System and method for controlling a roll rate of a torsionally-disconnected freewing aircraft
View Patent ↗An aircraft includes a fuselage, and first and second freewings. Each of the first and second freewings is separately mounted to the fuselage and independently freely pivotable about respective pivot axes. The aircraft includes an angular rate sensor configured to measure a roll rate of the fuselage and to output a first roll rate signal. The aircraft includes a controller in communication with the angular rate sensor and configured to receive a second roll rate signal from the pilot and to compare the first and second roll rate signals to generate first and second control surface control signals. The aircraft includes at least one control actuator in communication with the controller and configured to actuate a first control surface of the first freewing and a second control surface of the second freewing in response to the first and second control surface control signals, respectively, to control the roll rate of the aircraft.
1. An aircraft, comprising:
a fuselage;
a first main freewing and a second main freewing,
wherein each of the first and second main freewings is torsionally disconnected from each other, such that each of the first and second main freewings is decoupled from each other and the fuselage wherein each of the first and second main freewings is independently and freely pivotable
i) about its respective pivot axis,
ii) about the fuselage, and
iii) in regard to each other, and
wherein each of the first and second main freewings comprises a principal inertial axis, a tip and a base, and
wherein the principal inertial axis of each of the first and second main freewings is substantially aligned fore of the respective pivot axis at the tip of each of the first and second main freewings, and substantially aligned aft of the respective pivot axis at the base of each of the first and second main freewings;
an angular rate sensor,
wherein the angular rate sensor is configured to measure a roll rate of the fuselage and to output a first roll rate signal;
a controller in communication with the angular rate sensor,
wherein the controller is configured to receive a second roll rate signal from a pilot of the aircraft, and
wherein the controller is configured to compare the first and second roll rate signals to generate first and second control surface control signals; and
at least one control actuator in communication with the controller,
wherein the at least one control actuator is configured to actuate a first control surface of the first main freewing and a second control surface of the second main freewing in response to the first and second control surface control signals, respectively, to control a roll rate of the aircraft.
2. The aircraft of claim 1 , wherein the angular rate sensor comprises an angular rate gyroscope.
3. The aircraft of claim 1 , wherein each of the first and second control surfaces comprises an airfoil on a respective trailing edge of each of the first and second main freewings.
4. The aircraft of claim 1 , comprising:
an airspeed sensor in communication with the controller,
wherein the airspeed sensor is configured to measure an airspeed of the aircraft, and
wherein the controller is configured to modify the first and second control surface control signals in accordance with the airspeed of the aircraft.
5. The aircraft of claim 1 , wherein the respective pivot axes of the first and second main freewings comprise lateral axes of the fuselage.
6. A system for controlling a roll rate, comprising:
an aircraft;
a roll rate sensor configured to measure a roll rate of a fuselage of the aircraft and to output a first roll rate signal,
wherein the aircraft includes first and second main freewings, torsionally disconnected from each other, such that each of the first and second main freewings is decoupled from each other and the fuselage wherein each of the first and second main freewings is independently and freely pivotable
i) about its respective pivot axis,
ii) about the fuselage, and
iii) in regard to each other, and wherein each of the first and second main freewings comprises a principal inertial axis, a tip and a base, and
wherein the principal inertial axis of each of the first and second main freewings is substantially aligned fore of a respective pivot axis at the tip of each of the first and second main freewings, and substantially aligned aft of the respective pivot axis at the base of each of the first and second main freewings;
a control processor in communication with the roll rate sensor,
wherein the control processor is configured to receive a second roll rate signal from a pilot of the aircraft, and
wherein the control processor is configured to compare the first and second roll rate signals to generate first and second control signals; and
a control actuator in communication with the control processor,
wherein the control actuator is configured to actuate a first control member of the first main freewing and a second control member of the second main freewing in response to the first and second control signals, respectively, to control the roll rate of the aircraft.
7. The system of claim 6 , wherein the roll rate sensor comprises an angular rate gyroscope.
8. The system of claim 6 , wherein each of the first and second control members comprises an airfoil on a respective trailing edge of each of the first and second main freewings.
9. The system of claim 6 , comprising:
a dynamic pressure sensor in communication with the control processor,
wherein the dynamic pressure sensor is configured to measure an airspeed of the aircraft, and
wherein the control processor is configured to modify the first and second control signals in accordance with the airspeed of the aircraft.
10. The system of claim 6 , wherein the respective pivot axes of the first and second main freewings comprise lateral axes of the fuselage.
11. A method of controlling a roll rate of an aircraft, comprising the steps of:
a.) measuring a roll rate of a fuselage of the aircraft to generate a first roll rate signal,
wherein the aircraft includes first and second main freewings, torsionally disconnected from each other, such that each of the first and second main freewings is decoupled from each other and the fuselage wherein each of the first and second main freewings is independently and freely pivotable
i) about its respective pivot axis,
ii) about the fuselage, and
iii) in regard to each other, and
wherein each of the first and second main freewings includes a principal inertial axis, a tip and a base, and
wherein the principal inertial axis of each of the first and second main freewings is substantially aligned fore of a respective pivot axis at the tip of each of the first and second main freewings, and substantially aligned aft of the respective pivot axis at the base of each of the first and second main freewings;
b.) receiving a second roll rate signal from a pilot of the aircraft;
c.) comparing the first and second roll rate signals to generate first and second control signals; and
d.) actuating a first control surface of the first main freewing and a second control surface of the second main freewing in response to the first and second control signals, respectively, to control the roll rate of the aircraft.
12. The method of claim 11 , wherein each of the first and second control surfaces includes an airfoil on a respective trailing edge of each of the first and second main freewings.
13. The method of claim 11 , wherein step (a) is performed along a fore-aft axis of the fuselage.
14. The method of claim 11 , comprising the steps of:
e.) measuring an airspeed of the aircraft; and
f.) modifying the first and second control signals in accordance with the airspeed of the aircraft.
15. The method of claim 11 , wherein the respective pivot axes of the first and second main freewings comprise lateral axes of the fuselage.