Design And Realization Research On Predictive PID Controllers

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. 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. In the recent years, with the development of many kinds of the control theory, such as intelligent control, PID(proportion, integral and differential) control, wavelet theory, robust control, and hybrid system control etc, the theory of model predictive control has also obtained rapid development. Moreover, the theory researches and corresponding application reports of model predictive control also appeared in the field of variable structure control.Dynamic Matrix control (DMC), which appeared in 1980s, is a new type of computer control method and one of the most representative algorithm. It has received increasing attention in the field of control and industry. Based on lots of literature, this paper introduces fundamental principles of predictive control and the newly developments of DMC.Firstly, the thesis mainly researches PID control algorithm which is used widely in industry control, and reformative PID is studied by simulated. The control principle of neural network PID algorithm is expounded. Its control characters are analyzed and compared with traditional PID's through simulation. Then their merits and defects are indicated.Next, this paper introduces cascade controller system. The simulation results and comparison with PID cascade control show that the DMC-PID cascade control strategy can improve the controlled performance.At last, the different control arithmetic is studied by experiment. Thehardware platform lays an emphasis on the design of the model of the control system and the Ethernet control system. The software platform begins with the Virtual Instrument technology and LabVIEW, and then designs the subprograms of tank level control system. Finally, the thesis takes tank level control system for example to experiment. It uses PID control and DMC control, and gives the results and compares the two control algorithm. Their merits and defects are indicated through experimentation. Also proves the superiority and feasibility of DMC applied on industry control.