On-line evaluation of control loop performance

Industrial process control loops often suffer from poor control tuning or inaccurate devices. These will result in unnecessarily large output variance and oscillation. A new process control loop performance monitoring algorithm is developed based on a linear Laguerre model. It can detect if a process control loop is satisfactory, and if not, the cause for the bad performance. The algorithm has also been tested in a mill DCS in a Canadian paper and pulp mill