Robust fault-tolerant control for power systems against mixed actuator failures

Kaviarasan, B.,Sakthivel, R.,Kwon, O.M. Elsevier Ltd 2016 NONLINEAR ANALYSIS HYBRID SYSTEMS Vol.22 No.-

<P>This paper employs linear matrix inequality (LMI) based optimization algorithm to develop a method for designing fault-tolerant state feedback controller with mixed actuator failures for power systems subject to random changes. Meanwhile, the random abrupt changes are determined by a finite set Markov chain so the considered system is equivalently represented as a discrete-time Markov jump linear system (MJLS). Further, due to the variations of loading conditions in power system, an uncertainty term is incorporated to MJLS. For the proposed system, we construct a novel actuator fault model containing both linear and nonlinear terms which is more general than the conventional actuator fault models. The main purpose of this paper is to design the robust fault-tolerant controller such that for all possible actuator failures, time-varying delays and admissible parameter uncertainties, the closed-loop uncertain discrete-time MJLS is robustly stochastically stable. Based on free-weighting matrix approach and linear matrix inequality theory, anew set of sufficient conditions that guaranteeing the robust stochastic stability is presented by choosing an appropriate Lyapunov-Krasovskii functional candidate. In addition, a single-machine infinite-bus (SMIB) power system is considered as an application example and its simulation results demonstrate the effectiveness of the proposed design techniques. (C) 2016 Elsevier Ltd. All rights reserved.</P>

Reliable dissipative control of high-speed train with probabilistic time-varying delays

Kaviarasan, B.,Sakthivel, R.,Shi, Y. Informa UK (TaylorFrancis) 2016 International Journal of Systems Science Vol.47 No.16

<P>This paper investigates the reliable dissipative control problem for high-speed trains (HSTs) under probabilistic time-varying sampling with a known upper bound on the sampling intervals. In particular, random variables obeying the Bernoulli distribution are considered to account for the probabilistic time-varying delays. Based on Lyapunov-Krasovskii functional approach which considers full use of the available information about actual sampling pattern, a new set of sufficient condition is established to guarantee that the HST can well track the desired speed and the relative spring displacement between the two neighbouring carriages is asymptotically stable and the corresponding error system is strictly (Q, S, R)-dissipative. The existence condition of the dissipativity-based reliable sampled-data controller is obtained in terms of a set of linear matrix inequalities which are delay-distribution-dependent, i.e. the solvability of the condition depends on not only the variation range of the delay but also the probability distribution of it. Moreover, different control processes for the HST system can be obtained from the proposed design procedure and hence it can reduce the time and cost. Finally, the effectiveness and benefits of the proposed control law is demonstrated through a numerical example by taking the experimental values of Japan Shinkansen HST.</P>

Disturbance-observer-based control for synchronization of complex dynamical networks

Boomipalagan Kaviarasan,Oh-Min Kwon 제어로봇시스템학회 2022 제어로봇시스템학회 국제학술대회 논문집 Vol.2022 No.11

Using the disturbance observer method, an elegant synchronization control law is proposed for complex dynamical networks with constant coupling delay and multiple disturbances. To be more specific, the network is affected by two types of disturbances: (i) unknown and produced by exogenous systems, and (ii) norm-bounded. The goal is to estimate the unknown disturbance by designing a disturbance observer that combines with the proposed feedback controller to ensure network synchronization. Sufficient conditions for the desired synchronization are then derived and expressed as linear matrix inequalities using the augmented Lyapunov-Krasovskii functional and Wirtinger’s integral inequality. A simulation example based on the F-18 aircraft model is presented to validate the correctness of the developed theoretical results.

