关键词：钢铁；回路；控制系统；调试
摘 要：The number of control loops used in process industry is growing continuously, whilst manpower is being reduced. Consequently even companies that have embraced new control technologies struggle to maintain satisfactory performance over the long term. Numerous investigations have shown that the performance of control systems in the process industries is not satisfactory, as mentioned in Chap. 1. This particularly applies for the steel industry, where it is the norm to perform controller tuning only at the commissioning stage and then never again. A loop that worked well at one time is prone to degradation over time unless regular check and maintenance is undertaken.