Abstract: The present invention is an improved structure for robotic cleaner primarily comprising of a chassis with plurality of spherical casters fixed to the periphery of bottom deck, a dust collector mounted on the chassis, a lifting actuation mechanism mounted on the chassis that includes a lifting power supply at least to drive two parallel & extendable first swing arms and two parallel & extending second swing arms through a relevant linking device, a first gear train and a second gear train that can pivotally rotate in reverse direction, a drive wheel mounted at the moveable end of the two parallel & extending first swing arms each, a driven wheel mounted at the moveable end of the two parallel & extending second swing arms each, plural advancing power supplies mounted at the middle section of the first swing arms.