Twofields
Thetermremotemonitoringhastwomeanings.Boththecomputerfieldandthevideosurveillancefieldhavethetermremotemonitoring,butthemeaningiscompletelydifferent.
Computerfield
Remotemonitoringcanbeliterallydividedinto"monitoring"and"control".Amongthem,"monitoring"isremotemonitoring,whichcanbedividedintotwoparts.:Oneisthemonitoringoftheenvironment,andtheotheristhemonitoringofcomputersystemsandnetworkequipment.Inanycase,remotemonitoringreferstotheacquisitionofinformationthroughthenetwork;and"control"referstoremotecontrol,whichreferstotheremotecomputerthroughthenetworkThemethodofoperationincludesnotonlyrestartingandshuttingdowntheremotecomputer,butalsodailysettingoftheremotecomputer.Thefunctionofremotebootcanalsoberealizedthroughthecooperationofhardware.Allinall,ifyouwanttofullycontrolaremotecomputer,youshouldfirstbeabletomonitorit,thatis,youcanseethecomputer'sscreendisplay,andthenyoucantalkabout"control".Theremotecontrolmustbe"monitored"and"control".Combination,sowhatweusuallycallremotemonitoringgenerallyreferstothiskindofremotecontrol.Inaddition,fornetworkadministrators,remotecontrolalsoincludesthecontrolofnetworkdevices.Nowadays,mostnetworkdevicessupportTelnetandevenmanagethemremotelyviaWeb.Thisisalsoaremotecontrolmethod.
Videosurveillancefield
RemotesurveillanceinthefieldofvideosurveillancereferstotheconnectionofvideosurveillanceequipmenttotheInternettoenableviewingofremotevideoimagesthroughterminaldevicessuchascomputersormobilephones.Therearemanywaystoaccess,suchasportmapping,accessthroughipaddress;viewingthroughdomainnameresolution.
Workingprinciple
Forthefieldofvideosurveillance,thegeneralworkingprincipleisasfollows.
First,thevideosignalfromeachcameraisinputtothevideocaptureterminal,andthenthevideocaptureterminalusesanimagecompressionalgorithmtoconvertthevideosignalintoa25frame/seconddigitalimage,andthecompressedTheaudioandvideodatastreamisforwardedtothevideomonitoringcenterthroughthenetwork;finally,themonitoringcomputerofthevideomonitoringcenterdecompressesthereceivedimageandsounddatafromthefrontendandperformsreal-timemonitoringthroughthecomputerdisplayscreenandsoundcard.
Whenanalarmoccurs,thealarmdecoderwilllinkthealarmoutputdevice,andinputthealarmsignalintothevideoterminalthroughthealarmdecoder,andtransmitittothemonitoringcenter.ThevideoserverofthemonitoringcenterimmediatelyreceivesthealarmsignalSendoutsoundsignals,recordalarmevents,andperformalarmoperationssuchasharddiskvideorecording.
Controlsignalssuchascameracontrolandarmingaretransmitteddownstream.Themonitoringcentermonitorhostsendsoutvariouscontrolsignals.Afterreceivingthecontrolsignals,thevideocaptureterminalcontrolsthecamerathroughthepan-tiltlenscontrollerordirectly.Orcompletethearmingoperation.
Thesystemadoptshardwarecompressionandsoftwaredecompressiontechnology,andthecorrespondingsoftwareisaddedtothecomputerterminaloftherelevantdepartmentortheWebfunctionoftheIEbrowserthatcomeswithWindowscanrealizetheremotevideomonitoringfunction,andsetitasvideomonitoring.workstation.
NetworkcommunicationadoptsTCP/IPandnetworkmulticast(Multicast)technologytomaximizetheuseofnetworktransmissionperformanceandnetworkbandwidth,andavoidnetworkcongestion.
