Autonomous Flight of a Quad-rotor UAV based on Sliding Mode Control

Abstract

This study discusses the practical usefulness of Sliding Mode Control (SMC) in application to a quad-rotor vehicle as an autonomous flight control system. SMC shows high robustness to disturbances and modeling errors in theoretical conditions, where control inputs are assumed to be switched in a very high frequency. However in real systems, control input is calculated after a specified time interval, and furthermore rotors of vehicles have time delays due to motor's time constants. Thus, it is not clear that SMC systems can keep flying stability and robustness to disturbances and errors. In this paper, the effects of time interval of SMC and time constants of rotors are investigated in numerical simulations as a preliminary study of experiments.