Abstract:Mechanical seals is operated by a thin fluid film to separate the pair of seal faces for lubricating and sealing,so the film thickness needs to be measured. Because the current technique is not suit for industry,a method for measurement of film thickness of mechanical seals based on acoustic emission technique was presented.Through the direction of direct measurement,a detection model based on acoustic emission signal was built.First,the signal was processed by empirical mode decomposition,and kernel principal component analysis was used to optimize data features.Then,a cascaded decision model based on artificial neural network was presented to estimate the film thickness.The model has better recognition rate than a single neural network, and has a wide industrial prospect.