The partial stability problems naturally arise in applications either from the requirement of proper performance of a system or in assessing system capability. In addition, a lot of actual (or desired) phenomena can be formulated in terms of these problems and be analyzed with these problems taken as the basis. The following multiaspect phenomena and problems can be indicated: adaptive stabilization; spacecraft stabilization (especially stabilization by rotors); drift of the gyroscope axis; Lotka-Volterra ecological principle, e.t.c. Also very effective is the approach to the problem of stability with respect to all variables based on preliminary analysis of partial stability. The article studies the problem of partial stability for nonlinear stochastic systems of differential equations Ito: stability with respect to a part of the variables in probability of "partial" zero equilibrium position. Initial perturbations of variables that do not define the given equilibrium position can be large (belonging to an arbitrary compact set) with respect to one part of the variables and arbitrary with respect to their other part. A conditions of stability of this type are obtained in the context of a stochastic analog of the Lyapunov functions method, which generalize a number of existing results. Example is given. The problem of unification of process of studying partial stability problems of stationary and non-stationary nonlinear stochastic systems of differential equations is also discussed.

The method of forming optimization algorithms for non-stationary control systems is developed in the article, based on the application of the Hamilton-Jacobi equation and the Pontryagin minimum principle. In this article, the original nonlinear differential equation that describes the original control system is transformed into a system with a linear structure, but with State Dependent Coefficient (SDC) parameters. The use of the quadratic quality criterion in problems with unlimited time of the transient process makes it possible, in the synthesis of control for the transformed system, to move from the need to search for the solution of a scalar partial differential equation (the Hamilton-Jacobi-Bellman equation) to a Riccati-type equation with state-dependent parameters. However, solving the resulting equation in the rate of the object's operation is no less difficult. For its solution, an algorithmic method for the synthesis of controls is proposed. The behavior of the Hamiltonian under optimal control changes during the transient process along a well-defined trajectory. This property of the Hamiltonian was used as the basis for the design of algorithms for optimizing the control system. When the formulated conditions are met, a "transfer" of the quality functional from peripheral values to its minimum value is guaranteed asymptotically. The effectiveness of the developed algorithms is demonstrated by the example of the synthesis of control controlling the supply of antiretroviral drugs HAART to the human body in the presence of HIV. The simulation was carried out in the MATLAB package.

We consider dynamic model of the motion in the sagittal plane of the exoskeleton of lower limbs, integrated with the similar model of the human operator by means of straps with one or two controllable actuators in each leg. The exoskeleton is additionally loaded with heavy point weight. Considered models of visco-elastic and the rigid attachment of the exoskeleton to the person. The model also takes into account the dynamics of the electric actuators. We study the possibility of designing control systems for various options of the actuators in the joints of the exoskeleton (knee or both in the knee and hip), which also take into account the different degrees of force action of the human operator on the process of movement. The synthesis is based on the method of solving the inverse tasks of the dynamics. The analytical motion control for exoskeleton was designed, which provided locomotion to the hip and knee joints in accordance with the selected desired mode. Synthesis of the control system was carried out on the example of a flat, single support for comfortable walking. The algorithms provide a good quality performance of a given motion and an acceptable cost of energy from the human operator. With sufficient size nominal torque for actuators, the exoskeleton is able to provide substantial assistance to the person carrying the heavy weight, as is evident from the analysis of energy costs. The best energy results with good precision implementation can be obtained in the case of a perfectly rigid model, in which the design of the exoskeleton and the human body are one.

