Holistic Indices for Productivity Control Assessment, Applied to the Comparative Analysis of PID and Fuzzy Controllers Within an Isasmelt Furnace

This research aims to contribute to the analysis of control performance assessment in extractive metallurgy. Productivity-based indices are proposed in addition to current measuring techniques. Such criteria are employed to compare conventional PID and fuzzy-based controllers in copper smelting. This process is mathematically modeled in order to be simulated. The comparison confirms a better performance of the fuzzy controller in dealing with the molten bath temperature within an Isasmelt furnace. In normal operating conditions (online tests), the proposed controller achieves a consistent mean square relative error reduction of 72% between measured values and the temperature setpoint and standard deviation of approximately 60% (from 27.8 °C to 11.1 °C). The productivity criteria establish a lower consumption of raw materials (13%) and energy supply (29%).