A type-2 fuzzy logic controller for dynamic positioning systems

This paper presents an approach to design type- 2 fuzzy logic controllers (FLCs) for dynamic positioning (DP) systems, and the design process can be easily extended to other multi-input multi-output (MIMO) systems with coupling between loops. The combination of FLCs and nonlinear observers removes the need to linearize the kinematic equations of motion when designing control systems for the DP systems. Simulations with a supply vessel demonstrate the performance of the proposed controller. Comparisons show that the type-2 FLC outperform the linear quadratic regulator (LQR) controller and is more robust. In the face of disturbances, the type-2 FLC has better disturbance rejection property than its type-1 counterpart.