2-DOF H∞ Output Feedback Control of Quadrotor Subject to Parametric Uncertainties and Time Delay

This article presents the problem of position tracking control of quadrotor subject to parametric uncertainties, time delay, and external disturbances, which cause performance degradation and instability in the quadrotor control system. Two degree-of-freedom (DOF) $\mathcal{H}_{\infty}$ control scheme is designed for the 6-DOF model of quadrotor. Parametric uncertainty and time delay are lumped into a single complex multiplicative perturbation. Multiplicative weights, which are rational transfer functions, are determined using frequency domain approach. Robustness and performance are demonstrated by numerical simulations. The simulation’s results indicate effective tracking and disturbance rejection.