Air traffic management evaluation tool

• US 7,702,427 B1
• Filed: 07/30/2004
• Issued: 04/20/2010
• Est. Priority Date: 07/30/2004
• Status: Active Grant

• Current Assignee: USA As Represented By The Administrator Of The NASA
• Original Assignee: The United States Of America As Represented By The National Aeronautics And Space Administration
• Inventors: Bilimoria, Karl D., Chatterji, Gano Broto, Grabbe, Shon, Sheth, Kapil S., Sridhar, Banavar, Schipper, John F.
• Primary Examiner(s): Tran; Khoi
• Assistant Examiner(s): Amin; Bhavesh V
• Application Number:
  US10/914,783
• Time in Patent Office: 2,090 Days
• Field of Search: 701/3, 701/120, 701/121, 701/122, 701/300, 701/301
• US Class Current: 701/4
• CPC Class Codes: G08G 5/045 Navigation or guidance aids, e.g. determination of anti-collision manoeuvers radar or analogous systems specially adapted for anti-collision between aircraft G01S13/933

Abstract

Method and system for evaluating and implementing air traffic management tools and approaches for managing and avoiding an air traffic incident before the incident occurs. The invention provides flight plan routing and direct routing or wind optimal routing, using great circle navigation and spherical Earth geometry. The invention provides for aircraft dynamics effects, such as wind effects at each altitude, altitude changes, airspeed changes and aircraft turns to provide predictions of aircraft trajectory (and, optionally, aircraft fuel use). A second system provides several aviation applications using the first system. These applications include conflict detection and resolution, miles-in trail or minutes-in-trail aircraft separation, flight arrival management, flight re-routing, weather prediction and analysis and interpolation of weather variables based upon sparse measurements.

Claims

1. A method for estimating a minimum distance of approach of two aircraft that are airborne, the method comprising:

providing information on an initial location vector r0(t=t1;

n), on an initial velocity vector r1(t=t1;

n) and on an initial acceleration vector r2(t=t1;

n) at a selected time t=t1, for each of N aircraft, numbered n=1, . . . , N (N≧

2) that are airborne;

approximating said location vector r(t;

n) for aircrafts number n=n1 and n=n2 (n1≠

n2) over a selected time interval [t1,t2] by quadratic vector functions of time,

r(t;

n1;

app)=r0(n1)+r1(n1)·

(t−

t1)+r2(n1)·

(t−

t1)²,

r(t;

n2;

app)=r0(n2)+r1(n2)·

(t−

t1)+r2(n2)·

(t−

t1)²,

Δ

r(t;

app)=r(t;

n1;

app)−

r(t;

n2;

app)=Δ

r0+Δ

r1(t−

t1)+Δ

r2(t−

t1)²,

respectively, where t1 is a selected time within a selected time interval [T1,T2], each of the location vectors r(t;

n1;

app) and r(t;

n2;

app) substantially describes motion on a great circle in a plane, and the vector coefficients r0;

n1), r1(n1), r2(n1), r0(n2), r1(n2) and r2(n2) are chosen to optimally match the vector functions r(t;

n1;

app) and r(t;

n2;

app) in the selected time interval [T1,T2]; and

estimating a minimum distance of approach d(min) for a magnitude |r(t;

n1)−

r(t;

n2)| of a vector difference, by identifying at least one real time t(min) for which a time derivative of the quantity |r(t;

n1)−

r(t;

n2)|² is zero,

2Δ

r0Δ

r1+{Δ

r1·

Δ

r1+2Δ

r0·

Δ

r2)(t−

t1)+6Δ

r1·

Δ

r2(t−

t1)²+4Δ

r2·

Δ

r2(t−

t1)³=0,

and by interpreting the vector magnitude |r(t=t(min);

n1)−

r(t=t(min);

n2)| as the minimum distance d(min).

10. The method of claim 1, further comprising:

when said minimum distance of approach is less than a selected threshold number for a value of said time t=t(min) within said selected time interval [t1,t2], advising at least one of said aircraft number n1 and number n2 interpreting this condition as indicating that an aircraft conflict is likely to occur between said aircrafts n=n1 and n=n2 within said selected time interval; and

when an aircraft conflict is determined to be likely to occur, allowing at least one of said aircraft number n=n1 and n=n2 to adopt a conflict avoidance response from a group of avoidance responses comprising;

(1) changing a heading angle for said at least one of said aircrafts number n=1 and n=2;

(2) changing a velocity vector for said at least one of said aircrafts number n=1 and n=2;

(3) changing a magnitude of at least one of said initial velocity vectors v₀₁ and v₀₂;

(4) changing an altitude of flight for said at least one of said aircrafts number n=1 and n=2; and

(5) changing at least one of an aircraft ascent rate and an aircraft descent rate for at least one of said aircrafts number n=1 and n=2.

11. The method of claim 1, further comprising providing a desired route for at least one aircraft that is substantially at least one of a wind-optimal route and an NPR route.

12. The method of claim 1, further comprising choosing said selected difference value to lie in a range of 3-5 nautical miles in a horizontal direction and 1000-2000 feet in a vertical direction.

