System for reducing aircraft fuel consumption
First Claim
1. A control system for improving the fuel economy of an operating aircraft during flight by sensing current values of operating parameters of said aircraft and adjusting controls of said aircraft as a function of said current values, said control system comprising:
- input means for repetitively generating first, second, third, fourth, and fifth input signals representing current sensed values indicative of rate of climb, fuel flow rate, ground speed, distance remaining to destination, and total fuel already consumed during cruise respectively;
computing means including a first logic circuit for receiving said first signals and generating first output command signals in response thereto, and a second logic circuit for receiving said second, third, fourth, and fifth signals and generating second output command signals in response thereto;
selection means for enabling a selected one of said first and second logic circuits in response to a selection input; and
an aircraft control including a pitch angle control for effecting incremental changes in the pitch attitude of the aircraft in response to said first output command signals, and a throttle control for effecting incremental changes in the thrust of said aircraft in response to said second output command signals,whereby when said first logic circuit is enabled for a climb portion of said flight the rate of climb of said aircraft is substantially maximized during said climb portion, and when said second logic circuit is enabled for a cruise portion of said flight the total quantity of fuel consumed during said cruise portion is substantially minimized.
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Abstract
A control system including both a method and apparatus for use on an aircraft during flight utilizes real-time data provided by sensing equipment on the aircraft to iteratively generate values for an efficiency parameter. The aircraft controls are adjusted after each iteration, and successive values of the efficiency parameter are compared until such comparison shows that the parameter has been substantially optimized. Iterations may then continue without corresponding control adjustments until comparison indicates that a current parameter value differs by a predetermined magnitude from the previously determined optimum value, at which time control adjustments resume in order to bring the efficiency parameter to a new substantially optimum parameter value.
52 Citations
45 Claims
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1. A control system for improving the fuel economy of an operating aircraft during flight by sensing current values of operating parameters of said aircraft and adjusting controls of said aircraft as a function of said current values, said control system comprising:
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input means for repetitively generating first, second, third, fourth, and fifth input signals representing current sensed values indicative of rate of climb, fuel flow rate, ground speed, distance remaining to destination, and total fuel already consumed during cruise respectively; computing means including a first logic circuit for receiving said first signals and generating first output command signals in response thereto, and a second logic circuit for receiving said second, third, fourth, and fifth signals and generating second output command signals in response thereto; selection means for enabling a selected one of said first and second logic circuits in response to a selection input; and an aircraft control including a pitch angle control for effecting incremental changes in the pitch attitude of the aircraft in response to said first output command signals, and a throttle control for effecting incremental changes in the thrust of said aircraft in response to said second output command signals, whereby when said first logic circuit is enabled for a climb portion of said flight the rate of climb of said aircraft is substantially maximized during said climb portion, and when said second logic circuit is enabled for a cruise portion of said flight the total quantity of fuel consumed during said cruise portion is substantially minimized. - View Dependent Claims (2, 3, 4, 5, 6)
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7. Apparatus for substantially maximizing the contribution of fuel consumed by an aircraft during a climb portion of a flight to overall fuel economy for the flight by sensing values indicative of the current rate of climb of said aircraft and adjusting the pitch attitude of said aircraft as a function of said sensed values, said apparatus comprising:
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input means for repetitively generating input signals representative of current values of rate of climb for said aircraft, computing means for iteratively receiving and processing said input signals and generating output command signals in response to the iterations of said computing means, and a control for repeatedly maximizing said current rate of climb by effecting incremental changes in the pitch attitude of said aircraft in response to said output command signals. - View Dependent Claims (8, 9, 10)
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11. Apparatus for substantially maximizing the contribution of fuel consumed by an aircraft during a climb portion of a flight to overall fuel economy for the flight by sensing values indicative of the current rate of climb of said aircraft and adjusting the pitch attitude of said aircraft as a function of said sensed values, said apparatus comprising:
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input means for repetitively generating input signals representative of current values of rate of climb for said aircraft, computing means for iteratively receiving and processing said input signals and generating output command signals in response to the iterations of said computing means, and a control for effecting incremental changes in the pitch attitude of said aircraft in response to said output command signals, said computing means including a memory for storing the rate of climb value determined from one iteration, and means for determining the difference between said stored value and the rate of climb value determined during a subsequent iteration, said output command signals being generated as a function of the determined difference, said apparatus further including comparator means and means for providing a reference value to said comparator means, said comparator means comparing the absolute value of said determined difference with said reference value, and said output command signals being generated only when the absolute value of said determined difference is greater than said reference value. - View Dependent Claims (12, 13)
