{"title":"Control and Simulation of FOPDT Food Processes with Constraints using PI Controller","authors":"M.Y. Pua, M.C. Tan, L.W. Tan, N. Ab.Aziz, F.S. Taip","volume":42,"journal":"International Journal of Nutrition and Food Engineering","pagesStart":522,"pagesEnd":525,"ISSN":"1307-6892","URL":"https:\/\/publications.waset.org\/pdf\/11463","abstract":"The most common type of controller being used in\r\nthe industry is PI(D) controller which has been used since 1945 and\r\nis still being widely used due to its efficiency and simplicity. In\r\nmost cases, the PI(D) controller was tuned without taking into\r\nconsideration of the effect of actuator saturation. In real processes,\r\nthe most common actuator which is valve will act as constraint and\r\nrestrict the controller output. Since the controller is not designed to\r\nencounter saturation, the process may windup and consequently\r\nresulted in large oscillation or may become unstable. Usually, an\r\nantiwindup compensator is added to the feedback control loop to\r\nreduce the deterioration effect of integral windup. This research\r\naims to specifically control processes with constraints. The\r\nproposed method was applied to two different types of food\r\nprocesses, which are blending and spray drying. Simulations were\r\ndone using MATLAB and the performances of the proposed\r\nmethod were compared with other conventional methods. The\r\nproposed technique was able to control the processes and avoid\r\nsaturation such that no anti windup compensator is needed.","references":"[1] Lavretsky, E., & Hovakiyman, N. (2007). Stable adaption in the\r\npresence of input constraints. System and Control Letters , 56 (6), 722-\r\n729.\r\n[2] Zhang, M., & Jiang, C. (2008). Problem and its solution for actuator\r\nsaturation of integratinf process with dead time. ISA transactions , 47,\r\n80-84.\r\n[3] \u00c5str\u00f6m, K. J., & H\u251c\u00f1gglund, T. (1988). Automatic Tuning of PID\r\nControllers. North Caralina: ISA Research Triangle Park.\r\n[4] Zaccarian, L., & Teel, A. R. (2004). Nonlinear scheduled anti-windup\r\ndesign for linear systems. IEEE Transactions on Automatic Control ,\r\n49 (11), 2055-2061.\r\n[5] Tavakoli, S., Griffin, I., & Fleming, P. J. (2006). Tuning of\r\ndecentralised PI (PID) controllers for TITO processes. Control\r\nEngineering Practice , 14, 1069-1080.\r\n[6] Seborg, D. E., Edgar, T., & Mellichamp, D. (2003). Process Dynamics\r\nand Control (2 ed.). USA: John Wiley and Ins.","publisher":"World Academy of Science, Engineering and Technology","index":"Open Science Index 42, 2010"}