Non-linear QFT Robust Control of an Underactuated RC Hovercraft

An analysis and design of a multivariable nonlinear quantitative feedback theory (QFT) robust control for underactuated systems have been carried out. The system in study is a hovercraft. The model is a nonlinear MIMO 2x3 system. An interesting question is that the plant has less degree of freedom for actuation and is more difficult to control. The goal is to achieve a trajectory tracking control. The approach to non-linear QFT synthesis consists of a local linearization of the non-linear plant about closed-loop acceptable outputs. It is shown that the control achieves the position tracking control.