Automatic aircraft separation assurance

Abstract

The present invention replaces the use of a pilot information display method and instead relies upon an automated three dimensional aircraft tracking system using only aircraft tracking data supplied by internal spherical coverage dual mode sensor system. Separation is accurately predicted and minimum flight path separation (from all nearby aircraft) is automatically assured by signals to the aircraft flight control system without action or intervention by the pilot. When predicted separation is less than minimum separation for the host aircraft, flight control is temporarily removed from the pilot until the automated system redirects the flight path to enable the predicted separation to exceed the minimum separation for the host aircraft. When on-board sensor system predicts separation greater than required minimum, then flight control is returned to the pilot.

Description

REFERENCES CITED

U.S. Pat. No. 8,744,738 June 2014 Bushwell

This patent describes prediction of flight path for own aircraft and for second aircraft, determines minimum projected separation, but relies on data supplied from external data sources. No description of on-board sensor data to provide tracking data for second aircraft

U.S. Pat. No. 8,380,424 February 2013 Bushwell

This patent describes prediction of flight path for own aircraft and for second aircraft, determines minimum projected separation, but relies on data supplied from external data sources. No description of on-board sensor data to provide tracking data for second aircraft

U.S. Pat. No. 7,706,979 April 2010 Hefferwitz

Data source used for developing tracking predictions and separation are only from outside the aircraft. No description of on-board sensing.

U.S. Pat. No. 7,580,776 August 2009 McCusker

This patent has no description of on board sensor capability, but does use path prediction to project minimum separation. Pilot notified, pilot has final responsibility for collision avoidance.

All current references and published literature for aircraft separation assurance and/or air traffic collision avoidance systems are based on using data supplied by external sources, and/or internal data sources, but wherein pilot (human operator) has ultimate responsibility for air collision prevention (URCP). Pilot's own aircraft flight path control (whether pilot is in cockpit or in a ground station for UAS) is via manual operational control means. Pilot flight path control is optionally aided by automated navigation and flight control systems that collect and employ the referenced external/internal data sources. The pilot is assisted by displays during manual and automated flight control, including those displays associated with an on-board Traffic Collision Avoidance System (TCAS, when that system is installed). Result is that pilot (human) inspection of a display plus exercise of human judgement is required before adequate separation from other aircraft can be achieved for the host aircraft. This shortcoming of existing flight control systems can result in pilot error regarding maintenance of adequate separation and guarantee of collision avoidance at all times. Elevation of the separation assurance (and collision avoidance) probability (to level that is guaranteed) requires the temporary elimination of the human pilot (on the ground or in the cockpit) in the flight control loop. That probability elevation step requires use of an on-board system that is independent of all external sources of traffic control data. Guarantee of automatic separation assurance under the described invention is enabled by incorporation of features that also automatically and continually calibrate and functionally validate reliable system operation. Therefore, the method and system herein described temporarily accepts and guarantees URCP.

The present invention replaces the use of a pilot information display method and instead relies upon an automated three dimensional aircraft tracking system so that separation is accurately measured and minimum flight path separation (from all nearby aircraft) is automatically assured by signals to the aircraft flight control system without action or intervention by the pilot. The pilot will be notified by a display that the automated separation assurance system is temporarily controlling the aircraft flight and the pilot will again be notified when flight control is returned to the pilot. Three dimensional separation tracking is enabled by use of dual sensor modes; that is use of co-bore-sighted high resolution three dimensional radar with two dimensional electro-optical camera. This use of three dimensional tracking assures higher reliability of the separation assurance system and allows the separation assurance and collision avoidance to be automated. This system eliminates any possible pilot error and results in greater air safety for manned or unmanned aircraft. A display showing minimum separation distance (in KM), based upon tracking data and projected flight path for all aircraft in the vicinity is provided at all times to the pilot of a manned aircraft or to the operator of unmanned aircraft. This data provides direct evidence that the system is functional and reliable. This system only removes flight control from the pilot if separation distance is compromised and only for a brief period of time until separation distance is restored to a value higher than the minimum. This automated system operates in virtual real time and has higher probability of preventing collision threat from nearby aircraft that systems that rely on pilot display and pilot decision by eliminating all possibility of human error.

