A domestic robotic system comprising a robot and data storage operable to store data defining the boundary of a working area, the robot comprising: a payload actuable to perform work on a portion of the working area adjacent the robot ; a first positioning system ; and a second positioning system that uses one or more sensors (S A1 -S A6 ) operable to sense directly the boundary of the working area and the robot's current distance thereto, said boundary being a pre-existing feature of the environment and not part of the robotic system; wherein the robot is programmed to operate in at least the following two modes: (i) an area coverage mode, wherein the robot navigates within the working area, with said payload active, using said first positioning system and said stored data defining the boundary of the working area, and (ii) a boundary proximity mode, wherein the robot navigates within the working area using said second positioning system ; characterised in that: the robot is further programmed to switch between said area coverage mode and said boundary proximity mode when said second positioning system detects the boundary of the working area with a confidence level greater than a predetermined value; and a further condition for said switch between said area coverage mode and said boundary proximity mode is that said first positioning system and said stored data defining the boundary of the working area indicate that the robot is within a predetermined distance of the boundary. a payload actuable to perform work on a portion of the working area adjacent the robot ; a first positioning system ; and a second positioning system that uses one or more sensors (S A1 -S A6 ) operable to sense directly the boundary of the working area and the robot's current distance thereto, said boundary being a pre-existing feature of the environment and not part of the robotic system; wherein the robot is programmed to operate in at least the following two modes: (i) an area coverage mode, wherein the robot navigates within the working area, with said payload active, using said first positioning system and said stored data defining the boundary of the working area, and (ii) a boundary proximity mode, wherein the robot navigates within the working area using said second positioning system ; (i) an area coverage mode, wherein the robot navigates within the working area, with said payload active, using said first positioning system and said stored data defining the boundary of the working area, and (ii) a boundary proximity mode, wherein the robot navigates within the working area using said second positioning system ; characterised in that: the robot is further programmed to switch between said area coverage mode and said boundary proximity mode when said second positioning system detects the boundary of the working area with a confidence level greater than a predetermined value; and a further condition for said switch between said area coverage mode and said boundary proximity mode is that said first positioning system and said stored data defining the boundary of the working area indicate that the robot is within a predetermined distance of the boundary. the robot is further programmed to switch between said area coverage mode and said boundary proximity mode when said second positioning system detects the boundary of the working area with a confidence level greater than a predetermined value; and a further condition for said switch between said area coverage mode and said boundary proximity mode is that said first positioning system and said stored data defining the boundary of the working area indicate that the robot is within a predetermined distance of the boundary. <EOS>