The functional purpose of the correcting links in the structure of the automatic regulation systems (ARS) is improvement of the precision and dynamic quality of the regulation processes. In the classical methods of ARS design two types of the correcting links are used: of the sequential and parallel feedback. At the same time there is one more type of correction. It has been insufficiently studied within the framework of the classical automatic regulation theory and practically ignored in the modern researches. It is a parallel feedforward correction (PFC). A logical question appears concerning the usefulness of the given type of correction for the developers of ARS. This question is exactly the subject of the given paper. Three methods of PFC application are considered: compensation of the transfer poles of the control channel, its control by the transfer zeroes, and correction of the amplitude-phase characteristics of an open loop. The method of compensation of the transfer poles of an object reduces the order of the transfer functions of the control channel, and, as a result, the dimension of the regulation problem to be solved is reduced. Its auxiliary effect is analyzed, that is formation of a non-control and non-observed subsystem in ARS structure, the spectrum of which coincides with that of the compensated poles. "The bad" transfer zeroes of an object are problematical for a great many methods of synthesis of ARS. The right zeroes, and also the left zeroes, which are in the immediate proximity to the imaginary axis, are among them. By means of PFC it is possible to change purposefully the transfer zeroes and even to exclude them from the corrected control channel. Correction of the frequency characteristics of the direct chain of PFC is realized with a view to ensure the desired phase and amplitude stability for the closed system. The authors demonstrate good prospects of its use in the regulation tasks with big amplification factor. The conducted researches demonstrate wide functional potentials of the considered mechanism of PFC and expediency of its use alongside with the classical methods of correction. In this connection the question about development of a methodology of PFC and its inclusion in the modern engineering instrument of ARS design is quite appropriate.

One of the most common methods of synthesis of the nonlinear control systems is the method of a feedback linearization (FL). The idea of this method consists in conversion of the original nonlinear system into a linear one by means of a state feedback and coordinate transformation. Then, the methods of control theory for the linear systems are used for the system design. If the original nonlinear system cannot be linearized exactly by the state feedback, the method of the approximate feedback linearization (AFL) is used. The essence of AFL method lies in the feedback linearization only of a certain part of the original nonlinear system (not of the entire system). In this paper, the author proposes a method of an approximate feedback linearization control of the nonlinear singularly perturbed (SP) systems. The proposed method is based on a decomposition of the original SP system and construction of AFL control in the form of composite FL controls for the slow and fast subsystems. In general, a nonlinear SP system cannot be easily separated into slow and fast subsystems, because the conditions of Tikhonov theorem are not complied. In order to overcome this, the author proposes to perform the feedback linearization method at first for the system's part, which describes the fast state variables. Thus, a fast control is chosen, so that the conditions of Tikhonov theorem would be met. Then, using a standard singular perturbation technique, we obtain a slow subsystem. Further the problem of FL control for a slow subsystem is solved. The resulting AFL control is obtained in the form of a composite control. Application of the proposed approach is illustrated with two examples.

The topic of the article is the mobile objects' control, a model of which is presented by the equations of kinematics and dynamics of rigid bodies and the specific features of control for maneuvers requiring pitch angles of 90 degrees or over. Such tasks may involve specific problems, which do not allow us to present the desired dynamics of the closed-loop system in the form of a linear equation, that is, the system cannot be linearized by a feedback. The problem is solved due to application of the adaptive control systems with a reference model. In the article a procedure is proposed for a synthesis of a basic position-trajectory control. Basic control for a reference model was designed on the base of the method of Lyapunov functions. Adaptation of the basic control is carried out by the proportional and integral algorithms. The article presents a block-diagram of the closed-loop system and proves the stability of the adaptive control system. It shows that in a linear approximation, a characteristic equation of the closed-loop system is a product of a characteristic equation of the reference model, the mobile object, and the adaptation subsystem. The authors also present the modeling results. The proposed approach can also be used for different nonlinear systems with peculiarities. For example, in the electrical drives the field control voltage ensures a nonzero nominal flux at the first stage. Then, the supply control voltage ensures a nominal shaft rotation speed or torque. This approach allows us to control the shaft rotation speed with a zero field control voltage.

