Design of a new Predictive Functional Control algorithm based on linear difference equation model

Abstract

Predictive Functional Control (PFC) algorithm is a kind of Model Predictive Control (MPC) algorithms, and PFC is suitable for control of fast processes with its unique feature that is able to follow up a target or set point with no lag. In this paper, the PFC strategy is extended to linear discrete-time system input/output difference equation model, and a new PFC algorithm (named LDE-PFC) is developed in detail. The structure of the new LDE-PFC algorithm is mainly composed of four parts: the linear difference model, output prediction, reference trajectory, and calculation of control action. Based on a predictive control performance (or cost) function, the LDE-PFC is to make the prediction as close to the reference trajectory as possible in some coincidence points, and at the same time to reach the set point quickly and smoothly. In order to demonstrate the effectiveness of the LDE-PFC algorithm, some simulation experiments of the LDE-PFC algorithm applied to the control of discrete-time systems are carried out and implemented in Matlab/Simulink. The simulation results show that the LDE-PFC algorithm can make the system output follow up various types of set point curves quite well.