For track guiding of automated guided vehicles (AGV), inductive guidance systems have proven to be very reliable. A frequency generator feeds a current into a guidance wire installed in the ground. Along this wire an alternating magnetic field is generated. The inductive antenna detects the horizontal and vertical components of the magnetic field by a specific set of coils.

When moving the antenna perpendicularly over the guide wire two characteristic voltages are induced. The Uref (sum voltage) shows a bell shaped curve with a maximum directly above the wire. The Upos (difference voltage) shows maxima at both sides of the wire and falls to zero directly above the wire.

The two output voltages can be used to determine the lateral deviation of the antenna from the wire. For a simple steering function connect Upos to the steering drive using a P-controller. The digital Wire-Detect output switches to +24 VDC if the induced Uref voltage exceeds an adjustable threshold. The wire detect signal is often used to stop the AGV in case it drives off the track.

The downloadable data sheet below lists available variants (frequencies, reading height) and shows how to mount and adjust the antenna.