简介:Inthenormaloperationcondition,aconventionalsquare-rootcubatureKalmanfilter(SRCKF)givessufficientlygoodestimationresults.However,ifthemeasurementsarenotreliable,theSRCKFmaygiveinaccurateresultsanddivergesbytime.ThisstudyintroducesanadaptiveSRCKFalgorithmwiththefiltergaincorrectionforthecaseofmeasurementmalfunctions.Byproposingaswitchingcriterion,anoptimalfilterisselectedfromtheadaptiveandconventionalSRCKFaccordingtothemeasurementquality.Asubsystemsoftfaultdetectionalgorithmisbuiltwiththefilterresidual.Utilizingaclearsubsystemfaultcoefficient,thefaultysubsystemisisolatedasaresultofthesystemreconstruction.Inordertoimprovetheperformanceofthemulti-sensorsystem,ahybridfusionalgorithmispresentedbasedontheadaptiveSRCKF.Thestateanderrorcovariancematrixarealsopredictedbythepriorifusionestimates,andareupdatedbythepredictedandestimatedinformationofsubsystems.Theproposedalgorithmswereappliedtothevesseldynamicpositioningsystemsimulation.TheywerecomparedwithnormalSRCKFandlocalestimationweightedfusionalgorithm.ThesimulationresultsshowthatthepresentedadaptiveSRCKFimprovestherobustnessofsubsystemfiltering,andthehybridfusionalgorithmhasthebetterperformance.Thesimulationverifiestheeffectivenessoftheproposedalgorithms.
简介:MARPOL73/78的6个附则已全部生效,为使防污公约的履约工作得到有序、稳步推进,本刊特约请交通部环境保护中心顾问、教授、高级工程师、多年从事海洋环境保护、防止船舶污染水域监督管理工作的专家劳辉撰稿,就如何应对MARPOL73/78附则生效阐明他的观点。
简介:针对船舶动力系统润滑油水分检测耗时长的问题,根据润滑油导电性随含水率变化的特点,设计出基于电导传感器的润滑油水分在线、实时检测系统,系统通过获得电导传感器测量油水混合液的输出电压计算润滑油的含水率。该仪器主要包括电导传感器与激励源模块、单片机STM32F103C8模块、信号采集模块和液晶显示模块等构成。实验结果表明电导传感器润滑油水分检测系统能够准确、方便、快速地实现检测功能。
简介:教育部副部长袁贵仁在2005年12月4日举行的“中国高等教育学会后勤管理分会成立20周年庆祝大会暨高校后勤改革发展论坛”中指出:就全国而言,高校后勤社会化改革还远未完成,不少高校的后勤管理体制和运行机制还没有实现质的变化。后勤虽然已不是制约高等教育发展的“瓶颈”,但依然在较大程度上制约着高等教育的发展,后勤社会化的深入推进还面临着一系列困难。解决当前高校后勤中存在问题的根本出路,在于深化社会化改革。高校后勤社会化改革的目标,是要建立“市场提供服务,学校自主选择,政府宏观调控,行业自律管理,职能部门监管”的新型高校后勤保障体系,
简介:Acomplianttowerismodeledasapartiallydry,partiallytapered,dampedTimoshenkobeamwiththesuperstructuremodeledasaneccentrictipmass,andanon-classicaldampedboundaryatthebase.Thefoundationismodeledasacombinationofalinearspringandatorsionalspring,alongwithparallellinearandtorsionaldampers(Kelvin-Voigtmodel).Thesuperstructureaddstothekineticenergyofthesystemwithoutaffectingthepotentialenergy,therebyreducingthenaturalfrequencies.Theweightofthesuperstructureactsasanaxialcompressiveloadonthebeam,reducingitsnaturalfrequenciesfurther.Theemptyspacefactorduetothetruss-typestructureofthetowerisincluded.Theeffectofsheardeformationandrotaryinertiaareincludedinthevibrationanalysis;withthenon-uniformbeammode-shapesbeingaweightedsumoftheuniformbeammode-shapessatisfyingtheendcondition.TheweightsareevaluatedbytheRayleigh-Ritz(RR)method,andverifiedusingfiniteelementmethod(FEM).Theweightofthesuperstructureactsasanaxialcompressiveloadonthebeam.Kelvin-Voigtmodelofstructuraldampingisincluded.Apartofthestructurebeingunderwater,thevirtualaddedinertiaisincludedtocalculatethewetnaturalfrequencies.Aparametricstudyisdoneforvariousmagnitudesoftipmassandvariouslevelsofsubmergence.ThecomputationalefficiencyandaccuracyoftheRayleigh-Ritzmethod,ascomparedtotheFEA,hasbeendemonstrated.Theadvantageofusingclosed-formtrialfunctionsisclearlyseenintheefficacyofcalculatingthevariousenergycomponentsintheRRmethod.