Navigating a robotic mower along a guide wire

A method for guiding a robotic mower (2) along a wire (4a, 8, 10) to a predetermined position, said robotic mower (2) comprising at least one sensor (12;

• 14), the method comprising:
• navigating (S10) the robotic mower (2), by the at least one sensor (12, 14) detecting at least one signal of the wire (4a, 8, 10), such that the at least one sensor (12, 14) is located above the wire (4a, 8, 10) and
• controlling (S11) the robotic mower (2) to straddle along the wire (4a, 8, 10) towards the predetermined position using a polarity of at least one signal of the wire (4a, 8, 10) measured by the at least one sensor (12, 14);
• wherein,
• the wire (4a, 8, 10) includes a boundary wire loop (4a), a charging station loop (10) and one or several guide wires (8), the sensors (12, 14) are configured to sense a magnetic field generated in the boundary wire loop (4a), the charging station loop (10) and the one or several guide wires (8);
• the charging station loop (10) is a first wire loop (10), the boundary wire loop (4a) is a second wire loop (4a), both the first wire loop (10) and the second wire loop (4a) are in a charging station (11) and cross with each other to define the predetermined position in the charging station (11);
• controlling (S11) the robotic mower (2) to straddle along the wire (4a, 8, 10) towards the predetermined position using a polarity of at least one signal of the wire (4a, 8, 10) measured by the at least one sensor (12, 14) further comprising:
• detecting (S12), by the at least one sensor (12, 14), that the robotic mower (2) has entered the first wire loop (10) by measuring a polarity of at least one signal of the first wire loop (10), detecting a change of the polarity of the at least one signal of the first wire loop (10), and in response to detecting that the robotic mower (2) has entered the first wire loop (10), detecting (S14), by the at least one sensor (12, 14), that the robotic mower (2) has entered the second wire loop (4a) by measuring a polarity of at least one signal of the second wire loop (4a), so that the robotic mower returns to the predetermined position in the charging station;
• signals of the different wires (4a, 8, 10) are encoded differently, and the sensed magnetic field is decoded in a control unit (22) to determine from which loop or wire the sensed magnetic field is received.

A robotic mower (2) comprising at least two sensors (12;

• 14, and adapted to:
• detect, by at least two sensors (12, 14), at least one signal from a wire (4a;
• 8;
• 10),
• measure a polarity of the at least one signal of the wire by each one of the at least two sensors (12, 14),
• determine a direction based on the polarities measured by the at least two sensors (12, 14) and
• turn towards the determined direction;
• wherein, the wire (4a, 8, 10) includes a boundary wire loop (4a), a charging station loop (10) and one or several guide wires (8), the sensors (12, 14) are configured to sense a magnetic field generated in the boundary wire loop (4a), the charging station loop (10) and the one or several guide wires (8);
• wherein signals of the different wires (4a, 8, 10) are encoded differently, and the sensed magnetic field is decoded in a control unit (22) to determine from which loop or wire the sensed magnetic field is received.

A robotic mower (2) comprising at least one sensor (12;

• 14, and adapted to:
• navigate, by the at least one sensor (12, 14) detecting at least one signal of a wire (4a, 8, 10), such that the at least one sensor (12, 14) is located above the wire (4a, 8, 10) and
• straddle along the wire (4a, 8, 10) towards a predetermined position using a polarity of at least one signal of the wire (4a, 8, 10) measured by the at least one sensor (12, 14);
• wherein,
• the wire (4a, 8, 10) includes a boundary wire loop (4a), a charging station loop (10) and one or several guide wires (8), the sensors (12, 14) are configured to sense a magnetic field generated in the boundary wire loop (4a), the charging station loop (10) and the one or several guide wires (8);
• the charging station loop (10) is a first wire loop (10), the boundary wire loop (4a) is a second wire loop (4a), both the first wire loop (10) and the second wire loop (4a) are in a charging station (11) and cross with each other to define the predetermined position in the charging station (11);
• controlling (S11) the robotic mower (2) to straddle along the wire (4a, 8, 10) towards the predetermined position using a polarity of at least one signal of the wire (4a, 8, 10) measured by the at least one sensor (12, 14) further comprising:
• detecting (S12), by the at least one sensor (12, 14), that the robotic mower (2) has entered the first wire loop (10) by measuring a polarity of at least one signal of the first wire loop (10), detecting a change of the polarity of the at least one signal of the first wire loop (10), and in response to detecting that the robotic mower (2) has entered the first wire loop (10), detecting (S14), by the at least one sensor (12, 14), that the robotic mower (2) has entered the second wire loop (4a) by measuring a polarity of at least one signal of the second wire loop (4a);
• signals of the different wires (4a, 8, 10) are encoded differently, and the sensed magnetic field is decoded in a control unit (22) to determine from which loop or wire the sensed magnetic field is received.