کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
723601 | 892350 | 2007 | 6 صفحه PDF | دانلود رایگان |
The presence of nonlinearities in a process can affect its control performance adversely. Changes in operating conditions due to nonlinearities may render the current controller tuning as ‘non-optimal'. Nonlinearities in valves, e.g., stiction may cause oscillations in process variables. Such oscillations from one control loop can easily propagate to different units of the plant, thus resulting in a plant-wide oscillations. The detection and quantification of process nonlinearity can help decide whether to implement a nonlinear controller or not. It is also useful in diagnosing the root-cause of plant-wide oscillations. A new Total Nonlinearity Index (TNLI) has been developed to quantify process nonlinearity. The previously published Non-Gaussianity Index (NGI) and Nonlinearity Index (NLI) are modified to overcome their limitations. The efficacy of the proposed indices is demonstrated using an illustrative example and an industrial case study.
Journal: IFAC Proceedings Volumes - Volume 40, Issue 12, 2007, Pages 84–89