System for avoidance of collision between an aircraft and an obstacle

• US RE42,708 E1
• Filed: 01/11/2010
• Issued: 09/20/2011
• Est. Priority Date: 06/12/2003
• Status: Active Grant

• Current Assignee: Vestas Wind Systems A/S
• Original Assignee: Ocas AS
• Inventors: Bakken, Rolf, Mark, Morten
• Primary Examiner(s): Gregory; Bernarr E
• Application Number:
  US12/685,117
• Time in Patent Office: 617 Days
• Field of Search: 340/435, 340945-983, 701/1, 701 3- 18, 701120-122, 701/300, 701/301, 342/22, 342 27- 61, 342104-115, 342/118, 342145-147, 342/175, 342/195, 342/385, 342/386, 342/455, 342352-358
• US Class Current: 342/29
• CPC Class Codes: G01S 13/91 for traffic control G01S13/93 takes precedence
• CPC Class Codes: G01S 13/94 for terrain-avoidance
• CPC Class Codes: G01S 2013/0254 Active array antenna
• CPC Class Codes: G01S 7/003 Transmission of data between radar, sonar or lidar systems and remote stations
• CPC Class Codes: G08G 5/0013 with a ground station
• CPC Class Codes: G08G 5/0026 located on the ground
• CPC Class Codes: H01Q 1/06 Means for the lighting or illuminating of antennas, e.g. for purpose of warning
• CPC Class Codes: H01Q 1/1242 Rigid masts specially adapted for supporting an aerial
• CPC Class Codes: H01Q 1/42 Housings not intimately mechanically associated with radiating elements, e.g. radome
• CPC Class Codes: H01Q 21/065 Patch antenna array
• CPC Class Codes: H01Q 21/20 the units being spaced along or adjacent to a curvilinear path slotted waveguide arrays H01Q21/005; circularly or helically slotted waveguides H01Q21/0062
• CPC Class Codes: H01Q 21/205 providing an omnidirectional coverage turnstile aerials H01Q21/26
• CPC Class Codes: H01Q 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00

Abstract

A field unit for warning of a danger of collision between an aircraft and an obstacle, in particular a topographical ground obstacle or an obstacle formed by a mast, building or aerial cable structure, comprises a multi-part tubular mast having devices for fixing a solar panel and a radar antenna; an elongate radar antenna in an environment-protective casing, which, with an electronics unit, forms a radar system for synthesized radar detection of an aircraft in a radar coverage area; a central processing unit for identifying on the basis of information from the radar system an aircraft which is in a zone of the radar coverage area and which on the basis of radar information such as direction, distance and/or speed computes a collision danger area; and a high-intensity light system and radio transmitter system that can be activated by the central processing unit upon detection of an aircraft in a collision danger area. The radio transmitter system may be a VHF or UHF radio transmitter system for providing a radio signal modulated by an audible warning signal, preferably a voice warning signal, whilst the light system preferably comprises a stroboscope light system. The field unit is arranged for communication with other similar field units for remote activation of light or audio warnings in a neighbouring field unit.

Claims

1. A field unit for warning of a danger of collision between an aircraft and an obstacle, in particular a topographical ground obstacle or an obstacle formed by a mast, building or aerial cable structure, characterised in that it comprises:

a multi-part tubular mast having a fixing device on one side face for a solar panel and a fixing device at an upper end for a radar antenna;

an elongate radar antenna arranged vertically in the longitudinal direction and having a plurality of antenna panels and provided with an environment-protective casing, which radar antenna is in communication with radar electronics to form a radar system for synthesized radar detection of an aircraft in a radar coverage area;

a central processing unit in communication with the synthesized radar detection radar system for processing information from the radar system, which information includes at least one indication of direction and several indications of distance or at least one indication of direction, one indication of distance and one indication of speed, and for identifying a radar system detected aircraft that is in a zone of the radar coverage area computed by the central processing unit as a collision danger area on the basis of the information;

a high-intensity light system connected to and controlled by the central processing unit for providing a high-intensity light warning signal, the light system being activatable by the central processing unit upon the detection of an aircraft in the collision danger zone;

a VHF or UHF radio transmitter system connected to and controlled by the central processing unit for providing a radio signal modulated by an audible warning signal, the VHF or UHF radio transmitter system being activatable by the central processing unit upon the detection of an aircraft in the collision danger zone; and

an electric power supply system comprising a solar panel secured to a fixing device, a chargeable back-up battery and a power supply control for power supply to the radar system, the central processing unit, the high-intensity light system and the VHF or UHF radio transmitter system.

2. A field unit as disclosed in claim 1, further comprising a position transmitting device based on the global positioning system GPS.

3. A field unit as disclosed in claim 1, further comprising a communication device connected to the central processing unit and arranged for communication with a similar second field unit, wherein the central processing unit is arranged to transmit to the second field unit information from the local radar system about the detected aircraft, and is arranged to receive from the second field unit information from the second field unit'"'"'s local radar system about a detected aircraft and, on the basis of the information received, to activate the light system or the VHF or UHF radio transmitter system.

4. A field unit as disclosed in claim 1, wherein the detection zone is at least 3000 meters, and wherein a warning zone for the collision danger area is defined as an elongate area around an associated aerial obstacle extending to a distance from the aerial obstacle that corresponds to a flying time of preferably 15 seconds, and preferably not less than 4.5 seconds, on the basis of the aircraft'"'"'s speed for an aircraft that is within a computed height of less than 50 meters below a defined obstacle height.

