The paper considers the identification algorithm for unknown parameters of linear non-stationary control objects. It is assumed that only the object output variable and the control signal are measured (but not their derivatives or state variables) and unknown parameters are linear functions or their derivatives are piecewise constant signals. The derivatives of non-stationary parameters are supposed to be unknown constant numbers on some time interval. This assumption for unknown parameters is not mathematical abstraction because in most electromechanical systems parameters are changing during the operation. For example, the resistance of the rotor is linearly changing, because the resistance of the rotor depends on the temperature changes of the electric motor in operation mode. This paper proposes an iterative algorithm for parameterization of the linear non-stationary control object using stable LTI filters. The algorithm leads to a linear regression model, which includes time-varying and constant (at a certain time interval) unknown parameters. For this model, the dynamic regressor extension and mixing (DREM) procedure is applied. If the persistent excitation condition holds, then, in the case the derivative of each parameter is constant on the whole time interval, DREM provides the convergence of the estimates of configurable parameters to their true values. In the case of a finite time interval, the estimates convergence in a certain region. Unlike well-known gradient approaches, using the method of dynamic regressor extension and mixing allows to improve the convergence speed and accuracy of the estimates to their true values by increasing the coefficients of the algorithm. Additionally, the method of dynamic regressor extension and mixing ensures the monotony of the processes, and this can be useful for many technical problems.

In the paper, a characteristic polynomial of an interval control system, whose coefficients are unknown or may vary within certain ranges of values, is considered. Parametric variations cause migration of interval characteristic polynomial roots within their allocation areas, whose borders determine robust stability degree of the interval control system. To estimate a robust stability degree, a projection of a polytope of interval characteristic polynomial coefficients on a complex plane must be examined. However, in order to find a robust stability degree it is enough to examine some vertices of a coefficient polytope and not the whole polytope. To find these vertices, which fully determine a robust stability degree, it is proposed to use a basic phase equation of a root locus method. Considering the requirements to placing allocation areas of system poles an interval extension of expressions for angles included to the phase equation. The set of statements, allowing to find a sum of pole angles intervals in the case of degree of oscillating robust stability, were formulated and proved. From these statements, a set of double interval angular inequalities was derived. The inequalities determine ranges of angles of all root locus edge branches departure from every pole. Considered research resulted in a procedure of finding coordinates of verifying vertices of a coefficients polytope and vertex polynomials according to these vertices. Such polynomials were found for oscillating robust stability degree analysis of interval control systems of the second, the third and the forth order. Also, similar statements were derived for aperiodical robust stability degree analysis. Numerical examples of vertex analysis of oscillating and aperiodical robust stability degree were provided for interval control systems of the second, the third and the fourth order. Obtained results were proved by examining root allocation areas of interval characteristic polynomials examined in application examples of proposed methods.

An algebraic method for the synthesis of astatic continuous-time control systems is considered. The method is based on the construction of the desired transfer function (DTF) from given performance indicators (setting time, overshoot, etc.) and a given plant transfer function. The construction of DTF is based on the use of the desired normalized transfer function (NTF). The desired NTF is the transfer function whose denominator is a monic polynomial with unit free term and whose performance indicators, except for the setting time, coincide with those of the DTF. Therefore, one can obtain the DTF by constructing the desired NTF and then by applying the inverse transform with transformation ratio equal to the ratio of the setting time of the system to be synthesized to that of the system with the desired NTF. The desired NTF is assembled from standard NTFs. There are various standard NTFs: binomial, arithmetic, and geometric. The type of an NTF is determined by its characteristic polynomial; an NTF is said to be binomial if its characteristic polynomial is the Newton binomial and arithmetic or geometric if the roots of its characteristic polynomial form an arithmetic or a geometric progression, respectively. When constructing the desired NTF, three conditions must be met: the physical feasibility of the controller, solvability, and robustness. These three conditions determine the degrees of the characteristic equation of the system to be synthesized and the degrees of the unknown polynomials that are introduced in the synthesis process. After that, according to the given performance indicators, the type of the desired NTF is determined. Here we find only the denominator of the desired NTF. If the system to be synthesized is rth-order astatic and the plant does not contain right poles and zeros, then the numerator of the desired NTF is equal to the sum of the last r terms of the characteristic polynomial. After the system DTF has been obtained, the transfer function of the controller is determined by equating the transfer function of the closed-loop system with the DTF.

The paper describes the modelling of a demining manipulator that contains a pneumatic drive, an infrared mine detector and a mine neutralizator. The infrared mine detector identifies the mine position in the scanning mode of the manipulator and gives a control signal to an input of a manipulator drive control unit for accurate positioning of the neutralizator above the detected mine. A problem of the optimal manipulator positioning in the sense of the control energy consumption minimization is solved. The feedback loop contains only one sensor to perform the optimal positioning of the third-order control object due to an observer application. Modelling results of the infrared detector mine searching and of the neutralizator positioning by means of a pneumatic manipulator are presented. A comparison of modelling and experimental results shows that modelling assumptions correspond enough to real process parameters.

