Autonomous lawnmower

Abstract

A semi-autonomous or autonomous mowing vehicle with a sensor that detects the boundary between a first, relatively higher surface, such as the un-mowed vegetation and a second, a relatively lower surface, such as the mowed vegetation, and a controller for steering the semi-autonomous or autonomous vehicle along detected boundary. The detected boundary is based on height differential between the two surfaces and two methods are discussed. For one, the boundary between the two surfaces is detected using a plurality of non-contact distance measuring sensors aligned in same direction, and processes these distance measuring sensors for determining the distance sensors that measure said first relatively higher surface and the distance sensors that measure the second relatively lower surface. For two, the boundary between the two surfaces is detected using a plurality of rotatable contact members on a rotating shaft and a plurality of slip clutches, each slip clutch associated with each contact member coupling the shaft to the contact member in rotating engagement, and processes the internal sensors for detecting impeded rotation of said contact members do to slippage of said clutches in response to contact with said first surface, relatively higher surface, but not contact with said second surface, a relatively lower surface.