Table of Claims Comparison
Claim # and Summary	U.S. Pat. No. 8,744,738	U.S. Pat. No. 7,706,979	U.S. Pat. No. 7,580,776
1 Automatic Separation	Path prediction based on	Path prediction depends	Relies upon external
Assurance Sensor suite	externally supplied data	on externally supplied	data inputs to predict
uses dual mode sensor	generating commands to	data or use of	aircraft path; collision
(radar plus EO/IR	pilot for separation;	transponders (not on all	avoidance depends
camera) using only	commands that may be	aircraft) so method is	upon pilot decision,
internal sensor to	result in pilot decision	not universal to	which may be in error
eliminate pilot error &	error. No spherical sensor.	guarantee collision	based on supplied
2 ASAS	Computer predicts time of	Estimation of time of	No corresponding
characterized by	closest approach based	closest approach based	claim
on-board dual	on external inputs; no	on stored equations
mode sensor	internal sensor provides	using externally
having spherical	certain data for reliability	supplied data on aircraft
field-of-regard	of such prediction	future path
3 AASA spherical	Internal hemispherical	Additional cubic	No corresponding
coverage by combining	sensors not described	equation but no	claim
two opposing		external sensor to
hemispherical sensor		assure separation
4 Multiplicity of on-	Breach of closest	Estimated aircraft	No corresponding
board dual mode	approach based on	position vectors	claim
sector sensors make	external data, not on-	obtained from external
up the hemispherical	board sensor	sources
5 On-board Sector	Flight control commands	Air vehicle avoidance	No corresponding
sensors are dual mode	generated from external	by pilot flight control	claim
using radar and camera	data	using 3D display of
6 On-board 3D	Computer	Graphic	No on-
radar plus 2D	generates	displays for	board
video provide	commands	pilot based	sensor
data for	based on	on external	claim
7 3D tracking	Computer	Aircraft	No on-
provided by processor	alters flight	position	board
fusion of outputs from	path based on	vectors	sensor
two on-board sensors	externally	determined	claim
	supplied data	from
8 Hemispherical	Aircraft maneuver	Estimated closest	No corresponding
field-of-regard	altered by flight control	approach by computer	claim
provided by	based on externally	from external data for
combining on-board	supplied aircraft	pilot in cockpit or at
sensor output data	position data	ground station of
from sector field-of-		unmanned aircraft
view for all sectors
in the hemisphere
9 Spherical Field-	Commands for	Aircraft position	No corresponding
of-Regard	aircraft maneuver	projection and	claim
covered by	altered by flight	maneuver altered by
combining	control based on	flight control based
coverage of two	externally supplied	on externally
on-board	aircraft position data	supplied aircraft
10 Processor	Separation distance	Estimated closest	No corresponding
predicts	prediction is based on	approach by computer	claim
minimum	externally supplied	from external data for
separation	position data which may	pilot in cockpit or at
distance from	omit certain nearby	ground station of
on-board sensor	aircraft having lesser	unmanned aircraft but
tracking data for	separation distance	not tracking nearby non-
spherical field-		cooperating aircraft
of-regard
11 Processor	Pilot makes the decision	Graphic display for pilot	No corresponding
temporarily	to change aircraft flight	is used by pilot to	claim
disables pilot	if display indicates	enable flight control
flight control if	separation distance is	system to change
separation	less than minimum	direction if separation
distance is	separation distance	distance is below
below minimum		minimum separation
separation		distance for host aircraft
distance for
12 Cockpit	No indication in claims	2D or 3D display	No corresponding
display provided	that aircraft position and	provides prediction of	claim
indicating	minimum separation	separation distance
separation	distance is presented to	computation based on
distance	pilot on a cockpit display	externally supplied data
determined from		by GPS or other
on-board		external means
spherical dual
mode sensor
13 Processor	On board computer	Computer programmed	No corresponding
commands from	sends commands for	to reduce the delta	claim
on-board sensor	flight maneuver based	separation using
to flight control	on data provided by	external data from
enable reduction	external sources	satellite or other
in predicted		sources
separation
14 Pilot display	Pilot has flight control at	Computer programmed	No corresponding
indicator that	all times and makes any	to reduce predicted path	claim
pilot flight	decision to avoid	delta using externally
control has been	possible collision. Pilot	supplied location data
disabled when	error is not removed as	for host and other
predicted	possible cause for	aircrafts. Pilot controls
minimum	collision	flight path
separation has
been breached
15 When	Separation module	Computer estimates air	No corresponding
predicted	provides prediction of	vehicle position for	claim
separation	separation for the pilot	cockpit display enabling
exceeds	who retains flight control	pilot to operate flight
minimum	based on externally	controls to avoid
separation then	supplied location data.	collision. Possible pilot
pilot control is	Collision can result from	error is not avoided
restored based	pilot error or unreliable
on data from on-	external data
indicates data missing or illegible when filed

TECHNICAL FIELD

The invention relates to the field of avionics airborne flight safety and in particular to an apparatus and method for automatic air vehicle separation assurance (and collision avoidance) that eliminates any possibility for pilot error aboard a host aircraft (or at ground station for unmanned aircraft) or failure of external flight traffic control systems data input. Elimination of pilot or human error potentially elevates aircraft, separation assurance, collision avoidance and aviation safety to a new level for manned and unmanned aircraft.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a drawing of an aircraft in which forward and rearward hemispherical, 4Pi steradians, field-of-regard (180 degrees by 180 degrees) are shown along with indication of a small conical sector field-of-view (about 30 degrees by 30 degrees)

FIG. 2 is drawing of a hemispherical subsystem indicating separate conical sectors covering the entire 2Pi field-of-regard.

