Methods for suppressing nonlinear oscillations in astatic auto-piloted aircraft control systems

Journal of Computer and Systems Sciences International - This review is devoted to the control problem with constraints on the magnitude and rate of change of the control action in aircraft control...     

Global stabilization of the unstable Reaction-Wheel Pendulum

The paper deals with the problem of the Reaction Wheel Pendulum stabilization about unstable (inverted) position for arbitrary initial conditions. Considered mechanical system consists of a physical pendulum with a symmetric disk attached to the end of the pendulum, which is free to spin about an axis parallel to the axis of rotation of the pendulum. The disk is actuated by a DC-motor. The coupling torque generated by the angular acceleration of the disk is used to control of the pendulum. The switching control law is proposed to swinging up the pendulum and balancing it about the inverted position. The nonlinear swinging up control law is proposed ensuring global stabilization of the pendulum about inverted position. The Energy-based Speed-gradient (EBSG) control scheme is used to designing the swinging-up controller. The modification of the EBSG method is proposed to ensure attainability of the inverted position of the pendulum for all initial states of the system. The balance controller is designed on the basis of the Variable Structure Control with forced sliding mode. Numerical simulation results are presented showing achievement of the posed control goal by means of the control action of small magnitude.     

Control and estimation under information constraints: Toward a unified theory of control,computation and communications

An attempt is made to overview an emerging area of research devoted to analysis and design of control systems under constraints caused by limited information capacity of communication channels. The problem’s prehistory dating back to the 1960s–1970s, as well as the new approaches that appeared during the last decade were analyzed. Much attention was paid to various versions of the celebrated data rate theorem. Consideration was given to the problems of control through the communication networks and some results obtained for the nonlinear systems. The basic application areas were listed in brief.     

Adaptive-based methods for information transmission by means of chaotic signal source modulation

Three methods for information transmission based on chaotic signal source modulation based on: application of adaptive observers, adaptive identification with the Implicit Adjustable Model, and frequency modulation with the adaptive demodulator are described. Application of the proposed methods for information transmission by means of chaotic Chua generator modulation is presented.     

Effects of hydrated forms of C60 fullerene on amyloid 1-peptide fibrillization in vitro and performance of the cognitive task

It has been shown for the first time by transmission electron microscopy that the hydrated fullerene C60 inhibited the fibrillization of amyloid-beta25-35 peptide. The fullerene affected the amyloid-beta25-35 assembly, manifesting its anti-amyloidogenic capacity. Our in vivo investigations demonstrated also that a single intracerebroventricular injection of the C60 hydrated fullerene at a dose of 7.2 nmol/ventricle significantly improved the performance of the cognitive task in control rats. The intracerebroventricular injection of the C60 hydrated fullerene (3.6 nmol/ventricle) prevented the impairment of performance of the cognitive task induced by amyloid-beta25-35 (22.5 nmol/ventricle). The results obtained may be useful in the development of therapy of Alzheimer's disease.     

Improvement of rock fragmentation by distributed charge blasting

Formulas and schemes are presented to determine lengths of charges and their inert gaps. The calculations are based on the theory of superposition of seismic blasting waves in a rock mass. The proposed procedure enables calculating parameters of distributed charges under any ground and geotechnical blasting conditions ensuring high-grade fragmentation, elimination of flyrock and reduction in drilling operations.     

Is the C60 Fullerene Molecule Toxic?!

Presented theses criticize the hasty observations and conclusions about some toxic properties of various aqueous dispersions of C₆₀ nanoparticles. In turn, a number of arguments are made emphasizing that pristine fullerenes are non-toxic, but the supramolecular system of “fullerene-water” has a wide spectrum of positive and unique biological activity.     

Control of the coupled double pendulums system

Problems of excitation and synchronization of oscillations are considered in two coupled double pendulum mechatronic system. Hardware, data exchange interface and software for laboratory experiments and control are described. Pulse-modulated control law for oscillation excitation/synchronization is obtained via the speed-gradient method. Laboratory experiments are used for verification and parameter estimation of the adopted mathematical model. Comparison results of the simulations and laboratory experiments for excitation and synchronization analysis are given.     

Control of chaos: methods and applications in mechanics

A survey of the field related to control of chaotic systems is presented. Several major branches of research that are discussed are feed-forward ('non-feedback') control (based on periodic excitation of the system), the 'Ott-Grebogi-Yorke method' (based on the linearization of the Poincaré map), the 'Pyragas method' (based on a time-delayed feedback), traditional for control-engineering methods including linear, nonlinear and adaptive control. Other areas of research such as control of distributed (spatio-temporal and delayed) systems, chaotic mixing are outlined. Applications to control of chaotic mechanical systems are discussed.     

Multipendulum mechatronic setup: Design and experiments

In the paper a novel multipendulum mechatronic setup is described. The setup may be used for implementing different algorithms of estimation, synchronization and control and solving various research and educational tasks in hybrid modeling, analysis, identification and control of mechanical systems. It also allows one to study influence of the data communication protocols on dynamics of distributed mechatronic complexes. Experimental results confirming existence of the lower bound for transmission rate ensuring reasonable estimation accuracy under data rate constraints are presented.