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14. In an aircraft having an engine for developing thrust to propel said aircraft, a throttle control for controlling the thrust developed by said engine, a pitch axis control for controlling the pitch attitude of the aircraft, and instruments for sensing values indicative of and generating signals representing the current rate of climb of said aircraft;
- a control system for substantially maximizing the contribution of fuel consumed by an aircraft during a climb portion of a flight to overall fuel economy for the flight, said control system comprising;
selection means for selectively energizing said control system; parameter quantification means for repetitively receiving said signals from said instruments and iteratively generating a parameter value which is a function of said signals; a memory connected to said parameter quantification means for receiving said parameter value and storing said values; difference determining means for receiving current parameter values from said parameter quantification means and stored parameter values from said memory and determining the difference therebetween; and comparator means, including a stored reference value, for comparing said difference with said reference value and generating a response based on said comparison, said throttle control response to said selection means for maintaining said thrust at a maximum rated value throughout said climb portion of said flight, and said pitch axis control effecting an incremental change in said pitch attitude of said aircraft as a function of said response. - View Dependent Claims (15, 16, 17)
- a control system for substantially maximizing the contribution of fuel consumed by an aircraft during a climb portion of a flight to overall fuel economy for the flight, said control system comprising;
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18. A control system for an aircraft having a pitch axis control for controlling the pitch attitude of the aircraft, and instruments for sensing values indicative of and generating signals representing the current rate of climb of said aircraft, said control system comprising:
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parameter quantification logic connected to said instruments for repetitively receiving said signals therefrom and iteratively quantifying a parameter value from said signals; a memory connected to said parameter quantification logic, said memory receiving a parameter value from said parameter quantification logic for each iteration of said parameter quantification logic and storing each said parameter value; difference determining logic connected to said memory, said difference determining logic receiving the parameter value from the most recent iteration of said parameter quantification logic and a stored parameter value and determining the difference therebetween; comparator logic connected to said difference determining logic, said comparator logic receiving the absolute value of the determined difference from said difference determining logic and comparing said absolute value difference to a reference value, said comparator logic providing an output signal to said difference determining logic which is a function of the comparison, said pitch axis control connected to said difference determining logic and responsive to signals from said difference determining logic which are a function of the determined differences and said output signals from said comparator logic for incrementally adjusting the pitch attitude of said aircraft and thereby maintaining a generally optimum rate of climb for said aircraft. - View Dependent Claims (19)
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20. Apparatus for substantially minimizing the total quantity of fuel consumed by an aircraft during a constant-altitude cruise by sensing values indicative of the values of current operating parameters of said aircraft and adjusting the thrust of said aircraft as a function of said sensed values, said apparatus comprising:
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input means for repetitively generating input signals a, b, c, and d representative of current values of fuel flow rate, ground speed, distance remaining to destination, and total fuel already consumed during cruise; computing means for iteratively receiving and processing said input signals and generating output command signals in response to the iterations of said computing means; and a control for effecting incremental changes in the thrust of said aircraft in response to said output command signals. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27, 28, 29)
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30. In an aircraft having an engine for developing thrust to propel said aircraft, a control for regulating the thrust developed by said engine, and instruments for sensing values indicative of and generating signals representing current values of fuel flow rate, ground speed, distance to destination, and total fuel already consumed during cruise;
- a control system for substantially minimizing the total quantity of fuel consumed during a constant-altitude cruise portion of the flight of said aircraft, said control system comprising;
selection means for selectively energizing said apparatus; parameter quantification means for repetitively receiving said signals from said instruments and iteratively generating current values of an efficiency parameter which is a function of said signals; a memory connected to said parameter quantification means for receiving said current efficiency parameter values and storing said values; difference determining means for receiving current efficiency parameter values from said parameter quantification means and stored efficiency parameter values from said memory and determining the difference therebetween; and comparator means, including a stored reference value, for comparing said difference with said reference value and generating a response based on said comparison, said control effecting an incremental change in said thrust as a function of said response. - View Dependent Claims (31, 32, 33, 34)
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32. In an aircraft as claimed in claim 30 wherein said apparatus includes synchronizing means for providing at least a predetermined time interval between successive iterations of said parameter quantification means.
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33. In an aircraft as claimed in claim 30 wherein said apparatus includes synchronizing means for permitting iterations of said parameter quantification means only when said signals representing current values of said ground speed indicate a substantially constant ground speed.