FIG. 3 is a block diagram for the Automatic Aircraft Separation Assurance sensor suite system

DETAILED DESCRIPTION OF THE INVENTION

A sensor suite for a host aircraft (10) extends the field-of-regard to full spherical coverage, 4Pi steradians. The method and apparatus makes use of two hemispherical sensor subsystems as shown in FIG. 1. A first hemispherical subsystem field-of-regard (12) is directed forward of the aircraft (10) while a second hemispherical subsystem field-of-regard (11) is directed to the rear. Each hemispherical subsystem field-of-regard is composed of many instantaneous search sectors (13) each operating a dual mode sensor for detecting, tracking and characterizing other aircraft.

Drawing of an exemplary dual mode sensor hemispherical subsystem (20) is shown in FIG. 2. Individual sector conical fields-of-view (22) for radar sensor and EO/IR camera are positioned over a conical surface (21). One radar antenna option is a flat patch array (23), however, alternative antenna types include horn, horn-lens, etc. EO/IR camera apertures (24) share the field-of-view sector with a radar sensor antenna (23) and are typically co-boresighted with a radar beam.

A block diagram for the spherical coverage dual mode automatic aircraft separation assurance system (30) is presented in FIG. 3. A forward-directed hemispherical sensor subsystem (32) and a rear-directed hemispherical sensor subsystem (31) are indicated. Output (36) of forward-directed hemispherical subsystem (32) is connected to processor (33). Output (37) of rear-directed hemispherical subsystem (31) is connected to processor (33). Output (38) of the processor (33) is connected to the pilot display (34). A second output (39) of the processor (33) is connected to the host aircraft flight control system (35).

Claims

1. Automatic Aircraft Separation Assurance apparatus and method disposed aboard a host aircraft requiring minimum separation distance, said apparatus including a sensor suite, processor, separation assurance algorithms and pilot display, said method detecting and tracking all aircraft in the spherical field-of-regard of said host aircraft, said processor predicting said host aircraft separation distance, said pilot display informing pilot of predicted separation distance, said pilot display alerting pilot if flight control is removed from the pilot. Said processor operating said separation assurance algorithms on said sensor suite tracking data predicting said host vehicle tracking separation below specified minimum separation for said host aircraft, said AASA apparatus temporarily suspending pilot flight control, supplies direction/altitude commands to said host aircraft flight control system, indicates via said pilot display suspension of pilot flight control. Said direction/altitude commands enable increased tracking separation of said host aircraft to exceed said minimum separation distance. Said sensor suite track data processor separation assurance algorithms return pilot flight control when said separation distance exceeds said minimum separation distance.

2. The AASA apparatus of claim 1 further characterized by dual mode sensor suite for detection and tracking of aircraft in said spherical field-of-regard of said host aircraft.

3. The AASA apparatus of claim 1 further characterized by said dual mode sensor suite having first hemispherical dual mode sensor subsystem mounted and aligned with said host vehicle flight path direction plus second hemispherical dual mode sensor subsystem aligned with said first hemispherical dual mode sensor directed opposing said flight path direction.

4. The AASA apparatus of claim 1 further characterized by said hemispherical dual mode sensor subsystem consisting of a multiplicity of dual mode sector sensors arrayed on a hemispherical surface.

5. The AASA apparatus of claim 1 further characterized by said dual mode sector sensors covering a specified angular sector field-of-view of said hemispherical field-of-regard.

6. The AASA apparatus of claim 1 further characterized by said dual mode sector sensor consisting of three dimensional radar sensor disposed and aligned with two dimensional electro-optical video sensor sharing said sector field-of-view.

7. The AASA apparatus of claim 1 further characterized by said processor fusing output of said three dimensional radar sensor with output of said two dimensional electro-optical sensor to provide three dimensional tracking data for all detected aircraft in said sector field-of-view of said hemisphere field-of-regard.

8. The AASA apparatus of claim 1 further characterized by said processor combining three dimensional tracking data for said host aircraft in said sector field-of-view with three dimensional tracking data for said aircraft from all said dual mode sensor sectors in said first hemispherical field-of-regard.

9. The AASA apparatus of claim 1 further characterized by said processor three dimensional tracking data for said host aircraft spherical field-of-regard combining three dimensional tracking data for first hemispherical field-of-regard with three dimensional tracking data for said host aircraft second hemispherical field-of-regard.

10. The AASA apparatus of claim 1 further characterized by said processor predicting minimum separation distance enabled by said separation assurance algorithms operating on said three dimensional tracking data in said spherical field-of-regard.

11. The AASA apparatus of claim 1 further characterized by said processor temporarily disabling pilot flight control when said predicted separation distance is below said minimum separation distance for said host aircraft.

12. The AASA apparatus of claim 1 further characterized by said cockpit display of said predicted separation distance.

13. The AASA apparatus of claim 1 further characterized by said processor commands to said flight control system enabling change in said host aircraft direction and/or altitude to reduce predicted separation distance.

14. The AASA apparatus of claim 1 further characterized by said cockpit display indicator that pilot flight control has been disabled because said aircraft minimum separation distance has been breached.

15. The AASA apparatus of claim 1 further characterized by said cockpit display that pilot flight control has been restored when said minimum separation distance predicted by said processor has been exceeded.