Patent ID: 6975923

Claim:
A method for operating an autonomous vehicle at an airport, comprising the steps of: (a) providing ( 18 ) a first set of navigation signals for general purpose use; (b) providing ( 26 ) a second set of navigation signals ( 28 ), being supplementary to the first navigation signals, for guiding aircraft to land at the airport; (c) receiving ( 400 ), in the vehicle, the first set of navigation signals; (d) receiving ( 402 ), in the vehicle, the second set of navigation signals; (e) receiving ( 304 ; 404 ) constraint data representing a permitted area of operation; (f) calculating ( 406 , 310 ) a present position of the vehicle; (g) comparing ( 312 ) the calculated present position of the vehicle with the constraint data, thereby to determine whether the vehicle's present position lies within the permitted area; and (h) producing a signal ( 313 ; 315 ) indicative of the result of said comparing step; and (i) operating the vehicle in accordance with a predefined strategy ( 314 ) in response to the status of the signal ( 313 ; 315 ) of step (h).