Non-Linear Discrete Time Modelling and Control of a Pilot Neutralization Chemical Reactor

Abstract

Many continuous industrial processes working inside a large operating range can be modelled by variable parameter and/or bilinear continuous state equations. In the case of processes with variable parameters, the state affine models allow to get a discrete approximated representation. An original direct identification method, involving a variable parameter filter, is processed inside the whole operating range in order to estimate the model coefficients. A dual approach leads to state affine control algorithms by gathering a family of linear controllers into a unique control law. In the case of bilinear continuous processes, their discrete model is of linear time-varying type. A way for digitally controlling them can be a closed loop linearization which leads to an implicit control law. An improvement can be obtained by adding integrators. Experimental results got, in each operating case (variable parameter or bilinear system), from a pilot neutralization reactor show the applicability of the methods.