Network-based fuzzy adaptive sliding mode controller for the ship steering problem

In this paper, a networked ship course control system is considered, and the network-induced delay is the main problem in the networked control system (NCS). A network-based fuzzy adaptive nonlinear sliding model controller is proposed. The sliding surface is constructed with the time delay compensation. The unknown parts in the model, consisting of the external disturbances and the unmodeled dynamics, are approximately estimated by the fuzzy logic system. The sliding mode controller is designed to deal with the bad influence brought by both the time delay and the unknown terms. According to the Lyapunov theorem, the parameter vector of the fuzzy system is updated and the stability of the closed-loop system is proved. Finally, with the network environment simulated using the Truetime toolbox, simulation tests on a Mariner class vessel in waves are performed to validate the effectiveness of the proposed control scheme.