Toughness strengthening method of course changing control for ships based on nonlinear modification

To enhance the resilience of ship course-keeping and large-angle collision-avoidance maneuvers under cyberattacks, this study proposes a cyber-resilient course control methodology based on an innovative feedback-switching architecture. A dual-feedback automatic switching mechanism that integrates both positive and negative feedback modes is proposed. In this framework, sign inversion of measurement signals induced by simulated cyberattacks are interpreted as positive feedback, enabling automatic switching between positive and negative feedback. This transforms the large-angle collision avoidance task into a small-angle course deviation problem. The core design employs a second-order closed-loop gain-shaping algorithm to synthesize a robust linear controller, which is further augmented with a sine-based nonlinear compensator and implemented via zero-order hold. Compared with conventional designs, the combined approach reduces actuator amplitude by 41.7% reduction and rudder actuation frequency by 33.2%. Closed-loop stability is established through description–function analysis and verified via the Nyquist stability criterion. Full-scale simulations on the “Yupeng” training vessel under standard sea conditions demonstrate that the integrated system maintains course-keeping accuracy within 0.8° during signal-inversion attacks while reducing steering energy consumption by 18.6%. The proposed automatic switching architecture effectively mitigates cyberattack effects during large-angle evasive maneuvers, reduces actuator wear and energy consumption, and enhances the safety and reliability of intelligent ships.