| A quadrotor vehicle has particular special characters of nonlinear and lack of drive, and it has been become the hotspot of analysis of control technology those years. This paper depends on a quadrotor as analysis plat, and unit quaternoins representation is used for the attitude. Then the technology of identification in frequency horizon is combined to identify the parameters of model. Finally, a controller based on backstepping and characters of geometry for position control, and a controller based on feedback linear and LQR for attitude control. The main work are as follows:(1) The aerodynamic of rotor has been analyzed. Theorem of momentum has been used to calculate the thrusts and moment of rotor in macrograph, and the lift of paddle are analyzed using blade element theory in microcosmic. Finally, the relatively complete characters of rotor are obtained.(2) Unit quaternoins representation is used for the attitude. Attitude described by unit quaternoins has many advantages in coordinate variation and rotate especially.(3) The main part of design of controller is building a compact mathematics model, and a full states nonlinear system model has been derived in this paper.(4) In the system, some parameters of model could not measure directly, which has been identified by system identification. The combination of mechanism analysis and parameter identification method can enhance the accurate of system model.(5) A controller based on feedback linear and LQR for attitude control. The method of feedback linear can obtain a linear system, and a controller with LQR has been designed. Finally, the proposed nonlinear controller in feedback system is obtained.(6) A controller based on backstepping and characters of geometry for position control. A nonlinear controller used to achieve the transfer from position to hope attitude based on the characters of geometry of thrust and methods of backstepping, which in order to achieve the feedback of position control. |
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