Abstract: The present invention relates to a method for controlling a self-propelled robot device, such as a robot device for mowing grass, and a control system that carries out the aforementioned method. According to the invention, the self-propelled robot device is driven by an inertial navigation system for a set time period or distance and the device is periodically stopped for rectifying the position and advancing course thereof by a satellite detection system: the periodic correction of the inertial navigation system using satellite detections thus prevents course errors from accumulating. The correction based on the satellite detection system can be possibly optimized through a further selection of the obtained values according to a statistical basis. Preferably, the control method according to the invention also provides a procedure for detecting, recording and mapping the operating region wherein the device is operated.