In this paper we suggest estimation results for the reconfigurable mobile robot locomotion effectiveness. All estimations are performed via visual analysis of the virtual modelling results. In virtual modelling scenarios mobile robot were traversing through a space with consequently assembled obstacles of five main types: slope, ledge, step, stones, and tube array. Further we describe two robotic platform configurations: tracked and wheeled. Each mobile device is assembled from a set of specialized modules. Combining of these modules allows building different mobile (wheeled, tracked, leg-wheeled and etc.) and payload systems (sensor, manipulative). All modular subsystems have virtual representations with identical to their physical analogues mass and inertial properties. We propose two different payload types: payload for wheeled vehicle (represented with modular manipulation system) and payload for tracked vehicle (represented with video camera mounted on rotation module). Furthermore we describe control system that allows virtual model of mobile robot to move between preliminary defined waypoints. As a final result we provide sequences and following descriptions of the virtual modelling animation results. Research conclusions are made as follows: based on performed visual analysis we submit that both devices are able to traverse through rough terrain with relatively small obstacles or to climb slopes with different incline angles; our further work is focused on developing more effective mobile robot configurations and expanding the class of traversable obstacles.

Rising popularity of robotics in education leads to necessity for high-quality tool for modern training programs - robotic kit. Most of the existing solutions do not have sufficient element base for the correct execution of complex algorithms. Moreover, due to a large number of components and tiny connectors a large part of the learning process is spent on prototyping, not on the study of control problems. The authors propose a new kit for mobile robotics, which key feature is modularity. The kit includes control system module, autonomous power supply, power drive modules, communication module, and different mechanical transmission modules such as bearing unit, cylindrical gear, worm gear and angular bracket. Implementation of the most common control tasks (collision avoidance, path planning, etc.) is possible due to special instrumentation modules, which include light, temperature and microphone sensors; a touch sensor and a line sensor; an ultrasonic and infrared distance sensor. In addition to constructive configuration solutions, authors focus special attention on the circuit design of the future kit. On base of the proposed kit it is possible to prototype such robotic systems as wheeled and tracked platforms and robotic arm, which models and structural diagrams are shown in the article. The effectiveness of the developed kit is proved by powerful functional modules and modular construction in general that will reduce the time needed for prototyping robotic systems, and will allow focusing directly on the debugging of control algorithms.

It is well known that in normal technical condition of the objects of control and diagnostics for noisy signal which are received from corresponding sensors classical conditions such as normal distribution law, stationarity and etc. take place. Also it is well known that during exploitation of the control objects because of different defects like wear, microcracks, corrosion, deformation and etc. the hidden period of failure origin take place. In this period noise which have correlation with the useful signal appears. That is why determination of spectral and correlation characteristics of the noisy signal using traditional algorithms and technologies in the hidden stage of failures origin in the control objects take place with some errors. In this case the indication of the hidden stage of defects origin which lead to failures in the objects in some cases is belated. In the article algorithms and technologies of the substitution of unmeasurement readings of the noise for their approximate values are offered. Also the possibility of the use of the given readings for both determination the values of spectral and correlation characteristics of the noise and for providing the robustness of the results of correlation and spectral analysis in the hidden period of failures on the control objects is shown.

A three-phase distribution electrical network operating in an asymmetric mode is considered. As is known, the factor of asymmetry of phase currents leads to significant losses of active power in the network and transformer substations, as well as to the failure of household appliances and industrial installations. For the symmetry of distributed networks, a number of technologies have been proposed that have not found wide practical application because of their complexity and insufficient efficiency. In the traditional automated information and measuring systems of commercial electricity metering, the functions of data collection from a group of electricity meters installed at the network subscribers are realized, and, in general, the tasks of commercial metering of electricity are being solved. At the same time, in these systems, the optimization of the operating modes of distribution networks is not carried out. One of the possible approaches to solving the problem of balancing a three-phase network based on controlling the flow of electricity between the phases of the network is by switching single-phase electric receivers from a more loaded phase to a less loaded one. The implementation of this approach is implemented by introducing into the structure of the existing automated informative electric power accounting system an additional control subsystem - a digital controller that performs the functions of generating the appropriate control signals for switching electronic meters of electricity connected to the loads of the distribution network. The quality of control processes is evaluated by the objective (criterial) function, which characterizes the loss of active power in the network due to the asymmetry factor. A condition is obtained, the fulfillment of which guarantees the reduction of the value of the chosen indicator of system efficiency in a guaranteed way. A procedure for synthesizing a digital regulator has been developed that provides a reduction in the level of unbalance of phase currents based on the identification of the network load model and minimization of the selected criterial function. The obtained results make it possible to build information and control systems in place of the traditional automated informative electric power accounting systems, which are related to the class of information and measurement systems, which allow increasing the technical and economic performance of distribution companies.

