方形钕铁硼永磁铁是一种用于制作磁吸式陶瓷磁粉打印机内磁性打印版的磁性材料,因此有必要研究其磁场分布特征和磁力计算方法。先基于电磁场理论推导磁铁的磁力计算公式,再应用有限元法电磁学软件FEMM(Finite Element Method Magnetics...方形钕铁硼永磁铁是一种用于制作磁吸式陶瓷磁粉打印机内磁性打印版的磁性材料,因此有必要研究其磁场分布特征和磁力计算方法。先基于电磁场理论推导磁铁的磁力计算公式,再应用有限元法电磁学软件FEMM(Finite Element Method Magnetics)对其进行仿真分析,最后使用磁感应强度测量仪测量其磁感应强度。通过比较和分析计算、仿真和测量的结果,验证了理论计算和有限元仿真方法的有效性和可靠性,推导了方形钕铁硼永磁铁的表面磁感应强度随方形永磁铁尺寸变化的规律。展开更多
The test selection and optimization （TSO） can improve the abilities of fault diagnosis, prognosis and health-state evalua- tion for prognostics and health management （PHM） systems. Traditionally, TSO mainly focuse...The test selection and optimization （TSO） can improve the abilities of fault diagnosis, prognosis and health-state evalua- tion for prognostics and health management （PHM） systems. Traditionally, TSO mainly focuses on fault detection and isolation, but they cannot provide an effective guide for the design for testability （DFT） to improve the PHM performance level. To solve the problem, a model of TSO for PHM systems is proposed. Firstly, through integrating the characteristics of fault severity and propa- gation time, and analyzing the test timing and sensitivity, a testability model based on failure evolution mechanism model （FEMM） for PHM systems is built up. This model describes the fault evolution- test dependency using the fault-symptom parameter matrix and symptom parameter-test matrix. Secondly, a novel method of in- herent testability analysis for PHM systems is developed based on the above information. Having completed the analysis, a TSO model, whose objective is to maximize fault trackability and mini- mize the test cost, is proposed through inherent testability analysis results, and an adaptive simulated annealing genetic algorithm （ASAGA） is introduced to solve the TSO problem. Finally, a case of a centrifugal pump system is used to verify the feasibility and effectiveness of the proposed models and methods. The results show that the proposed technology is important for PHM systems to select and optimize the test set in order to improve their performance level.展开更多
文摘方形钕铁硼永磁铁是一种用于制作磁吸式陶瓷磁粉打印机内磁性打印版的磁性材料,因此有必要研究其磁场分布特征和磁力计算方法。先基于电磁场理论推导磁铁的磁力计算公式,再应用有限元法电磁学软件FEMM(Finite Element Method Magnetics)对其进行仿真分析,最后使用磁感应强度测量仪测量其磁感应强度。通过比较和分析计算、仿真和测量的结果,验证了理论计算和有限元仿真方法的有效性和可靠性,推导了方形钕铁硼永磁铁的表面磁感应强度随方形永磁铁尺寸变化的规律。
基金supported by the National Natural Science Foundation of China(51175502)
文摘The test selection and optimization （TSO） can improve the abilities of fault diagnosis, prognosis and health-state evalua- tion for prognostics and health management （PHM） systems. Traditionally, TSO mainly focuses on fault detection and isolation, but they cannot provide an effective guide for the design for testability （DFT） to improve the PHM performance level. To solve the problem, a model of TSO for PHM systems is proposed. Firstly, through integrating the characteristics of fault severity and propa- gation time, and analyzing the test timing and sensitivity, a testability model based on failure evolution mechanism model （FEMM） for PHM systems is built up. This model describes the fault evolution- test dependency using the fault-symptom parameter matrix and symptom parameter-test matrix. Secondly, a novel method of in- herent testability analysis for PHM systems is developed based on the above information. Having completed the analysis, a TSO model, whose objective is to maximize fault trackability and mini- mize the test cost, is proposed through inherent testability analysis results, and an adaptive simulated annealing genetic algorithm （ASAGA） is introduced to solve the TSO problem. Finally, a case of a centrifugal pump system is used to verify the feasibility and effectiveness of the proposed models and methods. The results show that the proposed technology is important for PHM systems to select and optimize the test set in order to improve their performance level.