2. A method for managing aircraft traffic, the method comprising:

providing information on location vector r_n(t=tm) and velocity vector v_n(t=tm) for each of N aircraft, numbered n=1, . . . , N (N≧

2) that are airborne and are located within a selected air route traffic control center (ARTCC), for at least one selected time t=tm, where each of the N aircraft is assigned to at least one ARTCC sector, numbered s=1, . . . , S (S≧

2) in the selected ARTCC;

at a time, t=tm′

>

tm, altering at least one boundary of each of at least two selected adjacent ARTCC sectors, numbered s=s1 and s=s2 (s1≠

s2), within the selected ARTCC to provide altered sectors, numbered s=s1′ and

s=s2′

, respectively, where the union of the at least two selected adjacent sectors encloses the union of the at least two altered sectors; and

providing information on location vector r_n(t=tm′

) and velocity vector v_n(t=tm′

) for each of the N aircraft, that is airborne and is located within the selected ARTCC, for the time t=tm′

, where each of the N aircraft is assigned to at least one ARTCC sector, numbered s=1, . . . , S (S≧

2) in the selected ARTCC.

3. A method for managing aircraft traffic, the method comprising:

providing information on an initial location vector r_0n(t=t0) and an initial velocity vector v_0n(t=t0) for each of N aircraft, numbered n=1, . . . , N (N≧

2) that are airborne;

approximating the location vector r(t;

n) for the aircraft number n=n1 and for the aircraft n=n2 (n1≠

n2;

n1, n2≦

N) by vector functions that are at least quadratic in a time variable t,

r(t;

n1;

app)=r0(t;

n1)+r1(t;

n1)·

(t−

t0)+r2(t;

n1)(t−

t0)²,

r(t;

n2;

app)=r0(t;

n2)+r1(t;

n2)·

(t−

t0)+r2(t;

n2)(t−

t0)²,

respectively, relative to a selected initial time t0, where each of the location vectors r(t;

n1) and r(t;

n2) substantially describes motion on a great circle in a plane, and the vector coefficients r0(t;

n1), r1(t;

n1), r2(t;

n1), r0(t;

n2), r1(t;

n2) and r2(t;

n2) are chosen to optimally match the vector functions r(t;

n1) and r(t;

n2) in a selected time interval [t1,t2]; and

determining a descent-start location at which the aircraft should begin its descent toward a destination airport along a substantially linear descent path, where an altitude descent rate experienced by the aircraft is a selected fraction f (0<

f≦

1) of a maximum altitude descent rate.

4. A method for managing aircraft traffic, the method comprising:

providing information on an initial location vector r_0n(t=t0) and an initial velocity vector v_0n(t=t0) for each of N aircraft, numbered n=1, . . . , N (N≧

2) that are airborne;

approximating the location vector r(t;

n) for the aircraft number n=n1 and for the aircraft n=n2 (n1≠

n2;

n1, n2≦

N by vector functions that are quadratic in a time variable t,

r(t;

n1;

app)=r0(t;

n1)+r1(t;

n1)·

(t−

t0)+r2(t;

n1)·

(t−

t0)²,

r(t;

n2;

app)=r0(t;

n2)+r1(t;

n2)·

(t−

t0)+r2(t;

n2)(t−

t0)²,

respectively, relative to a selected initial time t0, where each of the location vectors r(t;

n1) and r(t;

n2) substantially describes motion on a great circle in a plane, and the vector coefficients r0(t;

n1), r1(t;

n1), r2(t;

n1), r0(t;

n2), r1(t;

n2) and r2(t;

n2) are chosen to optimally match the vector functions r(t;

n1) and r(t;

n2) in a selected time interval [t1,t2];

providing an estimate of a wind velocity vector v_w=(v_w cos θ

_w,v_w sin θ

_w) at a specified location, where v_w is an estimated magnitude of the wind velocity vector and θ

_w is an angle of the wind velocity vector measured relative to a selected reference line or reference plane;

providing an estimate of a desired angle θ

_des of travel of said aircraft in an environment including the estimated wind velocity vector; and

orienting a velocity vector associated with said aircraft at an angle θ

_comp relative to the reference line or plane, where θ

_comp is determined by

tan θ

_comp={v_des sin θ

_des−

v_w sin θ

_w}/{v_des cos θ

_des−

v_w scos θ

_w}.

5. A method for managing aircraft traffic, the method comprising:

providing information on an initial location vector r_0n(t=t0) and an initial velocity vector v_0n(t=t0) for each of N aircraft, numbered n=1, . . . , N (N≧

2) that are airborne;

approximating the location vector r(t;

n) for the aircraft number n=n1 and for the aircraft n=n2 (n1≠

n2;

n1, n2≦

N) by vector functions that are quadratic in a time variable t,

r(t;

n1;

app)=r0(t;

n1)+r1(t;

n1)·

(t−

t0)+r2(t;

n1)·

(t−

t0)²,

r(t;

n2;

app)=r0(t;

n2)+r1(t;

n2)·

(t−

t0)+r2(t;

n2)(t−

t0)²,

respectively, relative to a selected initial time t0, where each of the location vectors r(t;

n1) and r(t;

n2) substantially describes motion on a great circle in a plane, and the vector coefficients r0(t;

n1), r1(t;

n1), r2(t;

n1), r0(t;

n2), r1(t;

n2) and r2(t;

n2) are chosen to optimally match the vector functions r(t;

n1) and r(t;

n2) in a selected time interval [t1,t2];

providing an estimate of a wind velocity vector v_w=(v_w cos θ

_w,v_w sin θ

_w) at a specified location, where v_w is an estimated magnitude of the wind velocity vector and θ

