Flight management system providing minimum total cost
First Claim
1. Flight Management System apparatus for aircraft comprisingmeans for generating a DOC signal which is a function of direct operating cost (DOC) versus arrival time in accordance with a range of cost index values,means for storing values of arrival time error cost (AEC) versus arrival time error and providing an AEC signal which is function of said values,means for combining said DOC signal with said AEC signal to provide a total flight cost signal which is a function of total flight cost, thereby establishing a signal representative of total flight cost versus arrival time,minimizing means responsive to said total flight cost signal for determining a minimum thereof to provide an optimum arrival time signal,means responsive to said optimum arrival time signal for providing an optimum cost index signal corresponding thereto,speed generator means responsive to said optimum cost index signal for generating an airspeed signal corresponding thereto in accordance with minimum direct operating cost,predictor means responsive to said optimum cost index signal for generating a predicted arrival time signal in accordance therewith, andspeed adjuster means responsive to said optimum arrival time signal, said predicted arrival time signal and said airspeed signal for adjusting said airspeed signal in accordance with the difference between said optimum arrival time signal and said predicated arrival time signal to provide an airspeed command signal for controlling the airspeed of said aircraft.
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Accused Products
Abstract
A flight management system that provides an airspeed command to control a flight profile pursuant to minimum total cost. Total cost is the sum of direct operating cost and arrival time error cost and direct operating cost is the sum of fuel cost plus flight-time cost. A predictor, in response to trial cost index values, generates direct operating cost and arrival time values corresponding to the trial cost index values. A parabolic function approximator generates a parabolic approximation to the direct operating cost vs. arrival time function corresponding to the trial cost index values. An arrival error cost function is added to the direct operating cost function and the minimum of the combined function is obtained to provide an optimum arrival time signal. The trial cost index values and the corresponding arrival time values are applied to a parabolic approximator to obtain a cost index vs. arrival time function. The optimum arrival time signal is applied to this function to provide the optimum cost index signal corresponding thereto. A speed generator is included for generating an airspeed signal corresponding to the optimum cost index signal in accordance with minimum direct operating cost. A predictor generates a predicted arrival time signal in accordance with the optimum cost index signal. A speed adjuster adjusts the airspeed signal to provide the airspeed command signal in accordance with the difference between the optimum arrival time signal and the predicted arrival time signal.
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Citations
30 Claims
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1. Flight Management System apparatus for aircraft comprising
means for generating a DOC signal which is a function of direct operating cost (DOC) versus arrival time in accordance with a range of cost index values, means for storing values of arrival time error cost (AEC) versus arrival time error and providing an AEC signal which is function of said values, means for combining said DOC signal with said AEC signal to provide a total flight cost signal which is a function of total flight cost, thereby establishing a signal representative of total flight cost versus arrival time, minimizing means responsive to said total flight cost signal for determining a minimum thereof to provide an optimum arrival time signal, means responsive to said optimum arrival time signal for providing an optimum cost index signal corresponding thereto, speed generator means responsive to said optimum cost index signal for generating an airspeed signal corresponding thereto in accordance with minimum direct operating cost, predictor means responsive to said optimum cost index signal for generating a predicted arrival time signal in accordance therewith, and speed adjuster means responsive to said optimum arrival time signal, said predicted arrival time signal and said airspeed signal for adjusting said airspeed signal in accordance with the difference between said optimum arrival time signal and said predicated arrival time signal to provide an airspeed command signal for controlling the airspeed of said aircraft. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29)
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15. The apparatus of claim 1 in which said means for storing comprises means for storing said AEC values with critical time points in accordance with connecting flight times.
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16. The apparatus of claim 1 in which said means for combining comprises means for adding said AEC signal to said DOC signal to provide said total flight cost signal.
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17. The apparatus of claim 1 in which said DOC signal generating means, said storing means and said combining means comprise means for generating said signal representative of total flight cost versus arrival time.
