Autonomous Flight Control And Visual Simulation Of Soft-Wing UAV

Soft-wing Unmanned Aerial Vehicle (soft-wing UAV) is a new kind of UAV, which is composed of soft ram air parafoil and powered vehicle hanged by ropes. Benefit from its simple structure, higher flight load ratio and less demands for takeoff and landing, soft-wing UAV has some incomparable advantages over other kinds of aircrafts in certain tasks execution, that will also makes it have a wide range of applications either in the military or civilian fields. However, because of its soft characteristics in aerodynamics and non-rigid connection between the parafoil and powered vehicle, soft-wing UAV possesses apparent mass, flexible structure and inside relative motions, which are the difficulties in the further research of soft-wing UAV. At present, foreign researchers have achieved some progress in mathematical modeling and actual flight tests of soft-wing UAV. However, the research on soft-wing UAV in China has just developed for a couple of years and there is a big gap to be caught up with other developed countries. Besides, there are a lot of problems needed to be dealt with in further deep study.In this thesis, with the center of soft-wing UAV autonomous flight control, the problems about kinetic and kinematic modeling, autonomous flight algorithms design and visual simulation system design were thoroughly and systematically studied through the methods of theoretical analysis, numerical and visual simulation. Some valuable conclusions were drawn, which can be a helpful foundation for soft-wing UAV practical flight experiment.In this thesis, firstly, the development overview of soft-wing UAV was systematically introduced and the research status in this field was also presented. Secondly, based on the self-developed soft-wing UAV system by Shenyang Institute of Automation Chinese Academy of Sciences, the kinetic and kinematic mathematical model of soft-wing UAV was built in the method of classical mechanics theory. This mathematical model was decoupled into two models, which are the longitudinal model and the lateral model. In order to easily analysis and study, the longitudinal and lateral linearized model were obtained in the method of linearization. Then, using the linear quadratic optimal control method, an autonomous flight controller for soft-wing UAV mathematical model was designed. The status variables of soft-wing UAV have been automatically controlled by the flight control algorithms. Besides, the simple following trajectory points flight was also accomplished. Finally, using the open source flight simulator - FlightGear, a visual simulation system for the autonomous flight control mathematical model of soft-wing UAV was designed. Through this visual simulation system, the flight status and position information can be vividly reappeared in the form of 3D visualization. In addition, the validations of the soft-wing UAV mathematical model, the autonomous flight control algorithms and the visual simulation system were also successfully verified.