Research On The Control Methods For Processes With Time-delay

Time-lag is actual production of more common phenomenon, because oneself the performance differences, also significantly impact on the quality of the products. Because delay phenomena exists, make the control system while working stability appear problem, may appear overshoots big, adjust time long wait for a phenomenon. So, delay process control methods has been control theory study important issue. This paper studied in industrial production process by large application PID control, internal model control and Smith prediction control, and with the current academic circles as the basis of the existing research results of delay process control method on the improvement and innovation.First,this article tells the story of the delay and the characteristics of the process of the influence of the performance index it, and introduces the present science of several common control method:mainly including the Z-N method, improvement of the Z-N method, Astrom method, method and the method of SPAM, PM and through the simulation method to the above several performance comparison method. And with Z-N method, Astrom method and SPAM method and so on as the example, this paper discusses the PID parameters setting method, and puts forward a kind of setting the PID parameters to, is to use standardization dead zone time and curve fitting least square method for setting formula.Secondly, the article expounds internal model control and classical feedback control, and internal model control and Smith estimate of the relationship between the control, according to estimates to process the Smith deviation model is very sensitive, does not apply to unstable and integral process defect, the thorough analysis Smith is estimated, the analytic design method and improved Smith is estimated control scheme. And on the basis of law in Majhi, and puts forward a kind of make use of the internal model control principle to design a revision of the Smith is estimated new method.Finally, through several simulation example shows the the proposed control the effectiveness of the proposed method, and with other existing performance comparison method.