A fault diagnosis method based on continuous wavelet transform and improved multi-dimensional residual network was proposed to solve the problem that the working environment of precision machining equipment is very co...A fault diagnosis method based on continuous wavelet transform and improved multi-dimensional residual network was proposed to solve the problem that the working environment of precision machining equipment is very complicated,and the fault characteristic signal is weak and hard to extract.Firstly,the best wavelet base Cmor 3-3 is selected by comparing 6 different wavelet base types.Secondly,continuous wavelet transform(CWT)is applied to the acquired original vibration signal to generate the feature map and process the gray level.Finally,the improved ResNeXt network is used to diagnose faults in precision machining equipment.The experimental results show that the proposed CWT and the improved ResNeXt algorithm have high accuracy in identifying precision machining equipment faults in complex environments,with an average accuracy of 99.4%。展开更多
Appropriate rock characterization is beneficial in providing a reliable judgment on rock properties which is crucial for the design process of rock engineering applications.However,it can be difficult to obtain consis...Appropriate rock characterization is beneficial in providing a reliable judgment on rock properties which is crucial for the design process of rock engineering applications.However,it can be difficult to obtain consistent mechanical parameters due to substantial variations in rock properties.In this research,uniaxial compression tests on dolerite specimens collected from a gold mine in Western Australia showed substantial scatter in the results.Rock categorization based on the P-wave velocities is as accurate as the thin section analysis,which suggests that they can be used together to gain a more accurate initial understanding of the rock types before any laboratory testing.The quality of specimen preparation and rockemachine interaction greatly affect the test results.For instance,non-parallelness of loading platens can lead to considerable scatter of the testing results,which would be perceived as rock variability.It is suggested that the current testing standards should be modified towards a better control of the loading machine performance and equipment precision.Finally,the possibility of pre-existing microcracks in rock,neither detected by the thin section analysis nor by the ultrasonic measurement,must be examined by computed tomography(CT)scanning as they can affect the test results.This study will enhance our knowledge about the sources of variability in laboratory test results of rock which is essential for obtaining reliable data.展开更多
This paper studies how to manage large and precise equipment effectively in colleges and universities and proposes the necessity to establish experiment centers on the level of university and department. Finally, new ...This paper studies how to manage large and precise equipment effectively in colleges and universities and proposes the necessity to establish experiment centers on the level of university and department. Finally, new thought on paying more attention to the construction of technical management team and gathering necessary expenses, such as use expenses, maintenance expenses, function development expenses, etc. is given out.展开更多
基金Funding from the Key Research and development plan of Shaanxi Province"Research on key problems of surface finishing for Aerospace Fastener"(2023-YBGY-386).
文摘A fault diagnosis method based on continuous wavelet transform and improved multi-dimensional residual network was proposed to solve the problem that the working environment of precision machining equipment is very complicated,and the fault characteristic signal is weak and hard to extract.Firstly,the best wavelet base Cmor 3-3 is selected by comparing 6 different wavelet base types.Secondly,continuous wavelet transform(CWT)is applied to the acquired original vibration signal to generate the feature map and process the gray level.Finally,the improved ResNeXt network is used to diagnose faults in precision machining equipment.The experimental results show that the proposed CWT and the improved ResNeXt algorithm have high accuracy in identifying precision machining equipment faults in complex environments,with an average accuracy of 99.4%。
基金the Curtin Strategic International Research Scholarship(CSIRS)and Mining Research Institute of Western Australia(MRIWA)-project M474 scholarshipthe Australian Research Council through project DP190103260.
文摘Appropriate rock characterization is beneficial in providing a reliable judgment on rock properties which is crucial for the design process of rock engineering applications.However,it can be difficult to obtain consistent mechanical parameters due to substantial variations in rock properties.In this research,uniaxial compression tests on dolerite specimens collected from a gold mine in Western Australia showed substantial scatter in the results.Rock categorization based on the P-wave velocities is as accurate as the thin section analysis,which suggests that they can be used together to gain a more accurate initial understanding of the rock types before any laboratory testing.The quality of specimen preparation and rockemachine interaction greatly affect the test results.For instance,non-parallelness of loading platens can lead to considerable scatter of the testing results,which would be perceived as rock variability.It is suggested that the current testing standards should be modified towards a better control of the loading machine performance and equipment precision.Finally,the possibility of pre-existing microcracks in rock,neither detected by the thin section analysis nor by the ultrasonic measurement,must be examined by computed tomography(CT)scanning as they can affect the test results.This study will enhance our knowledge about the sources of variability in laboratory test results of rock which is essential for obtaining reliable data.
文摘This paper studies how to manage large and precise equipment effectively in colleges and universities and proposes the necessity to establish experiment centers on the level of university and department. Finally, new thought on paying more attention to the construction of technical management team and gathering necessary expenses, such as use expenses, maintenance expenses, function development expenses, etc. is given out.
