65. State Identification of Automatic Gauge Control Hydraulic Cylinder Using Acoustic Emission

The growing requirements of steel products qualities bring even tricky restrictions to the hydraulic cylinder which acts as a screw down to maintain the rolling spaces precisely. However, faults and disfunctions are unavoidable and bring underlying safety issues. Working with un-expected loading is one of major impact that may cause catastrophic consequence happen to the cylinder, as the classical diagnostic process to-some-extent lack of cross-validating and time-consuming, the paper proposes the potentials of using acoustic emission to fill the dilemmas. The works include the data acquisition process to record the ultrasound acoustic signals from the hydraulic cylinder, application of modified image based acoustic emission approach to generate visual effects, as well as the application of principal component analysis to project the profiles onto the 3D plane for further analyses. Through the analysis of image based profiles, the subtle differences of various cylinder conditions can be examined using the pixel and intensity values. By assessing the projection of profiles in the principal component space, a clear trajectory can be observed with normal and overload conditions allocated upon the positive and negative sides of the axis. The result provided not only the potential of using acoustic emission for dynamic state identification of the subtle changes, but also opens up the possibility of preventive measures to the cylinder at risks.