简介：TheproblemofdistributedcoordinatedtrackingcontrolfornetworkedEuler-Lagrangesystemswithoutvelocitymeasurementsisinvestigated.Undertheconditionthatonlyaportionofthefollowershaveaccesstotheleader,slidingmodeestimatorsaredevelopedtoestimatethestatesofthedynamicleaderinfinitetime.Tocopewiththeabsenceofvelocitymeasurements,thedistributedobserverswhichonlyusepositioninformationaredesigned.Basedontheoutputsoftheestimatorsandobservers,distributedtrackingcontrollawsareproposedsuchthatallthefollowerswithparameteruncertaintiescantrackthedynamicleaderunderadirectedgraphcontainingaspanningtree.Itisshownthatthedistributedobserver-controllerguaranteesasymptoticalstabilityoftheclosed-loopsystem.Numericalsimulationsareworkedouttoillustratetheeffectivenessofthecontrollaws.