Stabilization of Markovian jump systems with time-varying delay using a nonlinear disturbance observer-based method

Boomipalagan Kaviarasan,Yong-Gwon Lee,Oh-Min Kwon 제어로봇시스템학회 2023 제어로봇시스템학회 국제학술대회 논문집 Vol.2023 No.10

Fault-tolerant SMC for Takagi–Sugeno fuzzy systems with time-varying delay and actuator saturation

Selvaraj, Palanisamy,Kaviarasan, Boomipalagan,Sakthivel, Rathinasamy,Karimi, Hamid Reza IET 2017 IET CONTROL THEORY AND APPLICATIONS Vol.11 No.8

<P>This study examines the problem of fault-tolerant sliding mode control (SMC) design subject to actuator saturation for a class of Takagi-Sugeno fuzzy systems with time-varying delay and external disturbances. Our main attention is to propose the fault-tolerant SMC such that for given any initial condition, the system trajectories are forced to reach the sliding surface within a finite time. On the basis of the SM surface and Lyapunov stability theorem, a new set of sufficient conditions in terms of linear matrix inequalities (LMIs) is established to not only guarantee the passivity and asymptotically stability of the resulting closed-loop system in the designed sliding surface, but also cover the issues of actuator saturation and performance constraints. Then, the desired gain matrix of the fault-tolerant SMC is obtained in respect of the previously established LMIs such that the reachability of the predefined sliding surface is ensured. It is worth pointing out that the obtained sufficient conditions can preserve the trade-off between the maximisation of admissible upper bound of time-varying delay and enlarging the estimation about the domain of attraction for the closed-loop system. Eventually, the effectiveness and robustness of the proposed control approach are demonstrated via simulation results.</P>

(-) Epigallocatechin gallate restores ethanol-induced alterations in hepatic detoxification system and prevents apoptosis

Anuradha, Carani V,Kaviarasan, Subramanian Kyung Hee Oriental Medicine Research Center 2007 Oriental pharmacy and experimental medicine Vol.7 No.3

The present study was designed to estimate the protective effect of (-) epigallocatechin gallate (EGCG) on ethanol-induced liver injury in rats. Chronic ethanol administration (6 g/kg/day ${\times}$ 60 days) caused liver damage that was manifested by the elevation of markers of liver dysfunction - aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, lactate dehydrogenase, bilirubin and ${\gamma}$-glutamyl transferase in plasma and reduction in liver glycogen. The activities of alcohol metabolizing enzymes such as alcohol dehydrogenase and aldehyde dehydrogenase were found to be altered in alcohol-treated group. Ethanol administration resulted in the induction of cytochrome p450 and cytochrome-$b_{5}$ activities and reduction of cytochrome-c reductase and glutathione-S-transferase, a phase II drug metabolizing enzyme. Further, ethanol reduced the viability of isolated hepatocytes (ex vivo) as assessed by trypan blue exclusion test and induced hepatocyte apoptosis as assessed by propidium iodide staining. Treatment of alcoholic rats with EGCG restored the levels of markers of liver injury and mitigated the alterations in alcohol metabolizing and drug metabolizing enzymes and cyt-c-reductase. Increased hepatocyte viability and reduced apoptotic nuclei were observed in alcohol + EGCG-treated rats. These findings suggest that EGCG acts as a hepatoprotective agent against alcoholic liver injury.

(-) Epigallocatechin gallate restores ethanol-induced alterations in hepatic detoxification system and prevents apoptosis

Carani V Anuradha,Subramanian Kaviarasan 경희대학교 융합한의과학연구소 2007 Oriental Pharmacy and Experimental Medicine Vol.7 No.3

The present study was designed to estimate the protective effect of (-) epigallocatechin gallate (EGCG) on ethanol-induced liver injury in rats. Chronic ethanol administration (6 g/kg/day × 60 days) caused liver damage that was manifested by the elevation of markers of liver dysfunction - aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, lactate dehydrogenase, bilirubin and γ-glutamyl transferase in plasma and reduction in liver glycogen. The activities of alcohol metabolizing enzymes such as alcohol dehydrogenase and aldehyde dehydrogenase were found to be altered in alcohol-treated group. Ethanol administration resulted in the induction of cytochrome p450 and cytochrome-b5 activities and reduction of cytochrome-c reductase and glutathione-S-transferase, a phase II drug metabolizing enzyme. Further, ethanol reduced the viability of isolated hepatocytes (ex vivo) as assessed by trypan blue exclusion test and induced hepatocyte apoptosis as assessed by propidium iodide staining. Treatment of alcoholic rats with EGCG restored the levels of markers of liver injury and mitigated the alterations in alcohol metabolizing and drug metabolizing enzymes and cyt-c-reductase. Increased hepatocyte viability and reduced apoptotic nuclei were observed in alcohol + EGCG-treated rats. These findings suggest that EGCG acts as a hepatoprotective agent against alcoholic liver injury.