At present, maneuverable thrust vectored aircraft are capable of performing a controlled flight beyond normal flight envelope, namely, for attack angles significantly exceeding the critical value. It is well known that in this case the aerodynamic processes fundamentally change in comparison with flight at small and average angles of attack. It is also known that the errors in the methods of computational aerodynamics and the wind-tunnel data for overcritical range increase significantly due to the essentially nonlinear and unsteady nature of the flow. Therefore, the problem of validation and estimation of aerodynamic coefficients based on the results of flight tests by methods of system identification is vital. It is obvious that agreement of aircraft dynamics models with the flight data is necessary for the development, modernization, testing, creation of simulators, investigation of flight incidents, i.e. for all the main stages of the aircraft life cycle. One of the most important poststall effects is the emergence of hysteresis in the dependences of the aerodynamic coefficients on the angle of attack. This phenomenon is due to the fact that the flow separation with increasing angle of attack and flow restoration with the subsequent decrease of the angle of attack occur asymmetrically. This effect takes place even for very small values of the derivative of the angle of attack with respect to time, and as a result it is called stationary hysteresis. This article deals with the problems concerning identification of the mathematical model for aircraft motion at the overcritical angles of attack by processing flight test data. Algorithms for obtaining estimates for coefficients of the lift force, the drag force and the pitching moment from the flight test data are proposed. The mathematical model of the hysteresis of the lift coefficient is considered, and its parameters are identified. Furthermore, article presents expressions allowing the calculation of the hysteresis of the drag coefficient and the pitch moment through the hysteresis of the lifting force and the coefficients analogous to the lift-drag ratio and static stability coefficients known from aerodynamics and flight dynamics.

During the flight of the aircraft (AC) in many cases, there is the problem of determining linear and angular parameters of its motion in the inertial (fixed to inertial space) coordinate system. Lately increasingly strapdown inertial navigation system (SINS) based on three accelerometers and three angular velocity sensors of the sensitivity axis with the axes associated with the body of the aircraft coordinate system. Issues of assessment of accuracy of determining navigation parameters AC, these systems cover a lot of work. However, they do not allow to assess the accuracy of the determination of motion parameters of the aircraft with a strapdown inertial navigation system in the inertial basis. This article presents the method of solving the problem of estimation of accuracy of definition of linear and angular motion parameters of the aircraft with a strapdown inertial navigation system in the inertial basis. A block diagram for explaining the principle of operation of the described the SINS. To describe the motion of AC and estimation of accuracy of definition of parameters of its motion, the SINS in the inertial basis is used two coordinate systems: inertial, the associated. As the main factors determining the errors, the SINS, are considered dead zones, errors of implementation and scale factors of reorthogonalize the installation of measuring devices. On the basis of the developed technique obtained numerical values of accuracy of calculation of parameters of motion of the aircraft. The proposed method allows to evaluate the accuracy of the determination of motion parameters of AC with the SINS in the inertial basis. This gives you the opportunity to decide on the satisfaction of specified requirements on the accuracy of sins with certain characteristics of measuring devices in each case, application of the АС to the destination. This technique can also be used in the error analysis of SINS used in the different types of АС, in determining the errors that have the most significant impact on the determination of motion parameters of АС, when forming recommendations on reducing the negative impact of these errors and validating requirements for strapdown inertial navigation systems of aircraft.