Abstract: A self-propelled lawn mower comprising a microprocessor and at least one cutter (10), wherein an elastic tension element (13) that is connected to the frame of the lawn mower and the at least one cutter (10) is provided. Central automatic adjustment of the height of the cutters (10) in relation to the ground is also provided. The cutters (10) consist of a rotary disk (3) with retractable blades (5) provided with a stop (4) underneath the lower surface in the form of a central extension that can come into contact with the ground.

Abstract: System of guidance and positioning relative to a fixed station (1) for an autonomous mobile robot (7) utilizing at least a directional infra-red beam (2′) emitted by the fixed station, the mobile robot being provided with a directional system of detection (10a, 10b) of infra-red emission connected to a microcomputer incorporated in the said robot, the robot moving on a work surface in an essentially random manner, the microcomputer (44) including an algorithm able to control the return to fixed station (1) by displacement of the robot (7) towards the direction of emission of said infra-red beam (2′), characterized in that the infra-red beam (2′) is a narrow directional beam and in that the system of detection (10a, 10b) is located on a frame at the center of rotation of the robot (7), oriented in the direction of movement of the robot, precise positioning in the fixed station (1) being carried out by rotation of the machine around a vertical axis according to an algorithm based on the detect

Abstract: The invention concerns a self-propelled lawn mower and a method adapted for using said machine. The machine comprises: a mobile frame (1) including at least one drive wheel (6) and at its lower surface at least two juxtaposed cutters (3), associated each with an electric motor; an electronic system for controlling the forward movement of the machine; an on-board computer; an electric power supply; means for measuring the force supplied by each cutter, said measurement being transmitted to the on-board computer; a memorized algorithm for seeking the grass surfaces to be mowed by the interaction of the machine forward movement system, said force measurements and the on-board computer; means for detecting the limits of the surface to be mowed by a magnetic field measurement or the variation of a magnetic field emitted or caused by a set or buried wire, located at said limits.