粉砕閉回路のロバスト制御に関する研究 第３報 セメント粉砕閉回路の多変数制御系の設計

Abstract

The authors have already constructed the transfer function model and proposed the control strategy for the cement grinding process. This paper presents the design of multivariable controller for the control systems considered, where the mill grinding property depends on its hold up and the mill dynamics vary with change of clinker grindability. Therefore applicability of the H∞ robust control to this process was investigated. The simplified model at a certain set-point was used as a nominal model of the process. The model deviation was determined based on the variation of coefficient ks of the model obtained by some plant data. The results showed that these transient responses in MIMO system were faster than those of conventional SISO systems. There was no remarkable difference in control performance between the two systems of type？ and type？. It was useful to apply a hierarchy control system in order to prevent the decrease of the product quantity, when clinker grindability decreases. Furthermore the authors studied applicability of a two-degree-of freedom method to type？ and that of a decoupling method to type？ respectively. As a result the transient characteristics in product quality could be improved by the two-degree-of-freedom method. The type？ system could be handled as a group of non interacting SISO systems by the decoupling method and the controller for each loop could be tuned independently.