Real-time application of discrete second order sliding mode control to a chemical reactor

Temperature control of processes that involve heating and cooling of semi-batch reactors can be a real problem for conventional controllers that do not put up with relatively large model uncertainty and external disturbances. The first order sliding mode control can be a solution for this problem; however, discrete-time implementation generates the chattering phenomenon. In order to reduce it, a second order discrete sliding mode control (2-DSMC) approach is proposed in this paper and used for the temperature control of a chemical reactor. As shown by the experimental results, this control law resolves the chattering problem while ensuring good robustness of the closed loop system behavior. (C) 2009 Elsevier Ltd. All rights reserved.