Fuzzy Variable Order Sliding Mode Control of Nonlinear MIMO System

In this study, a fuzzy variable graded Sliding Mode Controller has been designed for a twin rotor multi-input multi-output system (TRMS). The main purpose of this study is to change the sliding surface of the sliding mode controller which is adaptively designed as variable order with the help of fuzzy logic and also to investigate the effect of the designed control method on the performance of a MIMO system. The effects of sliding surface degree on the system performance shows different effects depending on the error. The gain and the order of the sliding surface affect the overshoot and the reach time. If the sliding surface is small, the rise time of the system increases and the overshoot decreases. In consideration of this information, system performance increases when the gain and order of sliding surface is changed according as error and error change. When examining the obtained results of the simulation and application, it is seen that this method improves performance index such as overshoot, rise time and settlement time.