Theremotevideomonitoringsystemiscomposedofsystemsub-stationsanddispatchingcentermasterstation.Thesystemsub-stationsaresetupinsubordinatecoalmines,powerplants,andsubstationsthatneedtobemonitored.Theyaremainlycomposedofvideocollectionterminals,computernetworkconnectionequipment,cameras,alarmprobes,alarmdecoders,etc.,andareresponsibleforthecollectionofaudioandvideosignalsandalarmsignals.Anddigitization,andusetheexistingcomputernetworktorealizethevideo/alarminformationtransmissionandremotemonitoringbetweenthesitesandthedispatchcenter.Themainstationofthemonitoringanddispatchingcenterismainlycomposedofvideomanagementserver,browser,computernetworkconnectionequipment,remotemonitoringandvideoserversoftware.Themonitoringcentercanmanagemultiplecollectionstationsthroughthenetwork,andcanswitchandcontroltoanymonitoringpointsitetoimplementoverallmonitoring,therebyrealizingvideomonitoringoftheentirearea.Throughthenetwork,itcannotonlybrowsethelivevideoofeachmonitoringpointinrealtime,butalsoremotelyaccessthevideofilesofthecollectionstation,downloadthevideofiles,andcanalsorecordinthemonitoringcenter.
Remotevideosurveillancesystemsgenerallycanadapttodifferentcommunicationnetworks,whichcanbeEthernet,E1,wirelessLANorothertransmissionchannels.
Sub-stationcollectionterminal
Thevideocollectionterminalprovidesvideoandaudioinput/outputinterfaces,whicharerespectivelyconnectedtothecameravideooutputormulti-screenprocessor,pickupsandspeakers;generallyprovideseveralTheinterfaceisconnectedwiththemonitoringterminalandserver;itmainlyrealizesthecollectionandcompressionofvideoandaudiosignals,andsendsthecompresseddatatothemonitoringcenterthroughthenetwork.
Collectionterminalcomposition
1.Videocaptureterminal
2.ScreenSplitter
3.Integratedcameraorothervariouscameras
4.Variousalarmsensorsandalarmequipment
5.Alarmdecoder
6.PTZandPTZdecoder
Collectionterminalfunction
1.Imageacquisition,recordingandremotetransmission;
2.Collectvariousalarmsignals,realizealarmlinkageandtransmitthemtothemonitoringcenterofthecentralizedcontrolstation;
3.ControlthemovementofPTZandlens;
4.Controlthematrixswitchertoswitchvideoimages;
5.Receiveremotecontrolcommandstocontrolpan-tiltrotation,lensmovementandalarmdeviceoutput
MonitoringCenter
Themonitoringcenterconsistsofacentralimageprocessingserver,imagemonitoringterminal,imageprocessingsoftware,andremoteVideomonitoring/networkingalarmsoftwareisusedtoreceiveimagesandalarmsignalstransmittedfromthescene,promptingsecuritypersonneltotakevariousmeasures,andcanrealizeremotecontrolofmatrix,camera,PTZandremotelinkagecontrol,andremoterecordingisalsopossibleFiledownload,imageretrievalanddigitalvideoplaybackandotheroperations.
Thecentralimagemanagementserverisusedtomanagethetransmissionandstorageofimages.Themanagementserverisequippedwithsystemmanagementdatabase,systemmanagementsoftwareandmonitoringterminalmodules,whichplayaroleinthemanagementandserviceoftheentiresystem..
Monitoringfunction
1.Receivevideodigitaldatafromthecollectionstation,replayandforwarditinrealtime;
2.Canrealizeremotecontrol;
3.Receivethealarmsignalfromeachcollectionstationandsendittothemanagementserver;
4.Configureandstoretheconfigurationinformationofeachcollectionworkstation,andmanagesystemusersanduserpermissions;
5.Theconsolecanissuecontrolcommandstoanycollectionstation,suchaspan-tiltmovement,imageswitching,etc.;
6.Providehistoricalvideoqueryandplaybackfortheconsolecomputerordispatchcenterclients;
7.Displaytheimageofanycameraonthescreenwall,andcanswitch;
8.ProvideWEBvideostreamingservicesfornetworkusers;
9.Realizethevideoconferencingfunctionwithafunctionalcomputerinthesystem
Theanti-interferencedesignofthecablewiringisbasedonthesystem’sspecialrequirementsforcableflameretardancyandfireprotection.Generally,allflameretardantshieldedcablesmustbeselected,andtheycanbeusedforhigh-voltageelectromagneticfields.Playagoodshieldingrole.Inaddition,theoutdoorburiedcablesarecoveredwithhot-dipgalvanizedpipes,theordinarycablesinthecabletrencharecoveredwithPVCpipes,andtheindoorcablesarecoveredwithPVCgrooves,sothatthesystemcancompletelyeliminatesomeinterferencessuchashighelectricfieldsandhighmagneticfieldsinahigh-voltageenvironment.Theimpactoffactorsonthesystem.
