Output feedback control of quad-rotor helicopter using linear parameter-varying method with saturation constraints

Abstract

This thesis presents the output feedback control of the quad-rotor helicopter (quadrotor) with input saturation constraints. The main idea underlying controller design is the transformation of the nonlinear model to a linear parameter-varying (LPV) model of the quadrotor. Then, the LPV control technique is applied. To design the LPV controller, we first consider the linear quadratic regulator control of LPV systems. This results in the linear parameter-varying quadratic regulator (LPVQR) control. Next, when the input saturation is taken into account, the LPVQR is inadequate to guarantee stability of the systems. Therefore, we propose the LPVQR control of the saturated LPV systems. Two approaches for saturated controller, the low-gain and the high-gain, are considered. As a result, the saturated LPVQR (SLPVQR) and the high-gain SLPVQR are obtained, respectively. Finally, to deal with the output feedback control problem, we consider the use of the extended Kalman filter for state estimation. The 3D visualization for the quadrotor simulation is given at the end to demonstrate the effectiveness of the controllers.