Objective To further study the quantization process of state signals in ship course-keeping control systems, a new controller with adaptive-gain sliding mode control is designed and a feedback control method of ship course-keeping based on a high-gain adaptive observer is proposed.

Methods The input and output quantization process of the system signals is described through constructing a second-order nonlinear motion analysis model. A quantized adaptive sliding mode controller is designed based on a high-gain observer and logarithmic quantizer. At the same time, the fan-shaped constraint method is combined to eliminate the impact of quantization errors on the system. A logarithmic quantizer is used to quantify the state variables and input variables in the designed control system, and the quantized state feedback information is applied to the design of the ship heading maintenance controller. Finally, the heading tracking performance and the stability of the closed-loop control system are verified based on MATLAB Simulink simulation analysis and Lyapunov stability theory.

Results The results analysis verifies the effectiveness of the designed observer in evaluating the relevant parameters of the heading and yaw angular velocity of the ship. Not only does the course-keeping error approach zero infinitely, but the observation error also converges to the origin. This proves that the controller has good course-keeping performance and the closed-loop control system has good stability.

Conclusion The findings of this study can provide valuable application references for the field of ship heading maintenance control.