Nonlinear Predictive Control And Its Application

Predictive control is a class of digital control algorithms developed in the late 1970's. The popularity of these methods is due to the facts that they can offer good performance, be understanded and formulated easily and accommodate inputloutput process constraints. Because of robustness to the model uncertainty, predictive control strategies have received much attention in the literatures and been applied in industries widely. By far, the theory of linear SISO predictive control has matured considerably. Unfortunately, MIMO andlor nonlinear systems are frequently encountered in most applications. It is imperative to improve control algorithm more adaptive to complex industrial processes. In this dissertation, nonlinear predictive control based on Wiener models is studied. A nonlinear predictive controller to the lever system is designed. The main contents are as follows: 1. The dissertation begins with a survey of predictive control. Current status of theoretic research and industrial application is reviewed. 2. An improved Wiener model is proposed in order to simplify design of controllers. The model predictive control algorithm is presented based on the improved model. and good performance is obtained. 3. Introduce the fundamental principle of the level control system of two tanks and build the dynamic models in the opinion of principle, obtains that the system have the nonlinearity time-lagger and coupling from the result. 4. The m odel o ft he I evel c ontrol s ystem is s implified, and an a fflne no nhinear system is obtained. A predictive controller combine with feedback linearization approach is applied and obtains good performance. 5. The dissertation concludes with a perspective of future predictive research.