Abstract. Thispaperintroducesadesignandimplementationofelectrically
assistedpowersteering(EAS)usingBLDCmotorforavehicle.Thecontrolarchi-
tectureconsistsoftwolayersofcontrol,namelythevehiclespeedassociatedcontrol
andthetorqueassistcontrol.Inthehigherlevelofcontrolarchitecture,thevehicle
speedcontrollerworksasanassistancelevelcontrollerforthesteeringeffort.In
thelowerlevel,thetorquecontrollergivestheeffortlevelcontrol.Thishasbeen
realizedbytorquesensorandvehiclesensorinterfacedintheDSP.Forimplement-
inginthesystem,aDSP-basedBLDCmotorcontrollerwiththree-phaseinverter
moduleisspeciallydesignedusingHall-effectsensorfeedbackandasingledc-link
currentsensor.ThisworkisimplementedinaLightCommercialVehiclehaving
arecirculatingballtypegear.Thisisforthe?rsttime(EAS)beingimplemented
forthistypeofvehicleanywhereintheworld.Generally,EAShavingclutchto
disconnectthemotorinhighspeedorabnormalconditionsfromthegearbox.In
thisimplementationthemotorisdirectlycoupledtogearboxwithoutclutchandall
abnormalitiesarehandledbytheprocessor.Thisisimplementedwithoutmodify-
ingthevehiclesupplysystemlikechangingtheexistingalternatororratingofthe
batteryandusingtheexistingsensors.Thedesignissuchawaythatthefeelofthe
driverassistancecanbevariedeasilyatanytime.Theperformanceofthecontrol
systemisexperimentallyveri?edanditistestedinoneoftheLightCommercial
Vehicle(LCV).