| The quadrotor is a flying robot,and belongs to the multirotor family.The quadrotor has several characteristics(mechanical structure of reduced size,reduced weight,agility,vertical takeoff and landing),which gives advantages over other types of flying robots.However,the quadrotor has a dynamic model that is strongly nonlinear and fully coupled,hence a robust and stable controller is required,and this thesis is about modeling and controlling flying robots,specifically a quadrotor.(1)The mathematical model of quadrotor is synthesized following the Newton-Euler Formalism and takes in consideration a couple of simplifying assumptions that ignore the influence of some effecting factors at a low speed.(2)As good stability and less dependence on the model plays an important role in quadrotor control,the linear PID controller or PD are employed.The design of these controllers is based on the assumption that the surge and heading dynamics of the system can be separated into independent subsystems,and each has only one control input.(3)We present control technique based on development and the synthesis of control algorithm sliding mode approach ensuring the locally asymptotic stability and desired tracking trajectories expressed in the center of the mass coordinate,and yaw angle is obtained directly while the desire roll and pitch angle are deduced.(4)The H? loop shaping and the fixed-structure H? control are two common methods of designing controller based on H? theory,vertical height,pitch angle,yaw angle and roll angle controllers of a quadrotor are designed with these two methods,respectively.The characteristics of these two methods are compared and analyzed through the design procedure and control performance.Meantime,a study and analysis of the results obtained between different control techniques in terms of robustness,the resulting controllers are tested through simulated maneuvers on Matlab,and the results are compared.Their ability to cope with disturbances is also tested. |
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