Application of disturbance observer-based enhanced composite cascade control scheme to outlet temperature in process furnace control system

The presence of strong disturbances usually causes great control performance degradation of outlet temperature in process furnace with the properties of time delay and inverse response. This article mainly focuses on lumped disturbance rejection of the processes with inverse response and time delay by disturbance observer-based (DOB) enhanced composite cascade control scheme. The disturbances considered here include not only internal disturbances caused by model mismatches, but also external disturbances. The observer is employed to estimate the disturbances of the closed-loop system, and the estimation is used for feedforward compensation design to reject disturbances. Both the simulation and comparison studies have been carried out to show the effectiveness and feasibility of the proposed control scheme.