Fault tolerant control based on multiple linear models in a chemical reactor

A new Fault Tolerant Control System (FTCS) is proposed in this paper. The FTCS consists of three elements: the basic controller, which in this paper is a multivariable model-based predictive control (specially the EPSAC: Extended Prediction Self-Adaptative Control with constraints), a FDI scheme that is based in a linear model of the system and thresholds verification and finally a reconfiguration module. This last module has a bank of linear models of the system, working around different operation points, each one calculated to obtain the maximum production at the output. When a fault is detected, with the information based in the FDI scheme and the sensors, the reconfiguration module switches for the best model in that situation. This model is introduced to the predictive control and to the FDI scheme to maintain the availability of the system. This new FTCS has been illustrated with a very non-linear system: a reaction tank by the Van der Vusse reation.