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Advanced Control Algorithm And Software Realization On Papermaking Process

Posted on:2003-10-21Degree:DoctorType:Dissertation
Country:ChinaCandidate:Y G KongFull Text:PDF
GTID:1118360092475614Subject:Control Science and Engineering
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n the complex industrial process system, we always meet such problems: multiple constraint conditions; multi variable system; strong coupling; nonlinear system; large time delay; multi control target; and so on. Custom control technique can't solve above problems. But Advanced control technique can deal well with those problems. How to use advanced control technique in industrial process and generate practical utility is a urgent problem in the industrial automate research realm. According as the galloping of computer technique, hardware technique, network technique, Industrialization of advanced control technique is realizable.In this dissertation, based on papermaking process, we discuss the application of advanced control software and advanced control algorithm in the control of basis weight and moisture of papermaking process. Papermaking system is a complicated transmit heat and character process, has many peculiarity such as disturb, strong coupling, great pure lag etc. We discuss the design of dedicated control equipment of basis weight and moisture for papermaking machine in detail including characteristic, correlative soft and hardware information and realization of control.The main contributions of the dissertation are as follows:1. We make an overview on the papermaking advanced control system in detail, including generation, development and the last achievement in the field. We also make a discussion on some difficulty and problem for advanced process control including theory analysis and application.2. The latest research pay-off are given including scheduling, optimization> control in the papermaking basis weight and moisture dedicated control system. In the scheduling layer, we discussed such papermaking workshop which has stochastic demand and failure. Mathematical model is setup. This problem are inverted into discrete dynamic programming. By exploring the properties of the optimal value function, several simple and realistic sub-optimal policies are presented. These sub-optimal policies are of threshold structure, which are featured only by a number of threshold parameters. The method which used to solve optimal value function are given in this paper.SN In the control layer, We design an algorithm which called multi variable auto learning dynamic decoupling control for basis weight and moisture system. Some general decoupling method are discussed in this paper. From the comparison of each method ,we can jump to conclusion that multi variable auto learning dynamic decoupling method has many properties such as good control effecU strong robust performance. It can be used in the complex industrial process which can't build a mathematical model. An optimal control algorithm :H2/l1 mixed optimal control which about two index of performance is given. Lower approximation algorithm and its solve of convex quadratic programming are also given in this article.4. Based on papermaking process, we give its software design scheme. OPC is introduced in this paper. We also analysis the application method about how to use OPC in the design of advanced control software. How to use OPC in DCS is also given. We give the implement method of the advanced process control software which developed independently by us.5. Dedicated control system is designed for papermaking basis weight and moisture control. Management and control are integrated in this system. Firstly, crafts flow and mechanism are analyzed. We adopted two control method to model and control for papermaking system. The scheme can real-time rectify control decision-making based on the change of system operating model, so the system can get the following properties: quick and robust adaptive ability; increase turnout; save material; enhance economy utility.6. Based on the performance of measure moisture hardly, we give its soft measurement model and online adjust plan.Finally, we makes a conclusion and proposes the future research directions.
Keywords/Search Tags:Advanced control, Decoupling, OPC, Dedicated control system
PDF Full Text Request
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