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18. The apparatus of claim 17 in which said minimizing means comprises search means for providing trial arrival time signals to said total flight cost versus arrival time signal generating means so as to activate said total flight cost versus arrival time signal generating means to provide signals to said search means representative of values of total flight cost corresponding to said trial arrival time signals.
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19. The apparatus of claim 18 in which said search means comprises means for comparing successive values of said total flight time costs corresponding to successive values of said trial arrival time signals for determining the trial arrival time signal corresponding to the minimum value of said total flight time costs.
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20. The apparatus of claim 19 in which said search means further includes
means for providing a minimum-not signal representative of a minimum total flight cost value not being detected, and means for providing a direction signal representative of whether said trial arrival time signals are increasing or decreasing when said minimum-not signal is generated. -
21. The apparatus of claim 1 in which said speed generator means includes means for providing measured aircraft and atmosphere parameter signals to said speed generator means for generating said airspeed signal in accordance with minimum direct operating cost.
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22. The apparatus of claim 21 in which said predictor means includes means for providing simulated aircraft and atmosphere parameter signals, corresponding to said measured aircraft and atmosphere parameter signals to said predictor means for generating said predicted arrival time signal in accordance with said optimum cost index signal.
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23. The apparatus of claim 22 in which said predictor means comprises means for generating said predicted arrival time signal, a TUP signal and a TDN signal, where said TUP and TDN signals represent predicted flight time adjusted for time segments having speed or acceleration limits associated therewith.
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24. The apparatus of claim 23 in which said speed adjuster means comprises
a speed adjustment factor generator responsive to said optimum arrival time signal and said predicted arrival time signal for generating a speed adjustment factor signal in accordance with the difference therebetween, and a speed adjuster responsive to said airspeed signal and said speed adjustment factor signal for providing said airspeed command signal in accordance therewith. -
25. The apparatus of claim 24 in which said speed adjustment factor generator comprises means responsive to said TUP and TDN signals for generating said speed adjustment factor further in accordance with a selected one of said TUP and TDN signals.
- 26. The apparatus of claim 25 in which said speed adjustment factor generator comprises means for generating said speed adjustment factor signal in accordance with
- space="preserve" listing-type="equation">K.sub.SA (new)=K.sub.SA (previous)+DELTA-#T/#T.sub.A
where KSA =said speed adjustment factor signal DELTA-T=T-TOPT T=said predicted arrival time signal TOPT =said optimum arrival time signal TA =TUP if DELTA-T>
0, TDN otherwiseTUP =the total time during a prediction when speed may be adjusted upwardly TDN =the total time during a prediction when speed may be adjusted downwardly.
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27. The apparatus of claim 26 in which said speed adjuster comprises means responsive to a measured wind signal for further adjusting said airspeed signal in accordance therewith.
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28. The apparatus of claim 27 further including means for generating an activation signal for activating said DOC signal generating means, said speed adjustment factor generator being responsive to said activation signal for setting KSA to zero when said DOC signal generating means is activated.
- 29. The apparatus of claim 26 in which said speed adjuster comprises means for providing said airspeed command signal in accordance with
- space="preserve" listing-type="equation">V.sub.R =(V.sub.0 +K.sub.SA V.sub.W)/(1-K.sub.SA)
where VR =said airspeed command signal VO =said airspeed signal VW =tail wind or negative head wind.
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30. A flight management system method for aircraft comprising the steps of
generating a function of direct operating cost (DOC) vs. arrival time in accordance with a range of cost index values, storing a function of arrival time error cost, (AEC) vs. arrival time error, combining said DOC function with said AEC function to provide a function of total flight cost vs. arrival time, determining the minimum of said total flight cost vs. arrival time function to provide an optimum arrival time signal, providing an optimum cost index signal corresponding to said optimum arrival time signal, generating an airspeed signal corresponding to said optimum cost index signal in accordance with minimum direct operating cost, generating a predicted arrival time signal in accordance with said optimum cost index signal, and adjusting said airspeed signal in accordance with the difference between said optimum arrival time signal and said predicted arrival time signal to provide an airspeed command signal for controlling the airspeed of said aircraft.
Specification