介绍微型飞行器的飞行测试

FlightTestingAMicroAirVehicle

UsingMorphingForAeroservoelasticControl

MujahidAbdulrahim,HelenGarcia,GregoryF.Ivey,andRickLind

Microairvehiclesareableto yinenvironmentswithlittlemaneuveringroom;however,such ightre-quireshighagilityandprecisionmaneuvering.Acurrentclassofmicroairvehicleisconstructedwithonlyrudderandelevatorforcontrolauthority.Suchsurfacesarenotoptimalfor ightcontrolbutaileronscannotbeinstalledonthemembraneusedforwingsonthesevehicles.Morphingisusedasanaeroservoelasticeffectorforcontrol.Vehiclesareconstructedusingthreadstocommandacurlofthewingsandusingtorquerodstocommandatwistofthewings.Ineachcase, ighttestsdemonstratetheactuationcausessuf cientdeformationofthewingtoresultinsigni cantcontrolauthority.The ightdynamicsshowturnsandspinscanberepeatedlyperformedusingthisaeroservoelasticcontrol.

I.Introduction

Microairvehicles(MAV)arerapidlygainingattentioninthe ighttestcommunity.Thesmallsizeandlightweightofthesevehiclesmakethemespeciallyattractiveforsomemissions.Thevehiclesarequiteportablesomaybeeasilytransportedtoremotelocations.AMAVisinherentlystealthybecauseofitssizeandquietbecauseofitselectricpropulsion.Furthermore,manytypesofsensorsarebeingminiaturizedandwould twithinthepayloadcapabilitiesofaMAV.

Someareasofoperation,suchasurbanenvironments,requireavehiclethatissmallbutalsoextremelyagile.Agilityisobviouslyneededsothevehiclecanmaneuverwithinsmallareasandbetweenobstaclesinadenseenviron-ment.Thevehiclemustalsobehighlyresponsivetorejectdisturbanceslikewindgustswhichmaybeconsiderablenearbuildings.

Theconceptofaeroservoelastictailoringthroughmorphingisbeingstudiedforcontrolonmanyvehicles.Thebasicconceptofthisapproachinvolvesactivelychangingtheshapeofavehicletoaffecttheaerodynamicsand,con-sequently,the ightdynamics.Suchcontrolinherentlyusesthecontrolandactuationthroughthestructuraldynamicstoaffecttheaerodynamicsasanaeroservoelasticsystem.Theresultingsystemhasdif cultdynamicssodesignandanalysisofaeroservoelasticcontrolisachallenge.1

Controlthroughaeroservoelasticity,whilenotcommon,iscertainlynotanewconcept.5ThemostfamousexampleisarguablythewingtwistingusedbytheWrightbrotherstooperatetheir ier.Academicstudieshavemainlyfocusedon uttercontrolbutseveralexamplesofmaneuveringdesignhaveincludedtheuseofdynamicinversion2androbust-ness3toaccountfortheaeroservoelasticdynamics.Inpractice,thedesignisoftenlimitedtosimplyformulatingnotch lterstoavoidinstabilitiesbutretainlow-frequencyperformance.4TheActiveAeroelasticWingprojecthasprobablybeenthe rstaircrafttodirectlyrequiredesignofanaeroservoelasticcontroller.15

Morphinghasmorerecentlybeenconsideredaviablemethodofcontrol.6Theapproachtochangetheshapeofavehiclewillclearlyaffectthe ightdynamicsandstaticpropertiessuchasliftanddrag.Issuesremaintobestudied

AmericanInstituteofAeronauticsandAstronautics