An Improved Control Algorithm for Ship Course Keeping Based on Nonlinear Feedback and Decoration

In order to make navigation more energy saving, this paper, based on fuzzy PID controller, uses nonlinear feedback and decoration (NFAD) technique, that is, two nonlinear functions are used to deal with the input and output of the controller respectively, to design the ship course keeping control algorithm, and the effectiveness of the control algorithm is verified by simulation experiments. The simulation results show that using NFAD technique to design the course keeping control algorithm can achieve the purpose of course keeping, and can also reduce the average rudder angle of about 22.1 %, and can still maintain course keeping when ship model occurs perturbation, which shows that the fuzzy PID control algorithm improved by NFAD technique has the characteristics of energy saving and strong robustness.