能勢 和夫

This paper deals with the problem of robust tracking and disturbance rejection for a linear time-invariant system where the uncertainty of the system is represented in a structured form and the output to be controlled may be different from the measurement output. First, the problem is considered in a rather classical setting in that the required property of tracking and disturbance rejection can be attained as long as the resulting closed-loop system remains stable. Conditions for solvability of the problem are given and two algorithms are presented for designing controllers having the robust tracking and disturbance rejection property. Second, the problem of robust output regulation with robust stability is formulated as one of finding a controller such that the resulting closed-loop system satisfies an additional requirement of robust stability and thus the output regulation property can be maintained for all perturbations of uncertain parameters within a prescribed set. A procedure based on a high gain observer approach is proposed to solve this problem. © 1998 Taylor &amp Francis Ltd.

To attain a successful width control for hot strip mill, it is important to control a width at each stand preventing excessive tension imbalance for some specified stands.<BR>Our research goal is to develop a multivariable control algorithm for the new width control system. In the proposed algorithm, the width is controlled by modifying the inter-stands tension, which value is derived from the measured width and the on-line calculated width. An optimal control principle is applied and the tension balance can be maintained by tuning the weighting matrix in the performance index. The on-line control algorithm is designed such that the tension modification value can be obtained in short time, compared with the optimal regulator. This calculation is realized using a formula manipulating procedure and the control performance is same to that by the optimal regulator.<BR>The control system based on this algorithm has been applied to the hot strip mill and the width deviation can be remarkably reduced than before.

This paper describes a multivariable algorithm for controlling the flatness of a multi-high rolling mill with actuators of crown control, lateral shift, and tilting rolling. First, the flatness control problem is formulated as a Linear-Quadratic control problem and the control law is derived. Second, to ensure the control constraints are satisfied, a practical flatness control algorithm is proposed. A non-interactive control algorithm is also proposed to compensate for the thickness disturbance caused by the flatness control. Finally, field test results are presented showing the performance of the proposed control algorithms.

To attain a successful width control for hot strip mill, it is important to control a width at each stand preventing excessive tension imbalance for some specified stands.<BR>Our research goal is to develop a multivariable control algorithm for the new width control system. In the proposed algorithm, the width is controlled by modifying the inter-stands tension, which value is derived from the measured width and the on-line calculated width. An optimal control principle is applied and the tension balance can be maintained by tuning the weighting matrix in the performance index. The on-line control algorithm is designed such that the tension modification value can be obtained in short time, compared with the optimal regulator. This calculation is realized using a formula manipulating procedure and the control performance is same to that by the optimal regulator.<BR>The control system based on this algorithm has been applied to the hot strip mill and the width deviation can be remarkably reduced than before.

This paper describes a multivariable algorithm for controlling the flatness of a multi-high rolling mill with actuators of crown control, lateral shift, and tilting rolling. First, the flatness control problem is formulated as a Linear-Quadratic control problem and the control law is derived. Second, to ensure the control constraints are satisfied, a practical flatness control algorithm is proposed. A non-interactive control algorithm is also proposed to compensate for the thickness disturbance caused by the flatness control. Finally, field test results are presented showing the performance of the proposed control algorithms.

We discuss the application of the expert system technology to the flatness control problem of the aluminum foil rolling process. Our expert system can adjust the target shape pattern on line for the automatic flatness control system according to the material characteristics and operating conditions. We have modelled the knowledge structure and inference mechanism in the target shape adjustment process that has been done by the experts and developed an expert system. This system has ability to solve the conflict between rules, and keeps consistency in actions. This system infers adaptively considering applied results of the past inference to accomodate the change of the characteristics of the rolling process. Further our model is useful for a class of adjustment problems in the process control.

We discuss the application of the expert system technology to the flatness control problem of the aluminum foil rolling process. Our expert system can adjust the target shape pattern on line for the automatic flatness control system according to the material characteristics and operating conditions. We have modelled the knowledge structure and inference mechanism in the target shape adjustment process that has been done by the experts and developed an expert system. This system has ability to solve the conflict between rules, and keeps consistency in actions. This system infers adaptively considering applied results of the past inference to accomodate the change of the characteristics of the rolling process. Further our model is useful for a class of adjustment problems in the process control.