Flight control system for a hybrid aircraft in the pitch axis
AssigneeSikorsky Aircraft Corporation
InventorsW. Douglas Kinkead, Mark W. Scott
Life of this patent
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Abstract
A flight control system includes a blending algorithm which evaluates the current flight regime and determines the effectiveness of the flight controls to effect the rotational moment of a hybrid vehicle about the pitch axis. Gain schedules for both pitch cyclic and elevator control provide a quantitative measure of control effectiveness. Based on the respective gain schedules, the algorithm determines how much of the control commands should be sent to each control surface. The result is that for a given control command, the same amount of pitch moment will be generated regardless of flight regime. This simplifies the underlying flight control law since the commands it generates are correct regardless of flight regime.
Claims19
A flight control system for a hybrid aircraft comprising:
- a movable first control surface not operably connected to a rotor system operable to direct an aircraft about a pitch axis;
- a movable second control surface on a rotor system operable to direct the aircraft about said pitch axis;
- a storage device having a blending algorithm, said blending algorithm determining a first gain for said first control surface according to a first gain schedule, and determining a second gain for said second control surface according to a second gain schedule in response to a control input for said pitch axis;
- and
- a controller in communication with said first control surface, said second control surface, and said storage device, said controller operable to receive a control command for said pitch axis and actuate said first control surface according to said first gain and said second control surface according to said second gain.
A method of controlling a hybrid aircraft about a pitch axis comprising the steps of:
- (1) providing a control command for a pitch vehicle axis;
- (2) splitting said control command to provide a first control command and a second control command;
- (3) multiplying said first control command by a first gain according to a first gain schedule to provide a first scaled control command;
- (4) multiplying said second control command by a second gain according to a second gain schedule to provide a second scaled control command;
- (5) communicating said first scaled control command to a first movable control surface not operably connected to a rotor system for control of the hybrid aircraft about the pitch axis;
- and
- (6) communicating said second scaled control command to a second movable control surface on a rotor system for control of the hybrid aircraft about the pitch axis.
A method of controlling a hybrid unmanned aerial vehicle (UAV) about a pitch axis within a transition flight region comprising the steps of:
- (1) providing a control command for a pitch axis;
- (2) splitting said control command to provide a first control command and a second control command;
- (4) multiplying said first control command by a first gain according to a first gain schedule to provide a first scaled control command;
- (4) multiplying said second control command by a second gain according to a second gain schedule to provide a second scaled control command;
- (7) communicating said first scaled control command to a rotor system for control of the UAV about the pitch axis;
- and
- (8) communicating said second scaled control command to an elevator for control of the UAV about the pitch axis.
Dependencies are inferred from the claim text.