US 3,945,593 A · Flight control apparatus

Abstract

A flight control apparatus for the control of the trajectory and the airspeed of an airplane comprises a measuring equipment for measuring the deviation of the aircraft position from a commanded trajectory, and a measuring equipment for measuring the deviation of the angle of attack from a commanded value. Both deviation signals are applied with appropriate transfer functions to both the throttle actuator and to the control surface actuator. The transfer functions, which in the simplest case are constants, may be selected such that a deviation of the trajectory and its correction is substantially without any influence on the angle of attack and a deviation of the airspeed and its correction is substantially without any influence on the trajectory. According to another aspect of the invention, the apparatus measures altitude, angle of attack, pitch rate and vertical and longitudinal acceleration of the aircraft. There is a pseudo-observer including a number of appropriately dimensioned filters to form a number of additional state variables derived from the variables directly measured, the additional state variables comprising the time integrals of both the trajectory deviation signal and the angle of attack deviation signal, and a signal indicative of vertical speed. All measured and derived signals are applied in linear combinations to a throttle actuator, a spoiler actuator and an elevator actuator. The output of the elevator actuator is applied to a model system simulating the actual elevator movements and applying a feedback signal to the elevator actuator.

Claims13

Dependent claims

In an apparatus for controlling the trajectory and aerodynamic condition of flow of an airplane having thrust changing actuator means and control surface actuator means, said apparatus comprising trajectory sensor means for producing an actual trajectory signal, aerodynamic condition of flow sensor means for producing an actual aerodynamic condition of flow signal, trajectory deviation detector means having a command value input and being connected to the trajectory sensor means to produce a trajectory deviation signal indicative of the deviation of the actual trajectory signal from a commanded value, aerodynamic condition of flow deviation detector means having a command value input and being connected to the aerodynamic condition of flow sensor means to produce an aerodynamic condition of flow deviation signal indicative of the deviation of the actual aerodynamic condition of flow signal from a commanded value, and control means connected to the actuator means and to the deviation detector means for controlling the actuators in accordance with said deviation signals, the improvement comprising:

said control means controlling the thrust changing actuator means in response to first control signals, which are related to the signals from both of the deviation detector means by given associated transfer functions, and controlling control surface actuator means in response to second control signals which are related to the signals from both of the deviation detector means by given associated transfer functions.

In a flight control apparatus for automatically controlling position and aerodynamic condition of flow of an aircraft, comprising devices for producing state variable signals including

first measuring means for producing a first signal indicative of aircraft position,
second measuring means for producing a second signal indicative of aerodynamic condition of flow,
first command signal generating means for producing an aircraft position command signal,
second command signal generating means for producing an aerodynamic condition of flow command signal,
a first comparator means for comparing said first signal and said aircraft position command signal to produce a position deviation signal,
second comparator means for comparing said second signal and said aerodynamic condition of flow command signal to produce a flow condition deviation signal, and
at least one measuring means for measuring an aircraft dynamics characteristic and producing a signal indicative of said aircraft dynamics characteristic,
a thrust actuator having an input and adapted to vary the thrust of the aircraft in response to signals at the input thereof, and a control surface actuator having an input and an output and adapted to vary the deflection of a control surface of the aircraft in response to signals at the input thereof, said apparatus being characterized by:
circuit means connected to said devices and the inputs of said actuators for applying a plurality of signals at each of said inputs as linear combinations, each signal of said plurality of signals being indicative of one state variable, said plurality of signals including said position deviation signal, said flow condition deviation signal, the time integral of said position deviation signal, the time integral of said flow condition signal, and a signal indicative of aircraft vertical speed,
said circuit means comprising at least one of each of the following items:
a. direct connection means for directly applying a state variable signal as one signal out of said plurality
b. filter means connected to receive one of said state variable signals and from it produce another state variable signal which then is applied to said inputs as being one of said plurality of signals.

9 more elements

Dependencies are inferred from the claim text.

Flight control apparatus

Life of this patent

Flight control apparatus

Life of this patent

Abstract

Claims13