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34. In an aircraft as claimed in claim 30 wherein said apparatus includes synchronizing means for preventing a new iteration of said parameter quantification means until the immediately preceding iteration has been completed.
- a control system for substantially minimizing the total quantity of fuel consumed during a constant-altitude cruise portion of the flight of said aircraft, said control system comprising;
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35. A control system for an aircraft having an engine for developing thrust to propel said aircraft, a control for regulating the thrust developed by said engine, and instruments for sensing values indicative of and generating signals representing current values of fuel flow rate, ground speed, distance remaining to point of decent, and total fuel already consumed during cruise;
- said control system comprising;
parameter quantification logic connected to said instruments for repetitively receiving said signals therefrom and iteratively quantifying an efficiency parameter value e from said signals in accordance with the relationship e=d+(ac/b), where a represents current fuel flow rate, b represents current ground speed, c represents the current distance remaining to point of descent, and d represents the total quantity of fuel already consumed during cruise; a memory connected to said parameter quantification logic, said memory receiving an efficiency parameter value from said parameter quantification logic for each iteration of said parameter quantification logic and storing each said efficiency parameter value; difference determining logic connected to said memory, said difference determining logic receiving the efficiency parameter value from the most recent iteration of said parameter quantification logic and a stored efficiency parameter value and determining the difference therebetween; comparator logic connected to said difference determining logic, said comparator logic receiving the absolute value of the determined difference from said difference determining logic and comparing said absolute value difference to a reference value, said comparator logic providing an output signal to said difference determining logic which is a function of the comparison, said control connected to said difference determining logic and responsive to signals from said difference determining logic which are a function of said determined differences and said output signals from said comparator logic for incrementally adjusting the thrust of said aircraft. - View Dependent Claims (36)
- said control system comprising;
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37. A method for substantially minimizing the total quantity of fuel consumed by an aircraft during the combined climb and cruise portions of a flight, said method comprising the steps of:
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(1) setting the thrust of said aircraft at a maximum rated value and maintaining the thrust at said maximum rated value during said climb portion of said flight, (2) repetitively sensing values indicative of current rate of climb of said aircraft, (3) iteratively processing the current values sensed in step (2) and generating signals as a function of said processing, (4) controlling the pitch attitude of said aircraft in response to the signals from step (3) so as to continuously maintain the aircraft at a substantially maximum rate of climb during said climb portion of said flight, (5) bringing the aircraft to a constant-altitude cruise and maintaining the constant altitude of said aircraft during said cruise portion of said flight, (6) repetitively sensing values indicative of current values for the aircraft of fuel flow rate, ground speed, distance remaining to destination, and total fuel already consumed during said cruise portion of said flight, (7) iteratively processing the current values sensed in step (6) and generating signals as a function of said processing, and (8) controlling the thrust of said aircraft during said cruise portion of said flight in response to the signals from step (7) so as to substantially minimize the total quantity of fuel consumed during said cruise portion of said flight.
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38. A method for substantially maximizing the contribution to overall fuel economy for a flight of fuel consumed by an aircraft during a climb portion of the flight during which said aircraft is climbing to a cruising altitude, said method comprising the steps of:
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(1) setting the thrust of said aircraft at a maximum rated value and maintaining the thrust at said maximum rated value during said climb portion of said flight, (2) repetitively sensing values indicative of current rate of climb of said aircraft, (3) iteratively processing the current values sensed in step (2) and generating signals as a function of said processing, and (4) repeatedly maximizing the current rate of climb of said aircraft during said climb portion of said flight by controlling the pitch attitude of said aircraft in response to the signals from step (3).
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39. A method for substantially minimizing the total quantity of fuel consumed by an aircraft during a cruise portion of a flight, said method comprising the steps of:
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(1) bringing the aircraft to a constant-altitude cruise and maintaining the constant altitude of said aircraft during said cruise portion of said flight, (2) repetitively sensing values indicative of current values for the aircraft of fuel flow rate, ground speed, distance remaining to destination, and total fuel already consumed during said cruise portion of said flight, (3) iteratively processing the current values sensed in step (2) and generating signals as a function of said processing, and (4) controlling the thrust of said aircraft during said cruise portion of said flight in response to the signals from step (3) so as to substantially minimize the total quantity of fuel consumed during said cruise portion of said flight.
