【作者】 张克正；

【导师】 魏海军；

【作者基本信息】 大连海事大学 ， 轮机工程， 2010， 硕士

【摘要】 随着科技的发展,传统的维修模式已逐渐被“视情维修”所取代,而此维修模式的基础是对机械设备进行监测,只有建立在监测基础上的诊断才能避免盲目性,具有针对性,因此,建立在监测基础上,对机械设备磨损状态进行有效地预测具有十分重大的意义。油液光谱分析技术在船舶工业领域已得到广泛应用,已成为对船舶机械设备进行工况监测、故障诊断和故障预测的有效技术手段之一,它可以有效地检测出油液中的磨损性元素的含量,分析出油液的污染程度以及添加剂的状况。油液光谱数据包含两方面内容,一方面,由于磨损金属成分与对应的摩擦副材质相对应,所以可以利用光谱分析进行故障定位；另一方面,机械磨损状态是一个逐步发展的过程,因此可以利用光谱数据来进行机械设备磨损状态的预测,前者属于故障诊断范畴,后者属于状态监测范畴,本文所做的研究工作即为后者。利用油液光谱分析技术对船舶的运行状态进行监测,能尽早地发现故障或故障趋势,避免重大故障的发生,达到视情维修的目的,因此建立光谱数据预测模型有非常重要的意义。由于船舶运行工况复杂,其尾轴和主机的润滑油中磨损元素含量受诸多因素影响,用传统的方法难以预测其变化趋势。本文提出基于遗传神经网络的润滑油铁元素含量预测方法,并用MATLAB分别对6组油样进行建模分析,其中2组来自尾轴处滑油,4组来自主机系统油。首先对油液光谱历史数据建立时间序列,然后,基于BP神经网络建立预测模型,对铁元素含量进行预测,最后结合遗传算法对BP神经网络进行改进,使预测值的平均相对误差在可接受的范围内。通过实例分析,该方法能够满足船舶状态监测的需要。更多还原

【Abstract】 With the development of science and technology, the traditional maintenance model has gradually been replaced by’condition-based maintenance’, which is based on the monitoring of machinery and equipment. Only by the basis of monitoring, diagnosis can avoid blindness and have specific aim.Oil spectroscopic analysis technology has been widely applied in ship building industry field. It has been one of the effective and technical means for ship machinery equipment monitoring, fault diagnosis and fault forecasting, it can effectively detect the content of abrasion resistant element in the oil, and analyze the condition of oil pollution and additives. Oil spectral data contains two aspects, on one hand, since the wearing metal components matches the materials of friction pair, so the spectral data can be taken on fault location, on the other hand, mechanical wearing condition is a process of gradual development, so the spectral data can also be taken on prediction of mechanical equipment wearing condition. The former belongs to the category of fault diagnosis, and the latter belongs to the category of condition monitoring. The specific research of paper is the latter. Oil spectral analysis technology is used for ship condition monitoring, which can find fault or fault trend soon, avoid large fault and achieve the purpose of’condition-based maintenance’. Therefore, the establishment of spectral data prediction model is of great importance.Due to the complicated condition of ship operation, the wearing element content in lubricating oil of propeller shaft and main engine is influenced by many factors, the changing trend can not be correctly predicted in traditional method. The research paper purposes a prediction method based on genetic algorithm and BP neural network for iron content in lubricating oil. What’s more,6 groups of oil sample is analyzed with MATLAB,2 of them is from propeller shaft, and another 4 is from main engine. First, it need to establish the time series of oil spectral historical data, and then, prediction model is established on BP neural networks to predict the iron element content, at last, the improved BP network with GA make the average relative error within acceptable limits. Through the case analysis, the method can satisfy the needs of ship condition monitoring.更多还原