Using Process Tomography as a Sensor in a System for Controlling Concentration in Fluid Flow

Stephen Duncan

Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ, UK stephen.duncan@eng.ox.ac.uk

ABSTRACT

This paper describes how process tomography can be used as a sensing device in a feedback control system for regulating the concentration of a substance in a fluid flow along a cylindrical pipe. The paper starts from the convection-diffusion equation, which is a partial differential equation describing the diffusion of a substance within the fluid flow and develops a state space description of the system. The state space model can be used as the basis of a state feedback design and a number of control strategies are proposed. Process tomography forms an integral part of the controller by providing estimates of the states of the system. A simulation of a feedback system based upon proportional plus integral control is presented.

Keywords Process tomography, modelling, control, observers.