New model of collision risk between vessels

In order to establish automatic decision making system of vessel collision avoidance, the essence of vessel collision risk is analyzed, the concept of space collision risk (SCR) and time collision risk (TCR) are explained, based on summary and analysis on the relative researches done before. On the basis of stimulating action theory, the concepts of vessel's domain and the last opportunity to use helm, the models of SCR, TCR and collision risk(CR)are established. The results of this paper develop and improve the concept and model of vessel collision risk, which have more logic and applicable value.