Improving extrapolation capabilities of a data-driven prediction model for control of an air separation unit

In model predictive control, fully data-driven prediction models can be used besides common (non-)linear prediction models based on first-principles. Although no process knowledge is required while relying only on sufficient data, they suffer in their extrapolation capability which is shown in the present work for the control of an air separation unit. In order to compensate for the deficits in the extrapolation behavior, a further data source, here a digital twin, is deployed for additional data generation. The plant data set is augmented with the artificially generated data giving rise to a hybrid model in terms of data generation. It is shown that this model can significantly improve the prediction quality in former extrapolation areas of the plant data set. Even conclusions about the uncertainty behavior of the prediction model can be found. • Data-driven prediction model is deployed in model predictive control of an air separation unit. • Extrapolation capability of prediction model is investigated. • Three different prediction models are trained and compared in terms of their prediction quality. • Digital twin is used as additional data source. • Model trained with hybrid combined data set can improve extrapolation capabilities.