Wyniki wyszukiwania - BazTech

1

An interval estimator for chlorine monitoring in drinking water distribution systems under uncertain system dynamics, inputs and chlorine concentration measurement errors

Łangowski R., Brdys M. A.

International Journal of Applied Mathematics and Computer Science

|

2017

|

Vol. 27, no. 2

309--322

EN

The design of an interval observer for estimation of unmeasured state variables with application to drinking water distribution systems is described. In particular, the design process of such an observer is considered for estimation of the water quality described by the concentration of free chlorine. The interval observer is derived to produce the robust interval bounds on the estimated water quality state variables. The stability and robustness of the interval observer are investigated under uncertainty in system dynamics, inputs, initial conditions and measurement errors. The bounds on the estimated variables are generated by solving two systems of first-order ordinary differential equations. For that reason, despite a large scale of the systems, the numerical efficiency is sufficient for the on-line monitoring of the water quality. Finally, in order to validate the performance of the observer, it is applied to the model of a real water distribution network.

2

A biochemical multi-species quality model of a drinking water distribution system for simulation and design

Arminski K., Zubowicz T., Brdys M. A.

International Journal of Applied Mathematics and Computer Science

|

2013

|

Vol. 23, no. 3

571--585

EN

Drinking Water Distribution Systems (DWDSs) play a key role in sustainable development of modern society. They are classified as critical infrastructure systems. This imposes a large set of highly demanding requirements on the DWDS operation and requires dedicated algorithms for on-line monitoring and control to tackle related problems. Requirements on DWDS availability restrict the usability of the real plant in the design phase. Thus, a proper model is crucial. Within this paper a DWDS multi-species quality model for simulation and design is derived. The model is composed of multiple highly inter-connected modules which are introduced to represent chemical and biological species and (above all) their interactions. The chemical part includes the processes of chloramine decay with additional bromine catalysis and reaction with nitrogen compounds. The biological part consists of both heterotrophic and chemo-autotrophic bacteria species. The heterotrophic bacteria are assumed to consume assimilable organic carbon. Autotrophs are ammonia oxidizing bacteria and nitrite oxidizing bacteria species which are responsible for nitrification processes. Moreover, Disinfection By-Products (DBPs) are also considered. Two numerical examples illustrate the derived model’s behaviour in normal and disturbance operational states.

3

Optimizing control by robustly feasible model predictive control and application to drinkingwater distribution systems

Tran V. N., Brdys M. A.

Journal of Artificial Intelligence and Soft Computing Research

|

2011

|

Vol. 1, No. 1

43--57

EN

The paper considers optimizing Model Predictive Control (MPC) for nonlinear plants with output constraints under uncertainties. Although the MPC technology can handle the constraints in the model by solving constraint model based optimization task, satisfying the plant output constraints under the model uncertainty still remains a challenge. The paper proposes Robustly Feasible MPC (RFMPC), which achieves feasibility of the outputs in the controlled plant. The RFMPC which is applied to control quantity in Drinking Water Distribution Systems (DWDS) is illustrated by application to the DWDS example. In the simulation exercise, Genetic Algorithm is selected as the optimization solver and the reduced search space methodology is applied in the implementation under MATLABEPANET environment.

4

Intelligent PI controller and its application to dissolved oxygen tracking problem

Zubowicz T., Brdys M. A., Piotrowski R.

Journal of Automation Mobile Robotics and Intelligent Systems

|

2010

|

Vol. 4, No. 3

16-24

EN

The paper addresses design, calibration, implementation and simulation of the intelligent PI controller used for dissolved oxygen (DO) tracking at wastewater treatment plant (WWTP). The calibration process presented in this paper utilizes both engineering and scientific methods. Verification of the control system design method was obtained via simulation experiments.

5

Modelling and control of wastewater treatment plants

Brdys M. A., Zhang Y.

Studia z Automatyki i Informatyki

|

1999

|

T. 24

17-32

EN

The paper concerns modelling and control of a typical municipal wastewater treatment plant. The modelling is based on a general activated sludge standard model proposed by the IAWPRC Task Group describing the relevant biochemistry and on the mass balance physical laws. A treatment plant composed of the denitrification unit, the aerobic unit and the setting tank with the sludge-controlled feedback is investigated. Results of the model simulation are presented for typical scenarios of real data records. The control objectives are formulated, as achieving a desired water quality at the plant output are expressed through the inequalities constraining allowed chemical oxygen demand (COD) and the nitrogen concentration. A three-layer control structure is proposed the exploit a two time-scale plant dynamics and the dynamics structure. An implementation of the structure involves an integration of recently developed model predictive, intelligent and linear robust control design techniques combined with a set membership modelling of uncertainty. The resulting control actions maintain sustainable and least energy operation of the plant and robustly keep a desired water quality at the plant output.

PL

Referat dotyczy modelowania i sterowania typową oczyszczalnią ścieków. Modelowanie jest oparte na ogólnym standardowym modelu oczyszczania metodą osadu czynnego, zaproponowanym przez Grupę Zadaniową IAWPRC (International Association on Water Pollution Research and Control), opisującym istotne procesy biochemiczne, i na fizycznych prawach bilansu masy. Badana jest oczyszczalnia ścieków składająca się z komory denitryfikacji oraz ze zbiornika osadowego sterowanego recyrkulacją osadu. Przedstawione są wyniki symulacji dla typowych scenariuszy z rzeczywistymi zestawami danych. Cele sterowania zostały sformułowane jako osiągnięcie pożądanej jakości ścieków oczyszczonych na wyjściu z oczyszczalni wyrażone przez nierównościowe ograniczenia na chemiczne zapotrzebowanie tlenu i stężenie azotu. Zaproponowana została trzywarstwowa struktura sterowania wykorzystująca różną dynamikę procesów oczyszczalni oraz strukturę tej dynamiki. Implementacja tej struktury sterowania integruje ostatnio opracowane techniki projektowania sterowania predykcyjnego, inteligentnego i krzepkiego. Deterministyczne "set-membership" modele niepewności zastosowane są w wyższych warstwach sterowania w celu uzyskania gwarancji spełnienia tych celów sterowań, które wyrażone są poprzez nierównościowe ograniczenia nałożone na wyjścia procesu. Zbiory rozmyte zastosowane są do modelowania niepewności w warstwie najniższej sprężonej bezpośrednio z procesem. Otrzymywane sterowania zapewniają minimalnoenergetyczne działanie oczyszczalni oraz bieżące utrzymywanie pożądanej jakości ścieków oczyszczonych na wyjściu z oczyszczalni.