摘要 |
<p>A method of controlling one or more automatically controlled vehicles (10) using beacons (14, 24) and receivers (13, 23) (beacons being fixed and receivers on vehicles, or vice versa) uses a sequential switching system such that the effects of malfunctioning or masked beacons (14, 24) or receivers (13, 23) can be allowed for. The beacons sequentially emit signals, intervals between consecutive signals being equal until all beacons have been caused to signal, then after a first pause time of a first integral number of intervals the beacons emit signals in reverse order, and after all the beacons have been caused to signal, after a second pause time of a second integral number of intervals, the steps are repeated. The first and second integrals differ by an odd number. The invention also concerns apparatus for carrying out the method.</p> |