Formation and Containment Fuzzy Control via Interval Type-2 Approach for Multiple Autonomous Ships with Complex Noises

An Interval Type-2 (IT-2) fuzzy control approach is proposed to solve the Formation-Containment (F-C) problem for nonlinear multiple Autonomous Ship (AS) systems with the consideration of uncertainties and multiplicative noises. Based on the IT-2 Takagi-Sugeno Fuzzy Model (T-SFM), the nonlinear control problem can be recast into a linear problem. Different from the existing F-C control research, the formation problem is solved by the individual IT-2 fuzzy tracking controller of each leader. As a result, the information communication between leaders, who are farthest from each other, is needless. Moreover, other valuable functions such as the avoidance of known obstacles and time-varying formation can also be accomplished by designing the proper target trajectories for the tracking of leaders. By virtue of the IT-2 T-SFM, the analysis methods for linear Multi-Agent Control Systems (MACSs) can be utilized to solve the containment analysis problem, which is caused by the leaders' control input. Finally, the simulation results of multiple ASs are provided to demonstrate the advantage of the IT-2 fuzzy controller design approach in the F-C problem.