This paper proposes a decision support model for USVs to improve the accuracy of collision avoidance decision-making. It is formed by Navigation Safety Domain (NSD) and domain-based Collision Risk Index (CRI), capable of determining the collision stage and risk between multiple ships. The NSD is composed of a warning domain and a forbidden domain, which is constructed under the constraints of COLREGs (International Regulations for Preventing Collisions at Sea). The proposed domain based CRI takes the radius of NSD in various encounter situations as threshold parameters. It is found that the value of collision risk in any directions can be calculated, including actual value and risk threshold. A catamaran USV and 6 given vessels are taken as study objects to validate the proposed model. It is found that the judgment of collision stage is accurate and the azimuth range of risk exists can be detected, hence the ships can take direct and effective collision avoidance measures. According to the relation between the actual value of CRI and risk threshold, the decision support rules are summarized, and the specific terms of COLREGs to be followed in each encounter situation are given.

本文提出了一种用于无人飞行器的决策支持模型，以提高防撞决策的准确性。它由导航安全域（NSD）和基于域的碰撞风险指数（CRI）组成，能够确定多艘船之间的碰撞阶段和风险。NSD由警告域和禁止域组成，该域是在COLREG（国际防止海上碰撞规则）的约束下构建的。所提出的基于域的CRI将在各种遭遇情况下的NSD的半径作为阈值参数。发现可以计算出任何方向的碰撞风险值，包括实际值和风险阈值。以双体船的USV和6艘给定的船只为研究对象，以验证所提出的模型。研究发现，碰撞阶段的判断是准确的，可以检测出存在危险的方位角范围，从而可以采取直接有效的避撞措施。根据CRI的实际值与风险阈值之间的关系，总结了决策支持规则，并给出了每种遭遇情况下应遵循的COLREG的具体术语。