This paper presents a method to design a control scheme for nonlinear systems using fuzzy optimal control. In the design process, the nonlinear system is first converted into local subsystems using sector non-linearity approach of Takagi-Sugeno (T-S) fuzzy modeling. For each local subsystem, an optimal control is designed. Then, the parameters of local controllers are defuzzified to construct a global optimal controller. To prove the effectiveness of this control scheme, simulations are performed using the mathematical model of Esso Osaka tanker ship for set-point regulation with and without disturbance and reference tracking. In addition, the simulation results are compared with that of a PID controller for further verification and validation. It has been shown that the proposed optimal controller can be used for the nonlinear ship steering with good rise time, zero steady state error and fast settling time.
Muhammad EJAZ, Mou CHEN. Fuzzy Optimal Control Design for Ship Steering[J]. Transactions of Nanjing University of Aeronautics & Astronautics,2019,36(3):459-467