Conference Paper

A Hovering Control Strategy for a Tail-Sitter VTOL UAV that Increases Stability Against Large Disturbance

Dept. of Aerosp. Eng., Tohoku Univ., Sendai, Japan
DOI: 10.1109/ROBOT.2010.5509183 Conference: Robotics and Automation (ICRA), 2010 IEEE International Conference on
Source: DBLP

ABSTRACT

The application range of UAVs (unmanned aerial vehicles) is expanding along with performance upgrades. Vertical take-off and landing (VTOL) aircraft has the merits of both fixed-wing and rotary-wing aircraft. Tail-sitting is the simplest way for the VTOL maneuver since it does not need extra actuators. However, conventional hovering control for a tail-sitter UAV is not robust enough against large disturbance such as a blast of wind, a bird strike, and so on. It is experimentally observed that the conventional quaternion feedback hovering control often fails to keep stability when the control compensates large attitude errors. This paper proposes a novel hovering control strategy for a tail-sitter VTOL UAV that increases stability against large disturbance. In order to verify the proposed hovering control strategy, simulations and experiments on hovering of the UAV are performed giving large attitude errors. The results show that the proposed control strategy successfully compensates initial large attitude errors keeping stability, while the conventional quaternion feedback controller fails.

Download full-text

Full-text

Available from: Atsushi Konno
  • Source
    • "In recent years, there has been a considerable attention towards the propeller-pushing and flapping-wing aircrafts which can not only take off vertically, but also fly forward with high speed. A successful example includes V-22 aircraft [8] as well as tail-sitter designs [9] [10] [11] [12] [13] [14] [15] [16] [17]. The T-wing is a VTOL UAV that is capable of both wing-born horizontal flight and propeller born vertical mode flight including hover and descent. "
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper presents a model of an agile tail-sitter aircraft, which can operate as a helicopter as well as capable of transition to fixed-wing flight. Aerodynamics of the co-axial counter-rotating propellers with quad rotors are analysed under the condition that the co-axial is operated at equal rotor torque (power). A finite-time convergent observer based on Lyapunov function is presented to estimate the unknown nonlinear terms in co-axial counter-rotating propellers, the uncertainties and external disturbances during mode transition. Furthermore, a simple controller based on the finite-time convergent observer and quaternion method is designed to implement mode transition.
    Full-text · Article · Sep 2015 · Journal of the Franklin Institute
  • Source
    • "In recent years, there has been a considerable attention towards the propeller-pushing and flapping-wing aircrafts which can not only take off vertically, but also fly forward with high speed. A successful example includes V-22 aircraft [8] as well as tail-sitter designs [9] [10] [11] [12] [13] [14] [15] [16] [17]. The T-wing is a VTOL UAV that is capable of both wing-born horizontal flight and propeller born vertical mode flight including hover and descent. "
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper presents a model of an agile tail-sitter aircraft, which can operate as a helicopter as well as capable of transition to fixed-wing flight. Aerodynamics of the co-axial counter-rotating propellers with quad rotors are analysed under the condition that the co-axial is operated at equal rotor torque (power). A finite-time convergent observer based on Lyapunov function is presented to estimate the unknown nonlinear terms in co-axial counter-rotating propellers, the uncertainties and external disturbances during mode transition. Furthermore, a simple controller based on the finite-time convergent observer and quaternion method is designed to implement mode transition.
    Preview · Article · Jun 2015
  • Source
    • "However, when the attitude error is large, the quaternion feedback control may fail to stabilize the UAV. Therefore, in this paper, " Resolved Tilt-Twist Angle Feedback Control " , proposed in our previous research [9], is used to calculate the attitude error for a tail-sitter VTOL UAV. The resolved tilt-twist angle feedback control increases stability against large attitude disturbance. "
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper presents development of a quad rotor tail-sitter VTOL UAV (Vertical Takeoff and Landing Unmanned Aerial Vehicle) which is composed of four rotors and a fixed wing. The conventional VTOL UAVs have a drawback in the accuracy of the attitude control in stationary hovering because they were developed based on a fixed-wing aircraft and they used the control surfaces, such as aileron, elevator, and rudder for the attitude control. To overcome such a drawback, we developed a quad rotor tail-sitter VTOL UAV. The quad rotor tail-sitter VTOL UAV realizes high accuracy in the attitude control with four rotors like a quad rotor helicopter and achieves level flight like a fixed-wing airplane. The remarkable characteristic of the developed quad rotor tail-sitter VTOL UAV is that it does not use any control surfaces even in the level flight. This paper shows the design concept of the developed UAV and experimental verification of all flight modes including hovering, transition flight and level flight.
    Full-text · Conference Paper · May 2013
Show more