The present invention relates to an arrangement and electronic navigational control system for a self-propelling device (5), preferably a lawn-mowing robot. The system comprises at least one navigational control system (3) connected to at least one signal generator (1) and a sensing unit arranged at the self-propelling device (5). The sensing unit senses at least one, in the air medium propagating, time and space varying magnetic field, at least transmitted via the navigational control station (3) and in turn retransmits at least one signal processed by the unit to at least one driving source which contributes to the device's movements across the surface. The system comprises means by which the signal generator (1) sends a current through the navigational control station (3), the current generating the time and space varying magnetic field, whereby the sensing unit comprises means by which the device (5) is manoeuvred based on the properties of the sensed magnetic field.