Soft Computing Based Sliding Surface Adjustment of Second Order Sliding Mode Controllers: An Application to Ship Steering Model

Abstract

This work introduces a novel second-order sliding mode (SOSM) controller for the control of dynamic
uncertain systems based on fuzzy logic. An efficient sliding surface design approach for improving controller
performance is to use time-varying sliding surfaces. The proposed controller incorporates second-order sliding
mode control, fuzzy logic control, and adaptive control benefits. The proposed controller ensures the system's
reaching conditions, stability, and robustness. The proposed controller is also well-suited for straightforward
design and implementation. In order to rotate the sliding surface in a way that improves the tracking
performance of the system under control, this control strategy uses a time-varying slope in the sliding surface
function and a straightforward two-input single-output fuzzy logic controller. The proposed controller is
studied with a ship steering model in comparison with a conventional second-order sliding mode controller
with a fixed sliding surface. Simulations of the ship steering system using MATLAB/SIMULINK show that
the proposed controller outperforms the typical second-order sliding mode controller.