LPV state-feedback controller for Attitude/Altitude stabilization of a mass-varying quadcopter

This paper concerns the problem of attitude/altitude control of a quadrotor. The main contribution consists of developing a simple Linear Parameter Varying (LPV) model which includes the motor dynamics, weight, and moment of inertia variations. In addition, a robust LPV H
_∞
state-feedback controller is proposed. It allows us to perform both a reference trajectory tracking and disturbance rejection for attitude/altitude control of a mass-varying quadcopter. First, an augmented state which includes the integration of the trajectory errors for improving tracking control is computed. Next, to penalize the control inputs of the attitude/altitude system, weight functions are also added to the previous augmented system. Then, an H
_∞
state-feedback controller is designed by solving a set of Linear Matrix Inequalities (LMI) obtained from the Bounded Real Lemma and LMI region characterization. Simulations are conducted for several types of disturbances (sine, impulse, step, and random) and variations (slow and abrupt) of mass and moments of inertia. The reference path (sine, impulse, and step) is well-followed showing the ability of the design method to handle different performance objectives.