Abstract: A method controls an apparatus comprising at least two sensors, and an active device interfering with signals detectable by the at least two sensors. The method comprises: detecting, by means of the at least two sensors, signals at different points in time, the signals including burst signals from a signal source, storing data indicative for the detected signals in a memory, comparing signal values determined based on the data indicative for the signals stored in the memory of three different points in time with one another to differentiate the signal values into a low signal value, an intermediate signal value and a high signal value, subtracting the intermediate signal value from a current signal value detected by means of at least one of the at least two sensors to obtain at least one processed signal value and controlling operation of the apparatus based on the processed signal value.

Abstract: A method and a system for controlling a self-propelling lawnmower including the self-propelling lawnmower having a control unit and at least one sensor, a boundary wire and a signal generator. The self-propelling lawnmower moves across an area surrounded by the boundary wire. By encoding a data frame with a recognition code in an alternating current that is Direct Current, DC-balanced and that is randomly transmitted within a predetermined period of time, by means of the signal generator, to the boundary wire a system robust against interference is accomplished. The data frame burst is received by a sensor and decoded by a control unit in the lawnmower. By comparing the received recognition code with a stored recognition code, the control unit determines that the lawnmower is on the inside of the boundary wire if the received recognition code matches the stored recognition code, and on the outside if the received recognition code matches the inverse of the stored recognition code.

Abstract: A bidirectional communication channel between a robotic lawnmower and a charging station for data communication between the robotic lawnmower and the charging station. The communication channel includes a first interface provided on the robotic lawnmower and a second interface provided on the charging station. The first and second interface are connected to each other through charging contacts and configured to communicate data in a Direct Current, DC-balanced way. Each interface is provided with an inductor in a charging power path between the charging station and the robotic lawnmower. Each inductor includes a high impedance for enabling a high data transmission rate for frequencies above 50 kHz.

Abstract: An adaptive boundary wire transmitter includes two bridge coupled power amplifiers, a sensing element, a feedback amplifier, a compensation network and an error amplifier. The adaptive boundary wire transmitter is connected to a boundary wire installation, including a boundary wire and feeds the boundary wire with a boundary signal current. By using a feedback amplifier to which the boundary signal current is fed together with the input signal together with compensation network and an error amplifier it is possible to generate a stable output signal from the adaptive boundary wire transmitter to the boundary wire that is independent of the boundary wire length.

Abstract: A bidirectional communication channel between a robotic lawnmower and a charging station for data communication between the robotic lawnmower and the charging station. The communication channel includes a first interface provided on the robotic lawnmower and a second interface provided on the charging station. The first and second interface are connected to each other through charging contacts and configured to communicate data in a Direct Current, DC-balanced way. Each interface is provided with an inductor in a charging power path between the charging station and the robotic lawnmower. Each inductor includes a high impedance for enabling a high data transmission rate for frequencies above 50 kHz.

Abstract: An adaptive boundary wire transmitter includes two bridge coupled power amplifiers, a sensing element, a feedback amplifier, a compensation network and an error amplifier. The adaptive boundary wire transmitter is connected to a boundary wire installation, including a boundary wire and feeds the boundary wire with a boundary signal current. By using a feedback amplifier to which the boundary signal current is fed together with the input signal together with compensation network and an error amplifier it is possible to generate a stable output signal from the adaptive boundary wire transmitter to the boundary wire that is independent of the boundary wire length.

Abstract: A method and a system for controlling a self-propelling lawnmower including the self-propelling lawnmower having a control unit and at least one sensor, a boundary wire and a signal generator. The self-propelling lawnmower moves across an area surrounded by the boundary wire. By encoding a data frame with a recognition code in an alternating current that is Direct Current, DC-balanced and that is randomly transmitted within a predetermined period of time, by means of the signal generator, to the boundary wire a system robust against interference is accomplished. The data frame burst is received by a sensor and decoded by a control unit in the lawnmower. By comparing the received recognition code with a stored recognition code, the control unit determines that the lawnmower is on the inside of the boundary wire if the received recognition code matches the stored recognition code, and on the outside if the received recognition code matches the inverse of the stored recognition code.