A chattering free second order discrete sliding mode observer: An experimentation on a chemical reactor

In this paper, the chattering phenomenon that characterizes discrete sliding mode systems is analyzed and illustrated by a simulation example. In order to resolve this problem, in case of relatively large parameter variations and/or external disturbances, a second order discrete sliding mode observer (2-DSMO) is proposed. A stability analysis of the proposed observer is developed and a real time application on a semi batch reactor is realized. The experimental results show a good performance in terms of precision of the state estimation and of chattering reduction.