Fault-tolerantControlSystems—AnIntroductoryOverview

？Thispaperpresentsanintroductoryoverviewonthedevelopmentoffault-tolerantcontrolsystems.Forthisreason,thepaperiswritteninatutorialfashiontosummarizesomeoftheimportantresultsinthissubjectareadeliberatelywithoutgoingintodetailsinanyofthem.However,keyreferencesareprovidedfromwhichinterestedreaderscanobtainmoredetailedinformationonaparticularsubject.Itisnecessarytomentionthat,throughoutthispaper,noeffortsweremadetoprovideanexhaustivecoverageonthesubjectmatter.Infact,itisfarfromit.Thepapermerelyrepresentstheviewandexperienceofitsauthor.Itcanverywellbethatsomeimportantissuesortopicswereleftoutunintentionally.Ifthatisthecase,theauthorsincerelyapologizesinadvance.Afterabriefaccountoffault-tolerantcontrolsystems,particularlyontheoriginalmotivations,andtheconceptofredundancies,thepaperreviewsthedevelopmentoffault-tolerantcontrolsystemswithhighlightstoseveralimportantissuesfromahistoricalperspective.Thegeneralapproachestofault-tolerantcontrolhasbeendividedintopassive,active,andhybridapproaches.Theanalysistechniquesforactivefault-tolerantcontrolsystemsarealsodiscussed.Practicalapplicationsoffault-tolerantcontrolarehighlightedfromapracticalandindustrialperspective.Finally,somecriticalissuesinthisareaarediscussedasopenproblemsforfutureresearch/developmentinthisemergingfield.