5. A field unit as disclosed in claim 1, wherein the detection zone is at least 3000 meters, and wherein a warning zone for the collision danger area is defined as a partly spherical area around an associated point obstacle extending to a distance from the point obstacle that corresponds preferably to a flying time of 15 seconds, and preferably not less than 4.5 seconds, on the basis of the aircraft'"'"'s speed for an aircraft that is within a computed height of less than 50 meters below a defined obstacle height.

6. A field unit as disclosed in claim 1, wherein the light system includes at least one stroboscope light system.

7. A field unit as disclosed in claim 1, wherein the audible warning signal is a voice signal that gives information specifying the obstacle.

8. A field unit as disclosed claim 1, further comprising a remote monitoring system for reporting to an operation centre at least one operating state of the field unit, and optionally for control or remote maintenance of the field unit.

9. A field unit as disclosed in claim 1, wherein the central processing unit is arranged to activate the light system and/or VHF or UHF radio transmitter system preferably 15 seconds before a computed collision time on the basis of the detected aircraft'"'"'s direction, distance and speed relative to the obstacle.

10. A field unit as disclosed in claim 1, wherein the light system is arranged to emit a flashing light with a repetition rate of about 40 flashes per minute.

11. An apparatus comprising:

a field unit for placement in the vicinity of an obstacle,

a central processing unit configured to receive course and height information from a detection system about a target approaching the obstacle, configured to identify when the target is entering a first and second warning zone in the vicinity of the obstacle computed by the central processing unit and configured to control a warning system to provide a first warning signal to the target when the target enters the first warning zone and a second warning signal to the target when the target enters the second warning zone.

12. The apparatus of claim 11, wherein the field unit provides for remote monitoring of the field unit from an operations centre.

13. The apparatus of claim 11, wherein the central processing unit activates a light system to provide the first warning signal.

14. The apparatus of claim 11, wherein the central processing unit activates a radio transmitter system to provide the second warning signal.

15. The apparatus of claim 14, wherein the radio transmitter system is included with the field unit.

16. The apparatus of claim 11, wherein the field unit is one of a plurality of field units having coverage areas and that are in communication to exchange information about target movements within the coverage areas and operational status information.

17. The apparatus of claim 11, wherein the field unit includes a radar system providing course and height information about the target to the central processing unit.

18. An apparatus comprising:

a field unit for placement in the vicinity of an obstacle including,

a central processing unit configured to receive course and height information from a detection system about a target approaching the obstacle, configured to identify a target entering a warning zone in the vicinity of the obstacle, and configured to control a warning system to provide a warning to the target when the target enters the warning zone, and desist from giving new warnings when the target stays inside the warning zone.

19. The apparatus of claim 18, wherein the field unit includes a radar system providing course and height information about the target to the central processing unit.

20. The apparatus of claim 18, wherein the central processing unit activates at least one of a light system and a radio transmitter system to provide the warning signal.

21. A method of warning a target of an obstacle comprising:

monitoring a coverage area in the vicinity of an obstacle using a field unit in the vicinity of the obstacle;

determining course and height information for a target in the coverage area;

calculating first and second warning zones based on the course and height information using a central processing unit;

providing a first warning to the target, when the target enters the first warning zone;

providing a second warning to the target, when the target enters the second warning zone.

22. The method of claim 21, wherein providing the first warning includes providing the first warning to the target using a light system activated by a central processing unit in the field unit.

23. The method of claim 21, wherein providing the second warning includes providing second warning to the target using a radio transmitter system activated by a central processing unit in the field unit.

24. The method of claim 21, wherein determining includes performing synthesized radar detection of the target to determine at least one of, at least one indication of direction and several indications of distance, and, at least one indication of direction, one indication of distance and one indication of speed.

25. The method of claim 21, wherein:

the providing a first warning to the target, includes providing a first warning by activating a light system to provide at least one flashing visible light in the vicinity of the obstacle; and

,

the providing a second warning to the target, includes providing a second warning by activating a radio transmitter to provide an audible warning to the target in at least one of the UHF and VHF radio frequency bands.

26. The method of claim 25, wherein the audible warning is provided in a plurality of frequencies.

27. The method of claim 25 further comprising configuring a light system and a radio transmitter to be in a sleep mode when not activated.

28. The method of claim 21, further comprising desisting from providing warnings when the target is inside the warning zone.

29. The method of claim 21, wherein,

monitoring includes providing at least first and second field units in communication to exchange information about target movements within respective coverage areas and operational status information;

and,

exchanging information between the field units relating to the target detected within the coverage areas.

30. The method of claim 21, further comprising:

communicating with other similar field units for remote activation of at least one of light and audio warnings in the similar field units.

31. An aircraft collision avoidance system comprising:

a field unit for placement in the vicinity of a ground obstacle including,

a radar system having a radar coverage area; and

a central processing unit in communication with the radar system for processing information from the radar system about aircraft in the radar coverage area, and for identifying aircraft entering a first and second warning zone of the radar coverage area computed by the central processing unit on the basis of the information;

a light system activated by the central processing unit to provide a light warning signal upon the identification of the aircraft entering the first warning zone; and

,

a radio transmitter system activated by the central processing unit to provide a radio frequency audible warning signal upon the identification of the aircraft entering the second warning zone.