Attitude Control Method Research On Two Modes Of UQTW

In recent years, a new kind of UAV called Unmanned Quad-Tilt-Wings(UQTW) integrates both advantages of helicopter and fixed-wing aircraft. It combines both advantages of Vertical Take-Off and Landing (VTOL) and high speed with grand voyage. As a result, UQTW is believed to have a wide range use for military and civilian. This paper focuses on UQTW and does some researches on attitude control of UQTW at the stage of VTOL and transition.At first, the components including micro controller, actuators and sensors are chosen. Then the circuit and the communication system are designed. In the end, UQTW experiment platform is established.Secondly, on the basis of analysis of UQTW in mechanics and dynamics, the dynamic equations of the UQTW are established and some simplifications are done. Under this condition, a control system based on adaptive Backstepping for transition mode is designed. Meanwhile, another control system based on the variable structure-model reference adaptive control (SMRAC) for VTOL mode is designed. As the designed control systems are based on closed-loop feedback, this paper adopts an attitude estimation algorithm based on quaternion and gradient descent multi-sensor data fusion. Simulation results show that the control system designed in this paper can control the attitude and achieve a smooth transition in the state of low-speed flight during the transition flight mode. In the VTOL mode, the designed attitude control system can track the remote control signals stably to achieve the attitude control.Finally, an embedded flight control software is designed to realize the attitude control method in VTOL mode. The flight results show that UQTW has a good performance in VTOL mode.