液位实时自动跟踪测量系统.pdf

第24卷第10期传感技术学报Vol．24No．10
2011年10月CHINESEJOURNALOFSENSORSANDACTUATORSOct．2011

AutomaticMeasuringSystemforHighPrecisionMeasurmentonHeightofWater*

XUChi1，SUNChangku1*，WANGPeng1，JIAWeiguang2
()1．StateKeyLaboratoryofPrecisionMeasuringTechnologyandInstruments，TianjinUniversity，Tianjin300072，China;
2．NationalCenterofOceanographicStandardsandMetrology，Tianjin300112，China

Abstract:InconsIderatIonofthetradItIonalmeasurementmethodfortheheIghtofwaterwIthloweraccuracyand
slowermeasurIngspeedandsmallmeasurIngscale，asetofheIghtmeasurIngsystembasedondIgItalImageprocess
theoryIsdesIgned．ThIssystemprocessestheImagesofrulerandwatertubecapturedfromCCDcamerabythree
stepstocompletethemeasurIngtask，thatIs:recognItIonofrulernumber;IdentIfIcatIonofrulerscrIbedlIne;recognI-
tIonofwaterlevel，thencontrolofthemotorattachedwIththeCCDcameraupordowntoadjusttheposItIonofCCD
cameratocompletereal-tImetrackIngmeasurement．DurIngtherecognItIonofrulernumber，thIssystemusesthe
NCC(NormalIzedCrossCorrelatIon)templatematchIngmethodwIthrespecttotherobustnessofalgorIthmandsta-
bIlItyofthemeasurIngsystem．AstotheIdentIfIcatIonofrulerscrIbedlIneandrecognItIonofwaterlevel，thIssystem
makesfulluseofthegrayfeaturesoftheImageandstructurecharacterIstIcsoftheruler．TheexperImentalresults
showthatthIssystemhassuperIorperformanceoverthemeasurementoflargescalewaterlevelwIthgoodrobustness
andItcouldcompleteameasurementwIth0．1mmaccuracy，soItcanbeusedInwater-levelmeasurementrequIred
hIghaccuracy．
Keywords:Imageprocess;real-tImemeasurementoflIquIdlevel;recognItIonofrulerCalIbratIon-value;recognItIon
ofrulerscrIbedlIne;templatematchIng
EEACC:7210A;7210X;7230Gdoi:10．3969/j．issn．1004－1699．2011．10．027

液位实时自动跟踪测量系统*

徐驰1，孙长库1*，王鹏1，贾伟广2
()1．天津大学精密测试技术及仪器国家重点实验室，天津300072;
2．国家海洋标准计量中心，天津300112

摘要:针对传统液位测量方法的精度低、速度慢、测量范围受限制等问题，设计了一套基于视觉图像处理的高精度、快速的
液位自动测量系统，它适用于测量范围大、液位变化速度快的实时液位测量。该系统以CCD摄像机采集的液位和钢尺图像为
基础，通过钢尺刻度识别、钢尺刻线及液位识别三大识别模块完成液位高度测量，根据液位高度反馈控制电机带动CCD相机
跟随液位实现实时自动跟踪测量。为了提高算法的识别速度，增强算法的鲁棒性，该系统采用了NCC(NormalIzedCrossCorre-
latI