The Research Of Control Methods For Time-delay Systems And The Application In Electrical Heating Instrument

The time delay control problems that occur in most of the industry processes are studied in this dissertation. Firstly, three of the advanced PID control algorithms are analyzed and the simulation results show these algorithms are effective. Next, Dynamic Matrix Control (DMC) algorithm is studied, and an improved algorithm of DMC is proposed for application. Finally, a temperature control system is designed for electrical heating instrument. The main research results are as follows: 1. As is known, the basic PID controller cannot have good control performance facing time delay . Three advanced PID algorithms, which are IMC-PID, PIP and FUZZY-PID, have been studied in Chapter 2. The simulations show that all the three algorithms have better performance than the basic PID and the Smith predictor. 2. DMC is widely used in industry and has been proved an effectivecontrol algorithm for time delay processes. The nonparametric model DMC and the state-space model DMC are introduced in Chapter 3.Since traditional DMC algorithm needs much calculation and memory space, a double point state-space DMC algorithm is proposed for application. The simulations show that the proposed algorithm has many merits such as better robust, lesser memory and fitting for thetime delay system.3. A temperature control system of electrical heating instrument is designed and implemented, which is based on MCS-51 series single chip computer, programmed with the assemble language and the C language. Both the double point DMC and Fuzzy-PID are applied for comparison. The implementation results indicate that the double point DMC has pretty much the same performance with Fuzzy-PID.