Self-propelled working device with obstacle detection

The invention relates to an autonomous lawn mower with a chassis (2) and a hood (3) held on the chassis (2), which covers device units arranged on the chassis (2). The hood (3) is movably held on the chassis (2) via fastening elements (6). A sensor (14, 15.1, 15.2, 15.3) is provided which monitors a relative movement between the hood (3) and the chassis (2) and outputs an output signal (S1, S2, S3) proportional to the deflection of the hood to a controller (51). In order to detect an obstacle and the direction of the obstacle, two Hall sensors (15.1, 15.2, 15.3) are arranged on the chassis (2) at a distance from one another and a permanent magnet (16) is attached to the hood (3). The magnetic field (21) of the permanent magnet (16) passes through the Hall sensors (15.1, 15.2, 15.3) in the rest position of the hood (3) such that upon a relative movement between the components a change in the output signal (S1, S2, S3) of the Hall sensors (15.1, 15.2, 15.3) occurs and the output signals (S1, S2, S3) of the Hall sensors (15.1, 15.2, 15.3) are evaluated in the controller (51).