High-Order Sliding Mode Observer for Outflow Reconstruction in a Branched Pipeline

This paper introduces a novel technique to reconstruct unmeasured outflow rates in pipelines with two branches, where only input-output flow rate and pressure information is available, by using High-Order Sliding Mode Observers and by exploiting the stable nature of the physical operation point. The performance of the technique is tested through simulation and by using experimental data from a pilot pipeline. A comparison with a First-Order Sliding Mode Observer in a cascade scheme is also performed. The proposed approach is particularly useful for estimating unknown signals in stable systems, which possess the Strictly Linked Upper and Lower Hessenberg structure.