Scalar product based spacing calculation

Patent metadata

Field	Value
Publication number	US-9384667-B2
Application number	US-201414334332-A
Country	US
Kind code	B2
Filing date	Jul 17, 2014
Priority date	Jul 17, 2014
Publication date	Jul 5, 2016
Grant date	Jul 5, 2016

Abstract

A method is described that includes receiving, by a spacing system of an ownship aircraft, a current position of the ownship aircraft and a reference position of a target aircraft, wherein the reference position is a position of the target aircraft prior to a current position of the target aircraft. The method may also include, projecting, by the spacing system of the ownship aircraft, the reference position on a trajectory of the ownship aircraft, determining a first distance between the projected reference position and the current position, projecting, by the spacing system of the ownship aircraft, the current position on a trajectory of the reference position, determining a second distance between the projected current position and the reference position, and adjusting, by the spacing system and based on an average between the first distance and the second distance, a velocity of the ownship aircraft.

First claim

What is claimed is:

1. A method comprising:
receiving, by a spacing system of an ownship aircraft, a current position of the ownship aircraft and a reference position of a target aircraft, wherein the reference position is a position of the target aircraft prior to a current position of the target aircraft;
projecting, by the spacing system of the ownship aircraft, the reference position on a trajectory of the ownship aircraft;
determining a first distance between the projected reference position and the current position of the ownship aircraft;
projecting, by the spacing system of the ownship aircraft, the current position of the ownship aircraft on a trajectory of the reference position;
determining a second distance between the projected current position of the ownship aircraft and the reference position; and
adjusting, by the spacing system and based on an average between the first distance and the second distance, a velocity of the ownship aircraft.

2. The method of claim 1 , wherein determining the first distance comprises:
subtracting the current position of the ownship aircraft from the reference position;
applying a dot product of a velocity vector of the reference position; and
dividing by a magnitude of the velocity vector of the reference position.

3. The method of claim 1 , wherein determining the second distance comprises:
subtracting the current position of the ownship aircraft from the reference position;
applying a dot product of a velocity vector of the current position of the ownship aircraft; and
dividing by a magnitude of the velocity vector of the current position of the ownship aircraft.

4. The method of claim 1 , wherein determining the first distance comprises:
determining an angle alpha, wherein the angle alpha is an angle between a position vector and a velocity vector of the current position of the ownship aircraft; and
applying a cosine of the angle alpha.

5. The method of claim 4 , wherein the position vector is between the current position of the ownship aircraft and the reference position.

6. The method of claim 1 , wherein determining the second distance comprises:
determining an angle alpha minus gamma, wherein the angle alpha minus gamma is an angle of a position vector and a velocity vector of the current position of the ownship aircraft minus the angle between a velocity vector of the reference position and the velocity vector of the current position of the ownship aircraft; and
applying a cosine of the angle alpha minus gamma.

7. The method of claim 6 , wherein the position vector is between the current position of the ownship aircraft and the reference position.

8. A method comprising:
receiving, by a spacing system of an ownship aircraft, a current position of the ownship aircraft and a reference position of a target aircraft, wherein the reference position is a position of the target aircraft prior to a current position of the target aircraft;
projecting, by the spacing system of the ownship aircraft, the reference position on a trajectory of the ownship aircraft;
determining a first time difference between the projected reference position and the current position of the ownship aircraft;
projecting, by the spacing system of the ownship aircraft, the current position of the ownship aircraft on a trajectory of the reference position;
determining a second time difference between the projected current position of the ownship aircraft and the reference position; and
adjusting, by the spacing system and based on an average between the first time difference and the second time difference, a velocity of the ownship aircraft.

9. The method of claim 8 , wherein determining the first time difference comprises:
subtracting the current position of the ownship aircraft from the reference position;
applying a dot product of a velocity vector of the reference position; and
dividing by a squared magnitude of the velocity vector of the reference position.

10. The method of claim 8 , wherein determining the second time difference comprises:
subtracting the current position of the ownship aircraft from the reference position;
applying a dot product of a velocity vector of the current position of the ownship aircraft; and
dividing by a squared magnitude of the velocity vector of the current position of the ownship aircraft.

11. A spacing system comprising:
a spacing module located on an ownship aircraft, wherein the spacing module is configured to:
receive a current position of the ownship aircraft and a reference position of a target aircraft, wherein the reference position is a position of the target aircraft N seconds prior to a current position of the target aircraft;
project the reference position on a trajectory of the ownship aircraft;
determine at least one of a first distance or a first time difference between the projected reference position and the current position of the ownship aircraft;
project the current position of the ownship aircraft on a trajectory of the reference position;
determine at least one of a second distance or a second time difference between the projected current position of the ownship aircraft and the reference position; and
adjust a velocity of the ownship aircraft based on an average between at least one of the first distance and the second distance or the first time difference and the second time difference.

12. The system of claim 11 , wherein to determine the first distance, the spacing module is further configured to:
subtract the current position of the ownship aircraft from the reference position;
apply a dot product of a velocity vector of the reference position; and
divide by a magnitude of the velocity vector of the reference position.

13. The system of claim 11 , wherein to determine the second distance, the spacing module is further configured to:
subtract the current position of the ownship aircraft from the reference position;
apply a dot product of a velocity vector of the current position of the ownship aircraft; and
divide by a magnitude of the velocity vector of the current position of the ownship aircraft.

14. The system of claim 11 , wherein to determine the first distance, the spacing module is further configured to:
determine an angle alpha, wherein the angle alpha is an angle between a position vector and a velocity vector of the current position of the ownship aircraft; and
apply a cosine of the angle alpha.

15. The system of claim 11 , wherein to determine the second distance, the spacing module is further configured to:
determine an angle alpha minus gamma, wherein the angle alpha minus gamma is an angle of a position vector and a velocity vector of the current position of the ownship aircraft minus an angle between a velocity vector of the reference position and the velocity vector of the current position of the ownship aircraft; and
apply a cosine of the angle alpha minus gamma.

16. The system of claim 11 , wherein to determine the first time difference, the spacing module is further configured to:
subtract the current position of the ownship aircraft from the reference position;
apply a dot product of a velocity vector of the reference position; and
divide by a squared magnitude of the velocity vector of the reference position.

17. The system of claim 11 , wherein to determine the second time difference, the spacing module is further configured to:
subtract the current position of the ownship aircraft from the reference position;
apply a dot product of a velocity vector of the current position of the ownship air

Assignees

• Honeywell Int Inc

Inventors

• Klang Pavel
• Casek Petr
• Brazdilova Silvie Luisa

Classifications

• G01C21/20

  Instruments for performing navigational calculations (G01C21/24, G01C21/26 take precedence) · CPC title

• G01C23/005

  Flight directors (indicating arrangements specially adapted for rotary gyroscopes G01C19/32) · CPC title

• G08G5/727

  from a ground station · CPC title

• G08G5/723

  from the aircraft · CPC title

• G08G5/70

  Arrangements for monitoring traffic-related situations or conditions · CPC title