Coordination of Controllers Based on Multiple Local Models

Abstract

This paper presents a new controller coordination method based on multiple local models for highly nonlinear chemical processes. In the proposed method, a bank of local controllers is designed based on multiple models and run in parallel. Manipulated variables are calculated by the affine combination of the weighted outputs of local controllers. The soft-max function with a tuning parameter is used to determine the weight coefficients of local controller outputs. This method is simulated to control the temperature of a non-isothermal continuous stirred-tank reactor (CSTR) whose liquid level changes according to the operational conditions. The proposed method exhibits good control capabilities over a wide range of operational conditions.