Method for Detecting a Working Area and Device Therefor

A method for detecting a position with respect to an area defined by an alternating magnetic field, comprising:

• receiving a detection signal which corresponds to a voltage induced by the alternating magnetic field;
• generating a reconstructed boundary signal from the detection signal;
• providing a reference signal, the reconstructed boundary signal and the reference signal corresponding to a pseudo-random signal;
• carrying out a correlation method in order to determine a temporal correlation offset between the reference signal and the reconstructed boundary signal and in order to determine a correlation value between the reference signal and the reconstructed boundary signal which have been shifted with respect to one another by the offset which has been determined;
• and
• determining a position inside or outside the area on the basis of the correlation value which has been determined.

A device, comprising:

• a detector unit configured to receive a detection signal from a magnetic field generated by the current signal in a boundary conductor;
• a reference signal generator configured to provide a reference signal which has a bit pattern corresponding to the boundary signal which has been provided;
• and
• an evaluation unit which is designed configured (i)
• to generate a reconstructed boundary signal from the detection signal,
• to carry out a correlation method in order to determine a temporal correlation offset between the reference signal and the reconstructed boundary signal and in order to determine a correlation value between the reference signal and the reconstructed boundary signal which have been shifted with respect to one another by the offset which has been determined, and
• to determine a position inside or outside the area on the basis of the correlation value which has been determined.