Supertwisting and terminal sliding mode control of course keeping for ships by using particle swarm optimization

Abstract

Ships are highly vulnerable to external disturbances like sea waves and sea winds; its course keeping is a core problem of ship motion control. In order to solve the problems of ship heading control a better rudder action is needed to control the ship motion. In this research study, variable structure based nonlinear control algorithms namely integral sliding mode, double integral sliding mode, terminal sliding mode and supertwisting sliding mode controllers have been proposed to provide the robust solution against external disturbances. Lyapunov stability theory has been considered to check the asymptotic stability of the system. Smoothness, energy consumption and output response performances have also been calculated to further validate the performance of suggested controllers. Robustness of all the suggested controllers have been validated by adding the disturbance effect into system model. Particle swarm optimization approach has been used to get the optimal performance of better performing controller by tuning its gains. Furthermore, suggested nonlinear controllers have been simulated in MATLAB/Simulink and their comparative analysis has been showed with each other and with the literature’s developed nonlinear controllers. To further ensure the superiority of best performing proposed controller, a real-time controller hardware in the loop experimental test has also been presented.