In this article the authors propose a trajectory control algorithm for an unmanned aerial vehicle (UAV), which is lifted and propelled by four rotors. The first step in designing of the above mentioned trajectory controller was development of a quadrocopter flight dynamic (math) model and its further linearization. The math model was based on Newton and Euler equation of motion. The next step was designing of a quadrocopter attitude control on the grounds of a linearized dynamic model and angular PD regulator. Then the authors were able to elaborate a trajectory control algorithm by using PD regulator for a trajectory error minimization. Finally, in order to verify the control algorithm the authors built a control system model in Matlab, designed a dynamic model in Universal Mechanism for flight simulation and conducted several experiments. The key idea of the developed trajectory control algorithm is that the control inputs are forces and momentums applied to a quadrocopter, as dynamics of the motor and propeller pairs are essentially faster compared to the rigid body dynamics. One of the major objectives in the attitude control design was to avoid the angels' subtractions in order to prevent singularities. For this reason the authors used rotation matrix error and PD regulator instead of Linear Quadratic Regulator. A set of experiments in the Universal Mechanism and Matlab proved the efficiency of the developed trajectory control algorithm. The paper also presents the modeling details and experiment results.

The problem of the optimal turn in the sense of minimal energy loss of a spacecraft as a rigid body with an arbitrary distribution of mass without constraint of a control action and under arbitrary boundary conditions is considered in the quaternion statement. In the class of the generalized conical motions a modification was made of the task of optimal rotation, which allowed to obtain analytical solution to the movement equations containing any constants and two any scalar functions (parameters of the generalized conic movement). Concerning these functions and their derivatives the optimizing problem with a square functionality, in which the second derivative of these two functions acts as control, was formulated and solved using Pontryagin maximum principle. Explicit expressions for the optimal angular velocity and the optimal control vectors of a spacecraft are presented. The motion trajectory of a spacecraft is generalized as a conical precession. Algorithm for the optimal turn of a spacecraft is given. The found analytical solution to the modified problem can be considered as an approximate solution to the classical problem of an optimal turn of a spacecraft under arbitrary boundary conditions. Numerical examples are presented showing that the solution of the modified problem well approximates the solution of the classical problem of a spacecraft optimal turn. These examples contain reorientations of the International Space Station and of the Space Shuttle.

The article is devoted to analysis of various approaches aimed to ensure adaptive properties of the automatic control systems designed for maintenance of the demanded reliability and functioning quality in the presence of disturbances and uncertainty factors. A review is provided of the development of the creation principles for the automatic control systems - from organization of an internal feedback, up to creation of intelligent feedback contours with self-training mechanisms. Examples of various robots equipped with intelligent self-learning control systems are presented. A list of tasks of self-learning of the intelligent control systems is presented both for the autonomous robots and for the multi-agent robot systems. A generalized structure of a control system of the autonomous mobile robots is offered based on the intelligent feedback as means of new knowledge formation. Knowledge formation is possible in a self-learning mode on the basis of processing of the accumulated sensory information. The main problems with creation of the intelligent self-learning control systems are discussed. It is shown that one of the most perspective approaches to realization of the self-learning process in the intelligent control systems of the autonomous robots and multi-robot systems is related to the method of classification of tree formation. The article gives an example of a practical solution to the self-learning problem of the autonomous mobile robots. The solution is based on the automatic knowledge formation of the passability characteristics of the surface underlying a robot. The results of a complex modeling are presented, which testify to the expediency and efficiency of incorporation of the self-learning methods in the structure of a mobile robot intelligent onboard control system for improvement of its adaptation properties. The prospects of the self-learning processes are described for the autonomous robots operating in the structure of the multi-agent systems. As a prove experimental estimates of the efficiency are given for application of the self-learning methods aimed at adaptation of the autonomous mobile robots under conditions of environmental uncertainty on the basis of a mutual exchange of the terrain passability knowledge.

