KALMAN-FILTER-BASED OBSERVER DESIGN AROUND OPTIMAL-CONTROL POLICY FORGAS-PIPELINES

Seeking the optimal operating policy by an off-line controller for pip elines carrying natural gas has an inherent state estimation problem a ssociated with deviations from demand forecast. This paper presents a Kalman-filter-based observer for the real-time estimation of deviation s from the states previously obtained by an off-line controller optima lly, around an expected demand function. The observer is based on the linearized form of the non-linear partial differential equations which are the state space representation of isothermal and unidirectional g as flow through a pipeline. Data for the observer are produced by a dy namic simulator. The simulator and linearized observer equations are s olved using an implicit finite element method. The observer has been t ested on a pipeline subject to certain deviations from demand forecast . It converges in a short span of time.