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随着发动机性能要求的不断提升,燃油控制系统服役的工况变得越来越恶劣、边界条件越来越复杂。燃油泵固有压力脉动与管路、活门的流固耦合振动,密封圈腐蚀或老化导致的泄漏,油液污染或润滑油失效而产生的磨损加剧等均会造成燃油控制系统的致命故障。同时,燃油控制系统具有少测点、变工况、强干扰及强非线性等特点,导致该领域对故障诊断技术存在迫切需求,同时也面临巨大挑战。为推动故障诊断技术在燃油控制系统领域的发展,总结燃油控制系统的特点与常见故障,并在此基础上介绍故障诊断技术的主要方法与分类。进一步从液压元件互换性角度,概述基于物理模型、信号处理和人工智能诊断方法在燃油控制系统关键部件中的研究现状。最后指出燃油控制系统故障诊断技术存在的挑战与机遇。 相似文献
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介绍了基于信息融合的舰载柴油机故障诊断技术.融合柴油机热工、油液及振动3大类信息,采用自适应谐振理论( ART)和BP网络相结合的决策级融合技术,建立了融合诊断技术模型,结合实例说明了该模型的诊断原理,并验证了该诊断方法的有效性.结果表明:新型神经网络模型既可以解决并发故障诊断问题,也可以解决新的故障类型诊断问题. 相似文献
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机器人路径规划方法的研究 总被引:1,自引:0,他引:1
路径规划技术是机器人学研究领域中的一个重要部分.目前的研究主要分为全局规划方法和局部规划方法两大类.通过对机器人路径规划方法研究现状的分析,指出了各种方法的优点及不足,并对其发展方向进行了展望. 相似文献
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对计算机辅助夹具设计(computer-aided fixture design,CAFD)技术的研究内容与发展沿革进行了全面综述,包括CAFD系统的研究内容、设计过程及研究进展等,指出了该技术领域目前存在的问题并分析了其发展趋势。 相似文献
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Chen Xuedong Guan Weihe Chen Wenhu Yao Zuoquan Hefei General Machinery Research Institute Hefei ChinaGu Xuedong Wang Zhaowei Shanghai Gaoqiao Petrochemical Company 《机械工程学报(英文版)》2002,15(2):167-172
The special subject "research on life prediction technology of important in-service pressure vessels" mainly analyzes the failure mechanism of large-sized important and critical in-service pressure vessels under the action of working medium and investigates safety assessment and life prediction technology with a view to enhance the operation reliability of in-service pressure vessels in China. Based on a series of accident investigation and test & measuring research, the cause of cracking of catalytic regenerator is analyzed and the in-line non-destructive examination method and failure prevention measures for the cracking of catalytic regenerator are proposed. 相似文献
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利用GPRS和D-S理论的数控设备远程故障诊断系统 总被引:1,自引:0,他引:1
研究利用中国移动GPRS公网进行分布式数控设备远程故障诊断技术,提出一种通过Internet使用户与制造商紧密联系起来,共同诊断并解决数控设备故障的系统架构,采用多传感器信息融合和D-S证据理论诊断技术提高了故障诊断效率和准确性,改变了传统的制造设备诊断方法,降低了设备维护成本,有利于技术的继承和更新. 相似文献
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Mei Wang Jie Wang 《The International Journal of Advanced Manufacturing Technology》2012,59(5-8):463-471
To solve the problems of tool condition monitoring and prediction of remaining useful life, a method based on the Continuous Hidden Markov Model (CHMM) is presented. With milling as the research object, cutting force is taken as the monitoring signal, analyzed by wavelet packet theory to reduce noise and extract the energy feature of the signal as a basis for diagnosis. Then, CHMM is used to diagnose tool wear state. Finally, a Gaussian regression model is proposed to predict the milling tool’s remaining useful life after the test sample data are verified to be consistent with the Gaussian distribution based on a reliable identification of the milling tool wear state. The probability models of tool remaining useful life prediction could be established for tools with different initial states. For example, when an unknown state of milling force signal is delivered to the milling tool online diagnostic system, the state and the existing time of this state could be predicted by the established prediction model, and then, the average remaining useful life from the present state to the tool failure state could be obtained by analyzing the transfer time between each state in the CHMM. Compared to the traditional probabilistic model, which requires a large amount of test samples, the experimental cost is effectively reduced by applying the proposed method. The results from the experiment indicate that CHMM for tool condition monitoring has high sensitivity, requires less training samples and time, and produces results quickly. The method using the Gaussian process to accurately predict remaining life has ample potential for application to real situations. 相似文献
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介绍了往复压缩机故障诊断技术中的若干问题,包括:故障模式与诊断方法、数学模型与故障样本、分级诊断策略与人工神经网络、智能诊断系统构造等的研究结果。提出应根据故障模式来选择诊断方法;对于多级压缩机应采用两级诊断方案等观点。文中还简述了基于人工神经网络的智能诊断系统构造,并给出该系统的结构简图。 相似文献
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非永久故障是导致机电系统BIT(built-in test)虚警的一个主要原因,诊断非永久故障既可保证BIT的高故障检测率,同时又可有效地抑制虚警。但是目前缺乏对非永久故障的机理分析与建模,相应的诊断研究也很少。在分析研究非永久故障的表现形式、产生原因与机理的基础上,对被测系统的状态进行马尔可夫建模,再根据被测系统和隐马尔可夫模(hidden Markov model,HMM)的状态都是通过表现来感知的特点,利用HMM对BIT被测系统建模,并提出基于HMM的BIT非永久故障诊断方法,最后通过实验验证表明,此方法能有效地诊断非永久故障,降低BIT虚警。 相似文献