Some Researches On Predictive Control

Predictive control is a kind of advanced control technologies that is based on the model of plants, so it is also called model predictive control. It is a novel computer control algorithm first appeared in industrial area in Europe and America in 1970s.French researcher Richalet et al first proposed the conception, background, mechanism and performance of the model predictive heuristic control. Then the theory of model predictive control was further developed by Mehra, Culter and Clark et al. In 1980s, model predictive control received extensive attention of the western researchers for its distinct merits and features and it has been deeply studied from different aspects with many mathematic methods.Predictive control is a form of control that developed rapidly and gained extensive application in recent years. Predictive control is a kind of advanced control technology, which is based on the model of plants. The model predictive control was straightly engendered and sophisticed from the applications of industrial process. Model predictive control requires low accuracy of model precision, but it can provide high performance.Predictive control's current control action is obtained by solving at each sampling instant, a finite horizon open-loop optimal control problem, using the current state of the plant as initial state, the optimization yields an optimal control sequence and the first control in this sequence is applied to the plant. An important advantage of this type of control is its ability to cope with hard constraints on controls and states. It has, therefore, been widely applied in petro-chemical and related industries where satisfaction of constraints is particularly important because efficiency demands operating points on or close to the boundary of the set of admissible states and controls。 Model predictive control is a quite effective optimal control algorithm, which made up the deficiency of modern model theory in complex plants. In the recent years, with the development of many kinds of the control theory, such as intelligent control, PID control, wavelet theory, robust control and hybrid systems control, the theory of model predictive control has also obtained rapid developments.Based on the study of model predictive control and the new requirements from the practice industrial processes for the theory of model predictive control, some desiderated problems for the theory of model predictive control, corresponding results are given. The main contents of this thesis are stated as follows:1) It completely reviewed the development of model predictive control and introduced and analyzed the main types of model predictive control,included Dynamic Matrix Control, Model Algorithm Control, and Generalized Predictive Control in the literature.2) we study the problem of constrained Generalized Predictive Control of MIMO system. We assume that the outputs satisfy some inequality constraints and solve the constrained problem by choosing suitable adjustable coefficientλ. To this end, we estimate parameters through the known data instead of the computation of the inverse matrix.3) Based on the DMC algorithm a decoupling design method of multi-variable system is presented. In the paper, the system is deposed with one to much upper triangular decoupling method, not with one to one diagonal decoupling method. So the decoupling problem is done step by step. The simulation of the decoupling algorithm is good.The conclusion and perspective are given in the end of the paper.