Compositionandfunction
Thesystemgenerallyconsistsofthreeparts:front-endequipment,imageprocessingandtransmissionequipment,andnetworkclient.
Thefront-endequipmentconsistsofcameras,pan-tilts,decoders,protectivecovers,brackets,alarmdetectors,pickups,etc.,responsibleforthecollectionofvideosignals,audiosignalsandalarmsignals;
Theimageprocessingandtransmissionequipmentinthesystemisanetworkvideoserver,whichisresponsiblefortransmittingaudio,videosignalsandalarmsignalstoaremoteclientthroughalocalareanetworkorwideareanetwork,andcanreceivePTZcontrolsignalsandaudiointercomsignalssentbytheclientatthesametime;
Thenetworkclientreferstotheuserterminalthatneedstoperformnetworkremotemonitoring.Itconsistsofacomputer(ordinaryofficecomputerorlaptop)andclientsoftware.Theclientismainlyresponsibleforfunctionssuchasimagedisplay,videorecording,playback,andPTZcontrol.Whentheclientperformsremotemonitoring,itneedstoenterausernameandpasswordforidentityverification,andremotemonitoringcanberealizedafterpassingtheauthentication.
Monitoringstatus
Systemfunctions
Therearetwotypesofremotemonitoringsystems.Oneisthatthereisnoon-sitemonitoringsystemattheproductionsite,butdirectlyafterdatacollection.Sendtoaremotecomputerforprocessing.Thiskindofremotemonitoringisnotmuchdifferentfromgeneralon-sitemonitoring,exceptthatthedatatransmissiondistanceisfartherthantheon-sitemonitoringsystem,andtheotherpartsarethesameastheon-sitemonitoringsystem;theotherison-sitemonitoringandremotemonitoringcoexist.Generally,fieldbustechnologyisusedtoconnectthesensors,monitoringequipment,etc.distributedineachdevice,sothatitenterstheintegratedunitstagefromthediscreteunitstage,andthentheservicesofeachmanagementsiteareconnectedwiththelocalareanetwork,thusformingtheinternalenterpriseNetwork(Intranet).Duetotheestablishmentofabasicnetworkinformationinfrastructure,equipmentmonitoringandmaintenancetechnologyhasenteredtheintegratedsystemstage,andresourcesandinformationsharingarebasicallyrealizedwithinaunit.
Thefunctionsrealizedbyremotecontrolareasfollows:
Samplingandprocessingfunctions:mainlydetecting,samplingandnecessarypreprocessingofvariousanalogordigitalquantitiesintheproductionprocess,andOutputincertainforms,suchasprintreports,displayscreensandTVs,toprovideproductionpersonnelwithdetaileddatatohelpthemanalyzeandunderstandtheproductionsituation;
Supervisionfunction:real-timedatadetected,Inaddition,theinstructionsandinputdataissuedbytheproductionpersonnelduringtheproductionprocessareanalyzed,summarized,sorted,calculatedandothersecondaryprocessing,andstoredasreal-timedataandhistoricaldatarespectively;
Managementfunctions:Useexistingvaliddata,images,reports,etc.toanalyzeworkingconditions,diagnosefaults,andpredictdangeroussituations,andalarmfaultsandemergenciesintheformofsoundandlight;
Controlfunction:Informationprocessingiscarriedoutonthebasis,andcontroloutputisformedaccordingtothecontrolstrategydecidedinadvance,whichdirectlyaffectstheproductionprocess.
