Control System Design On Tailsitter UAV

Tailsitter aircraft has the advantages of fixed-wing aircraft and rotary-wing aircraft.It has the characteristics of vertical take-off and landing,fast flight speed,and long endurance,and has a wide range of application prospects.However,the tailsitter aircraft has problems such as strong dynamic coupling of six degrees of freedom and singular Euler angles,which makes the design of the controller more difficult.This paper takes tailsitter UAV as the research object.First,according to the development of the tailsitter UAV,the configuration of the tailsitter UAV is designed and the relevant parameters of the UAV are measured.Then,the flying principle of the tail-mounted UAV is analyzed and mathematical model is established Finally,the design verification of the tailsitter UAV flight control method is carried out.The main tasks include:First of all,the tailsitter UAV model is designed according to the development of the tailsitter unmanned mechanism.According to the design goals,the wing,power system and battery of the tailsitter UAV are designed and selected.then the aerodynamic coefficient and aerodynamic moment coefficient of the model are measured,as well as the UAV’s moment of inertia and other related parameters.Secondly,according to the flying principle of the tailsitter UAV,the vertical Euler angle and the traditional Euler angle are used to express the attitude of the tailsitter UAV.The dynamic characteristics of the propeller slipstream and the UAV are analyzed,and the generation mechanism of force and moment is studied,thereby establishing a six-degree-of-freedom nonlinear dynamic model of the tailsitter UAV.Thirdly,the cascade PID vertical hover controller is designed by simplifying the mathematical model of the UAV to realize the vertical hover control.The transition process can be described as a large-angle fixed-wing maneuvering flight.For nonlinear systems with large changes in attitude angle,the speed controller of the longitudinal total energy control system and the attitude angle controller of the outer loop proportional control and inner loop sliding mode control are designed to achieve transitional flight and fixed-wing flight.The effectiveness of the controller is verified by simulation.Finally,an actual flight platform was built for actual flight test.Experimental results show that the UAV has high hover attitude control accuracy and fast switching of two-way flight modes.