Robust adaptive active disturbance rejection control of an electric furnace using additional continuous sliding mode component. (November 2022) - Rsetam, Kamal
Abstract: The temperature control process of electric heating furnace (EHF) systems is a quite difficult and changeable task owing to non-linearity, time delay, time-varying parameters, and the harsh environment of the furnace. In this paper, a robust temperature control scheme for an EHF system is developed using an adaptive active disturbance rejection control (AADRC) technique with a continuous sliding-mode based component. First, a comprehensive dynamic model is established by using convection laws, in which the EHF systems can be characterized as an uncertain second order system. Second, an adaptive extended state observer (AESO) is utilized to estimate the states of the EHF system and total disturbances, in which the observer gains are updated online by a non-linear observer bandwidth, that is as a function of the observation errors. Moreover, with the help of disturbance estimation, a novel sliding manifold is constructed with parameters adaptively adjusted by a dynamic nonlinear bandwidth function to reduce the impact of high gain problems, especially noise-sensitivity. A continuous sliding-mode (CSM) based component is also designed to handle disturbance estimation errors. Third, the stability of the closed loop system, including the proposed controller and estimator, is mathematically proved using the Lyapunov theorem. Finally, the comparative simulation results show that the proposed method has superior robustness and temperature tracking performance. Highlights: An adaptive active disturbance rejection control strategy with an adaptive continuous sliding mode component is proposed for an electric heat furnace. For the first time, the electric heat furnace plant is mathematically modeled and then evaluated by our novel scheme. The adaptive bandwidths are utilized in tuning the designed controller and observer to reduce the negative effects of the high gain. The proposed continuous sliding mode component not only rejects the lumped disturbance but also rejects the disturbance estimation error.