System as well as a method for controlling a self moving robot

Abstract

A system provided with a base station comprising a signal emitting module, a self movable robot comprising at least an energy storage, a sensor for sensing this signal emitted by signal emitting module of the base station and a processor for controlling the movement of the robot by means of the sensed signal to return the robot to the base station. The robot comprises means for controlling the movement of the robot to move the robot randomly over a surface, whereby the absolute position of the robot is not memorized, means for marking the interrupt location where the movement of the robot is interrupted to return to the base station and means for returning the robot from the base station to the interrupt location by means of said marking.

1 . A method for controlling a self-movable robot for cleaning a surface, said method comprising:
 moving the robot randomly over the surface without memorizing absolute positions through which said robot moves;   upon the occurrence of a predetermined condition of the robot, interrupting the random movement of said robot for return to a base station;   providing a marking at a location where the random movement of the robot is interrupted;   sensing a signal emitted from the base station and utilizing said signal for guiding the robot to the base station; and   returning the robot from the base station to the marking, where the random movement of the robot was interrupted.   
     
     
         2 . A method as in  claim 1  where the robot comprises a rechargeable energy storage and the predetermined condition comprises a charging level that is lower than a predetermined reference level. 
     
     
         3 . A method as in  claim 1  where the predetermined condition comprises the need to empty a dust container. 
     
     
         4 . A method as in  claim 1  where the predetermined condition comprises the need to refill a liquid container. 
     
     
         5 . A method as in  claim 1  where the marking provided at the location where the random movement of the robot is interrupted comprises a beacon. 
     
     
         6 . A method as in  claim 5  where the beacon emits a signal for guiding the robot to the location where the random movement of the robot is interrupted. 
     
     
         7 . A method as in  claim 1  further including memorizing movements of the robot from said location to the base station for use in returning the robot to said location.