Overall Assessment of Technical Conditions for Vessels

Abstract

Overall assessment of technical conditions for a vessel is the major guarantees of ships’ combat capability. They are created and completed based on data and information of vessel which are complicated and numerous, so the structure of the vessel system, the subsystems and equipment of the vessel should be investigated accurately and precisely. In this paper, three models, such as the key equipment, the subsystem and the vessel system are given to assess the technical conditions of the vessel by using D-S evidence theory, fuzzy theory and gray relative analysis. The basic probability assignment functions of the key equipment are obtained. The assessment matrix of the vessel for subsystem is given, and the relational degrees of the reference and comparison sequences of the vessel are derived in order to calculate the assessment value. Taking an equipment and a vessel for example, the numerical results show that multi-hierarchy assessment is a useful method for investigating the vessel technical conditions because it can take advantage of the assessment parameters to model and calculate effectively. The influence of the technical parameters of some key equipment for the vessel are considered in the assessment, the reliabilities of the procedures and the results of the assessment are promoted significantly based on D-S evidence theory. The present assessment methods are expected to be useful in the maintenance and management of the vessel and equipment.