TheremotemonitoringsystembasedonB/SandC/Sisamonitoringsystemthatusesthenetworkasacommunicationplatform.ItisbasedonHTTPtechnologyandhastheadvantagesofsimplicityandhighefficiency.Ithasbecomeoneofthemostadvancedinformationnetworks.Commonlyusedinformationinteractionplatform[2].UsingnetworkcommunicationtechnologySockettechnology,dataacquisitiontechnologyandobject-orientedsoftwaretechnologytorealizethesystemmanagement,usermanagement,equipmentmonitoringdatadisplayandalarmmodulesoftheentiresystem.Itsadvantageisthatitmakesfulluseofexistinglocalareanetworkresourcesandwideareanetworkresources.,Withthehighestprice-performanceratio,real-timeinformationacquisitionandreal-timecontrolasthecenter,torealizethecomprehensivesharingofinformation,resourcesandtasksandtheoverallmanagementofintegration.Forexample:themonitoringsystemprovidestheoperationstatusoftheequipmenttotheserver,andtheserversendsittotheclientsofeachnode.Thestaffcanunderstandtheworkingstatusandoperationstatusoftheentiresystemontheclientside(usuallyremote).Simplyput,forenterprises,itistomakefulluseofmoderntechnologytosolvetheproblemsofreal-timedatacollection,transmissionandprocessing,andreal-timecontrol.Itistheseadvantagesthatmakeitdeveloprapidly.
Withthecontinuousdevelopmentofnetworktechnology,remotemonitoringwillbemoreusedinthemanagementoftheproductionprocessofenterprises.ProfessionalandtechnicalpersonnelcanmanageandmaintaintheproductionprocessthroughtheInternet,optimizetheproductionprocess,andimprovetheequipmentTheavailabilityratewillultimatelyreduceproductioncostsandimproveefficiency.
Systemadvantages
Withthehelpofremotemonitoring,thecompany’sinternalinformationnetwork(Intranet)andcontrolTheoperationstatusiscloselyintegratedwiththebusinessmanagementstrategyoftheenterprise,soastorealizethecomprehensiveautomationoftheenterprise,andtoestablishanetwork-widemonitoringdataandonlineknowledgeresourcedatabase.Throughremotemonitoring,real-timecollectionandrapidconcentrationofon-siteoperatingdatacanbeachieved,andon-sitemonitoringdatacanbeobtained,whichprovidesamaterialbasisforremotefaultdiagnosistechnology;throughremotemonitoring,technicianscanmonitorandcontroltheproductionsystemwithoutvisitingthesiteorharshenvironments.Andtheoperatingstatusandvariousparametersofthefieldequipment,sothattheprofessionallytrainedpersonnel.virtual.Inmanymonitoringlocations,itisconvenienttousetherichlocalsoftwareandhardwareresourcestoperformadvancedprocesscontrolonremoteobjectstomaintainthenormaloperationoftheequipment,therebyreducingthenumberofpersonnelonduty,andultimatelyachievingremoteunmannedorfewpersonnelonduty.Thepurposeofdownsizingandincreasingefficiency[3].
Moreandmoreenterprisegroupsareshowingacross-regionaldevelopmenttrend,usingnetworktechnologytorealizeremotemonitoring,reducingproductioncostsforenterprises,increasinglaborproductivity,increasingthetechnologicalcontentofenterpriseproducts,andenhancingenterpriseintegrationCompetitivestrengthandotheraspectsareofgreatsignificance.
Technicalissues
Withtherapiddevelopmentofnetworktechnologyandtheexpansionofmonitoringscope,themonitoringsystemhastransitionedfromsingle-machinemonitoringtonetworkmonitoringinthepast,buttherearestillsomeproblems.Firstofall,theproblemofinsufficientnetworkcommunicationtechnology.Networkcommunicationtechnologyisthemostcriticaltechnologyinremotemonitoringtechnology.However,networkcommunicationgenerallysimplyusesSockettechnology,evenFTPorEmail,etc.Thesetechnologieshavegreatadvantagesintermsoftheamountofdatatransmitted,theflexibilityofprogramming,andthesecurity.Theshortcomings,especiallyforthedatacollectionofmultipleendpointsinthefield,willgreatlyincreasethecomplexityofprogrammingandcannotmeettheneedsofremotemonitoringtechnologyfornetworkcommunication;secondly,thecoexistenceofmultiplestructuresinnetworkcommunication.Thestructureoftheremotemonitoringsystemismostlycomplex,andthedistributeddistanceislong.Therearealsodifferentlocalareanetworks,differentplatforms,andeventheoperatingplatformandprogramminglanguageinthesamelocalareanetwork.Theremaybedifferentproblems,whichrequiresdifferentplatformsintheintegratednetwork.Toachievemutualcommunication,andtheseproblemsaredifficulttosolveusingtraditionalmethods.
