Robust Stability Analysis and Tuning of a Predictive Sliding Mode Controller

Predictive sliding mode controllers have been successfully implemented in the last 10 years, overcoming some of the disadvantages of traditional Sliding Mode Control and Generalized Predictive Control strategies. In particular, this paper presents the robust stability and feasibility analysis achieved on a constrained predictive sliding mode controller. This analysis is particularly necessary because the controller can tackle complex industrial processes approximated with first order plus dead time models. The controller shows improved performance and robustness by means of a reaching law to force a pseudosliding dynamic behaviour. Programmable rules based on modelled pole and delay were applied for a first robust tuning. They provide satisfactory results comparing the controller to others by the control simulation of a set of typical chemical plants and a field of distributed solar collectors. Finally, two real tests illustrate the correct tracking of set point steps when controlling the outlet water temperature of a heat exchanger with modelling errors.