A Study On Predictive Functional Control Technology And Its Applications

Predictive Control strategy has been developing quickly both in theory research and in applications, with its three characteristics of predictive model, receding horizontal optimization and feedback correction, which meet the needs of the industrial process control. Predictive Functional Control (PFC) is one of the most novel direction in this area, and it applies in fast processes initially, such as robot's arm control and radar tracking control, now it applies also in slow processes, such as temperature tracking control of batch reactors, etc. The theories and applications of PFC are studied in this dissertation. On the basis of the general principles, Predictive Functional Control method based on the state space model is discussed and several new Predictive Functional Control algorithms based on nonlinear systems are proposed. The applications of PFC include the three-tank water-level control system and the simulation studies for some industrial processes. The main research work of this dissertation are summarized as follows:1. The general principles of Predictive Control method are introduced systematically, and a survey on the development and status of Predictive Control method is given in Chapter One.2. Based on the general principles, the detailed state space PFC algorithm for SISO systems is discussed in Chapter Two. It is shown from the algorithm that it has less on line calculations, and simulation examples illustrate that the PFC method also has the following advantages: high control precision and disturbance attenuation.3. Almost all of the real industrial processes are nonlinear systems and many control strategies have been presented to deal with the control problems of nonlinear systems. But it remains a nut to be solved. The nonlinear PFC algorithmsof bilinear system and improved Hammerstein model are presented in Chapter Three. The feasibilities of the algorithms are verified through simulations. Dead zone is a typical nonlinearity, which will cause steady state error to the system. The PFC algorithm of dead zone nonlinear system is studied in Chapter Four, where a nonlinear pre-compensator is designed to linearize the system. The effectiveness of the algorithm is proved through simulations.4. Predictive Control strategy comes from the industry, and goes back to solve the control problems existed in real industrial processes. In Chapter Five, Predictive Functional Control strategy is applied to the three-tank water-level control system in the laboratory.Finally, the PFC research in this dissertation is summarized and the further research directions about PFC are discussed.