Abstract:To address the insufficient safety margins caused by traditional control methods for inland curved waterways,which are limited to precise centerline tracking and neglect key navigation practices such as“holding high and taking low”,a ship rudder-propeller coordinated control method integrating this good seamanship is proposed.The method features an improved LOS(line-of-sight)guidance law at the guidance layer.It algorithmically implements“holding high and taking low”by introducing a lateral offset,calculated based on operational conditions like vessel speed and current,to proactively generate a strategic,off-centerline reference trajectory.Furthermore,its adaptive integral mechanism effectively compensates for environmental disturbances and eliminates steady-state errors.The control layer employs a conventional PID (proportional-integral-derivative)controller for precise control of the rudder angle,forming a complete rudder-propeller coordinated control system.Simulation results verify that under a 2 m/s cross-current disturbance,the proposed method successfully executes the predetermined strategy,increasing the minimum safety distance to the concave bank by 34.4% compared with traditional methods and exhibiting superior robustness.The research confirms that the method effectively integrates navigation practice with modern control theory,providing a new solution for enhancing the navigational safety of ships in complex and confined waterways.