風浪因子對船舶避碰操縱影響之研究

THE STUDY ON SHIP COLLISION AVOIDANCE AND MANOEUVRING IN WIND AND WAVE FACTORS

本研究利用已發展之靜水中船舶避碰系統，考量風與浪之氣候因子，重新建立一套在風浪中船舶避碰系統，以改善其準確性與實用性。避碰數學模型包括野本謙作二階操縱反應式以及自行發展之真時操船模擬機系統（UMS）。運動數值模擬則採用日本MMG之真實操船模擬機。為了驗證此系統之實用性，本研究利用風浪中船舶避碰系統進行簡單與複雜避碰事件模擬，分別探討有環境外力及無環境外力對於船舶避碰操縱之影響。除此之外，本研究亦利用風浪中船舶避碰系統，以艉浪、斜浪及橫浪進行避碰模擬，據以探討不同風浪狀況對於船舶避碰之影響。由結果可知，在風浪中避碰時比在無環境外力避碰要來得困難，且在其艉浪狀況下之船舶避碰最為困難。透過本研究之簡化系統輔助，能夠使航海人員在面臨避碰決策時即時得到有效的避碰舵角之資訊，使航行更安全且有效率。

Based on the ship collision avoidance system in calm water developed by the authors, this paper plans to improve the original numerical simulation model by considering the wind-wave factors for moving ships in wind-waves. A real-time simulator based on the 6-D Manoeuvring Modelling Group (MMG) model is used to simulate the ship's motion in wind-waves. This study incorporates Nomoto's second-order model into a numerical model to calculate the turning characteristics of the ship in each time steps. The manoeuvring indices of Nomoto's model are the knowledge base of the simplified simulation model of ships. To verify the ship collision avoidance system with respect to the different traffic factors with wind-waves, the simple and complex collision avoidance cases have been designed in the fast-time. The results have been compared with the previous well-developed ship collision avoidance steering system in calm water. Besides, the stern wave, oblique wave and transverse sea conditions has been considered in this study. Under the effects of wind-wave factors, the manoeuvring of ship is more difficult than that in calm water. On the other hand, the stern wave condition is more difficult and dangerous than the oblique wave and transverse sea conditions when ship conducted the collision avoidance simulation. For the collision avoidance process, the safety distance is closer in wind-wave condition with lager rudder angle. The simplified simulation model can quickly determine the helm angle when the ship encounters collision avoidance in wind-wave conditions. It is helpful for the safety of ship navigation in wind-waves.