This work is not an overview paper and doesn't cover history of evolution of design methods of robust control systems with high gain coefficient. According to the chronology of the development there are discussed theoretical foundations and practical features of the main methods of this class allowing to control dynamic objects with functional uncertainties. The subject of the research is methods of "localization of motion", "robust correction" and a method based on Lyapunov functions, presented as "K_¥ - robust control systems". The first two methods lead to a two-loop scheme, and the second to a single-loop with robust controller. Despite the compensation of uncertainties and the ghosting of the system in a linear form, the regulators of the first two methods are not robust in relation to the reference trajectory and external disturbances. Therefore, when changing them, it is necessary to perform a structural-parametric change in the regulator in real time. Implementation of this concept in practice leads to the use of a complex adaptive system with a perturbation identifier. The advantages and disadvantages of the methods are analysed. The use of a high gain coefficient for suppressing uncertainties has a dialectical basis - the inverse proportionality of the static error to the open-loop gain. This feature led to a simple and universal engineering method of synthesis, which does not require the use of a special mathematical device. The main disadvantage of the first two methods is that there are prevailing heuristic reasonings while synthesis, mainly in the search for a structure that allows an unlimited increase in the gain without breaking stability. The results of computer simulation in the Matlab/Simulink software environment are presented.

The main aim of this paper is the robust control synthesis of the cascade system with discrete proportional integral (PI) controllers. The PI and proportional integral derivative (PID) controllers are employed for the control of the various, in particular, high order plants with structural and parametric uncertainties. But with PI controllers, only the low order plants can be correctly controlled. Consequently, the synthesis must be completed with the first order models of the plant in the control loops. Hence, the problem is to calculate the PI controller parameters in order to offer the dynamics quality in conditions of structural and parametric uncertainties of it he plant. The proposed parametric synthesis is based on the time scale approach and roots location on the complex plane. The small constant ε is denoted as a spectral value of the slow mode as percentage to the fast one. The nominal dynamics of each loop must be similar to the second order model dynamics. For the second order subsystems the regions of the admissible eigenevalues is denoted with limitations of real root boundary, bandwidth and damping. The analysis of the roots deviation on the complex plane with plant parameters variations allow to establish the conditions of dominant roots location in the denoted area. The values of small constant ε < 0,25 get the linear system with calculated discrete PI controllers and the valid (not reduced) plant similar to the chosen second order model dynamics. The proposed synthesis method is helpful for the system with the fast and slow components; in particular, the electrical drives control system. The numerical example of synthesis is presented with simulation results, which illustrate the application of the method

Consider a double aerodynamic pendulum that represents a double pendulum, the second link of which carries a thin wing with symmetrical airfoil. The entire system is placed in flow with the constant speed V and mounted in such a way that both axes of the pendulum are vertical. We assume that both joints of the pendulum are equipped with linear spiral springs. Systems of rigid bodies that move under the combined action of elastic forces and aerodynamic (or hydrodynamic) load are called aeroelastic systems and are of great interest from the point of view of basic research and applications (especially in the areas of aerospace and civil engineering). An elastically mounted double-link aerodynamic pendulum is considered. It is assumed that the flow acts only upon the second link of the system. Conditions of asymptotic stability of the trivial equilibrium "along the flow" (when both links are stretched along the flow) are obtained. Influence of position of the wing and of coefficients of structural stiffness upon the stability is discussed. Limit cycles are studied that arise in the system for a certain range of values of parameters. Dependence of their amplitude on coefficients of stiffness is analyzed. Experiments with such pendulum are performed in the wind tunnel of the Institute of Mechanics of Lomonosov MSU, where parameters of periodic motions are registered for different wind speeds, and different locations of the wing with respect to the second link. It is shown that experimental data is in qualitative agreement with results of numerical simulation.

In cases of emergency situations, accidents, disasters, in process of reclamation of Arctic and Antarctic, exploration other planets the maximum uncertainty in terms of anticipated working conditions makes it very hard or even impossible to plan and to choose the needed robotics. To perform tasks in such conditions, one should use robots with variable structure, i.e. modular mobile robots, which should have hardware and software capable of rapid reconfiguration. We propose a hardware and software solution for information-measuring and control system (IMCS) of a heterogeneous modular robot, which is sufficiently simple to implement and which is able to reconfigure automatically. It is necessary to require that each module's construction must correspond to its functional purpose and its own IMCS must provide informational and executional functionality. We implement distributed control in such structure, similar to multi-agent systems, via decoupling computational and control process of robot goal function execution into functional subprocesses and distributing them between microcomputers of modules. System-wide robot control is running on a separate module, which plays role of a supervisor for other modules. Executive module is fully responsible for functional subprocess realization. We propose usage of a broadband, reliable and low-cost interface on top of Ethernet standard to organize intermodular interaction. The choice of Ethernet standard enables local-area like design of robot IMCS with IMCS of modules as its nodes. One should use microcontrollers or, as maximum, singleboard computers, i.e. embedded systems as computational devices for IMCS of modules. Informational intermodular interaction is developed using ZeroMQ library with addition of UDP protocol with broadcast messages. This solution led to development of the specification for embedded systems (in contrast to Robotic Operating System), i.e. a unified system of driver development rules. Drivers are a set of control instructions and network protocols to create module's application programming interface (API). Proposed hardware and software solution was tested successfully using laboratory model of heterogeneous modular mobile robot, consisting of module-supervisor, wheeled transport module, close-range sensors module and power module (batteries). A new method of movement planning using two-dimension vector fields is proposed for transport module which is implemented as a full-functional mechatronics device.