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40. A method for substantially maximizing the contribution of fuel consumed by an aircraft during a climb portion of a flight to overall fuel economy for the flight, said method comprising the steps of:
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(1) setting the thrust of said aircraft at a maximum rated value and maintaining the thrust at said maximum rated value during said climb portion of said flight, (2) sensing a value indicative of the current rate of climb of said aircraft, (3) storing the value sensed in step (2), (4) incrementally adjusting the pitch attitude of said aircraft, (5) sensing a value indicative of the current rate of climb of said aircraft, (6) storing the value sensed in step (5), (7) determining the difference between the value sensed in the most recent iteration of step (5) and the value stored immediately prior to said most recent iteration, (8) incrementally adjusting the pitch attitude of said aircraft as a function of the difference determined in step (7), and (9) repeating steps (5) through (8) until a difference determined in step (7) indicates that the current rate of climb of said aircraft has been substantially maximized. - View Dependent Claims (41)
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42. A method for substantially maximizing the contribution of fuel consumed by an aircraft during a climb portion of a flight to overall fuel economy for the flight, said method comprising the steps of:
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(1) setting the thrust of said aircraft at a maximum rate value and maintaining the thrust at said maximum rated value during said climb portion of said flight, (2) sensing a value indicative of the current rate of climb of said aircraft, (3) storing the value sensed in step (2), (4) incrementally adjusting the pitch attitude of said aircraft, (5) sensing a value indicative of the current rate of climb of said aircraft, (6) storing the value sensed in step (5), (7) determining the absolute value difference between the last two stored values, (8) comparing the difference determined from step (7) with a reference value, (9) repeating steps (4) through (8) until a difference determined in step (7) is less than the reference value, (10) repeating steps (5) and (6), (11) determining the absolute value difference between the stored value from step (10) and the last stored value from step (6) just prior to proceeding with step (10), (12) comparing the difference from step (11) with the reference value, (13) repeating steps (10) through (12) until the difference from step (11) exceeds the reference value, and (14) repeating steps (4) through (14) until said climb portion of said flight is completed.
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43. A method for substantially minimizing the total quantity of fuel consumed by an aircraft during a cruise portion of a flight, said method comprising the steps of:
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(1) bringing the aircraft to a constant-altitude cruise and maintaining the constant altitude of said aircraft during said cruise portion of said flight, (2) sensing values indicative of current values for the aircraft of fuel flow rate, ground speed, distance remaining to destination, and total fuel already consumed during said cruise portion of said flight, (3) computing the current value of an efficiency parameter which is a function of the sensed values from step (2), (4) storing the parameter value computed in step (3), (5) incrementally adjusting the thrust of said aircraft, (6) sensing values indicative of current values for the aircraft of fuel flow rate, ground speed, distance remaining to destination, and total fuel already consumed during said cruise portion of said flight, (7) computing the current value of said efficiency parameter based on the sensed values from step (6), (8) storing the parameter value computed in step (7), (9) determining the difference between the efficiency parameter value sensed in the most recent iteration of step (7) and the efficiency parameter value stored immediately prior to said most recent iteration, (10) incrementaly adjusting the thrust of said aircraft as a function of the difference determined in step (9), (11) repeating steps (6) through (10) until a difference determined in step (9) indicates that a substantially optimum current aircraft thrust has been attained. - View Dependent Claims (44)
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45. A method for substantially minimizing the total quantity of fuel consumed by an aircraft during a cruise portion of a flight, said method comprising the steps of:
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(1) bringing the aircraft to a constant-altitude cruise and maintaining the constant altitude of said aircraft during said cruise portion of said flight, (2) sensing values indicative of current values for the aircraft of fuel flow rate, ground speed, distance remaining to destination, and total fuel already consumed during said cruise portion of said flight, (3) calculating the current value of an efficiency parameter based on the values from step (2), (4) storing the parameter value calculated in step (3), (5) incrementally adjusting the thrust of said aircraft, (6) sensing values indicative of current values for the aircraft of fuel flow rate, ground speed, distance remaining to destination, and total fuel already consumed during said cruise portion of said flight, (7) calculating the current value of said efficiency parameter based on the sensed values from step (6), (8) storing the parameter value calculated in step (7), (9) determining the absolute value difference between the last two stored values of said efficiency parameter, (10) comparing the difference determined from step (9) with a first reference value, (11) repeating steps (5) through (10) until a difference determined in step (9) is less than said first reference value, (12) repeating steps (6) through (8), (13) determining the absolute value difference between the stored value from step (12) and the most recently stored value from step (8) just prior to proceeding with step (12), (14) comparing the difference from step (13) with a second reference value, (15) repeating steps (12) through (14) until the difference from step (13) exceeds the second reference value, and (16) repeating steps (5) through (16) until said cruise portion of said flight is concluded.
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Specification