Estimation of the Spatial Alumina Concentration of an Aluminium Smelting Cell Using a Huber Function-Based Kalman Filter

The distribution of alumina concentration is important for optimal cell operations in the aluminium smelting process. However, continuous real-time measurement of alumina concentration is generally infeasible due to the hostile environment in the cell. As such a soft sensor is often needed to estimate the alumina concentration from readily available measurements (e.g., cell voltage and line current). However, these approaches often suffer from poor estimation accuracy when the model error increases (e.g., during the anode effect). To address these problems, this work develops a robust Kalman filter to estimate the spatial alumina concentration using voltage measurements and individual anode current data. The proposed method utilises a Huber function to deal with model errors, resulting in more robust estimations. The effectiveness of this approach is validated through experimental data, demonstrating its potential for improving spatial alumina concentration estimation in the aluminium smelting process.