불확실성과 성과간의 관계에서 역동적 긴장의 매개효과

김달곤(Kim, Dal-Gon),김재열(Kim, Jae-Yeol) 대한경영학회 2007 大韓經營學會誌 Vol.20 No.5

Command Filter-based Backstepping Control for the Speed and Tension System of the Reversible Cold Strip Rolling Mill Using Disturbance Observers

Le Liu,Nuan Shao,Suyan Ding,Yi-ming Fang 제어·로봇·시스템학회 2020 International Journal of Control, Automation, and Vol.18 No.5

This paper investigates the decoupling and coordinated tracking control problem for the speed and tension system of the reversible cold strip rolling mill. Using a diagonal matrix decoupling network and neural network disturbance observers, we propose a command filter-based backstepping control strategy. First, the diagonal matrix decoupling network is constructed to weaken the coupling between the speed and tension of the rolling mill system, which reduces the complexity of the system model effectively. Second, controllers are designed by combining the backstepping with the command filter, which solves the “explosion of complexity” problem in backstepping procedure, and optimizes the system’s control structure. Next, neural network disturbance observers are developed to observe the uncertain items of the system, which improve the tracking control precision of the system effectively. Theoretical analysis shows that all signals in the closed-loop system are uniformly ultimately bounded. Finally, simulation research is carried out on the speed and tension system of a 1422 mm reversible cold strip rolling mill; results show that using the proposed control strategy increased the dynamic response speed of the system by approximately 1s, and the stability precision improved by approximately 2000 N.

A Web Tension Control Strategy for Multi-span Web Transport Systems in Annealing Furnace

Lee, Gyoo Taek,Shin, Jong Min,Kim, Han Me,Kim, Jong Shik The Iron and Steel Institute of Japan 2010 ISIJ international Vol.50 No.6

<P>This paper presents a web tension control strategy for multi-span web transport in a continuous annealing process (CAP) used in steel manufacture. In the CAP, the temperature of the steel web is varied over a wide range, and this generates a thermal strain in the web. In addition, in order to save workspace, vertical type web transport systems are usually used, and the weight of the web causes a gravity strain in the web. These strains in the web induce the variation of the web tension. To control the web tension in the CAP, a feed-forward tension control scheme is suggested, which is based on a mathematical model considering the additional strains due to thermal and gravity effects. The performance of the proposed feed-forward tension control scheme is experimentally evaluated in an actual CAP. In addition, to respond to the variations of many system parameters, a feedback tension control scheme based on the tension observer is proposed. The performance of the feedback tension control system is evaluated by computer simulation.</P>

DP보조계류시스템의 위치제어를 위한 격자 기반의 제어목표점 선정 전략

최솔미,이재용,이승재,이대수,정광효 한국해양공학회 2019 韓國海洋工學會誌 Vol.33 No.2

Unlike typical a dynamic positioning (DP) system, a DP-assisted mooring system must determine a set point (SP) that can ensure a mooring tension safety range to prevent an excessive increase in mooring tension. In this paper, a new algorithm for determining the SP is suggested in order to reduce the tension on all the mooring lines. To determine the SP, a working area around the vessel is represented by a rectangular grid. Thus, the size of the grid area is limited considering the offset of a vessel with a mooring system. At each grid’s nodes, the resultant tension from all the mooring lines is estimated using the time history of the tension and vessel’s position. The results of static analyses for each grid position are used to estimate the global tension. Consequently, the SP is automatically selected as a position satisfying criterion for minimizing the total tension. In order to validate the suggested algorithm, a motion simulation with the control system in the time domain and a discussion of the results are presented.

Dynamic Simulation of AGC/LPC Synthetical System for Hot Strip Finishing Mill

Xiaoying Wang,Jingcheng Wang 한국지능시스템학회 2008 INTERNATIONAL JOURNAL of FUZZY LOGIC and INTELLIGE Vol.8 No.1

A simulation of hot strip finishing mill automatic gauge control (AGC) system is built, which is divided into four modules such as rolling mill system, AGC module, looper system and strip model. The rolling mill system is built by mechanism modeling, the looper system and strip model are built by function modeling, and the AGC model is tried to use intelligent control of a multi-function AGC system. The target is attempted to use this simulation object to minimize finisher exit strip thickness deviation resulting from strip entry thickness disturbance and rolling force deviation. Simulation results show that the result of this AGC/LPC synthetical system module simulation is quite close to the actual result. The simulation system can also analyze most kinds of disturbance which affect the rolling process. It is proved that the system can represent practical situation of hot strip finishing mill process control, and be used as a basic platform of research and development for researcher and engineer.

