简介:Recentresultsonthedevelopmentofanavigationsystemforasmartwheelchairarepresentedinthispaper.Inordertoreducethedevelopmentcost,amodularsolutionisdesignedbyusingcommercialandlowcostdevices.Thefunctionalitiesofthetrackingcontrolsystemaredescribed.Experimentalresultsoftheproposedassistivesystemarealsopresentedanddiscussed.
简介:Inaerialrobots’visualnavigation,itisessentialyetverydiffculttodetecttheattitudeandpositionoftherobotsoperatedinrealtime.Byintroducinganewparametricmodel,theproblemcanbereducedfromalmostunmanageabletobepartlysolved,thoughnotfully,aspertherequirement.Inthisparametricapproach,amulti-scaleleastsquaremethodisformulatedfirst.Bypropagatingaswellasimprovingtheparametersdownfromlayertolayeroftheimagepyramid,anewglobalfeaturelinecanthenbedetectedtoparameterizetheattitudeoftherobots.Furthermore,thisapproachpavesthewayforsegmentingtheimageintodistinctparts,whichcanberealizedbydeployingaBayesianclassifieronthepicturecelllevel.ComparisonwiththeHoughtransformbasedmethodintermsofrobustnessandprecisionshowsthatthismulti-scaleleastsquarealgorithmisconsiderablymorerobusttonoises.Somediscussionsarealsogiven.
简介:Toimprovethereliabilityandaccuracyoftheglobalpositioningsystem(GPS)/microelectromechanicalsystem(MEMS)inertialnavigationsystem(INS)integratednavigationsystem,thispaperproposestwodifferentmethods.Basedonwaveletthresholddenoisingandfunctionalcoefficientautoregressive(FAR)modeling,acombineddataprocessingmethodispresentedforMEMSinertialsensor,andGPSattitudeinformationisalsointroducedtoimprovetheestimationaccuracyofMEMSinertialsensorerrors.ThenthepositioningaccuracyduringGPSsignalshortoutageisenhanced.ToimprovethepositioningaccuracywhenaGPSsignalisblockedforlongtimeandsolvetheproblemofthetraditionaladaptiveneuro-fuzzyinferencesystem(ANFIS)methodwithpoordynamicadaptationandlargecalculationamount,aself-constructiveANFIS(SCANFIS)combinedwiththeextendedKalmanfilter(EKF)isproposedforMEMS-INSerrorsmodelingandpredicting.Experimentalroadtestresultsvalidatetheefficiencyoftheproposedmethods.
简介:The‘FreedomofNavigation'issuehasbeenvolatileandofteninfluencedbySino-USrelationsinrecentyears.ThisproblemwasrootedindifferentinterpretationoftheUNCLOSbyChinaandtheUS.IthasalsoreflectedtheirdifferentnationalInterestsandmaritimestrategies.Thisissuehascausedfrequentfrictionsbetweenthetwosidesandmayleadtotheirfuturecontestforseapower.Atthesametime,italsourgesthebothsidestosetupnewmechanismforconfidencebuildingthatmayhelpthemtomanageitinamorerationalway.
简介:-BasedonthefeasibilitystudyofdevelopingthenavigationresourcesoftheGuanheRiverandthemodeltestresultsofthemouthbarregulation,thispaperpresentssomebasicprinciplesfortheregulationofthechannelonthemouthbar,forinstance,thedirectionofnavigationchannelshouldbeidenticalwiththatoftheebbtidecurrentandthemainwaves,andperpendiculartothebathymetriccontours.Theprinciplesforregulatingmouthbarsarealsodiscussedinthispaper.
简介:Thecapabilityandreliabilityarecrucialcharacteristicsofmobilerobotswhilenavigatingincomplexenvironments.Theserobotsareexpectedtoperformmanyusefultaskswhichcanimprovethequalityoflifegreatly.Robotlocalizationanddecisionmakingarethemostimportantcognitiveprocessesduringnavigation.However,mostofthesealgorithmsarenotefficientandarechallengingtaskswhilerobotsnavigatethroughcomplexenvironments.Inthispaper,weproposeabiologicallyinspiredmethodforrobotdecision-making,basedonrat’sbrainsignals.Rodentsaccuratelyandrapidlynavigateincomplexspacesbylocalizingthemselvesinreferencetothesurroundingenvironmentallandmarks.Firstly,weanalyzedtherats’strategieswhilenavigatinginthecomplexY-maze,recordedlocalfieldpotentials(LFPs),simultaneously.TherecordedLFPswereprocessedanddifferentfeatureswereextractedwhichwereusedastheinputintheartificialneuralnetwork(ANN)topredicttherat’sdecision-makingineachjunction.TheANNperformancewastestedinarealrobotandgoodperformanceisachieved.Theimplementationofourmethodonarealrobot,demonstratesitsabilitiestoimitatetherat’sdecision-makingandintegratetheinternalstateswithexternalsensors,inordertoperformreliablenavigationincomplexmaze.
简介:-Thispaper,afterbrieflyreviewingtheexperimentalresearchonsedimenttransportonmuddybeachsincethe1950s,improvesandperfectsthemethodforforecastingsiltationinnavigationchannelsandharbourbasinswhichwasfirstputforwardinChinabytheauthors.Inconsiderationofsiltysedimentandsand,somefactorsinforecastingmethodshavebeenchangedandmodified.Consequently,themodifiedmethodscanbeusedeithertocomputesiltationinnavigationchannelsandharbourbasinsonmuddybeachortocomputesiltationandscouringinnavigationchannelsandharbourbasinsonbothsiltybeachandsandybeach.Theverificationoffielddatafromelevenlarge,mediumandsmallnaturalharboursshowsagoodagreementbetweentheforecastingbythemodifiedmethodandthenaturalconditions.Finally,thepaperdealswiththerationalutilizationofwaterareaaftertheconstructionoftheWestDykeinLianyungang,themaintenanceofwaterdepthofthenavigationchannelattheentrance,siltationdistribution,siltationinthenavigationchannelandharbourbasinforshipsof100thousandtonnnage.ResultsonceagainprovethattheprospectofconstructingLianyungangHarbourintoadeepwaterharbourisbright.
简介:SeveralfiltertechniqueswereavailablefortheGPSpositionestimationproblemofmaneuveringvehiclerangingfromusingdifferentprocessnoisestoInteractiveMultipleModel(IMM).ThelimitationofusingstandardKalmanfiltersislisted.Theperformanceofproposedadaptivefilteriscomparedwiththatofthestandardones,twotypesofdynamicmodelingofthemaneuveringvehicleareused.ThesimulationisbasedonthealmanacdataoftheGPSsatellitestocomputeitsfeasibilityduringthesimulationtimeandpositiononshape8trackwithcontinuousvehiclemaneuvering.Thegoalistoobtaincomputationallyefficientfilterwithreasonableaccuracyforvehicleinmaneuveringsituation.ThefilterproposedisanalternativetothefilterproposedinRef.[1]withlowcomputationalburden.