Abstract: Embodiments of the disclosure provide a robot cleaner for cleaning a stair. The robot cleaner includes a main body configured to rotate around a first shaft. The robot cleaner further includes at least one leg each configured to rotate around a second shaft. The robot cleaner also includes at least one connector each configured to connect each leg to the main body. Each connector comprises a first end attached to the first shaft and a second end attached to the second shaft. The robot cleaner is configured to climb the stair by first lifting the main body onto a tread of the stair through rotations of the main body and the at least one connector and then lifting the at least one leg onto the tread through rotations of the at least one connector and the at least one leg.

Abstract: Embodiments of the disclosure provide a method for controlling a robot cleaner to climb a stair. The robot cleaner includes a main body, at least one leg, and at least one connector connecting each leg to the main body. The method includes rotating the main body relative to the at least one leg to be substantially vertical to a thread of the stair. The method further includes rotating the main body to lay flat on the tread. The method also includes rotating the at least one leg to align with the at least one connector. The method additionally includes rotating the at least one leg to lay flat on the tread.