Establishing And Converting Mathematical Model Of Mobile VTS Target

VTS plays an important part in the enhancement of traffic safety and efficiency of ships, and in environmental protection. So far, the built and invested VTS in our country still havn't covered all the vital water area. To better play the function of VTS and broaden the compass of competency, the essay introduced the concept of Mobile VTS. Let the mobile traffic control ship work in the vital water area that VTS cannot control, convert the relative navigation information of the targets obtained by ARPA of the mobile ship, and draw the relative navigation information among the targets. Then accordingly judge the collision risks among the targets, and give the alarms to the possibly encountered ships. Mobile VTS means to perform the auxiliary function of shore-based VTS.The essay firstly establishes the coordinate system of Mobile VTS to build the mathematical model and convert navigation information of the target ships, and analyses the factors which affect the collision risks on the base of the obtained relative navigation information among the targets. With the CPA and TCPA as the main judgment basis, builds the space and time collision risk models, and reasonably determines the synthesis between the two models to build the dynamic collision risk model of Mobile VTS which takes into account of multi-factors.And then, considering the navigators'cognitions of the encountered situation do not always coincide, and that is one of the main reasons of the incompatible actions and even the collisions, the essay analyses and divides the encountered situations of the ships on the condition if they are made sure to crash. Applying the division in Mobile VTS will help the navigators judge the encountered situation and coordinate avoidance actions.Electronic chart ETN system is a navigation information system, it can design route, monitor wake, and send out alarms etc. The simulation of Mobile VTS relays on ETN system, by reading external ARPA data, on one hand display the targets on electronic chart, and on the other hand build the mathematical model and convert the navigation information of Mobile VTS showing the alarms information of the dangerous ships on the working area. This satisfies Mobile VTS's demand of checking traffic image and alarm information synchronously.