Operating method of a mobile device for the maintenance of land in a working area, said working area being delimited by at least one contour, wherein at least one first region and a second region are obtained from said working area, by the definition in said working area of at least one first boundary marking out said first region and said second region, said first region extending between said contour and said first boundary and said second region extending internally starting from said first boundary, wherein said first region is assigned a first tolerance threshold, wherein said method comprises the steps of: i) detecting and/or estimating the position of said mobile device in said working area and the uncertainty in position of said mobile device; ii) identifying the region of said working area wherein said mobile device is positioned; iii) if said first region is identified to be the region of said working area wherein said mobile device is positioned, comparing the uncertainty in the detected and/or estimated position of said mobile device with said first tolerance threshold; wherein, if said first region is identified to be the region of said working area wherein said mobile device is positioned and if the uncertainty in the detected and/or estimated position of said mobile device is minor or equal to said first tolerance threshold, said mobile device is moved within said first region, characterised in that said second region is assigned a second tolerance threshold, said second tolerance threshold being greater than said first tolerance threshold, wherein said method further comprises the step of: iv) if the uncertainty in the detected and/or estimated position of said mobile device is greater than said first tolerance threshold, comparing the uncertainty in the detected and/or estimated position of said mobile device with said second tolerance threshold, wherein, if said first region is identified to be the region of said working area wherein said mobile device is positioned and if the uncertainty in the detected and/or estimated position of said mobile device is greater than said first tolerance threshold, but is minor or equal to said second tolerance threshold, said mobile device is moved from said first region to said second region, crossing said first boundary, and therefore is moved within said second region. wherein at least one first region and a second region are obtained from said working area, by the definition in said working area of at least one first boundary marking out said first region and said second region, said first region extending between said contour and said first boundary and said second region extending internally starting from said first boundary, wherein said first region is assigned a first tolerance threshold, wherein said method comprises the steps of: i) detecting and/or estimating the position of said mobile device in said working area and the uncertainty in position of said mobile device; ii) identifying the region of said working area wherein said mobile device is positioned; iii) if said first region is identified to be the region of said working area wherein said mobile device is positioned, comparing the uncertainty in the detected and/or estimated position of said mobile device with said first tolerance threshold; i) detecting and/or estimating the position of said mobile device in said working area and the uncertainty in position of said mobile device; ii) identifying the region of said working area wherein said mobile device is positioned; iii) if said first region is identified to be the region of said working area wherein said mobile device is positioned, comparing the uncertainty in the detected and/or estimated position of said mobile device with said first tolerance threshold; wherein, if said first region is identified to be the region of said working area wherein said mobile device is positioned and if the uncertainty in the detected and/or estimated position of said mobile device is minor or equal to said first tolerance threshold, said mobile device is moved within said first region, characterised in that said second region is assigned a second tolerance threshold, said second tolerance threshold being greater than said first tolerance threshold, wherein said method further comprises the step of: iv) if the uncertainty in the detected and/or estimated position of said mobile device is greater than said first tolerance threshold, comparing the uncertainty in the detected and/or estimated position of said mobile device with said second tolerance threshold, wherein, if said first region is identified to be the region of said working area wherein said mobile device is positioned and if the uncertainty in the detected and/or estimated position of said mobile device is greater than said first tolerance threshold, but is minor or equal to said second tolerance threshold, said mobile device is moved from said first region to said second region, crossing said first boundary, and therefore is moved within said second region.