A ship’s automatic steering system is the basis for addressing control difficulties related to course-changing and course-keeping during navigation through heading angle control, and is a link in realizing unmanned and autonomous ships. This study proposes a robust RCGA-based linear active disturbance rejection controller (LADRC) design method considering environmental disturbances, measurement noise, and model uncertainties in designing a ship heading controller for use when the ship is sailing. The LADRC consisted of a transient profile, a linear extended state observer, and a PD controller. The control gains in the LADRC with the linear extended state observer were adjusted by RCGAs to minimize the integral of the time-weighted absolute error (ITAE), which is an evaluation function of the control system. The proposed method was applied to ship heading control, and its effectiveness was validated by comparing the propulsive energy loss between the proposed method and a conventional linear PD controller. The simulation results showed that the proposed method had the advantages of lower propulsive energy loss, more robustness, and higher tracking precision than the conventional linear PD controller.

Abstract
1. Introduction
2. Dynamic Model and Performance Index
    2.1 Ship motion and steering gear model
    2.2 Ocean wave model
    2.3 Performance evaluation
3. LADRC for Heading Angle Control
    3.1 Transient Profile
    3.2 LADRC design
4. Simulation Results and Review
    4.1 Tuning of LADRC
    4.2 Ship heading control simulation
5. Conclusion
References

• Jong-Kap Ahn(Technical Director, Seaward Ship Management)
• Myung-Ok So(Division of Marine Engineering, National Korea Maritime and Ocean University) Corresponding author