Systemdevelopment
Videosurveillancesystemhasdevelopedinjusttwodecades,analogsurveillanceishot,anddigitalsurveillanceisintheascendantofnetworkvideosurveillance.Earth-shakingchanges.AsIPtechnologygraduallyunifiestheworldtoday,itisnecessaryforustore-understandthehistoryofthedevelopmentofvideosurveillancesystems.Fromatechnicalpointofview,thedevelopmentofvideosurveillancesystemsisdividedintothefirstgenerationofanalogvideosurveillancesystems(CCTV),tothesecondgenerationofdigitalvideosurveillancesystems(DVR)basedon"PC+MultimediaCard",tothethirdgenerationofvideosurveillancebasedentirelyonIPnetworksSystem(IPVS).Thefirstgenerationofvideosurveillance:thetraditionalanalogclosed-circuitvideosurveillancesystem(CCTV):reliesonspecialequipmentsuchascameras,cables,videorecordersandmonitors.Forexample,thecameraoutputsavideosignalthroughadedicatedcoaxialcable.Thecableisconnectedtodedicatedanalogvideoequipment,suchasvideoscreensplitter,matrix,switcher,videocassetterecorder(VCR)andvideomonitor,etc.AnalogCCTVhasalotoflimitations:limitedmonitoringcapabilitiesonlysupportlocalmonitoring,whichislimitedbyanalogvideocabletransmissionlengthandcableamplifiers.Scalability-limitedsystemsareusuallylimitedbytheinputcapacityofvideosplitters,matrices,andswitchers.
Userswithheavyvideoloadsmustremovethemfromthevideorecorderorreplacethemwithnewvideotapesforstorage,andthevideotapesarepronetobelost,stolenoraccidentallyerased.
Poorvideorecordingqualityisthemainlimitingfactor.Thevideoqualitydecreasesasthenumberofcopiesincreases.
Thesecondgenerationofvideosurveillance:Thecurrent"analog-digital"surveillancesystem(DVR):videosurveillance
The"analog-digital"surveillancesystemisbasedonDigitalharddiskvideorecorderDVRisthecoresemi-analog-semi-digitalsolution.FromthecameratotheDVR,thecoaxialcableisstillusedtooutputvideosignals.TheDVRsupportsbothrecordingandplayback,andcansupportlimitedIPnetworkaccess.BecauseDVRproductsarediverseandthereisnostandard,Therefore,thisgenerationofsystemsisanon-standardclosedsystem,andtheDVRsystemstillhasalotoflimitations:
Thecomplexwiring"analog-digital"solutionstillneedstoinstallaseparatevideocableoneachcamera,resultinginwiringcomplexity.ThetypicallimitationofaDVRwithlimitedscalabilityisthatitcanonlyextendupto16camerasatatime.
LimitedmanageabilityYouneedexternalserversandmanagementsoftwaretocontrolmultipleDVRsormonitoringpoints.
Limitedremotemonitoring/controlcapabilitiesYoucannotaccessanycamerafromanyclient.YoucanonlyaccessthecameraindirectlythroughtheDVR.TheriskofdiskfailureComparedwithRAIDredundancyandtape,the"analog-digital"schemehasnoprotectionforvideorecordingandispronetoloss.Thethirdgenerationofvideosurveillance:thefuturecompleteIPvideosurveillancesystemIPVS:
Comparedwiththeprevioustwosolutions,therearesignificantdifferencesbetweentheall-IPvideosurveillancesystem.Theadvantageofthissystemisthatthecamerahasabuilt-inwebserveranddirectlyprovidesanEthernetport.ThesecamerasgenerateJPEGorMPEG4datafiles,whichcanbeaccessed,monitored,recordedandprintedbyanyauthorizedclientfromanylocationonthenetwork,ratherthangeneratingimagesintheformofcontinuousanalogvideosignals.