Matrix equations in multivariable control

The contribution is focused on a control design and simulation of multi input output (MIMO) linear continuous-time systems. Suitable and efficient tools for description and controller derivation are algebraic notions as rings, polynomial matrices, and Diophantine equations. The generalized MIMO PI controller design is studied for stable and unstable systems. A unified approach through matrix Diophantine equation can be applied in both cases. All stabilizing feedback controllers are obtained via solutions of a matrix Diophantine equation. The methodology allows defining scalar parameters (one or more) for tuning and influencing of controller parameters. A Matlab-Simulink program implementation was developed for simulation and verification of the studied approach. Illustrative examples show the effectiveness and flexibility of the proposed method for some simple MIMO systems. © 2015 World Scientific and Engineering Academy and Society. All rights reserved

Assessment of shielding effectiveness and percolation threshold of composite materials

This paper deals with the protection of avionics of small airplanes in an electromagnetic environment. Various composite materials are used for this purpose. The mechanical properties of these materials are very well described. On the other hand, the electrical properties are described insufficiently. A fabric with long copper-plated polyamide fibers was selected as a suitable shielding material. The aim is to verify the shielding effectiveness of the fabric by measuring the transverse electromagnetic wave on the coaxial line. Further, determine the flat fiber concentration required to achieve a certain shielding efficiency of given composite sample and its percolation threshold which is an important parameter determining the conductivity of the composite material. It is therefore possible to determine the critical content of the filler in which the composite material starts to act as a conductor

Accuracy of relay identification depending on relay parameters

Combination of relay feedback experiment and control synthesis is usually a part of autotuning principles. This contribution deals with the relay based identification of continuous time plants because the knowledge of the controlled system parameters is important for the quality of control. The feedback relay schemes can use different types of relays. This paper is focused on biased relay with hysteresis. The controlled system is identified as a first order transfer function because most of industrial plants can be sufficiently approximated by a first order linear stable system with time delay term. The main aim is to analyze the precision of controlled system parameters identification when the feedback relay parameters will vary. Matlab program environment is used for all simulations conducted in this paper. © 2015 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license

Design and implementation of lenses for shaping the beam of millimeter waves in free space

This paper deals with the beam forming of the electromagnetic waves with a wavelength in the order of millimeters. The goal is to design, implement and verify the dielectric lens of a suitable material for shaping the beam of millimeter waves to the plane wave and refine and analyze signal frequency range from 220 GHz to 325 GHz. For this purpose a specialized measuring workplace is used. It is equipped with the vector network analyzer ZVA67 by Rohde and Schwarz. It also includes millimeter wave converter for achieving the frequency range up to 325 GHz. The measurement is performed in free space with respective circular antennas. Three measurement methods are used to verify the proper function of developed lenses. The aim is to get the system of dielectric lenses in the millimeter band, which would replace the complicated system of mirrors. In the implementation of the system it is necessary to pay attention to the accuracy of manufacture and the quality of the chosen material

Algebraic principles as a tool for energy saving

This paper discusses algebraic approaches of control design for a set of Single Input - Single Output (SISO) delayed systems that are further developed and discussed. The first principle utilises a special ring RQM, - a set of RQ-meromorphic functions. The second one is based on a ring of proper and stable rational functions RPS and can be considered as a special case. Controller parameters are derived through the general solution of linear Diophantine equations in the appropriate ring. A final controller can be tuned by the scalar real parameter m0>0. The methodology is illustrated by a comparison with another approach, some analyses of a tuning parameter and example. The simulations are performed in the Matlab environment. Copyright © 2020, AIDIC Servizi S.r.l

Robust stabilization of a heating-cooling system by using two feedback controllers: A numericalgraphical analysis

This contribution is intended to present a numerical-graphical method for analyzing the robust stability of a control loop which contains two feedback controllers and a heating-cooling system with a heat exchanger. The controlled plant is described by the anisochronic model with internal delays and the parameters of this model are supposed to vary within given intervals. The applied technique for robust stability analysis is based on the numerical calculations of the value sets in combination with the graphical test via the zero exclusion condition

Autotuning for delay systems using meromorphic functions

The paper presents an autotuning method for time delay systems. The novelty in principles is a new combination of biased-relay feedback identification and an algebraic control design method for timedelay systems. The estimation of the controlled process is based on an asymmetrical limit cycle data experiment. Then, a stable transfer function with a dead-time term is identified. The controller is designed through solutions of Diophantine equations in the ring of stable and proper retarded quasipolynomial meromorphic functions. Controller parameters are tuned through a pole-placement problem as a desired multiple root of the characteristic closed loop equation. First and second order identification gives Smith-like feedback controllers with the realistic PI and PID structure. The design principle also offers a scalar tuning parameter m 0 > 0 which can be adjusted by a suitable principle or an optimization method. The developed approach is illustrated by examples in the Matlab + Simulink environment

Genomic characterization of large rearrangements of the LDLR gene in Czech patients with familial hypercholesterolemia

<p>Abstract</p> <p>Background</p> <p>Mutations in the <it>LDLR </it>gene are the most frequent cause of Familial hypercholesterolemia, an autosomal dominant disease characterised by elevated concentrations of LDL in blood plasma. In many populations, large genomic rearrangements account for approximately 10% of mutations in the <it>LDLR </it>gene.</p> <p>Methods</p> <p>DNA diagnostics of large genomic rearrangements was based on Multiple Ligation dependent Probe Amplification (MLPA). Subsequent analyses of deletion and duplication breakpoints were performed using long-range PCR, PCR, and DNA sequencing.</p> <p>Results</p> <p>In set of 1441 unrelated FH patients, large genomic rearrangements were found in 37 probands. Eight different types of rearrangements were detected, from them 6 types were novel, not described so far. In all rearrangements, we characterized their exact extent and breakpoint sequences.</p> <p>Conclusions</p> <p>Sequence analysis of deletion and duplication breakpoints indicates that intrachromatid non-allelic homologous recombination (NAHR) between <it>Alu </it>elements is involved in 6 events, while a non-homologous end joining (NHEJ) is implicated in 2 rearrangements. Our study thus describes for the first time NHEJ as a mechanism involved in genomic rearrangements in the <it>LDLR </it>gene.</p

Výstup důlních plynů z hlediska zásahu IZS

Import 20/04/2006Prezenční výpůjčkaVŠB - Technická univerzita Ostrava. Fakulta bezpečnostního inženýrství. Katedra (030) požární ochrany a ochrany obyvatelstv

Smith predictor in relay autotuning

This contribution is focused on utilization of the Smith predictor in the automatic control design method. The first phase consists from the biased relay experiment where the unknown parameters of the low order controlled system with time delay are identified. The following control design is based on the algebraic methods through a general solution of Diophantine equations in the ring of proper and stable rational functions. The time delay term is neglected in the control design because the control loop contains a model of the controlled system which was identified by the relay experiment