A robotic mower sensor assembly for detecting a boundary wire signal. The sensor assembly includes a plurality of analog inductive sensors with a first inductive sensor oriented along a first axis and a second inductive sensor oriented along a second, different axis. Each inductive sensor is configured to generate a signal indicative of the distance of the robotic mower from the boundary wire. A control unit communicating with the sensor assembly is configured to operate the robotic mower in response to the signals from the sensor assembly which are indicative of the distance of the robotic mower from the boundary wire.