船舶风险评估.doc

船舶风险评估学院建工学院专业船舶与海洋工程年级姓名指导教师余建星 2016 年 12月 12日摘要关键词: 船舶工程; 模糊逻辑系统; 风险评估; 模糊规则; 层次分析法 ABSTRACT The paper proposes a new risk assessment method for marine engineering based on the fuzzy-logic system. According to the theory of the fuzzy-logic system, a fuzzy-logic mode for risk assessment was set up. According to the national standards, rules and experiences, the paper presents the fuzzy risk variables sets, risk matrix and fuzzy rules, then makes fuzzy reasoning, and finds the risk level of the system, and takes some measures to avoid the risk. The theory method of quantitative risk assessment is selected, and the risk assessment model is established by the analytic hierarchy process and the prehensive evaluation method. Key words: marine engineering; fuzzy-logic system; risk assessment; fuzzy rules; AHP 目录第一章模糊逻辑系统概述................................................................................. 5 模糊规则库........................................ 5 模糊推理机....................................... 5 模糊化........................................... 5 清晰化............................................ 5 第二章船舶系统风险评估的模糊逻辑模型.................................................... 6 风险指标的模糊集合............................... 6 风险评估模型的模糊规则........................... 7 船舶系统风险评估的流程........................... 7 基于风险等级的系统维护..................... ...... 8 船舶评估指标权重.................................. 8 船舶评估指标隶属度............................... 10 第四章结束语.................................................................................................................. 11 天津大学 2016 级船舶与海洋工程新技术研究结课论文第一章模糊逻辑系统概述模糊逻辑系统[1 ,2 ,4] 是一个建立在知识库、模糊规则库基础上的逻辑推理系统, 主要由模糊规则库、模糊推理机、模糊化和清晰化 4 个部分组成, 其信息处理流程如图 1 所示. 文中仅讨论多输入单输出的模糊逻辑系统, 多输出的模糊逻辑系统可分解为多个单输出系统来分析. 输入信号( 风险参数)U= U1 × U2 ×?× Un< Rn , 经系统处理后得到输出信号( 即评估等级)V < R. 模糊规则库模糊规则库是模糊逻辑系统的核心, 它由一系列 IF2THEN 形式的模糊规则组成. 其格式为: Ru( l)∶ IF x1 is Al1 and ?and xn isA ln, THEN y is Bl (1) 式中: Ali( i=1 ,2, ?, n); Bl 分别为 Ui< R和V