Research And Application Of Condition Monitoring And Fault Diagnosis For Strip Mill AGC Systems

Condition Monitoring and Fault Diagnosis (CMFD), involved many theories and technical methods, is a comprehensive edge subject, which has been developed in recent years. Along with the development of sciences, technologies and economic, condition monitoring and fault diagnosis of large-scale equipments and their control systems have become an essential technology and important method to guarantee equipments or system to work stably, reliably and safely, to improve the product quality and the production efficiency. Now, CMFD is attached importance widely by many domestic and foreign scholars day by day.Automatic gauge control (AGC) system is the key control system of strip rolling mills to realize high accuracy of strip exit thickness. AGC system is a complex integrated control system, including mechanical, hydraulic and electrical comprehensive information. As a result, not only faults in mechanical devices but also those in hydraulic system could happen possibly in the AGC system. Therefore, failure rate of AGC system always is high, and its fault reasons are always complex, which is the key and difficult point to maintain strip rolling mills, and is also the main reason causing strip rolling mills to break down and product quality to become poor.Based on the study background described above, this dissertation focuses on the key technologies and methods of CMFD for the AGC system of a strip rolling mill. Taken the practical application as the goal, main work below has been studied:First, we picked out 26 kinds of characteristic signals used in the fault diagnosis, and established a condition monitoring system of the strip rolling mill for signals gathering, processing and memory.Then, the fault diagnosis idea including three levels, namely equipment hardware, control system and finished product, was proposed for the first time.Next, the fault diagnosis idea based on system model was brought forward, and the mathematical model of AGC system in the strip rolling mill was established. Two suitable fault detection observers for this AGC system were designed, and several kinds of typical fault detection and diagnosis were realized.The fault diagnosis idea based on rule and case was proposed. On the same time, 18 fault...