Online optimization-based flight control system
Techniques to control flight of an aircraft are disclosed. In various embodiments, a set of inputs associated with a requested set of forces and moments to be applied to the aircraft is received. An optimal mix of actuators and associated actuator parameters to achieve to an extent practical the requested forces and moments is determined.
1 . A method of controlling flight of an aircraft, the method comprising:
receiving flight control inputs generated via operation of one or more flight control input devices of the aircraft;
receiving sensor data generated by one or more sensors of the aircraft, wherein the sensor data is indicative of one or more operational parameters of the aircraft;
computing, based on the flight control inputs, a set of forces and moments to be applied to the aircraft via operation of a set of actuators of the aircraft;
computing an optimal set of operational parameters for the set of actuators for applying the set of forces and moments to the aircraft via minimizing a cost function for a total cost of operating the set of actuators to apply the set of forces and moments to the aircraft; and
controlling flight of the aircraft based on the optimal set of operational parameters.
2 . The method of claim 1 , wherein the flight control inputs comprises a set of inceptor outputs.
3 . The method of claim 1 , wherein the flight control inputs are provided by an autopilot or other automated flight computer.
4 . The method of claim 1 , wherein the optimal set of operational parameters for the set of actuators is computed onboard the aircraft in real time.
5 . The method of claim 1 , wherein computing the optimal set of operational parameters for the set of actuators comprises enforcing one or more constraints with respect to operation of the set of actuators.
6 . The method of claim 5 , wherein:
the set of actuators comprises lift fans; and
the one or more constraints comprises one or more of minimum and/or maximum rotation speed or torque, minimum and/or maximum deflection angle, and minimum and/or maximum rate of change.
7 . The method of claim 1 , wherein the optimal set of operational parameters for the set of actuators is computed based at least in part on a linear cost model for an actuator of the set of actuators.
8 . The method of claim 7 , wherein the linear cost model is linearized about a current operating point of the actuator of the set of actuators.
9 . The method of claim 1 , wherein the cost function comprises at least one of:
an actuator power consumption term that penalizes actuator power consumption;
a reference position deviation term that penalizes deviation from a reference position; and
an uneven distribution term that penalizes uneven distribution across the set of actuators.
10 . The method of claim 1 , wherein:
the cost function includes an actuator power consumption term that penalizes power consumption of an actuator of the set of actuators; and
the actuator power consumption term is modeled by a linear approximation or a set of piecewise linear approximations.
11 . The method of claim 1 , wherein computing the optimal set of operational parameters for the set of actuators comprises determining a solution space containing the optimal set of operational parameters based at least in part on the sensor data.
12 . The method of claim 11 , further comprising processing the sensor data to determine a current effectiveness of at least one actuator of the set of actuators.
13 . The method of claim 11 , wherein the sensor data is used to determine a current availability of at least one actuator of the set of actuators.
14 . The method of claim 1 , further comprising providing to each actuator of the set of actuators a respective control signal reflecting a corresponding actuator parameter determined for the actuator.
15 . The method of claim 1 , wherein one or both of the cost function and a set of one or more constraints used to compute the optimal set of operational parameters for the set of actuators varies with an operational state of the aircraft.
16 . The method of claim 15 , wherein the operational state of the aircraft comprises one or more of airspeed, angle of attack, and mode of operation.
17 . The method of claim 15 , wherein the set of one or more constraints comprises a maximum power constraint.
18 . An aircraft comprising a flight control system implementing the method of claim 1 .
19 . The aircraft of claim 18 , further comprising:
lift fans;
a fuselage, a right wing attached to the fuselage, and a left wing attached to the fuselage;
a first plurality of the lift fans is attached to the left wing; and
a second plurality of the lift fans is attached to the right wing.
20 . The aircraft of claim 18 , further comprising:
lift fans;
a fuselage, a right wing attached to the fuselage, and a left wing attached to the fuselage;
the left wing comprises a left wing first pylon, a left wing second pylon, and a left wing third pylon;
the right wing comprises a right wing first pylon, a right wing second pylon, and a right wing third pylon;
two of the lift fans are attached to the left wing first pylon;
two of the lift fans are attached to the left wing second pylon;
two of the lift fans are attached to the left wing third pylon;
two of the lift fans are attached to the right wing first pylon;
two of the lift fans are attached to the right wing second pylon; and
two of the lift fans are attached to the right wing third pylon.