The continuous annealing process line (CAPL) has complex process characteristics, such as strong correlation of a large number of process variables and interconnected multi-subsystems and multiple operation zones. Practitioners are concerned with typical process faults, such as strip-break and roll-slippage, whose effects are often confined in a specific zone. Considering the large-scale process characteristics and fault characteristics, a multi-block fault diagnosis method is proposed. A novel reconstruction-based block contribution (RBBC) is first proposed in order to diagnose the faulty block. The reconstruction-based variable contribution (RBVC) within a block is also proposed to determine the faulty variables. The proposed RBBC-RBVC hierarchical scheme is applied successfully to a real CAPL on two fault cases. A finite state machine is utilized to diagnose strip-break and reconstructed combined index is studied to diagnose roll-slippage. © 2012 Elsevier Ltd.
Bibliographical noteThis work was supported by the National Basic Research Program of China (973 Program) under Grant 2009CB320601, the 111 Project of Ministry of Education of China under Grant B08015, the Natural Science Foundation of China under Grant 61020106003, the State Administration of Foreign Experts Affairs of China's Special Program for Elite Overseas Experts (for S. Joe Qin), and the Funds for Creative Research Groups of China under Grant 60821063.
- Continuous annealing processes
- Fault diagnosis
- Reconstructed index
- Reconstruction-based block contribution