Robust control of a class of nonlinear systems and its application to a twin rotor MIMO system

In this paper, we proposed a new robust control scheme for a class of cascade-connected uncertain nonlinear systems. A key feature of this control scheme is that an ideal inverse complementary control law for the driven subsystem is firstly obtained with asserted good tracking performance. Then, a terminal sliding mode control law is derived for the driving subsystem to diminish the error arises from the deviation of the practical inverse control from the idea inverse control for the driven subsystem. An experimental setup, called twin rotor multi-input multi-output system (TRMS), was used to illustrate the controller design.