Sliding Mode Control for Ride Control System of SES

Abstract

The Surface Effect Ship (SES) has very good speed performance and ride quality in the calm sea. However, in case of rough seas, it may deteriorate its performance due to the air leak from the gap between the hull and water surface. The ship is equipped with louvers and fins to control the ship motion.In previous papers by present authors, linear and Pseudo-Bang-Bang controllers and Fuzzy controller ware introduced for Ride Control System (RCS) of SES. But switching algorithm included in the control law was not clearly defined, which left ambiguity in the design of the control system. In this paper, the Sliding Mode Control (SMC) for RCS of SES is examined since SMC would provide the switching algorithm theoretically.As a result that, the original SMC may not give good controller because the controller cannot keep the state in the switching hyperplane due to relatively big disturbance. The modification which eliminates the equivalent control term is named Modified Sliding Mode Control (MSMC). The controller provides the control to bring the state toward the switching hyperplane.Comparison based on the simulation shows that MSMC can achieve the good control performance for the SES among waves.