The problem of the occurrence and rapid suppression of vibrations arising in the process of milling using robot arm is considered. It is assumed that the tool (cutter) is connected with the robot by an elastic suspension, which is used for the force sensation of the robot. Based on the mathematical model of regenerative self-excited vibrations (chattering), the simulation of the system "robot-tool-work surface" was carried out. The tool moves evenly along the work surface with a given pressure on it. The cutter is pressed using the position-force control algorithm based on two PID-controllers with coordinate and force feedbacks. It provides the necessary axial depth of cut. Uniform movement along the work surface is carried out using the velocity control algorithm based on PID-controller with velocity feedback. It provides the required tool feed. Several authors have experimentally and analytically shown that in the process of milling "on the track" unstable regenerative self-oscillations can occur. Track remains on the machined surface during the previous cutter tooth pass. Chattering is a deterrent to increase productivity which mainly depends on rotation speed of cutter and the axial depth of cut. In this paper we consider the possibility of promptly detecting the onset of unstable auto-oscillations from the amplitude spectrum of the sensor readings of the horizontal forces of interaction between the instrument and the work surface. The amplitude spectrum is obtained using the fast Fourier transform, which allows to promptly determine the beginning of unstable processes in system. The subsequent decrease of the axial depth of cut (within one to two percent) almost completely stabilizes the cutting process. This paper proposes a variant of adaptation contour for the robot vertical movement control system based on the allowable change of the axial depth of cut.

This article focuses on the development of a two-axis solid state micro gyroscope (SMG) on surface acoustic waves (SAW). The described gyroscope belongs to the category of inexpensive sensing elements featuring a high degree of longtime overload stability. This advantage seems to make SAW SMGs a priority choice for navigation and control systems functioning in severe overload environments of up to 65,000 g. As of today SAW SMGs are designed according to a number of known principles. Such SMGs may also operate on standing SAWs or traveling SAWs. This article addresses the first gyro type. Unfortunately, the existing standing SAW SMGs share a common limitation of measuring angular rates in relation to one axis only. This research attempts to introduce an innovative two-axis standing SAW SMG. The influence of the basis rotation on the parameters of the elastic waves traveling within the substrate layer was carefully studied. Incident and reflected wave models were also elaborated. The numerical simulation results demonstrate the effects of the basis rotation on the complex factors of the volume waves reflected by the substrate layer and on the phase velocity and frequency thereof as well as on the oscillation amplitude of the particles involved in SAW transition, and on the elliptical particle movement path configuration. Also, the SAW SMG is compared to the existing micromechanical gyroscopes, and the basic SAW SMG production technologies are reviewed.

A problem of a formation flying satellites maneuver control is presented. Among the most important criteria for satellite formation flying control system are active period maximization, precision of the configuration, secure motion (without collisions of satellites). Several methods for group configuration are presented: periodic impulse correction of each flying satellite position formation ("continuous order"); method of a satellite positioning on non-coplanar orbits ("variable order"). Other methods include combinations of methods mentioned above. Recommendations for their application are given. Two ideologies for satellite formation flying can be presented. The first one includes independent maintenance of each satellite a priori specified orbital parameters. The second one implies specialization of satellites: leaders provide orbital parameters for following satellites. Theory of the optimal control of multiobject multi-criteria systems is supposed to be rational for the maneuver control of a group of satellites. Based on this theory algorithm consists of the following phases. On the first phase current intergroup orbiting parameters are measured. On the second phase direction, capacity and duration of the control impulse are estimated based on the forecast of satellite orbital parameters and optimization criteria. On the last phase, the thrusters are used to issue a control impulse. In the presented paper such algorithm is adopted for a task of a formation flying control based on criterion, which consists of two parts. The first part is a configuration deformation minimization. The second one is a distance maximization near orbital node. Algorithm consists of three phases. On the first phase current intergroup orbiting parameters are measured. On the second phase orbital parameters in the "nodе" points are forecasted. On the third phase control parameters are estimated. A model example is given, computational complexity for different number of satellites is determined. Recommendations for practical application of the algorithm are given.

The work is devoted to solving the problem of justifying the rational composition of a team of specialists who provide preparing for a group of aircraft for a given time. To substantiate the optimal composition of the team, it is necessary to solve the problem of scheduling work on a group of aircraft with different composition of specialists. This, in turn, requires consideration of the huge number of options for streamlining work performed on each aircraft, and options for organizing the sequence of maintenance by one specialist of several aircraft. Finding solutions using combinatorial optimization requires an unacceptably high computational cost. The article proposes an approach for finding not the optimal, but some rational admissible solution, which is not much worse than the optimal one, but its definition does not require large computational resources. An algorithm for rational work scheduling based on discrete-event modeling is proposed. Planning is carried out sequentially in time. When planning the sequence of work, it was suggested first of all to put the work with the maximum duration possible. The developed algorithm is software implemented, which allowed to investigate some properties of the solutions obtained. Examples of calculating the schedule of work on a group of aircraft with a different composition of the team of specialists are given. The problem of justification of rational structure of the team is solved by rational planning algorithm works by sequentially increasing the number of specialists. An example of substantiating the rational composition of a team of specialists performing preparing of a group of eight aircraft, each of which performs five types of work, is given and analyzed in details. The high speed of the calculations for the rational planning of work by a given team allowed to consider all possible options for the team (tens of thousands of options) and substantiate such an option that the number of specialists in the team would be minimal, but they would ensure the preparation of aircraft for a given time. Low requirements for computing resources allow solving problems with a sufficiently large number of types of work performed on each aircraft of the group.