Taming Heterogeneity and Complexity of Embedded Control

Hybrid Predictive Control of a Simulated Chemical Plant

 

M. Rodríguez — D. Sarabia — C. de Prada

Dept. Systems Engineering and Automatic ControlUniversity of ValladolidFaculty of Sciencesc Real de Burgos s/n47011Valladolid, [e-mail]

ABSTRACT. This paper deals with the MPC control of a chemical process where continuous and batch units operate jointly. The paper describes a plant-wide predictive controller that takes into account, both, the continuous objectives and manipulated variables, as well as the ones related to the scheduling of the batch units. The MPC is formulated avoiding the use of integer variables, so that a NLP optimization technique could be applied. Simulation results of the controller operation are provided.

KEYWORDS: Hybrid predictive control, mixed continuous-batch processes, on-line scheduling, hierarchical control, plant-wide control, non linear optimization, non model predictive control

1. Introduction

Many processes, even those of continuous nature, involve signals or working rules that make them different from the classical continuous operating environment where only magnitudes represented by real variables and modelled by differentialalgebraic equations (DAE) are present. In practice, these processes include on/off valves or other binary actuators, are subjected to logical operational rules, or are mixed with sequential operations. As a result, classical control does not fit very well with the ...