Flight Control Method And Experimental Study Of Small Tailsitter Vertical Takeoff And Landing Unmanned Aerial Vehicle

Tailsitter vertical takeoff and landing unmanned aerial vehicle combines the advantages of rotorcraft unmanned aerial vehicle(uav)and fixed-wing unmanned aerial vehicle.Not only can be like a helicopter vertical take-off and landing,but also has high-speed cruise flight ability of fixed-wing aircraft,which has important application prospects in civil and military fields.The tailsitter unmanned aerial vehicle has three flight modes: vertical flight mode,horizontal flight mode and transitional flight mode.So will involve the issue of mode conversion,which adds difficulties to aircraft modeling and control.Establishing the mathematical model of the tailsitter unmanned aerial vehicle.Usually aircraft attitude can be made of three euler angle(roll angle and pitch angle and yaw angle)to determine,but the tailsitter unmanned aerial vehicle in vertical flight mode when making large Angle maneuver,pitching angle changed close to 90 °,the conventional euler angle is used to describe the aircraft attitude will produce strange.This article introduces quaternion to analyze and solve the attitude of the tailsitter unmanned aerial vehicle.When the tailsitter unmanned aerial vehicle is in vertical flight mode,due to low airspeed and large windward surface,it is easy to be disturbed by gusts and cause attitude oscillation,which is greatly affected by the environment.In this paper,PID control theory is used to complete the design of the flight controller of the tailsitter unmanned aerial vehicle,the gazebo simulation is used to obtain the optimal control parameters,and the hovering and low-speed forward flight tests are completed.The specific work is as follows:1.Explain the test system in detail and introduce the functional principles of various components in the control system,power system and mechanical system of the tailsitter unmanned aerial vehicle.Introduce the flying principle of tailsitter unmanned aerial vehicle.2.Define the coordinate system,establish the dynamics model of the tailsitter unmanned aerial vehicle,Introduce the quaternion in detail,and its representation method is used to describe the attitude of unmanned aerial vehicle.Use the mature PID algorithm as the attitude control algorithm of tailsitter unmanned aerial vehicle.3.The motion simulation model of tailsitter unmanned aerial vehicle is built with gazebo software,through the simulation experiment to determine the PID parameters of the best flying state.The simulation results show that the PID controller designed in this paper can effectively control the tailsitter aircraft.4.Finally,the test platform of the tailsitter vertical takeoff and landing unmanned aerial vehicle is built,and the flight control system of pixhack was used to coordinate with the ground station of QGroundControl for the test.By analyzing and summarizing the test data,the test results show that the modeling and control method proposed in this paper can effectively control the hovering and low-speed forward flight test of the tailsitter unmanned aerial vehicle.