Sergey A. Kolyubin

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.

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.

An Iterative Algorithm of Adaptive Output Control with Complete Compensation for Unknown Sinusoidal Disturbance

The problem is considered for the output control of a linear, parametrically indeterminate object subjected to the effect of an external unknown, sinusoidal disturbing influence. The solution of this problem is found in the class of iterative adaptive algorithms involving the channels of stabilization and identification of the frequency of a disturbing influence.

Adaptive stabilization of a reaction wheel pendulum on moving LEGO platform

In this paper an adaptive control algorithm of a reaction wheel pendulum on a movable platform is proposed. Obtained hybrid control system allows to stabilize a pendulum fixed on the movable platform at the top unstable equilibrium. Tasks of swinging up and stabilizing of a pendulum is solved in conditions of a full parametric uncertainty of a plant and constrained control channel. In contrast to other approaches, this algorithm has adaptive adjusting of controllers parameters in “on-line” mode without any preliminary identification procedure. The second goal of this work is a development of applications used in an educational process because an investigation of control theory problems with real plants very important for students and their experience.

Output controller for quadcopters with wind disturbance cancellation

In the paper an output control approach for a class of nonlinear MIMO systems is presented. A multicopter with four symmetrical rotors, i.e. a quadcopter, is chosen to illustrate proposed adaptive control approach based on the high-gain principle, so-called, “consecutive compensator”. Output controller is designed by decomposition of the mathematical model on two parts. The first one is a static MIMO transformation (more precisely, in the considering case a system of linear equations which relates control signals for actuators and virtual control inputs). The second one is a few SISO channels. Such trick allows to design a control law in two steps. At the first step we design virtual controls for each SISO channel. Here we apply the mentioned systematic approach “consecutive compensator”, which also allows to cancel unknown wind disturbances changing their values and directions negligibly slowly. Then after the inverse MIMO transformation we get control signals for actuators.

Output controller for quadcopters based on mathematical model decomposition

In the paper an output control approach for a class of nonlinear MIMO systems is presented. A multicopter with four symmetrical rotors, i.e. a quadcopter, is chosen to illustrate effectiveness of the proposed adaptive control approach based on the high-gain principle so-called “consecutive compensator”. Output controller is designed by decomposition of the mathematical model on two parts. The first one is a static MIMO transformation (more precisely, in the considering case a system of linear equations which relates lift forces generated by the actuators and virtual control inputs). The second one is a few SISO channels. Such trick allows to design a control law in two steps. At the first step we design virtual controls for each SISO channel. Here we apply the mentioned systematic approach “consecutive compensator”. And then after the inverse MIMO transformation we get a set of real lift forces.

Simple Output Stabilization Approach for Robotic Systems

Abstract The problem of control design for a class of nonlinear system is considered. It is assumed that the linear part is unknown and 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. A regulator ensuring semiglobal stability is designed. The output of a plant, but not its derivatives is used as a measured variable. Some application results of proposed output control algorithm for a number of Lego Mindstorms NXT mobile robots (track, wheel and walking ones) are presented in the paper.

Estimation of polyharmonic signal parameters

A new algorithm was proposed to estimate all parameters of the polyharmonic signal such as frequencies, amplitudes, phases, and shifts. Exponential convergence to zero of the errors of estimating the desired parameters was shown. The algorithm features noise-immunity to additive noise in the measurement channel. The dynamic dimensionality of the estimation algorithm is 3k, where k is the number of harmonics

Compensation of polyharmonic disturbance of state and output of a linear plant with delay in the control channel

A new adaptive algorithm to compensate the unknown a priori multisinusoidal disturbance affecting the plant state and the measured output was proposed. It was intended for the plants that can be unstable, have time delay in the control channel and arbitrary relative degree of the model, as well as be nonminimal-phase, which is much superior to the existing counterparts.

Fast Compensation of Unknown Multiharmonic Disturbance for Nonlinear Plant with Input Delay

Abstract In this paper a new approach for fast rejection of unknown multiharmonic disturbance is proposed. To design this algorithm the method of cascade reduction is used that allows to accelerate the process of convergence of unknown frequencies estimates. Additionally, the proposed approach differs from the known results. In this article we consider the case of disturbance rejection, when a relative degree of the plant can be arbitrary and only an output is variable, the control signal is measured and the control channel is characterized by delay.