Quadrotor Control Design with Attitude Constraints

This paper presents a two-layer controller strategy for the quadrotor with attitude constraints. The inner layer called angular rate controller layer uses PID control to handle the unknown quadrotor parameters. The fast dynamic of the closed-loop system of the inner layer is checked though identifying the system's model. After then, the smooth bounded hyperbolic functions of the state variables are used with the nonlinear control technology to achieve trajectory tracking for the outer-loop layer. Finally, the simulation results demonstrate the effectiveness of the proposed controller.