Research And Application Of Advanced Control Strategy Based On Plc

PLC has become the mainstream control device according to its powerful technic dominance, such as highly dependability, anti-jamming, abundant function and so on. But now, PLC mostly still take on the most essential control, such as sequential and PID feedback. With the development of Industly, profess objective is more and more complicated, non-linear, large delay, and hard to build models. So it is difficult to fulfil the request only by PID control. However, advanced control strategies show strong advantages for resolving these problems in the control system. So the research of advanced control based on PLC is to be a current focus.In the first place, combining the research work of many predecessors in the relevant field, this paper summarize the research status quo of PLC and analyse the realization method of PLC fuzzy-PID controller. Subsequently this paper discusses the process flow of product line that the Double Cannulation Rolling mill (DCRM) in TI Automation.This paper takes Double Cannulation Rolling mill (DCRM) as the test facility. At first, it analyzes the operating principle and mechanical character of DCRM. Then, based on these, it analyzes the elements that have influences on steel strip velocity. At last, the fuzzy-PID control strategy is determined. The hardware system is designed using Mitsubishi FX2N PLC and its analog unit. Based on above paragraphs, we stress the research of advanced control strategy, fuzzy arithmetic. Combining the characteristic of FX2N PLC, the realization method of fuzzy control and PID control based on PLC is provided. At the same time, the designing approach of PLC-fuzzy-PID controller is discussed in detail.A fuzzy control table is designed using fuzzy box of MATLAB.The resealing factors of fuzzy variables are determined based on test. The system control program is designed by macking use of GX Developer 7.0 and GT Designer 2.0. In the end, by making use of consulting table, the system realizes the fuzzy-PID control.The actual steel strip velocity is measured in open-loop control, fuzzy control and fuzzy-PID control modes.The analysis of the steel strip velocity error proves the feasibility of fuzzy-PID control in this problem.