Alexey A. Bobtsov

Identification of Frequency of Biased Harmonic Signal

We consider a problem of identification of unknown frequency of a biased sinusoidal signal y(t) = σ0 + σ sin(ωt + φ) + δ(t) with bounded disturbance or harmonic noise δ(t). A new proposed approach to estimation of frequency of biased sinusoidal signal is robust with regard to unaccounted disturbances, which are present in measurement of effective signal. Unlike known analogs, this approach allows to regulate time of estimation of unknown frequency ω. The proposed approach also allows online amplitude and bias estimation. The proposed identification algorithm has smaller dimension than other known analogs.

Compensation of unknown multi-harmonic disturbances in nonlinear plants with delayed control

A new algorithm is developed for compensation of parametrically uncertain multi-harmonic disturbances affecting a control plant. In contrast to the known results, this paper deals with the situation where the relative degree of the plant is arbitrary, the only measured signals are output and control, and there exist delays in the control channel.

Switched Algorithm for Frequency Estimation with Noise Rejection

The problem of parametric estimation of harmonic signals in the presence of noise and computational constraints is an important issue in many engineering fields. This technical note proposes an algorithm for frequency and bias estimation under noisy measurements. An approach for high-frequency noise rejection by switching is proposed and applied for improvement of the estimation accuracy. Efficiency of the approach is demonstrated through numerical simulations.

Compensation of unknown sinusoidal disturbances in linear plants of arbitrary relative degree

A new algorithm is proposed for compensating parametrically uncertain harmonic disturbances. In contrast to the known results, the compensation is carried out in the situation where only the output variable and the control signal are measured, and the relative degree of the plant is arbitrary.

Technical communique: A note to output feedback adaptive control for uncertain system with static nonlinearity

The problem of control design for a system represented as linear stationary and static nonlinear parts is considered. It is assumed that the linear part is unknown and strictly minimum phase. The nonlinear part is known inaccurately, it is irreducible to an input of the linear block, and generally does not satisfy sector restrictions. An adaptive regulator ensuring asymptotic stability is synthesized. The output of a control system, but not its derivatives, is used as a measured variable.

Adaptive observer of an unknown sinusoidal output disturbance for linear plants

A new algorithm is proposed to the design of an adaptive observer for an unknown sinusoidal disturbance that affects the output of a non-minimum phase linear control plant.

The compensation of a harmonic perturbation under conditions of a delay in control

The paper is devoted to the development of the methods of compensation of harmonic perturbations based on measurements of the plant output variable. An approach of compensation of a harmonic perturbation of unknown frequency, acting on a linear controlled plant is proposed. Unlike known analogs, in this paper, the problem of perturbation compensation is considered for the case, when the control channel is characterized by a delay.

A robust algorithm for identification of the frequency of a sinusoidal signal

The problem of identification of an unknown frequency of a sinusoidal signal is considered. A new approach to estimating the frequency of a sinusoidal signal that is robust relative to unaccounted perturbations in the measurement of the useful signal is proposed.

Compensation of harmonic disturbances in nonlinear plants with parametric and functional uncertainty

Methods of compensation of harmonic disturbances from the measurements of the output variable are developed for nonlinear plants with parametric and functional uncertainty. A new control algorithm is proposed, which outperforms known methods in simplicity of implementation and some other characteristics.

Using of LEGO Mindstorms NXT Technology for Teaching of Basics of Adaptive Control Theory

Abstract An article describes laboratory plants based on LEGO Mindstorms NXT Technology and made of several electromechanical systems. These plant are used both for research and educational purposes. They allow to study and to compare different identification and adaptive control algorithms. Certain results of application of theoretical adaptive control algorithms for various Lego Mindstorms NXT mobile robots (track, wheel and walking ones) and reaction-wheel pendulum-cart systems are presented in the article.