Geometry-based flight control system

1. A method of controlling flight of an aircraft, comprising:

receiving a set of inceptor inputs associated with a requested set of forces and moments to be applied to the aircraft;

computing an optimal mix of actuators and associated actuator parameters to achieve to an extent practical the requested forces and moments, including by taking into consideration dynamically varying effectiveness of one or more actuators based on a current dynamic state of the aircraft, the dynamic state including aircraft wing tilt angle, wherein the optimal mix of actuators includes one or more rotors and for each rotor taking into consideration dynamically varying effectiveness includes using a moment vector, a control surface performance matrix, and a dynamically updated rotor geometry matrix to determine the effect of said one or more rotors under various combinations of actuators and associated parameters given the current dynamic state of the aircraft, wherein the computing of the optimal mix of actuators and the associated actuator parameter includes:

computing the moment vector based on the set of inceptor inputs and a current state of the aircraft, comprising:

determining the current state of the aircraft, wherein the current state of the aircraft is determined based on sensor data and an estimate of the current state of the aircraft, the sensor data including a wing tilt angle of the aircraft, wherein the estimate of the current state of the aircraft is determined based on past actuator commands, wherein the wing tilt angle of the aircraft includes a first wing tilt angle and a second wing tilt angle, wherein the first wing tilt angle relates to an angle of a front wing, and wherein the second wing tilt angle relates to an angle of a back wing;

computing the control surface performance matrix based on the first wing tilt angle and the second wing tilt angle; and

computing the dynamically updated rotor performance matrix based on the first wing tilt angle and the second wing tilt angle; and

providing an output comprising for each actuator in the optimal mix a corresponding set of one or more control signals associated with the actuator parameters computed for that actuator.

2. The method of claim 1 , wherein the optimal mix is computed at least in part by formulating an associated optimization problem as a quadratic program.

3. The method of claim 1 , wherein the optimal mix is computed at least in part by formulating an associated optimization problem comprising a rotor performance matrix, control surface performance matrix, and the requested set of forces and moments to be applied to the aircraft.

4. The method of claim 1 , wherein computing the optimal mix includes determining a set of thrusts for rotors of the aircraft and a set of angles for control surfaces of the aircraft.

5. The method of claim 1 , wherein the non-linear model for actuator performance is determined based on spatial rotation information.

6. The method of claim 1 , wherein the optimal mix is computed at least in part by determining a model for control surface performance based on the dynamic state of the aircraft.

7. The method of claim 1 , wherein computing the optimal mix includes optimizing for an equal utilization of all rotors relative to their maximum and minimum thrusts.

8. The method of claim 1 , wherein computing the optimal mix includes optimizing for an equal utilization of all control surfaces relative to their maximum and minimum possible angles.

9. The method of claim 1 , wherein computing the optimal mix includes determining weights to prioritize roll, pitch, yaw, and thrusts in relation to each other.

10. The method of claim 1 , wherein computing the optimal mix includes monitoring actuator health and adjusting an associated optimization problem accordingly.

11. The method of claim 1 , wherein the wing tilt angle of the aircraft is determined based on the past actuator commands.

12. An aircraft flight control system, comprising:

an interface configured to receive:

a set of inceptor inputs associated with a requested set of forces and moments to be applied to the aircraft; and

a set of sensor inputs reflecting a current dynamic state of the aircraft, the dynamic state including aircraft airspeed and wing tilt angle; and

a processor coupled to the interface and configured to:

compute an optimal mix of actuators and associated actuator parameters to achieve to an extent practical the requested forces and moments, including by taking into consideration dynamically varying effectiveness of one or more actuators based on the current dynamic state of the aircraft, wherein the optimal mix of actuators includes one or more rotors and for each rotor taking into consideration dynamically varying effectiveness includes using a moment vector, a control surface performance matrix, and a dynamically updated rotor performance matrix to determine the effect of said one or more rotors under various combinations of actuators and associated parameters given the current dynamic state of the aircraft, wherein the computing of the optimal mix of actuators and the associated actuator parameter includes to:

compute the moment vector based on the set of inceptor inputs and a current state of the aircraft, comprising to:

determine the current state of the aircraft, wherein the current state of the aircraft is determined based on sensor data and an estimate of the current state of the aircraft, the sensor data including the wing tilt angle of the aircraft, wherein the estimate of the current state of the aircraft is determined based on past actuator commands, wherein the wing tilt angle of the aircraft includes a first wing tilt angle and a second wing tilt angle, wherein the first wing tilt angle relates to an angle of a front wing, and wherein the second wing tilt angle relates to an angle of a back wing;

compute the control surface performance matrix based on the first wing tilt angle and the second wing tilt angle; and

compute the dynamically updated rotor performance matrix based on the first wing tilt angle and the second wing tilt angle; and

provide an output comprising for each actuator in the optimal mix a corresponding set of one or more control signals associated with the actuator parameters computed for that actuator.

13. The system of claim 12 , wherein the optimal mix is computed at least in part by formulating an associated optimization problem as a quadratic program.

14. The system of claim 12 , wherein the optimal mix is computed at least in part by formulating an associated optimization problem comprising the rotor performance matrix, the control surface performance matrix, and the requested set of forces and moments to be applied to the aircraft.

15. The system of claim 12 , wherein computing the optimal mix includes determining a set of thrusts for rotors of the aircraft and a set of angles for control surfaces of the aircraft.

16. The system of claim 12 , wherein the non-linear model for actuator performance is determined based on spatial rotation information.

17. A computer program product to control flight of an aircraft, the computer program product being embodied in a non-transitory computer readable medium and comprising computer instructions for:

receiving a set of inceptor inputs associated with a requested set of forces and moments to be applied to the aircraft;

computing an optimal mix of actuators and associated actuator parameters to achieve to an extent practical the requested forces and moments, including by taking into consideration dynamically varying effectiveness of one or more actuators based on a current dynamic state of the aircraft, the dynamic state including aircraft wing tilt angle, wherein the optimal mix of actuators includes one or more rotors and for each rotor taking into consideration dynamically varying effectiveness includes using a moment vector, a control surface performance matrix, and a dynamically updated rotor geometry performance matrix to determine the effect of said one or more rotors under various combinations of actuators and associated parameters given the current dynamic state of the aircraft, wherein the computing of the optimal mix of actuators and the associated actuator parameter includes:

computing the moment vector based on the set of inceptor inputs and a current state of the aircraft, comprising:

determining the current state of the aircraft, wherein the current state of the aircraft is determined based on sensor data and an estimate of the current state of the aircraft, the sensor data including a wing tilt angle of the aircraft, wherein the estimate of the current state of the aircraft is determined based on past actuator commands, wherein the wing tilt angle of the aircraft includes a first wing tilt angle and a second wing tilt angle, wherein the first wing tilt angle relates to an angle of a front wing, and wherein the second wing tilt angle relates to an angle of a back wing;

computing the control surface performance matrix based on the first wing tilt angle and the second wing tilt angle; and

computing the dynamically updated rotor geometry performance matrix based on the first wing tilt angle and the second wing tilt angle; and

providing an output comprising for each actuator in the optimal mix a corresponding set of one or more control signals associated with the actuator parameters computed for that actuator.