against real data sets. The influence of some parameters of this algorithm on the approximation accuracy are analyzed. Estimates of the approximation accuracy and the number of fuzzy rules are compared with four known methods of design

Issues of designing gradiometric transducers with ferroprobe sensors are considered. The regions of application of magnetic flux field gradiometers are determined. The structure and the relative position of a bi-element transducer with ferroprobe sensors are proposed. It is assumed that the ferroprobe sensors are strictly coaxial in the body a gradiometric transducer (GMT). Elements of the classical approach to the mathematical modeling of the spatial position of solids are considered. The bases of the body of the GMT and their transformation during spatial displacement of the gradiometer are given. The problems of mathematical modeling of gradiometric transducres are formulated, basic mathematical models of GMT with a bi-element ferroprobe are developed, and the mathematical models are analyzed. A computer experiment was performed. Difference signals from the ferroprobe sensors of the gradiometer for the vertical and horizontal position of its body are shown graphically as functions of the magnitude and direction of the geomagnetic field strength vector.

This paper describes the study of temperature in the flowing part of a turbine on the informative parameters (equivalent to the inductance of primary coils of matching transformers) of single-coil eddy current sensors with a sensitive element in the form of a conductor section, which are used as part of automation systems for testing gas turbine engines. In this case, the objects of temperature influences are both sensors and controlled turbine blades. The existing model of electromagnetic interaction of a sensitive element with the end part of a controlled blade is used to obtain quantitative estimates of temperature changes of equivalent inductances of sensitive elements and primary coils of matching transformers. This model is also used to determine the corresponding changes of the informative parameter of the sensor in the process of experimental studies of temperature influences on it (in the absence of blades in the sensitive region). This paper also presents transformations in the form of relationships of informative parameters with radial and axial displacements at normal (20 ºC) and nominal (1000 ºC) temperatures, and their difference is used to determine the families of functions of temperature influences, which characterize possible temperature errors for any radial and axial displacements in the ranges of their variation.

In most widely used wavelet filtering algorithms, the decomposition coefficients are processed with the use of threshold functions, which makes it possible to account for the ``energy” feature of each expansion coefficient. To some extent, this disadvantage is removed in a class of multiplicative algorithms, which account for the energy of expansion coefficients located in a given proximity from a processed expansion coefficient. However, the effective error minimization in image wavelet filtering requires that a parameter, the choice of the optimal value of which remains to be an unsolved problem, is introduced into these processing algorithms. Therefore, the problem solved in this paper is the estimation of the optimal value of this parameter, which minimizes the root-mean-square error of the filtering. The performed studies showed the effectiveness of the proposed estimation algorithm and the possibility of its use in practice.

This paper describes a model for detection of images obtained in circular microscanning. To detect objects on a low background with the use of an image detection system based on circular microscanning, an approach to image filtering is proposed. The calculation of the noise covariance matrix with respect to the data obtained by the numerical simulation method is used. The calculated matrix is used in filter construction. It is shown that the applied approach makes it possible to increase the signal/noise ratio in image processing with a low background component.

This paper touches upon the problems of constructing a basis for stochastic functions, which represent samples of random numbers with a given distribution law. The algorithm for constructing an approximation model with the use of this basis is described. The general algorithm for signal recovery using the stochastic basis by the least squares method with a given weight function is given. The approach to solving the problem of recovery of blurred images with a known point scattering function by constructing an inverse filter model is proposed.