100 may determine that it is operating on grass if the surface is determined to be grass even if no edge is detected in the images.

FIG. 2 shows a robotic lawnmower system 200 in some embodiments. The schematic view is not to scale. The robotic lawnmower system 200 comprises one or more robotic lawnmowers 100 according to the teachings herein arranged to operate in one or more operational areas 205 possibly bounded by a boundary 220. It should be noted that the operational area 205 shown in FIG. 2 is simplified for illustrative purposes.

The view of the operational area 205 is also intended to be an illustration or graphical representation of the map application 120A discussed in the above.

A server 240 is shown as an optional connected device for the robotic lawnmower 100 to communicate with—possibly for receiving maps or map updates. The server 240 comprises a controller 240A for controlling the operation of the server 240, a memory 240B for storing instructions and data relating to the operation of the server 240 and a communication interface 240C for enabling the server 240 to communicate with other entities, such as the robotic lawnmower 100, and/or a User Equipment such as a mobile phone. The controller, the memory and the communication interface may be of similar types as discussed in relation to FIG. 1 for the robotic lawnmower 100.

The server 240 may be a cloud service, a dedicated service provider server, or an application running in a local personal computer, a tablet computer or a smart phone. For the reasons of this application it should be noted that there will be made no difference between the types of servers, but the description will focus on a server being implemented in an application for execution in a user equipment such as a smartphone, a personal computer, or a tablet computer.

As is shown in FIG. 2 there may be obstacles such as houses, structures, trees to mention a few examples in the operational area 205. In FIG. 2 such obstacles are indicated and referenced H (as in house).

It should be noted that any processing may be done in any, some or all of the controller 110 of the robotic lawnmower 100 and/or the controller 240A of the server 240 and that the processing may also be done partially in one controller 110/240A for supplemental processing in the other controller 110/240A. This is indicated in FIG. 2 in that a dashed arrow is shown between the server 240 and the robotic lawnmower 100 for indicating that information may be passed freely between them for (partial) processing.

FIG. 3A shows an example of a work area 205 for a robotic lawnmower system 200. In this example the work area basically comprises a grass lawn 205 and in FIG. 3A the grass is indicated as the marked area. On the grass area one or more features may be present and in this illustrated example a house (H) and a path (P) to the house is shown as examples of features.

- as the inventors have realized, marking such an irregular work area accurately constitutes tedious work, no matter if it is done virtually on a map application, in real life by teaching the robotic lawnmower or by laying a boundary wire. The inventors are therefore proposing to provide a simplified manner of establishing a working area boundary, wherein a rudimentary boundary is provided and the robotic lawnmower 100 is configured to operate in the work area based on the rudimentary boundary 220 and the grass sensor 185.

In some embodiments the rudimentary boundary is provided by a user through an application in the server 240 such as by drawing a boundary on a map representation.

In some embodiments the rudimentary boundary is provided by the server 240 by the server approximating a boundary from a map representation of the work area, such as through image analysis based on a satellite image of the work area.

FIG. 3B shows an example embodiment of the same work area 205 as in FIG. 3A, but where the rudimentary boundary 220 is also indicated. As can be seen a rudimentary boundary is a boundary that does not follow the edges of the work area, and wherein the work area may in some cases extend beyond the rudimentary boundary in one, some or all portions of the work area and/or in some cases not extend out to the rudimentary boundary in one, some or all portions of the work area.

In some embodiments, the rudimentary boundary has the shape of one or more geometrical shapes, such as a rectangle, an oval, a circle, a stadium, or a diamond or any such shape which is angled or otherwise rotated.

In such embodiments, several (individual) shapes may be placed together to form a composite rudimentary boundary, the composite rudimentary boundary being the union of the individual shapes. The individual shapes may be of a same or of different shapes or some of the same shape and some of different shapes. Of course, two boundaries of a same shape may be of different extents (such as different radii).

To enable a robotic lawnmower 100 to properly cover a work area 205 utilizing a rudimentary border, the robotic lawnmower 100 is configured to operate based on the grass sensor as well. The robotic lawnmower 100 is thus configured to determine a position and to determine that the robotic lawnmower 100 is operating on grass and as long as the position is on grass and within the rudimentary boundary 220, the robotic lawnmower 100 continues operating. The robotic lawnmower 100 will thus continue operating until it either reaches the rudimentary boundary or an edge E of the grass.

The robotic lawnmower 100 is configured to determine the position based on any of the navigational means discussed above, be it satellite navigation sensor 175, deduced reckoning sensors 180, visual navigation sensors 180 or magnetic sensors 170 in combination with deduced reckoning sensors to mention a few examples.

The robotic lawnmower 100 is configured to determine that it is operating on grass based on the grass sensor as discussed in the above, for example with reference to FIG. 1B.

This allows the robotic lawnmower to safely operate on most of the grass of the work area, without risking to leave the work area 205.

FIG. 3B shows an example where a rudimentary boundary 220 has been overlaid the work area 205 and from this it can be seen how the robotic lawnmower 100 will be able to cover most of the work area 205 safely without departing from the bounded area.

FIG. 3B shows two examples of rudimentary boundaries. One of these 220-1 is big and covers most of the work area