Autonomous navigation on the open sea involving automatic collision avoidance and route planning helps to ensure navigational safety. To judge whether all target ships (TSs) will pass safely and find the optimal route under multi-ship encounter situations, the relationship between the variations in the own ship (OS) velocity vector after nonlinear course altering motion and the collision avoidance result, which is defined as the collision avoidance mechanism, was analyzed. Methods producing the optimal route were also proposed. First, the static collision avoidance mechanism based on the ship domain and velocity obstacle (VO) was introduced. On that basis, the collision-free course alteration range of the OS, without consideration of the real manoeuvring process, was presented. Second, the ship motion equations and fuzzy adaptive proportion integral derivative (PID) control method were combined to develop a course control system. This system was then used to predict OS motions during the course-altering process. Based on this prediction, TS positions were calculated. Subsequently, the dynamic collision-free course altering ranges for the OS were obtained. Third, a model to compute the optimal route was introduced. Finally, simulations were performed under a situation including six TSs and two static objects, and the shortest collision-free route that satisfies both regulations for preventing collisions and good seamanship was found.

中文翻译：

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多船相遇情况下动态自动避碰机制及最优航线

涉及自动避碰和路线规划的公海自主航行有助于确保航行安全。为了判断多船相遇情况下所有目标船舶（TS）是否会安全通过并找到最佳路线，非线性航向改变运动后本船（OS）速度矢量的变化与避碰结果之间的关系，其中被定义为碰撞避免机制，进行了分析。还提出了产生最佳路线的方法。首先，介绍了基于船舶域和速度障碍物（VO）的静态避碰机制。在此基础上，给出了不考虑真实机动过程的操作系统无碰撞航向改变范围。第二，结合船舶运动方程和模糊自适应比例积分微分（PID）控制方法，开发了航向控制系统。然后，该系统用于在改变路线的过程中预测 OS 运动。基于该预测，计算TS位置。随后，获得了操作系统的动态无碰撞航向改变范围。第三，引入了计算最优路线的模型。最后，在包括六个TS和两个静态物体的情况下进行了模拟，并找到了同时满足防止碰撞和良好航海规范的最短无碰撞路线。计算TS位置。随后，获得了操作系统的动态无碰撞航向改变范围。第三，引入了计算最优路线的模型。最后，在包括六个TS和两个静态物体的情况下进行了模拟，并找到了同时满足防止碰撞和良好航海规范的最短无碰撞路线。计算TS位置。随后，获得了操作系统的动态无碰撞航向改变范围。第三，引入了计算最优路线的模型。最后，在包括六个TS和两个静态物体的情况下进行了模拟，并找到了同时满足防止碰撞和良好航海规范的最短无碰撞路线。