Robust Control for Quadrotors With Multiple Time-Varying Uncertainties and Delays

Robust trajectory tracking control problem is dealt with for quadrotors with multiple uncertainties and multiple delays. The vehicle model is described as a multiple-input multiple-out time-varying system subject to parametric perturbations, nonlinear and coupled dynamics, external disturbances, and state and input delays. A robust cascade controller including an attitude controller and a position controller is proposed based on the hierarchical control scheme and the robust compensating technique. It is proven that the position and attitude tracking errors can converge into the given neighbourhood of the origin in a finite time, subject to multiple uncertainties and delays. Experimental results on the quadrotor system are provided to verify the effectiveness of the proposed controller.