AUTOMATIC TAKEOFF METHOD FOR AN AIRCRAFT WITH A FLEXIBLE AIRFOIL, AND AIRFOIL AND AIRCRAFT

• US 20120109427A1
• Filed: 10/28/2009
• Published: 05/03/2012
• Est. Priority Date: 10/30/2008
• Status: Active Grant

• Current Assignee: Swissavia SA
• Original Assignee: Swissavia SA
• Inventors: Berthier, Bernard
• Granted Patent: US 8,855,838 B2
• Time in Patent Office: Days
• US Class Current: 701/15
• CPC Class Codes: B64C 31/036 having parachute-type wing
• CPC Class Codes: B64C 39/024 of the remote controlled vehicle type, i.e. RPV
• CPC Class Codes: B64U 10/50 Glider-type UAVs, e.g. with parachute, parasail or kite for landing B64U70/83
• CPC Class Codes: B64U 30/12 Variable or detachable wings, e.g. wings with adjustable sweep

Abstract

The invention relates to an automatic takeoff method for an aircraft with a flexible airfoil, comprising a carriage suspended by rigging lines from an airfoil. According to said method:—said carriage is provided with an autopilot controlling actuators that control said rigging lines;—said airfoil is provided with an airfoil attitude sensor, comprising a biaxial accelerometer and a biaxial rate gyro, capable of defining the position of an airfoil reference frame in relation to the ground, and means for communicating with said autopilot;—during takeoff, information is received from said airfoil attitude sensor and transmitted to said autopilot for the purpose of controlling said actuators. The invention also relates to an airfoil for the implementation of said method, comprising an airfoil attitude sensor with an inertial unit with a biaxial accelerometer and a biaxial rate gyro, and means for communicating with an autopilot. The invention further relates to an aircraft comprising such an airfoil.

Claims

1. A method of automatic takeoff management for a flexible-airfoil drone or aircraft comprising at least one sail, which comprises at least one carriage or harness suspended by suspension lines from at least said sail, said method being characterized in that:

said carriage or harness is equipped with at least one autopilot designed to be able to give motion orders to actuators with which said drone or aircraft is equipped so as to act at least on said suspension lines;

said sail is equipped with at least one airfoil attitude sensor, comprising at least one accelerometer on at least two axes and at least one gyrometer on at least two axes, designed to be able to define the position of a so-called sail benchmark with respect to a ground benchmark, as well as means of communication with said autopilot;

at least during the takeoff of said drone or aircraft, information originating from said airfoil attitude sensor is recovered and communicated to said autopilot so as to give orders to said actuators.

2. The method as claimed in claim 1, characterized in that raw inertial measurements are transmitted, from said airfoil attitude sensor to said autopilot, which processes them by estimating in an optimal manner the attitude and the angular speeds of said sail, by integration of the angular speeds provided by said gyrometer or gyrometers and determination of the direction of gravity according to the measurements of said accelerometer or accelerometers.

3. The method as claimed in claim 1, characterized in that said autopilot is piloted by a finite element integration program so as to compute the values of the orders given to said actuators, said program being based on the theory of Euler angles, or the theory of quaternions, or the theory of direction cosines.

4. The method as claimed in claim 1, characterized in that said autopilot is made to control the actuators that said drone or aircraft comprises so as to act on internal engine means when said drone or aircraft comprises same, or/and so as to act on control surfaces when said drone or aircraft comprises same.

5. The method as claimed in claim 1, characterized in that said autopilot is further made to control means of steering, or/and of airfoil braking, or/and of flight control, or/and control surfaces, when said drone or aircraft comprises same.

6. The method as claimed in claims claim 1, characterized in that:

said carriage or harness is equipped with at least one carriage attitude sensor designed to be able to define the position of a so-called carriage benchmark with respect to a ground benchmark;

at least during the takeoff of said drone or aircraft, a switching means is used to give precedence to said airfoil attitude sensor over said carriage attitude sensor so as to communicate with said autopilot to give orders to said actuators.

7. The method as claimed in claim 1, characterized in that:

said sail is equipped with at least one airfoil attitude sensor comprising at least one accelerometer on three axes and at least one gyrometer on three axes, designed to be able to define the position of a so-called sail benchmark with respect to a ground benchmark, as well as means of communication with said autopilot.

8. A sail for the implementation of this method, characterized in that it comprises at least one airfoil attitude sensor itself comprising an onboard inertial platform equipped with at least one accelerometer on at least two axes and with at least one gyrometer on at least two axes, and in that it further comprises means of communication with an autopilot.

9. A flexible-airfoil drone or aircraft, which comprises at least one carriage or harness suspended by suspension lines from at least one sail as claimed in claim 8, said carriage or harness comprising said autopilot designed to be able to give orders to actuators that said drone or aircraft comprises so as to act on said suspension lines, or/and to act on engine means or/and to act on control surfaces, characterized in this said communication means are designed to be able to transmit information originating from said airfoil attitude sensor so as to communicate said information to said autopilot so as to give orders to said actuators.

10. The flexible-airfoil drone or aircraft as claimed in claim 9, characterized in that it further comprises internal engine means designed to be able to allow its takeoff, or/and means of linking to external engine means designed to be able to allow its takeoff such as a winch or similar, and that said actuators are designed to be able to control said engine means, internal or/and external, as the case may be.

11. The flexible-airfoil drone or aircraft as claimed in claim 9, characterized in that it further comprises control surfaces, or/and means of steering, or/and of airfoil braking, or/and of flight control, that said actuators are designed to be able to control.

12. The flexible-airfoil drone or aircraft as claimed in claim 9, characterized in that said carriage or harness comprises a carriage attitude sensor designed to be able to define the position of a carriage benchmark with respect to a ground benchmark, characterized in that said drone or aircraft further comprises a switching means designed to be able to give said airfoil attitude sensor priority over said carriage attitude sensor so as to inform said autopilot and generate the commands dispatched by the latter to said actuators.