基于船舶旋回的变向避碰解算方法

Calculation methods of changing course to avoid collision based on ship turning

通过建立船舶运动方程,导出最近会遇距离、最近会遇时间以及不考虑旋回时避让航向方程,并分左舷来船向右避让和右舷来船向右避让两种情况,对旋回半径及旋回时间大小不同的船舶,分析旋回的影响.结论是大型船舶在变向避碰中,因吨位大、旋回半径大、旋回时间长,其避碰效果受旋回的影响较大,使实际最近距离小于安全距离.为了克服船舶旋回对避碰效果的影响,提出大型船舶变向避碰中基于旋回的解析计算方法和图解方法,前者可应用于计算机解算避碰问题,后者可应用于人工绘算.

After set up ship movement equation,the paper educes equations of distance of the closest point of approach(dDCPA),time to the closest point of approach(tTCPA) and course of collision avoidance which takes no account of ship turning.Based on ship turning of different radius and period,the influence of turning is analyzed in turning to starboard to avoid collision for ship from port and starboard. In the conclusion,the influence of turning is great for the ship of great tonnage,big turning radius and long turning period,which distance of the closest point of approach(dDCPA) will be less than safe distance.At the end of this paper,the caculation methods of changing course to avoid collision is given for large ship to overcome the influence of turning,the calculation method can be used in computer to calculate collision avoidance and diagram method can be used in manual work.