Semi-automatic flight control system utilizing limited authority stabilization system
AssigneeSperry Rand Corporation
InventorsEverett R. Tribken, Ronald J. Miller, Carl D. Griffith
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Abstract
A flight control system utilizing a limited authority stability augmentation system having a long term attitude and/or path control input to enhance the automatic flight capability of the stability augmentation system. A position sensor coupled with the limited authority stability augmentation actuator provides an indication to the human pilot via a suitable indicator when the actuator is near or at the limit of its authority thereby permitting the human pilot to effect manual trim, thus recentering the actuator.
Claims10
A flight control system for aircraft having an attitude controlling element for controlling the attitude of said craft about an axis thereof and a manual controller for controlling said attitude controlling element, comprising
- a stability augmentation system having sensor means for sensing short term attitude changes of said craft about said axis and providing short term stabilization signals in response thereto and actuator means coupled to said attitude controlling element and responsive to said short term stabilization signals for suppressing said short term attitude changes, said actuator means having a limited displacement capacity from a reference position and tending to reach the limit of said displacement capacity in response to long term reference signals,
- position sensing means coupled to said actuator means for providing an actuator position signal representative of the position of said actuator with respect to said reference position,
- reference means for providing a long term reference signal,
- first coupling means for coupling said long term reference signal to said stability augmentation system for providing corresponding long term control of said craft through said limited displacement capacity actuator means,
- indicator means coupled to said position sensing means for displaying a visual command to the pilot in response to said actuator position signal to manipulate said manual controller to return said actuator means to said reference position when said actuator means approaches the limit of its displacement capacity in its response to said long term reference signal, and
- second coupling means coupling said position sensing means to said indicator means for providing a trim demand signal to said indicator means in response to said actuator position signal when said position signal exceeds a threshold representative of an actuator position near said limit of said displacement capacity and after said threshold has been exceeded a trim demand signal that diminishes toward zero as said manual controller is manipulated to return said actuator means to said reference position, thereby providing said visual command to said pilot.
A combined manual automatic control system for an aircraft having a controlling element for controlling the attitude of the craft about an axis thereof and a manual controller for enabling the pilot to control said element, the combination comprising,
- (a) automatic stability augmentation apparatus having sensor means for sensing short term attitude changes of said craft about said axis and actuator means coupled with said controlling element and responsive to said sensor means for suppressing said short term attitude changes, said actuator having a displacement capacity from a normal reference position sufficient only to suppress said short term attitude changes and insufficient to control substantial long term changes in craft attitude under all normal flight conditions,
- (b) position sensing means coupled with said actuator and providing a signal proportional to the movement thereof from said normal reference position substantially to said displacement capacity thereof,
- (c) flight director computer apparatus for said aircraft including means for providing a computed long term attitude reference signal and indicator means responsive to said reference signal for displaying to the pilot the motion of said manual controller required to cause said craft to approach and maintain said reference attitude,
- (d) first coupling means coupling said reference signal to said actuator means for automatically controlling said craft to approach and maintain said computed reference attitude, thereby relieving the pilot of the need to operate said manual controller in response to said computed reference signal to cause said craft to approach and maintain said computed long term craft attitude, and
- (e) second coupling means coupled to receive said actuator position signal for providing a further signal to said indicator means upon said position signal reaching a value corresponding to said displacement capacity of said actuator and thereafter gradually decaying to said normal actuator position value in response to a corresponding operation of said manual controller.
Dependencies are inferred from the claim text.