_w is an angle of the wind velocity vector measured relative to a selected reference line or reference plane;

providing an estimate of a desired angle θ

_des of travel and a desired magnitude of velocity of travel v_des of said aircraft;

providing an estimate of a desired magnitude of velocity of travel v_des in an environment including the estimated wind velocity vector; and

providing said aircraft with an associated magnitude of aircraft velocity v_comp, in the absence of said wind velocity vector, that is given by

v_comp={v_des²+v_w²−

2v_{des vw} cos(θ

_des−

θ

_w)}^1/2.

6. A method for managing aircraft traffic, the method comprising:

receiving and storing in a database an estimated location vector for a sequence of times over a time interval that includes at least at two flight days; and

using information in the database to estimate a number of flights in a selected region, including at least one identified ARTCC sector, for at least one prediction time that is not included in the at least two flight days;

estimating a number of aircraft that will be located in the selected region at each of a second selected sequence of times; and

when the at least one identified ARTCC sector will contain more than a selected threshold number of the aircraft at an identified time among the second sequence of times, changing at least one boundary between the at least one identified ARTCC sector and an adjacent ARTCC sector to reduce the number of aircraft contained in the at least one identified ARTCC sector at a time preceding the identified time; and

displaying a selected area including the selected region, after the at least one boundary is changed, in a visually distinguishable format, when the selected region will contain no more than the selected threshold number of the aircraft at the identified time.

7. A method for managing aircraft traffic, the method comprising:

receiving and storing in a database an estimated location vector and estimated velocity vector for each of N aircraft (N≧

2) at each of a selected sequence of times over a time interval that includes at least at two flight days;

using information in the database to estimate a number of flights within an identified ARTCC sector, including a selected airport at which the N aircraft are expected to land, for at least one prediction time that is not included in the at least two flight days;

estimating a number of the N aircraft that will descend and land at the selected airport within each of a selected sequence of time intervals; and

estimating a demand on at least one of (i) at least one runway at the selected airport and (ii) a selected group of arrival-departure gates at the selected airport.

8. A method for managing aircraft traffic, the method comprising:

receiving and storing in a database an estimated location vector and estimated velocity vector for each of N aircraft (N≧

2) at each of a selected sequence of times over a time interval that includes at least at two flight days;

using information in the database to estimate a number of flights within an identified ARTCC sector, including a selected airport at which the N aircraft are initially located, for at least one prediction time that is not included in the at least two flight days;

estimating a number of the N aircraft that will take off and ascend from the selected airport within each of a selected sequence of time intervals;

estimating a demand on at least one of (i) at least one runway at the selected airport and (ii) a selected group of arrival-departure gates at the selected airport;

providing information on an initial location vector r_0n(t=t0) and an initial velocity vector v_0n(t=t0) for each of N aircraft, numbered n=1, . . . , N (N≧

2) that are airborne;

aircraft at a time t(est) that is displaced from an initial time t0 by approximate time increments Δ

tm, numbered m=1, . . . , M (M≧

2), where 0<

Δ

t1<

Δ

t2≦

. . . <

Δ

tM; and

where the magnitude |r₀₁−

r₀₂| of the difference of the location vectors of aircrafts number n=1 and n=2 is estimated to be less than a selected difference value for at least one of the time increments Atm, assigning a conflict avoidance response to at least one of the aircrafts number n=1 and n=2 so that, with the conflict avoidance response implemented, the magnitude of the difference of the location vectors of aircrafts number n=1 and n=2 for each of the time increments Δ

tm is no less than the selected difference value.

9. A method for estimating a minimum distance of approach of two aircraft that are airborne, the method comprising:

providing information on an initial location vector r0(n)=r(t=t1;

n) and an initial velocity vector v0(n)=v(t=t1;

n) for each of N aircraft, numbered n=1, . . . , N (N≧

2) that are airborne;

estimating a location separation vector Δ

r(t;

n) for each of at least two aircraft, number n=n1 and n=n2 (n1≠

n2), as Δ

r(t;

n)=r0(n)+v0(n)(t−

t1) for a selected reference time t1;

estimating a time at which a minimum distance of separation occurs for the aircraft, n=n1 and n=n2, to be about Δ

t(min)=t1−

(Δ

r_1,2·

Δ

v_,2)/)/(Δ

v_1,2)², where Δ

r_1,2=r0(n1)−

r0(n2) and Δ

v_1,2=v0(n1)−

v0(n2); and

estimating a minimum distance of separation to be about |Δ

r(min)|={Δ

r_1,2²Δ

v_1,2²−

Δ

r_1,2·

Δ

v_1,2)}/(Δ

v_1,2)².