Fault diagnosis of hydraulic system in large forging hydraulic press

The leakage is a common fault in the hydraulic system of the large forging hydraulic press. The large forging hydraulic press is usually used in the high temperature situations. Hence once leakage happens, the fire hazard can be caused and the huge economic losses can be taken place. Therefore, detecting and positioning leakage is also of great importance for the fault diagnosis of hydraulic system. A new method of fault diagnosis is proposed based on extracting leakage information in this paper. Firstly, the double inverse limit space is established. Secondly, the leakage information will be mapped into the double inverse limit space via the homeomorphism mapping. The leakage is detected with equicontinuity. The leakage positioning can be realized according to the topological transitivity in the double inverse limit space. Finally, the method of fault diagnosis is feasible according to the simulation results. Hence the fault diagnosis of hydraulic system in large forging hydraulic press is realized by adopting the method proposed in this paper. The leakage can be forecasted in real-time. (C) 2013 Elsevier Ltd. All rights reserved.