Threat avoidance system and method for aircraft

• US 5,631,640 A
• Filed: 02/21/1995
• Issued: 05/20/1997
• Est. Priority Date: 01/18/1994
• Status: Expired due to Term

• Current Assignee: Honeywell Incorporated (Honeywell International Inc.)
• Original Assignee: Honeywell Incorporated (Honeywell International Inc.)
• Inventors: Deis, David L., Gjullin, Robert M.
• Primary Examiner(s): SWARTHOUT, BRENT
• Application Number:
  US08/393,513
• Time in Patent Office: 819 Days
• Field of Search: 340/945, 340/961, 340/988, 340/968, 340/980, 364/424.06, 364/429, 364/439, 364/441, 364/461, 364/462, 342/29, 342/36, 342/453, 342/65
• US Class Current: 340/961
• CPC Class Codes: F41G 7/343 comparing observed and stored data of target position or of distinctive marks along the path towards the target
• CPC Class Codes: G01C 21/005 with correlation of navigation data from several sources, e.g. map or contour matching G01C21/30 takes precedence
• CPC Class Codes: G05D 1/0202 specially adapted to aircraft

Abstract

A computer-based process for rapidly responding to previously unknown threats to airborne aircraft. The process makes quick, automatic decisions when required for close-range threats, yet provides the aircraft operator an opportunity to choose the appropriate response when time permits.

Claims

1. A computerized method for an airborne aircraft to respond to an unknown threat where the aircraft detects a previously unknown threat, comprising the following steps:

determining a zone of intervisibility for the previously unknown threat;

determining if an aircraft'"'"'s planned route intersects the zone of intervisibility with the threat;

if not, maintaining the aircraft'"'"'s planned route;

if intersection of aircraft'"'"'s planned route with the zone of intervisibility is less than a predetermined distance from the aircraft, automatically executing a lateral route change;

if intersection of aircraft'"'"'s planned route with the zone of intervisibility is greater than the predetermined distance from the aircraft, notifying an aircraft operator of the threat and checking the threat against set clearance levels to determine if the aircraft'"'"'s planned route may be followed at another acceptable set clearance level; and

if another acceptable set clearance level is found, permitting the operator to choose between following the aircraft'"'"'s planned route at said acceptable set clearance level or choosing the lateral route change.

2. The method of claim 1 wherein the step of executing a route change comprises:

calculating a startpoint for the route change;

determining the next waypoint in the planned route beyond the startpoint; and

if the next waypoint is less than a predetermined distance from the aircraft, choosing a waypoint following the next waypoint as an endpoint for the route change.

3. The method of claim 2 wherein the step of executing a route change further includes:

if the next waypoint is greater than the predetermined distance from the aircraft, choosing the next waypoint as the endpoint for the route change, unless a threat'"'"'s intervisibility also intersects the route planned between the next waypoint and the following waypoint.

4. The method of claim 1 including:

if no acceptable set clearance level is found, automatically executing a route change.

5. A system for an airborne aircraft to respond to an unknown threat where the aircraft detects a previously unknown threat, comprising:

means for determining a zone of intervisibility for the previously unknown threat;

means for determining if an aircraft'"'"'s planned route intersects a zone of intervisibility with the threat and for responding as follows;

if not, maintaining the aircraft'"'"'s planned route;

if intersection of aircraft'"'"'s planned route with the zone of intervisibility is less than a predetermined distance from the aircraft, automatically executing a lateral route change;

if the intersection is greater than the predetermined distance from the aircraft, notifying an aircraft operator of the threat and checking the threat against set clearance levels to determine if the aircraft'"'"'s planned route may be followed at another, acceptable set clearance level; and

if an acceptable set clearance level is found, permitting the operator to change between following the aircraft'"'"'s planned route at said acceptable set clearance level or choosing the lateral route change.