In the paper, a comparative case study covering different control strategies of unstable and nonlinear magnetic levitation process is investigated. Three control procedures are examined in order to fulfill the specified performance indices. Thus, a dedicated PD regulator along with the hybrid fuzzy logic PID one as well as feed-forward neural network regulator are respected and summarized according to generally understood tuning techniques. It should be emphasized that the second PID controller is strictly derived from both arbitrary chosen membership functions and those ones selected through the genetic algorithm mechanism. Simulation examples have successfully confirmed the correctness of obtained results, especially in terms of entire control process quality of the magnetic levitation system. It has been observed that the artificial-intelligence-originated approaches have outperformed the classical one in the context of control accuracy and control speed properties in contrary to the energy-saving behavior whereby the conventional method has become a leader. The feature-related compromise, which has never been seen before, along with other crucial peculiarities, is effectively discussed within this paper.

In this paper a new SVD-based inverse of nonsquare parameter matrices is presented. An intriguing impact of H-inverse on minimum-energy design of perfect control inputs is emphasized. Now, the new inverse corresponds to the polynomial matrix S-inverse introduced by Hunek and Latawiec for systems described in the input-output framework. Note that the new inverse can be extended to cover the polynomial and rational forms, thus giving rise to the introduction of a new class of expected inverses.

This paper presents a new simple form of a polynomial matrix σ-inverse introduced as a result of research works on minimum variance control (MVC) for LTI MIMO nonsquare systems. A new approach to construction of a σ-inverse of a nonsquare polynomial matrix can result in e.g. pole-free design of MVC, which is provided by specially selected degrees of freedom of the σ-inverse. A simulation example in the Matlab ^® environment illustrates theoretical achievements of the paper.

In this paper new results in adaptive (generalized) minimum variance control of packet switching computer networks are presented. New solutions, corresponding to the new inverses of the nonsquare polynomial matrices, can be used for design of robust control of multivariable systems with different number of inputs and outputs. Application of polynomial matrix inverses with arbitrary degrees of freedom creates the possibilities to optimal control of computer networks in terms of usage their maximal bandwidth. Simulation examples made in Matlab environment show big potential of presented approach. DOI: http://dx.doi.org/10.5755/j01.itc.43.3.6268

In this paper, a new definition of a right inverse of nonsquare parameter matrices is derived from MVC-related inverses of nonsquare polynomial matrices. The new definition is employed in a stabilizing state-space perfect control law for nonsquare LTI MIMO systems. A simulation example shows that the new inverse outperforms the classical minimum-norm right inverse.