Automatic takeoff method for an aircraft with a flexible airfoil, and airfoil and aircraft

• US 8,855,838 B2
• Filed: 10/28/2009
• Issued: 10/07/2014
• Est. Priority Date: 10/30/2008
• Status: Expired due to Fees

• Current Assignee: Swissavia SA
• Original Assignee: Swissavia SA
• Inventors: Berthier, Bernard
• Primary Examiner(s): Tran, Khoi
• Assistant Examiner(s): NGUYEN, ROBERT T
• Application Number:
  US13/381,197
• Publication Number:
  US 20120109427A1
• Time in Patent Office: 1,805 Days
• Field of Search: 701/3, 701/11, 701/15, 701/1, 701/4, 244/138.R, 244/139, 244/142, 244/152, 244900-904
• 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 having at least one sail and at least one carriage or harness suspended by suspension lines at least from the at least one sail, the method comprising:

equipping the at least one carriage or harness with at least one autopilot constructed for giving motion orders to actuators with which the drone or aircraft is equipped, acting at least on the suspension lines with the actuators during the takeoff;

equipping the at least one sail with at least one airfoil attitude sensor having at least one accelerometer on at least two axes and at least one gyrometer on at least two axes, and being constructed for being able to define a position of a sail benchmark with respect to a ground benchmark, the at least one airfoil attitude sensor having means of communication with the at least one autopilot;

at least during the takeoff of the drone or aircraft, recovering information originating from the at least one airfoil attitude sensor and communicating the information to the at least one autopilot so as to give orders to the actuators.

2. The method as claimed in claim 1, further comprising transmitting raw inertial measurements from the at least one airfoil attitude sensor to the at least one autopilot, processing the raw inertial measurements by estimating the attitude and the angular speeds of the at least one sail, by integration of the angular speeds provided by the gyrometer or gyrometers and determination of the direction of gravity according to the measurements of the accelerometer or accelerometers.

3. The method as claimed in claim 1, further comprising piloting the at least one autopilot by a finite element integration program for computing the values of the orders given to the actuators, the 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, further comprising making the at least one autopilot control the actuators so as to act on internal engine means of the drone or aircraft or/and so as to act on control surfaces of the drone or aircraft.

5. The method as claimed in claim 1, further comprising making the at least one autopilot control means of steering, or/and of airfoil braking, or/and of flight control, or/and control surfaces of the drone or aircraft.

6. The method as claimed in claim 1, further comprising:

equipping the at least one carriage or harness with at least one carriage attitude sensor constructed for being able to define the position of a carriage benchmark with respect to a ground benchmark;

at least during the takeoff of the drone or aircraft, using a switching means for giving precedence to the at least one airfoil attitude sensor over the at least one carriage attitude sensor so as to communicate with the at least one autopilot for giving orders to the actuators.

7. The method as claimed in claim 1, further comprising:

equipping the at least one sail with at least one airfoil attitude sensor having at least one accelerometer on three axes and at least one gyrometer on three axes, and being constructed for being able to define the position of a sail benchmark with respect to a ground benchmark, as well as means of communication with the at least one autopilot.

8. A sail for the implementation of the method according to claim 1, the sail comprising:

at least one airfoil attitude sensor having 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 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 at least one carriage or harness including said autopilot, said autopilot configured for giving orders to actuators to act on said suspension lines, or/and to act on engine means or/and to act on control surfaces, said communication means being configured for transmitting information originating from said at least one airfoil attitude sensor so as to communicate said information to said autopilot for giving orders to said actuators.

10. The flexible-airfoil drone or aircraft as claimed in claim 9, further comprising internal engine means constructed for allowing takeoff, or/and means of linking to external engine means constructed for allowing takeoff such as a winch or similar, and that said actuators are constructed for controlling said engine means, internal or/and external, as the case may be.

11. The flexible-airfoil drone or aircraft as claimed in claim 9, further comprising control surfaces, or/and means of steering, or/and of airfoil braking, or/and of flight control, that said actuators are constructed to control.

12. The flexible-airfoil drone or aircraft as claimed in claim 9, wherein said at least one carriage or harness includes a carriage attitude sensor constructed to be able to define the position of a carriage benchmark with respect to a ground benchmark, a switching means constructed for giving said at least one 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.

13. A sail comprising:

suspension lines, actuators connected to said suspension lines, and at least one airfoil attitude sensor mounted on the sail, said at least one airfoil attitude sensor having 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 means of communication with an autopilot, said airfoil attitude sensor configured for communicating information obtained by said airfoil attitude sensor during takeoff for actuating said suspension lines.