Tension Control of Wire Rope in Winch Spooler using Magneto Rheological Brake

이재학,윤영원,홍현욱,박명관 한국정밀공학회 2016 International Journal of Precision Engineering and Vol.17 No.2

While operating conventional spooler system in heavy industries such as winch reel and cranes, wire rope tangling and twisting leads wire aging with short life cycle and entangling occurs catastrophic damage to the whole system. The aim of this work is investigating a tension control system using a magneto rheological brake (MRB) to provide back tension to prevent frequent part changes and fatal malfunction. In order to achieve this aim, a basic MRB is first designed and analyzed using finite element method (FEM) with electromagnetic field and fluid analysis are performed. As second step, a prototype of the an MRB is fabricated with the optimized structural parameters and experimental apparatus is constructed. Moreover, output torque characteristics of the designed MRB with the various input current and rotational speed are evaluated. Consequently, a conventional proportional-integral-derivative (PID) controller is designed for a tension control, and the control results show the feasibility for tension control of winch spooler system.

열연 루퍼시스템의 퍼지 장력제어

허윤기(Yone-Gi Hur) 제어로봇시스템학회 2010 제어·로봇·시스템학회 논문지 Vol.16 No.10

The hot rolling process ranks the highest position for production in steel making process. The hot strip manufacturing processes consist of the reheating furnace, roughing and finishing mill and coiler. The reheating furnace heats the slab. The roughing and finishing mill produce the hot strip from slab. The hot strip quality mainly depends on finishing mill, which consists of 4-high 7 stands. The looper is installed between stands and is used for controlling the strip tension by the looper angle for better material flow. It is difficult to control the strip tension with the coupled looper system from interaction between the looper angle and strip tension. Too much deviation of strip tension severely affects the poor width quality of the hot strip. It is important to control simultaneously both the looper angle and strip tension with each of their target values. This paper proposes the fuzzy tension control, which is developed to minimize the width deviation of the hot strip by maintaining the proper strip tension between stands and to achieve the stable operation of the coupled looper system. The fuzzy tension control performance is compared with the conventional PID control by experimental results.

동적제어 시스템을 이용한 막장력 복원 실험

하창우(Ha, Chang-Woo),강주원(Kang, Joo-Won),김재열(Kim, Jae-Yeol) 대한건축학회 2017 大韓建築學會論文集 : 構造系 Vol.33 No.8

This paper explains the outline of dynamic tension control system of flexible membrane structures. Due to the long time loading of external loading such as creep load or snow load on the installed membrane, the tension becomes more relaxed than the initially designed tension. This is a system that recovers the initially designed tension automatically operating the tension jacking system when it reaches a specified value by real time monitoring the tension value. It performed tension recovery test using the suggested dynamic tension control system for the membrane of tension relaxation due to creep load that is caused by rain weight and snow load. The suggested system worked very well according to the designed algorithm. It is believed that it could be used efficiently as recovery equipment for relaxed tension.

장력 관측기를 이용한 웹 이송 시스템의 피드백 장력제어

한성익(Seong Ik Han),김한메(Han Me Kim),김종식(Jong Shik Kim) 대한기계학회 2006 대한기계학회 춘추학술대회 Vol.2006 No.11

The main object of continuous web transport systems is to maintain a desirable tension of the web between rollers. The maintenance of a desirable tension in web transport systems has closely relation to prevent a fracture of the web and to improve web quality for manufactured goods. The common web transport systems usually maintain the tension between webs through modulating the velocity of rollers by doing feedback of a measured tension signal from only a few tension meter. This means that the part of measured tension signal as feedback signal is constructed to the closed-loop system structure and others except it are constructed to the open-loop system structure. Thus, in order to modify a partial closed-loop system structure to a complete closed-loop system structure, tension observer for estimating unmeasurable tension signal is proposed. From the results of computer simulation, the performance of the proposed system shows better than one of the common web transport system.

Dynamic Simulation of AGC/LPC Synthetical System for Hot Strip Finishing Mill

Wang, Xiaoying,Wang, Jingcheng Korean Institute of Intelligent Systems 2008 INTERNATIONAL JOURNAL of FUZZY LOGIC and INTELLIGE Vol.8 No.1

A simulation of hot strip finishing mill automatic gauge control (AGC) system is built, which is divided into four modules such as rolling mill system, AGC module, looper system and strip model. The rolling mill system is built by mechanism modeling, the looper system and strip model are built by function modeling, and the AGC model is tried to use intelligent control of a multi-function AGC system. The target is attempted to use this simulation object to minimize finisher exit strip thickness deviation resulting from strip entry thickness disturbance and rolling force deviation. Simulation results show that the result of this AGC/LPC synthetical system module simulation is quite close to the actual result. The simulation system can also analyze most kinds of disturbance which affect the rolling process. It is proved that the system can represent practical situation of hot strip finishing mill process control, and be used as a basic platform of research and development for researcher and engineer.