🚀 go-pugleaf

In <kwilli.2@elaine.ee.und.ac.za> kwilli@elaine.ee.und.ac.za (KEVIN WILLIAMS : THIRD) writes:
>I am currently investigating circuitry to provide automated guidance to a 
>model car by means of a wire taped to the floor carrying some high frequency 
>signal which is detected by sensors on the car. This is used to provide 
>steering information etc.

      This is a common way of guiding factory robot vehicles.  The wire
usually carries a current modulated with some audio frequency, and the
vehicle has a pair of tuned amplifiers connected to sensing coils.
The difference from the amplifer outputs is used to generate steering
corrections, and the sum of the amplifier outputs must be above some
threshold to indicate that the wire is actually being sensed.

      You can also transmit other control info over the wire, using a
carrier-current radio system.  This is all standard technology in 
factory automation today.

      The latest generation of AGVs have enough navigational capability
to leave the guide wire for short distances.  So typically the wire
can run straight down an aisle, and the AGV can turn off the wire to make
a stop at some machine it feeds.  Caterpillar makes a lift truck like
AGV that uses this approach.

					John Nagle