An unmanned wheeled vehicle is configured to clean a first floor surface at a first height level, while supported on a second floor surface at a second height level, wherein the first height level is higher than the second height level. The vehicle comprises a main body comprising a support side and a cleaning side, and a support device to support the main body on the second floor surface, wherein the main body comprises at the cleaning side a contact cleaning device configured to clean the first floor surface. A tilting device tilts the main body between a tilted position in which the cleaning side of the main body can be moved over the first floor surface without contact between the contact cleaning device and the first floor surface, and a cleaning position, in which the contact cleaning device is in contact with the first floor surface.