Aircraft surface navigation system

• US 5,689,273 A
• Filed: 01/30/1996
• Issued: 11/18/1997
• Est. Priority Date: 01/30/1996
• Status: Expired due to Term

• Current Assignee: OL Security LLC (Intellectual Ventures LLC)
• Original Assignee: Alliedsignal Inc. (Honeywell International Inc.)
• Inventors: Bailey, Charles Gary, Hieber, John Edward
• Primary Examiner(s): Tarcza, Thomas H.
• Assistant Examiner(s): PHAN, DAO LINDA
• Application Number:
  US08/594,099
• Time in Patent Office: 658 Days
• Field of Search: 342/410, 342/411, 342/412, 342/413, 342/444, 342/407, 455/41, 364/429, 340/957, 340/979
• US Class Current: 342/407
• CPC Class Codes: G01S 1/16 Azimuthal guidance systems, e.g. system for defining aircraft approach path, localiser system

Abstract

A surface guidance system for guiding aircraft equipped with Instrument Landing Systems along taxiways which utilizes two inductive loops (14,16) installed around the right half and the left half of the taxiways. Audio amplifiers (18,20) drive one loop (14) with an 90 Hz signal and the other loop (16) at 150 Hz. A sensor (22) mounted on the aircraft detects the composite magnetic field induced by the surface loops (14,16). The detected signal is conditioned and supplied to the ILS system to provide left/right lateral guidance to the pilot. Longitudinal aircraft position is determined by using dipole marker antennas (52) embedded near the taxiway center line. Each marker antenna (52) has a unique code identifier. Existing ILS equipped aircraft can sense the marker signal and transmit the aircraft position to the ATC facility. Additional pairs of loops (14,16) and marker antennas (52) are used for different taxiway or runway sections.

Claims

1. A ground guidance system for guiding an aircraft equipped with an Instrument Landing System (ILS) along a defined path comprising:

a pair of inductive loops, the first loop disposed around the right side half of the path and the second loop disposed around the left side half of the path;

a first audio amplifier for driving the first loop at a first audio frequency;

a second audio amplifier for driving the second loop at a second audio frequency;

an inductive sensor mounted on the aircraft for receiving the composite magnetic field induced by the pair of inductive loops;

signal processing means connected to said inductive sensor for converting the signal received by said inductive loop to an RF signal compatible with the aircraft ILS; and

,

indicator means in the ILS display responsive to the radio frequency signal from said signal processing means for providing an indication of deviation of the aircraft from the center line of the path for providing both lateral position guidance to the pilot of a taxiing aircraft.

2. A ground guidance system as claimed in claim 1 comprising a switch disposed between said signal processing means and said indicator means for selecting when the ground guidance system is operable.

3. A ground guidance system as claimed in claim 1 wherein said first audio frequency is 90 Hz and said second audio frequency is 150 Hz.

4. A ground guidance system as claimed in claim 1 comprising means for detecting the longitudinal position of the aircraft along the path.

5. A ground guidance system as claimed in claim 4 wherein said means for determining the longitudinal position of the aircraft comprises:

a dipole antenna, disposed near the center line of the path, which radiates a beam across the runway having unique position information;

a receiver located on the aircraft for receiving the unique position information; and

means for appending information identifying the aircraft to the unique position information and for transmitting such information to an ATC facility.

6. A surface navigation system for navigating aircraft equipped with ILS on runways and taxiways comprising:

(a) first and second loop conductors capable of transmitting an audio frequency magnetic field and situated so that the equipotential interface between said conductors define the lateral centerline of said runway or taxiway;

(b) means for exciting said first and second loop conductors with an alternating current;

(c) aircraft receiver means for detecting said magnetic field signal of said first and second loop conductors;

(d) signal processing means for accepting the output of said aircraft receiving means and converting said output to an input signal compatible with said ILS; and

(e) indicator means responsive to said ILS signal;

wherein said indicator means indicates the position of said aircraft with respect to the lateral centerline.

7. The surface navigation system of claim 6 wherein said first conductor is excited at a frequency of 90 Hz , and said second conductor is excited at a frequency of 150 Hz.

8. The surface navigation system of claim 6 further comprising:

(f) a ground position signal transmitter positioned adjacent said runway or taxiway and having a gain antenna that radiates a carrier signal which modulates one of three audio frequencies;

(g) an aircraft ILS marker receiver having an antenna input for receiving said carrier frequency and generating an output responsive to said input to provide one of the three audio frequencies; and

,

(h) indicating means responsive to said output.

9. The surface navigation system of claim 8 wherein said indicating means comprises audio tones.

10. The surface navigation system of claim 8 wherein said indicating means comprises lights.

11. The surface navigation system of claim 8 further comprising:

an aircraft position transmitter connected to receive outputs from said ILS marker receiver; and

,

wherein said ground signal transmitters output contains a unique identifier code which is received by said ILS marker receiver via said antenna input, and said unique identifier code is appended to the aircraft ID code and transmitted by said position transmitter to the ATC facility.

12. The surface navigation system of claim 8 wherein the three audio frequencies are 400 Hz, 1300 Hz, and 3000 Hz.