Modeling and Sliding Mode Control for Chaotic Yawing Phenomenon of Large Oil Tanker

Abstract

In order to explain and control the unexpected yawing phenomenon of large oil tankers, a pilot model is used to replace the original proportional model and is combined with the nonlinear ship responding model to construct a model of the whole closed-loop maneuvering system, which is found to be similar to the chaotic Duffing equation, and to be able to have a positive Lyapunov exponent after parameter adjustment, indicating that the chaotic theory can be used to explain this unexpected yawing phenomenon. In order to realize course keeping control with robustness to parameter uncertainty, based on the model built and the backstepping method, a sliding mode control scheme is proposed. The simulation illustrates that the static state rudder angle is smaller than 5° and course deviation is smaller than 0.07° when the chaotic yawing is at the theoretical maximum. Chaotic yawing is eliminated. The idea of establishing man-in-the-loop chaotic system is novel, and the method of solving backstepping parameter uncertainty through sliding mode is easy and effective.

Keywords

• chaos
• pilot model
• chaotic system modeling
• backstepping method
• sliding mode control
• course keeping control