The Coupling Of Control System And Study Of Control Strategy Of Basis Weight, Moisture And Ash Of Paper

Paper is indispensable to the daily life, but also an important consumer of industrial production of the important raw materials. With the culture and the rapid development of the information industry, the higher yield and quality is required. People are constantly to adopt new technology and equipment to expand the scale of papermaking machines, to improve the speed of papermaking machines and the yield and quality of paper. The increasingly serious global energy nervous and industrial pollution makes paper production process is becoming more and more complicated. In order to pursue higher economic benefit, computer automatic control in production process has become inevitable.The basis weight, moisture and ash of paper are the most important quality indexes of the paper, their strict control has become the primary goal of paper. At the conclusion of the related literature at home and abroad, this paper give the thoroughly discussion on the measuring principle of basis weight, moisture and ash, correction and compensation of detection signals, the control characteristics and decoupling control of basis weight, moisture and ash, etc. several theories.The paper briefly tells the technological process and analyzes the control characteristics of basis weight, moisture and ash of paper in detail. The paper introduces the home and abroad control algorithms of quality control system and advantages and disadvantages of each control algorithm.The paper gives a detailed introduction on the characteristics of measuring objects, the measuring principle of basis weight, moisture and ash of paper, the sensor technologies of basis weight, moisture and ash of paper, the mutual influence characteristics of measuring signals and the processing and compensation of measuring signals. This thesis has studied the transfer function model of the control system of basis weight, moisture and ash. According to related references,steps response curve is used to establish the mathematical model of the control system, and the simulation analysis, based on the coupling characteristics among them, are made.According to the characteristics of paper quality control system, this paper designs the three controllers, namely the dual-freedom Smith predictor and feed-forward decoupling controller and the fuzzy adaptive Smith predictor decoupling controller with self-adjustment function. This paper gives the detailed design steps of two control algorithms, and analysis simulation result based on MATLAB simulation tools. It proves that these two methods have good effectiveness and feasibility under different conditions.