Fenugreek seed polyphenols inhibit RBC membrane Na⁺/K⁺-ATPase activity

Anuradha, Carani V.,Kaviarasan, Subramanian,Vijayalakshmi, Kodali Kyung Hee Oriental Medicine Research Center 2003 Oriental pharmacy and experimental medicine Vol.3 No.3

The hypoglycemic and hypolipidaemic effects of fenugreek seeds (Trigonella foenum graecum) are well established. Owing to the wide spread use of the seeds by healthy individuals and by diabetic patients we wanted to test whether the seeds can affect biological systems such as membrane transport function. In the present study fenugreek seed polyphenols were extracted and their effect on erythrocyte membrane-bound sodium-potassium adenosine triphosphatase $(Na^+/K^+-ATPase)$ activity was studied in vitro. Fenugreek seed polyphenols inhibited $Na^+/K^+-ATPase$ in erythrocyte membrane of diabetic and normal subjects. Maximum inhibition was observed at $100\;{\mu}l$ of extract containing 0.75 mM gallic acid equivalents. The uncoupling of membrane ATPases in vitro suggest that polyphenols from fenugreek seeds may possess a positive inotropic effect.

Dissipative analysis for network-based singular systems with non-fragile controller and event-triggered sampling scheme

Sakthivel, R.,Santra, S.,Kaviarasan, B.,Venkatanareshbabu, K. Pergamon Press [etc.] 2017 Journal of the Franklin Institute Vol.354 No.12

<P>This paper investigates the problem of dissipative based non-fragile controller for network-based singular systems with event-triggered sampling scheme. Based on the Lyapunov-Krasovskii functional approach which fully uses the available information about the actual sampling pattern, a new set of sufficient conditions is obtained to guarantee that the closed-loop network-based singular systems are regular, impulsive free, asymptotically stable and strictly (Q, S, R)-theta dissipative. Moreover, a design algorithm for the desired controller with event-triggered sampling scheme is formulated in terms of linear matrix inequalities. By solving an optimization problem with some inequality constraints, the explicit expression of the non-fragile controller gain matrix is characterized to achieve the required result. Finally, two numerical examples are provided to demonstrate the effectiveness and superiority of the proposed control design scheme. (C) 2017 The Franklin Institute. Published by Elsevier Ltd. All rights reserved.</P>

Synchronization and state estimation for stochastic complex networks with uncertain inner coupling

Sakthivel, R.,Sathishkumar, M.,Kaviarasan, B.,Marshal Anthoni, S. Elsevier 2017 Neurocomputing Vol.238 No.-

<P><B>Abstract</B></P> <P>This paper addresses the synchronization and state estimation problems for an array of coupled discrete-time stochastic complex networks (SCNs) with uncertain inner couplings in which time-varying delay is considered both in the network couplings and dynamical nodes. In particular, the uncertainties encountering in coupling terms are characterized by using the interval matrix approach. By constructing a suitable Lyapunov–Krasovskii functional and utilizing Kronecker product properties, a new set of sufficient conditions is established in terms of linear matrix inequalities to guarantee the synchronization of the addressed SCNs with a prescribed mixed <I>H</I> <SUB>∞</SUB> and passivity performance index. Moreover, the state estimation problem is then studied for the same SCNs with uncertain inner coupling strength and subsequently, the estimator is designed. More precisely, Schur complement, discrete-time Jensen’s inequality together with reciprocally convex combination approach are used to simplify the derivations in the main results. Finally, numerical examples are exploited to illustrate the effectiveness of the proposed synchronization and state estimation results.</P>