Research On Attitude Control And Trajectory Planning For Quadrotor Aircraft

In this thesis, the dynamic model of the small scale unmanned quad-rotor helicopter is set up. Research on attitude control, optimal trajectory generation, and tracking controller design are presented. Active disturbance rejection control(ADRC) technology is applied in attitude control algorithm. Differential flatness theory is introduced in optimal trajectory generation; a new tracking controller design is conducted with relevant tests. The main researches are as follows:Firstly, three different description methods of craft attitude are introduced. The relationship between different coordinate system is studied. The Newtown Principle was employed to derive the system dynamic according to the flight principle of a quadrotor.Secondly, the active disturbance rejection control(ADRC) technology is applied to the design of flight control schemes; the effectiveness of it is then illustrated via simulation. ADRC controller contains three parts: Tracking Differentiator(TD), Extended State Observer(ESO), Nonlinear State Error Feedback(NLSEF), which are introduced respectively. Each control path of pitch, roll and yaw is decoupled by ADRC technology with virtual controllers.Thirdly, a flatness-based moving target tracking strategy for a quadrotor unmanned aerial vehicle(UAV) is discussed. A simple version of the dynamical system obtained from a suitable coordinate transformation of the Euler- Lagrange model is applied to avoid the system singularities. Based on flatness and exact tracking error linearization, a dynamic feedback solution to the tracking trajectory problem is presented. This controller will push the quadrotor to chase the target along the time-optimal trajectory. The reference trajectory can be obtained by solving a constrained optimization problem whichis formulated by means of flatness approach.Finally, an aircraft platform of the X650 quadrotor is established with flight control module, attitude detection module, power module and communication module. On the basis of the final debug of the quadrotor, the construction of the quadrotor test platform is completed. Hovering test and remote control test with quadrotor are conducted, feasibility of test platform and effectiveness of control algorithm are verified by analyzing the collected flight data.