简介:ThispaperpresentsanewPulseWidthModulation(PWM)controllerforUnmannedAerialVehicle(UAV)precisionsprayerforagricultureusingaTL494fixed-frequencypulsewidthmodulatortogetherwithadataacquisitionboardanddevelopedsoftware.AnUAVcanberemotelycontrolledorflownautonomouslybypre-programmedflightplans.ThePWMcontrollerwasimplementedthroughtheguidancesystemontheUAVwithcontrolcommandssentbetweentheUAVhelicopterandthegroundcontrolstationviaawirelesstelemetrysystem.ThePWMcontrollerwastestedandvalidatedusingLabVIEW8.2.Severalanalyseswereperformedinalaboratorytotestdifferentcontrolsignals.TheresultsshowthatthePWMcontrollerhaspromiseasahigherprecisiontechniqueforsprayapplications,whichwillimproveefficiencyofpesticideapplication,especiallyincropproductionareas.
简介:Thepropertyofsiliconmicro-capacitiveaccelerometerisanalyzedanddiscussedbyestablishingthemodelofthesensor,tolayabasisforoptimizationdesignofsensorsystemstructure.Discussedissuesincludethestaticmodelinganddynamicbehaviorofthetwocommnlyusedstructures,i.e.,double-cantileversupportedandfour-beamsupportedstructures,andalsothemeasurementrangeofthesedevices.