在分析振动加速度信号的基础上,提出了新的粗糙集属性约简算法,并应用于轴承复合故障诊断。将最大-最小蚂蚁系统(max-min ant system,简称MMAS)引入条件属性约简中,以最坏Fisher准则函数作为启发式信息以提高搜索效率,综合考虑分类正确...在分析振动加速度信号的基础上,提出了新的粗糙集属性约简算法,并应用于轴承复合故障诊断。将最大-最小蚂蚁系统(max-min ant system,简称MMAS)引入条件属性约简中,以最坏Fisher准则函数作为启发式信息以提高搜索效率,综合考虑分类正确率和条件属性个数两方面因素,利用粗糙集理论约简故障诊断决策表,有效地提高了轴承故障诊断的效率。展开更多
The process of Electrical slag surfacing with liquid metal(ESS LM)is a complex physical and chemical process including electric field,magnetic field,flow field and temperature field,etc.As the complicated technology a...The process of Electrical slag surfacing with liquid metal(ESS LM)is a complex physical and chemical process including electric field,magnetic field,flow field and temperature field,etc.As the complicated technology and high cost of manufacturing compound rolls,simulating the relationship between ESS LM process parameters and physical fields of ESS LM process is important.Through the numerical simulation of finite volume method to the process of ESS LM in the conditions of different roll core diameters,slag amount,pouring speed,pouring temperature and input power,temperature field and flow field in different conditions were obtained.When the diameter of core material, operation voltage,pouring rate,pouring temperature and slag height of conductive mold was 250mm,40V,8mm/min, 1750K and 50mm respectively,the depth of molten metal was 30mm and fusion thickness of core material was 5mm which was consistent with the experiment results.According to the simulation results,operation with voltage of 42V, cladding speed of 10mm/min,pouring temperature of 1760K and slag height of 54mm in the conductive mould,achieved much more shallow metal pool,which is beneficial to vertical crystallization.展开更多
文摘在分析振动加速度信号的基础上,提出了新的粗糙集属性约简算法,并应用于轴承复合故障诊断。将最大-最小蚂蚁系统(max-min ant system,简称MMAS)引入条件属性约简中,以最坏Fisher准则函数作为启发式信息以提高搜索效率,综合考虑分类正确率和条件属性个数两方面因素,利用粗糙集理论约简故障诊断决策表,有效地提高了轴承故障诊断的效率。
基金Item Sponsored by Central University of basic scientific research expenses in graduate students' research projects(N090602006)the National Natural Science Fund Project(50904015)+1 种基金National Natural Science Foundation of China Youth Project(51104038)Basic scientific research expenses of young teachers' scientific research project(N100302006)
文摘The process of Electrical slag surfacing with liquid metal(ESS LM)is a complex physical and chemical process including electric field,magnetic field,flow field and temperature field,etc.As the complicated technology and high cost of manufacturing compound rolls,simulating the relationship between ESS LM process parameters and physical fields of ESS LM process is important.Through the numerical simulation of finite volume method to the process of ESS LM in the conditions of different roll core diameters,slag amount,pouring speed,pouring temperature and input power,temperature field and flow field in different conditions were obtained.When the diameter of core material, operation voltage,pouring rate,pouring temperature and slag height of conductive mold was 250mm,40V,8mm/min, 1750K and 50mm respectively,the depth of molten metal was 30mm and fusion thickness of core material was 5mm which was consistent with the experiment results.According to the simulation results,operation with voltage of 42V, cladding speed of 10mm/min,pouring temperature of 1760K and slag height of 54mm in the conductive mould,achieved much more shallow metal pool,which is beneficial to vertical crystallization.
