Supervisory Fuzzy Controller for Thickener Underflow Solids Concentration on a Simulated Platform

Autor(es): Magalhães, Sabrina; Euzébio, Thiago
Resumo: (EN) A thickening process produces continuously a high-density slurry on its underflow, and water free of solids on its overflow. This process is highly non-linear and it is subject to random disturbances from previous process on its operations, consequently its control is challenging. A controller with fixed set point for the underflow solids concentration causes a frequently fluctuation on the underflow flow rate, leading to major disturbances in following processes. Allowing the underflow solids concentration to change inside a range, reduces the variation on the manipulated variable, thus there is a decrease in disturbances in next processes. The proposed controller in this work is a supervisory fuzzy controller, which monitors the process behavior and then act on the underflow flow rate control loop. The control task is to maintain the underflow flow rate and the underflow solids concentration within a specified range. These variables should be in the range even during an occurrence of a random disturbance on the feed flow rate and the feed solids concentration. Both the continuous thickening process and the controller are simulated on dynamic simulation software, which includes data from a real plant located at a Vale S.A. plant in Itabira, Brazil. When using such software, it is possible to simulate a variety of disturbances scenarios to evaluate the controller performance. The controller tuning was simple, as it relies on process dynamics regarding only the underflow solids concentration. Simulated results show that the controller can successfully control the underflow solids concentration and flow rate inside their targeted ranges, and that without the supervisory controller the process gets unstable. As future work, flocculent dosage rate loop will be added and the controller will be applied to a real plant.
Periódico: International Congress on Automation in Mining ( Automining 2018)
Ano: 2018
Volume: 6
Páginas: p. 1-8
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