Chapter 19 - Sliding mode controller design for unmanned aerial vehicles with unmodeled polytopic dynamics

Abstract

Unmodeled dynamics is one of the problems found in mathematical modeling of many kinds of physical systems, such as electrical and mechanical systems. For this reason, robust control is a solution for this kind of problem, considering the unmodeled dynamics as a matched uncertainty. Unmodeled dynamics affect the robust stability and robust performance of many mechanical systems, reducing the overall efficiency of the designed controller. Therefore, the sliding mode controller (SMC) is designed for unmanned aerial vehicles (UAVs) with unmodeled polytopic dynamics. In this case, this kind of disturbance is considered as unmatched. The polytopic uncertainty found in the mathematical modeling of a UAV can be found in the inertia, Coriolis, and gravity components. The SMC techniques explained in this chapter will overcome this problem considering the disturbance rejection properties of this kind of controller. The proposed SMC techniques consist of robust H-infinity controllers in order to improve the controller design when polytopic uncertainties are found in the system. Adaptive higher-order SMCs are also implemented taking into account the disturbance rejection properties of SMC and the versatility of adaptive control. Some numerical experiments are shown to validate the theoretical results and simulate the SMCs for UAVs under different conditions.