Total energy based flight control system
First Claim
1. An aircraft longitudinal flight control system for automatically controlling the aircraft'"'"'s flight path and speed, using engine thrust and elevator control surface position, comprising:
- means for developing an incremental net thrust command signal Δ
Tc which is a linear combination of a signal representative of the aircraft'"'"'s total energy error with respect to the flight path and speed command targets and a signal representative of the rate of change of the aircraft'"'"'s total energy;
thrust control means for automatically controlling the incremental net thrust of the engines to said incremental net thrust command signal Δ
Tc, such that said total energy error is reduced to zero;
means for developing an incremental elevator position command Δ
δ
e.sbsb.c for controlling the deviation of the aircraft from a commanded flight path; and
elevator position control means for automatically positioning the elevator to said incremental elevator command signal Δ
δ
e.sbsb.c such that said deviation of the aircraft from the commanded flight path is reduced to zero.
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Accused Products
Abstract
An integrated aircraft longitudinal flight control system uses a generalized thrust and elevator command computation (38), which accepts flight path angle, longitudinal acceleration command signals, along with associated feedback signals, to form energy rate error (20) and energy rate distribution error (18) signals. The engine thrust command is developed (22) as a function of the energy rate distribution error and the elevator position command is developed (26) as a function of the energy distribution error. For any vertical flight path and speed mode the outerloop errors are normalized (30, 34) to produce flight path angle and longitudinal acceleration commands.
The system provides decoupled flight path and speed control for all control modes previously provided by the longitudinal autopilot, autothrottle and flight management systems.
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Citations
52 Claims
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1. An aircraft longitudinal flight control system for automatically controlling the aircraft'"'"'s flight path and speed, using engine thrust and elevator control surface position, comprising:
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means for developing an incremental net thrust command signal Δ
Tc which is a linear combination of a signal representative of the aircraft'"'"'s total energy error with respect to the flight path and speed command targets and a signal representative of the rate of change of the aircraft'"'"'s total energy;thrust control means for automatically controlling the incremental net thrust of the engines to said incremental net thrust command signal Δ
Tc, such that said total energy error is reduced to zero;means for developing an incremental elevator position command Δ
δ
e.sbsb.c for controlling the deviation of the aircraft from a commanded flight path; andelevator position control means for automatically positioning the elevator to said incremental elevator command signal Δ
δ
e.sbsb.c such that said deviation of the aircraft from the commanded flight path is reduced to zero.
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2. An aircraft longitudinal flight control system for automatically controlling the aircraft'"'"'s flight path and speed using engine thrust and elevator control surface position, comprising:
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means for developing an incremental thrust command signal Δ
Tc which is a linear combination of a signal representative of the aircraft'"'"'s total energy error with respect to the flight path and speed command targets and a signal representative of the rate of change of the aircraft'"'"'s total energy;thrust control means for automatically controlling the incremental thrust to said incremental thrust command signal Δ
Tc such that said total energy error is reduced to zero;means for developing an incremental elevator command signal Δ
δ
e.sbsb.c which is a linear combination of a signal representative of the aircraft'"'"'s total energy distribution error with respect to the flight path and speed targets, a signal representative of the rate of change of the total energy distribution, and pitch control damping signals; andelevator position control means for automatically controlling the incremental elevator position to said incremental elevator command signal Δ
δ
e.sbsb.c such that said aircraft'"'"'s total energy distribution error is reduced to zero. - View Dependent Claims (39)
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3. An automatic flight control system for controlling an aircraft'"'"'s vertical flight path and speed, comprising:
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means for developing a flight path angle command signal γ
c for guiding the aircraft to, or holding the aircraft on, a desired vertical flight path;means for developing a longitudinal acceleration command signal Vc for guiding the aircraft to, or holding the aircraft on, a desired speed; means for providing signals representative of the aircraft'"'"'s vertical flight path angle γ and
longitudinal acceleration V;means for simultaneously processing said γ
c, γ and
said Vc, V signals to produce an incremental net thrust command signal Δ
Tc and an incremental elevator command signal Δ
δ
e.sbsb.c, said Δ
Tc and Δ
δ
e.sbsb.c signals being related to the aircraft'"'"'s total energy error and total energy distribution error, respectively, with respect to the flight path and speed command targets, and said Δ
Tc and Δ
δ
e.sbsb.c signals coordinated in time and in magnitude to provide decoupled vertical flight path and speed command control;means for receiving the incremental thrust command signal Δ
Tc and controlling the net thrust of the engines in response thereto; andmeans for receiving the incremental elevator command signal Δ
δ
e.sbsb.c and controlling the elevator position in response thereto. - View Dependent Claims (6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 40, 41, 42, 43, 44, 45, 46, 47, 48)
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4. An automatic flight control system for controlling the aircraft'"'"'s vertical flight path and speed, comprising:
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means for developing a flight path angle command signal γ
c for guiding the aircraft to, or holding the aircraft on, a desired flight path;means for developing a longitudinal acceleration command signal Vc for guiding the aircraft to, or holding the aircraft on, a desired speed; means for providing signals representative of the aircraft'"'"'s vertical flight path angle γ and
longitudinal acceleration V;means for developing a signal Es.sbsb.ε
representative of the specific total energy rate error, where Es.sbsb.ε
=(γ
c -γ
)+(Vc -V)/g and a signal D.sub.ε
representative of the energy rate distribution error where D.sub.ε
=-(γ
c -γ
)+(Vc -V)/g;automatic thrust control means for controlling the net thrust in linear proportion to the time integral of said Es.sbsb.ε
signal;automatic elevator position control means controlling the elevator position in linear proportion to the time integral of said D.sub.ε
signal;said simultaneous thrust and elevator control causing the flight path and speed to track the commanded flight path and speed.
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5. An automatic flight control system for controlling an aircraft'"'"'s vertical flight path and speed, comprising:
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means for developing a flight path angle command signal γ
c and a longitudinal acceleration command signal Vc for guiding the aircraft to, or holding the aircraft on, a desired flight path and speed;means for providing signals representative of the aircraft'"'"'s flight path angle γ and
longitudinal acceleration V;means for developing an incremental thrust command signal Δ
Tc by forming a linear combination of the time integral of the aircraft'"'"'s specific total energy rate error signal Es.sbsb.ε
, where Es.sbsb.ε
=(γ
c -γ
)+(Vc -V)/g and the specific total energy rate signal Es, where Es =γ
+V/g;
##EQU16## and means for developing an incremental elevator position command signal Δ
δ
e.sbsb.c, by forming a linear combination of the time integral of the aircraft'"'"'s energy rate distribution error signal D.sub.ε
, where D.sub.ε
=-(γ
c -γ
)+(Vc -V)/g and the energy rate distribution signal D, where D=-γ
+V/g;
##EQU17## thrust control means for coupling said incremental thrust command signal Δ
Tc to the engine and controlling the thrust thereto; andelevator position control means for coupling said incremental elevator command signal Δ
δ
e.sbsb.c to the elevator and controlling the position thereto. - View Dependent Claims (49, 50, 51, 52)
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Specification