A method is proposed for identification of the static characteristics of the synthesis gas generators, allowing us to obtain the dependences of the output variables - mass flow components of the synthesis gas (hydrogen and carbon monoxide) - on the input variables - the mass flow of hydrocarbon fuel and oxidizer. The technique is illustrated by calculation of the characteristics of the original high-energy managed core engine of STS type, in which diesel fuel and oxygen are treated as the initial feed components. According to the preliminary thermodynamic calculations of the hydrogen-containing gas at the outlet of the combustion chamber of STS models, the obtained mass flow increments the components of the synthesis gas in the vicinity of the nominal technological mode, allowing calculation of the output characteristics of the STS as an object of regulation. The presentation models were confirmed by the linear dependencies. A relative invariability to the variations in the parameters of the models of a fractionary oxidation mode was proved. The models, which were obtained for example, are applicable for a given pair of the input components, but have sufficient flexibility, as they permit to take into account the scale factor - the core engine efficiency. The proposed method of identification and the obtained models based on it allow a synthesis of the control laws for the fractionary oxidation process and simulation modes of the core engine. In particular, these models can be used for an optimal automatic control of the performance of the core engine, while ensuring the desired ratio of the synthesis gas components, which is especially important when the hydrocarbon fuel is used as the APG with an unstable composition.

Design of the modern on-board equipment for visualization of the air navigation parameters and geodetails (digital district map) is determined by certain requirements to the quality of the visualized information to be displayed. This kind of quality may be characterized quantitatively in terms of brightness and contrast of each color displayed on the screen. In order to ensure a stable readability of an image for a pilot, a special procedure should choose chromaticity of the coordinates of the image elements. This article deals with the designing problem of selection of the optical parameters of the on-board indication equipment based on a liquid crystal panel. Solution to the problem is of practical importance, because at the design stage indication in the documentation introduces the design solutions, which determine the quality and operational characteristics of the future product. The following relevant parameters for designing were defined: nonuniformity of brightness, brightness value, color contrast, brightness contrast, diffuse reflection factor, mirrored reflection factor, and gamut. An algorithm for an automated selection of the parameters, based on the lexicographic evaluation procedure was proposed. A lexicographic evaluation procedure involves ranking of the design parameters by their relative importance and a further search for the optimal value of each parameter, regardless of the other parameters. The expressions for calculation of the estimated parameters were proposed, and a way for the searching procedure to find the best value for each of the parameters was described. The algorithm is based on certain quotient decisive rules, which establish the boundary values for the analyzed parameters. Feedback in the algorithm ensures an iterative way to achieve the best value for each parameter. The results of the research were obtained during implementation of the developmental works and can be used by the developers of the on-board indication equipment to perform circuit calculations.

Associativity tool paths for the original design model in CAM-systems is an important prerequisite for the product life cycle management (PLM) from designing up to manufacturing on CNC machines. The article describes implementation of the associativity of the control program in the new CAM-application "CNC-module. Lathe operation" based on KOMPAS-3D CAD-platform. The application is the first application library developed for CAD-systems KOMPAS-3D and is intended to simulate the processing on CNC lathes. The application is fully integrated into KOMPAS-3D environment and uses a 3D-model created directly in the KOMPAS-3D. Implementation of the principle of associativity is based on the notion of a technological model. The technological model is described by a set of geometric elements, which exist virtually in the intermediate process steps and cannot really be present as features of the design model. CAM-application is implemented in the programming language of C++ using KOMPAS-3D API-interface. The user interface of CAM-application ensures a single-window integration into KOMPAS-3D and uses its interface elements such as toolbars, its own tab in the browser model and the properties panel. The tool paths generation and its solid verification are fully completed inside the KOMPAS-3D environment. It is demonstrated that associativity is most effective for the parametrized components. In combination with parameterization, the associativity provides opportunity to reuse a technology project for different sizes of parts.