A method and a system can generate a representation of a working area of an autonomous lawn mower. The system can include an autonomous lawn mower and a base station, and a boundary wire forming a closed loop which can be connected with the base station. The lawn mower and the base station interact such that the lawn mower can determine whether it is in its home position, a predetermined position that is taken when the mower returns to the base station. The lawn mower further includes a memory, for storing values from a movement sensor. A trajectory is generated based on the values, wherein a processor is configured to calculate an error between the position and orientation according to the trajectory and the home position. This total position error and total orientation error is then used to correct the position and corresponding orientations of the trajectory.