Actual problem is the study of oscillation acting on functional characteristics of miniature robots based on frequency modulation and changing of pulse recurrence frequency. Such robots are the systems with electromagnetic action, investigation of which is performing in many scientific centers of the world. Study of oscillation processes satisfy the receiving of relationships between functional and frequency characteristics, determine conformity working and required parameters and to extend robot's possibilities. Miniature robots with electromagnetic drive system and technological on board sensors are intended mainly for direct or inverse motion inside of pipes with small diameter (5-20 mm) and analyze of the quality internal surfaces of the pipes, for nondestructive testing and other inspection operations in energy, nuclear power stations for example, in aviation and space technologies. In this paper the motion equations of electromagnetic in-pipe robot are presented, as so as nomographs and characteristics, those may use under design of miniature robots for the purposes of target applications. The results of investigations of oscillatory processes in miniature in-pipe robots of the electromagnetic principle of action are presented. Robots are equipped with coupling devices with internal surfaces of small diameter pipes. Dependences of the robot's parameters on the frequency, length and duration of the control pulses are given. The oscillations effects for a different frequency on the characteristics of the robot with the possibility of reversible motion when moving in media of different viscosities are analyzed.

The promising development of minimally invasive laser surgery for the treatment of hemorrhoids is associated with a combination of diagnosis and treatment in time and space. The purpose of this study was to develop the structure of such a device allowing performing minimally invasive hemorrhoids treatment with laser coagulation under interstitial ultrasound visualization in real time. The medical complex includes a diagnostic unit, a laser unit and a control system. In turn, the diagnostics module, which allows real-time monitoring, includes a Doppler sensor for performing blood vessel search and measuring blood flow velocity, an ultrasonic sensor for visualization of soft tissues, and monitoring of the laser vascular coagulation operation. The laser unit consists of a laser emitter; a fiber-optic instrument serving to deliver laser radiation to the impact zone; the power and cooling system necessary to maintain the operating temperature of the laser. To carry out numerical calculations of laser radiation parameters, a mathematical model was developed. For its implementation, a computer program was developed that allows a numerical evaluation of the effects of laser vascular coagulation. The given program allows to estimate the influence of laser radiation on blood vessels and perivenous tissue and to analyze the degree of denaturation of tissue molecules. For calculations, optical and thermodynamic parameters of biological tissues are used, which ensure a satisfactory match of the simulation results with known literary data.

The optimal control problem of slew maneuver of a spacecraft (as solid body) from arbitrary initial attitude into required final angular position is considered and solved. Designing and construction of optimal control of spacecraft rotation is based on the quaternion variables and Pontryagin's maximum principle. The case when the conditions of transversality have crucial significance is investigated. The minimized functional takes into account energy of rotation and duration of maneuver. Using the necessary conditions of optimality in the form of maximum principle and the quaternion method for solving the control problems of spacecraft motion, an analytical solution to the formulated problem was obtained. On basis of the conditions of transversality as the necessary conditions of optimality, main properties, laws and key characteristics (parameters, constants, integrals of motion) of optimal solution of control problem, including the maximal rotation energy for optimum motion and duration of maneuver are determined. The formalized equations and the calculated expressions and dependences for synthesis of the optimal program of reorientation are obtained. The estimation of influence of constraint and narrow-mindedness of the controlling moment onto character of optimal motion and onto indexes of quality of control is given. It is shown that the accepted criterion of optimality guarantees motion of a spacecraft with energy of rotation which does not exceed the required value. For spherically symmetric spacecraft and dynamically symmetric spacecraft, the complete solution of reorientation problem is presented in the closed form. The example and results of mathematical simulation of spacecraft motion under optimal control, showing a practical realizability of the developed method for control of spatial orientation of a spacecraft, are given.

The study of security control system for aircraft which can to class threat accident and transmit data about it to the crew. A feature of the proposed system is the use and sale in its structure algorithms, fuzzy logic and decision support device. The authors proposed the method for prediction of aircraft accident which is different from others by calculation of values. It values are characterization of change variables which affect flight safety and can be use for flight conditions assessment. The advantage of this method is increase of reliability calculating of threats and effects of accident in the process of control of an aircraft. This result is achieved prediction changes the different variables of flight security. The practical significance is timely parrying accident by the crew and automatic of aircraft. This method can be implemented by algorithm of accident for prediction in the security control system of aircraft.

According to estimates of numerous publications around the world, more than 50 % of all flight accidents occur on the takeoff and landing phases of aircraft flight. The main reason for these events is the "human factor". To reduce psychological stress and assist the pilot in making urgent decisions, various methods of information support have been developed previously. Pilot alert message contain information about the current and future situation. In the presented paper, we propose new efficient methods for predicting the coordinates of the aircraft on the runway during the braking phase. Predicting methods are based on the energy balance equation. For ground modes, the equation has been expanded by introducing a new member describing the mechanical resistance force of the chassis. The problem of finding the predicted coordinates of the aircraft is formulated as a terminal problem of achieving the desired value of total energy at the end point of the trajectory. This formulation made it possible to determine the length of the brake-way before reaching the stopping or taxiing speed. The information presented to the pilot should be not only accurate, but also reliable. To improve accuracy, a new correction circuit's structure was developed. The methodology of research and proof the prediction algorithm's reliability on the basis of statistical tests results is also developed. A computer stand for prediction algorithms testing was developed. The stand is equipped with service tools for registration and statistical analysis of the results. A large amount of deterministic and statistical tests of prediction algorithms in a wide operating range of flight regimes has been performed. Statistical characteristics of errors are obtained. Average prediction errors in different situations are 10-20 m. Confidence intervals of predicted brake-way expectation are calculated. They are in the range of 1.5-2 m.