Ship Dynamic Collision Avoidance Mechanism Based on Course Control System

To explore the relationship between the variation of ship speed vector and the effect of collision avoidance, the static collision avoidance mechanism with the combination of ship domain and velocity obstacle methods was analyzed. Ship speed vector range for the avoidance of all objects without considering the motion process of ship course altering and the external environment was then determined. A course control system based on fuzzy adaptive proportional integral differential (PID) and ship motion equations was developed to reconstruct the nonlinear variation of ship speed vector during course altering process. The dynamic collision avoidance mechanism was then established based on the static collision avoidance mechanism and the course control system. The dynamic course altering range that satisfies the non-linear variation of ship speed was then obtained. The results indicate that in open waters where multiple objects are randomly located, the course altering ranges that satisfy the non-linear speed variation are [−90°, −72°], [31°, 47°], [62°, 79°], under the influence of ship dynamics, the course altering ranges that could cause collision are (−72°, 31°), (79°, 90°]. The obtained results are consistent with the influence of ship motion characteristics on collision avoidance with course altering and can provide a theoretical reference for the development of decision-support for ship collision avoidance, automatic collision avoidance and dynamic ship route planning.