Time-frequency methods are effective tools in identifying the frequency content of a signal and revealing its timevariant features.This paper presents the use of instantaneous features(i.e.,instantaneous energy and si...Time-frequency methods are effective tools in identifying the frequency content of a signal and revealing its timevariant features.This paper presents the use of instantaneous features(i.e.,instantaneous energy and signal phase)of acoustic emission(AE)in the detection of thermal damage to the workpiece in grinding.The low-order frequency moments of a scalogram are used to obtain both the instantaneous energy and the mean frequency at which the signal phase is recovered.The grinding process is monitored using AE for a variety of operating conditions,including regular grinding,grinding at higher cutting speed and larger feed,and small dressing depth of cut.The instantaneous features extracted by the scalogram are compared with the results obtained by the empirical mode decomposition.It has been found that both the instantaneous energy and phase deviation indicate the presence of burn damage and serve as robust and reliable indicators,providing a basis for detecting the grinding burn.展开更多
文摘Time-frequency methods are effective tools in identifying the frequency content of a signal and revealing its timevariant features.This paper presents the use of instantaneous features(i.e.,instantaneous energy and signal phase)of acoustic emission(AE)in the detection of thermal damage to the workpiece in grinding.The low-order frequency moments of a scalogram are used to obtain both the instantaneous energy and the mean frequency at which the signal phase is recovered.The grinding process is monitored using AE for a variety of operating conditions,including regular grinding,grinding at higher cutting speed and larger feed,and small dressing depth of cut.The instantaneous features extracted by the scalogram are compared with the results obtained by the empirical mode decomposition.It has been found that both the instantaneous energy and phase deviation indicate the presence of burn damage and serve as robust and reliable indicators,providing a basis for detecting the grinding burn.
