Ship propeller air entrapment identification method based on evidence reasoning rules and self-adaptive lifting

Abstract

The invention relates to a ship propeller air entrapment identification method based on evidence reasoning rules and adaptive lifting, and the method comprises the steps: obtaining a three-phase current root-mean-square value and a torque characteristic value from a ship electric propulsion system frequency converter in real time, determining the degree of an air entrapment effect caused by a severe sea condition according to a propeller torque loss coefficient, and setting three levels; firstly, an input feature reference value of each evidence reasoning rule weak learner is given through a K-means clustering method; establishing a fault reliability distribution matrix, converting the input into diagnosis evidence by using the matrix, calculating a reliability factor of the diagnosis evidence, fusing the evidence according to the reliability factor, and estimating the propeller air entrapment effect grade from a fusion result; counting the precision of the current weak learner, and calculating the learning coefficient of the weak learner; and repeating the process to finally obtain a self-adaptive lifting strong classifier composed of a plurality of weak learners, and obtaining anestimated value of the strong classifier for the air entrainment effect level, thereby realizing identification for the propeller air entrainment effect.

Description

technical field [0001] The invention relates to the technical field of safe operation and maintenance of water transportation, in particular to a ship propeller air entrainment identification method based on evidence reasoning rules and self-adaptive upgrading. Background technique [0002] When a ship is sailing, the quality of the sea condition is related to the stability and safety of the ship. According to the normal carrying condition of the ship in the mission sea area, when the sea state in the sea area is in a disastrous sea state or a dangerous sea state, when it is impossible to carry out sea work, it is called a severe sea state. With the continuous development of marine resources, the safety and economy of marine operations have been paid more and more attention. The operation of current marine operations is often restricted by harsh sea conditions. If it is necessary to continue to operate under harsh sea conditions while ensuring safety, how to accurately and ...

AI Technical Summary

Problems solved by technology

[0003] At present, there are few corresponding researches at home and abroad, and most of them only stay in using empirical formulas to fit and calculate the propeller thrust loss coefficient, so as to judge the type of sea state. It is not suitable for practical engineering applications, and for different ship types, the empirical formulas are quite different, so it is difficult to effectively promote

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