1,721,155 research outputs found
Modelli di dispersione atmosferica con scenari emissivi multipli - Una metodologia sistematica per la riduzione del numero di sorgenti
No full textFEEDFORWARD CONTROL IN THE PRESENCE OF UNCERTAINTY
No full textIn this paper, a new systematic approach to the design of feedforward-feedback (FF-FB) control systems is proposed, applicable in cases where bounds on plant and disturbance uncertainties are known. The robust performance of this control scheme is compared with that of two alternative feedback designs, on the basis of a test case in which the superiority of pure feedforward control is guaranteed for perfect models. On the basis of the results, the limits to the advantages of a combined feedforward-feedback controller over the optimal feedback compensator are determined as a function of plant and disturbance uncertainties. Design guidelines are laid for both FB and FB-FF designs where the significant disturbance can be measured and where model and disturbance uncertainties can be quantifie
Performance of Optimal and Standard Controllers for Disturbance Rejection in Industrial Processes
No full textImproved Qualitative Shape Analysis Technique for Automatic Detection of Valve Stiction in Flow Control loops
No full textValve stiction is a frequent cause of loop performance deterioration and in recent literature many techniques have been proposed for its automatic detection, [Yamashita (2006). An automatic method for detection of valve stiction in process control loops. Control Engineering Practice, 14, 503–510] proposes a method based on qualitative shape analysis, which is very effective for flow control loops where the valve position (or the proportional flow rate) is available as measurement.
However, additional stiction patterns observed in industrial data are not included in the original
algorithm. This paper provides an analysis and explanation of these patterns on the basis of valve type,
loop dynamics and control system setup, by means of simulation and comparison with industrial data.
The technique is then extended and applied to a plant data set in order to show the improved efficiency
in detecting stiction
Identification for Control Purposes by Relay Methods: Achievable Performance versus Complexity
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Controllability Analysis by Plant Oriented Techniques: Application to the Tennessee Eastman Benchmark
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