Risk Assessment Of Marine Diesel Engine System Based On Fuzzy Hierarchy Analysis

With the rapid development of ship technology,shipping industry has entered the era of intelligent ship.In order to meet the needs of autonomous navigation of ships safety,for autonomous navigation of ship in unmanned scenario the new evolution regularity of diesel engine fault are presented,and the autonomous navigation of ship risk of lack of statistical data,not directly quantitative assessment of risk of diesel engine,this study through research of diesel engine fault information in detail,and then summarizes the fault characteristics of mining failure regularity,and use the fuzzy hierarchy analysis method,the risk research of ship diesel engine,combined with the expert experience and knowledge,comprehensive evaluation level of risk of ship diesel engine,affecting the reliability of the diesel engine key risks,So as to provide guidance for the development of intelligent risk control scheme for autonomous navigation ships.The main work is as follows:Firstly,the risk identification of diesel engine is carried out.The diesel engine is divided into fuel system,lubricating oil system,cooling system,exhaust gas system and starting air system.By collecting related failure cases of the system,the potential failure of Marine diesel engine is identified,and the formation mechanism and impact consequences of the failure are studied to generate the evolution fragments of the failure.On this basis,the fault evolution fragments are integrated,the fault network of diesel engine is constructed,and the fault rules of Marine diesel engine are expounded.Second,the establishment of risk level evaluation criteria.In order to let the experts risk score,under the unified standards to ensure that the evaluation scores of comparability,the reference QS9000 standard indicators of risk for hierarchies,and connecting with the diesel engine of the specific conditions of the risk assessment,based on the risk matrix,the risk level evaluation criterion of establishing Marine diesel engine to ask an expert in the context of autonomous navigation,evaluate the risk of diesel engine fault rate.Then,the theory of fuzzy evaluation and analytic hierarchy process is expounded.This paper analyzes and studies the process and steps of fuzzy comprehensive evaluation,determines the membership function and fuzzy operator suitable for Marine diesel engine risk evaluation,and defines the method of AHP to determine the weight of each risk factor in the system.Then,the fuzzy comprehensive evaluation of Marine diesel engine is carried out.According to the theory of Analytic Hierarchy Process（AHP）and fuzzy mathematics,build diesel engine system hierarchy,and then establish a fuzzy comprehensive evaluation model of Marine diesel engine,and expert evaluation data can be converted to the corresponding fault fuzzy evaluation vector,and combined with Analytic Hierarchy Process（AHP）to obtain the fault in the evaluation of the weight distribution,thereby on the system of diesel engine comprehensive assessment of risk.Finally,the sensitivity analysis of the comprehensive assessment results of Marine diesel risk is carried out to find out the fault factor which has the greatest influence on the risk level of diesel engine as the key fault.It is concluded that the risk level of the diesel engine running under the condition of autonomous navigation is "medium",among which the key faults are fault of highpressure oil pump,injector,lubricating oil pump,lubricating oil filter and air cooler.