INTEGRATING FUZZY LOGIC PROCEDURE FOR SIGNAL VALIDATIONS: MALTA COLORING AS STUDY CASE

Abstract

ABSTRACT In this study, the use of fuzzy logic for signal validation is introduced. This tool uses the sensor readings at the current time step to predict system state at the next time step using observers. The deviation between the sensor reading and the model prediction rises, leading to fault detection and isolation. The fault is accommodated by replacing the reading of the faulty sensor by the model prediction. The results presented in this article demonstrate that a simple scheme can carry out sensor fault detection, isolation and accommodation using a fuzzy rule‐based system based on experience of an operator into heuristics. Although the method lacks the mathematical basis that other analytical methods provide, this method is simple, effective and useful. PRACTICAL APPLICATIONSThe coloring process has to be controlled and monitored carefully because if the color of the MALTA is not adequate, then the MALTA has to be recycled to another unit (dilution unit) where the colorant is eliminated. This recycling process uses delay around 3 working days, and the economic impact is high. The validation of signal and reduction of fault sensor contribute to the reduction of the recycling process. In this study, the incorporation of fuzzy logic in the treatment of sensor signal represents a significant factor in the improvement of MALTA production units.