• 전자공학회논문지SC
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• 제40권2호
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• pp.19-25
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• 2003

본 논문에서는 주어진 작업을 반복적으로 수행하는 다입력 다출력 비선형시스템에 대하여 시스템의 (벡터)상대차수 개념을 이용한 확장된 형태의 직접학습제어를 제안한다. 기존의 직접학습제어가 적용될 수 있는 시스템은 상대차수가 제한적인 시스템임을 보이고 고차의 상대차수를 갖는 시스템에 적용 가능한 제어 법칙을 제시한다. 이 제어법칙을 이용하여 다른 형태의 출력 궤적들에 대한 학습을 통하여 얻어진 제어입력들로부터 새로 주어진 원하는 출력 궤적에 대응하는 제어입력을 직접적으로 생성한다. 제안된 직접학습제어의 타당성 및 성능을 보이기 위하여 2축 스카라 로봇에 대한 궤적추종제어의 시뮬레이션 결과를 제시한다

• 보건행정학회지
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• 제22권1호
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• pp.109-128
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• 2012

The purpose of this study is to analyze the performance difference between multi-hospitals and free-standing hospitals. Scholars in industrial economics argue that, due to economies of scale and integration, multi-hospital system may have a better performance compared to freestanding hospitals. The study overturned the hypothesis based on a theory. By analyzing 425 acute-care hospitals in Korea, this research shows that multi-hospital systems and market factors, which have been perceived to be strengths to hospitals, are negatively related to hospitals' financial performance. Specifically, the results showed a better performance of freestanding hospitals compared to multi-hospital systems. Higher labor and administrative cost by multi-hospital system may be the reason for the difference, and it means they are not more effective at cost control. Managers in multi-hospital system, therefore, should pay attention on cost-reducing issues to regain managerial efficiency of organizations.

• Wind and Structures
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• 제6권5호
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• pp.387-402
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• 2003

In the past decades, much effort has been made towards the study of single-mode-based vibration controls with dynamic energy absorbers such as single or multiple Tuned Mass Dampers(TMDs). With the increase of bridge span length and the tendency of the bridge cross-section being more slender and streamlined, multi-mode coupled vibrations as well as their controls have become very important for large bridges susceptible to strong winds. As a simple but effective device, the TMD system especially the semi-active one has become a promising option for such coupled vibration controls. However, despite various studies of optimal controls of single-mode-based vibrations with TMDs, research on the corresponding controls of the multi-mode coupled vibrations is very rare so far. For the development of a semi-active control strategy to suppress the multi-mode coupled vibrations, a comprehensive parametric analysis on the optimal variables of this control is substantial. In the present study, a multi-mode control strategy named "three-row" TMD system is discussed and the general numerical equations are developed at first. Then a parametric study on the optimal control variables for the "three-row" TMD system is conducted for a prototype Humen Suspension Bridge, through which some useful information and a better understanding of the optimal control variables to suppress the coupled vibrations are obtained. This information lays a foundation for the design of semi-active control.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2004년도 학술대회 논문집
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• pp.365-370
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• 2004

The integration of intelligent devices, devices-level networks, and software into motor control systems can deliver improved diagnostics, fast warnings for increased system reliability, design flexibility, and simplified wiring. Remote access to motor-control information also affords an opportunity for reduced exposure to hazardous voltage and improved personnel safety during startup and trouble-shooting. This paper presents LonWorks fieldbus networked intelligent induction control system architecture. Experimental bed system with two inverter motor driving system for controlling 1.5kW induction motor is configured for LonWorks networked intelligent motor control. In recent years, MCCs have evolved to include component technologies, such as variable-speed drives, solid-state starters, and electronic overload relays. Integration was accomplished through hardwiring to a programmable logic controller (PLC) or distributed control system (DCS). Devicelevel communication networks brought new possibilities for advanced monitoring, control and diagnostics. This LonWorks network offered the opportunity for greatly simplified wiring, eliminating the bundles of control interwiring and corresponding complex interwiring diagrams. An intelligent MCC connected in device level control network proves users with significant new information for preventing or minimizing downtime. This information includes warnings of abnormal operation, identification of trip causes, automated logging of events, and electronic documentation. In order to show the application of the multi-motors control system, the prototype control system is implemented. This paper is the first step to drive multi-motors with serial communication which can satisfy the real time operation using LonWorks network.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1107-1114
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• 2005

The running condition of multi-system air conditioner is prone to vary largely as it is designed for individual conditioning in each space of middle and small sized buildings. This leads to overcooling in case of partial load run, while the lack of capacity happens in case of full load run. Besides these, there exist such problems as instabilities due to the uneven refrigerant distribution caused by fluctuation of load and the change in piping line. Based upon the basic study on the function characteristics found in parts needed for maximized system working design in order to troubleshoot, the system functioning pattern should be identified through the different tests with various operating circumstances and the analysis models should be developed. With this ground, the control logic has to be made to have a control over capacity and make possible the efficient distribution of refrigerant.

• 제어로봇시스템학회논문지
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• 제5권1호
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• pp.79-87
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• 1999

For its simplicity and cost effectiveness in implementation, the Inverted DGPS is well suited for some specific applications like automatic vehicle location systems, where the monitoring station needs accurate position of the vehicles in the street. In the Inverted DGPS, the user sends its GPS position and associated satellite informations to the reference station, and the corrections are made at the reference station to get differentially corrected user position. A fundamental requirement in IDGPS is that the user and the reference station must use the same satellites when the corrections are made. But in practice, it is not often satisfied. Inverted DGPS is also suffered from performance degradation as the baseline become large like DGPS. IDGPS system using multi-reference station can resolve this problem. In this paper a simple multi-reference IDGPS algorithm is proposed and some experiments and analysis are peformed. Experiment results show that IDGPS can achieve the positioning performance as accurate as the DGPS can provide.

• International Journal of Aeronautical and Space Sciences
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• 제18권3호
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• pp.522-534
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• 2017

According to the characteristics of salvo attack for the multiple flight vehicles (MFV), the design of cooperative guidance law can be converted into the consensus problem of multi-vehicle system through the concept of multi-agent cooperative control. The flight vehicles can be divided into leader and followers depending on different functions, and the flight conditions of leader are independent of the ones of followers. The consensus problem of leader-follower multi-vehicle system is researched by graph theory, and the consensus protocol is also presented. Meanwhile, the finite time guidance law is designed for the flight vehicles via the finite time control method, and the system stability is also analyzed. Whereby, the guidance law can guarantee the line of sight (LOS) angular rates converge to zero in finite time, and hence the cooperative attack of the MFV can be realized. The effectiveness of the designed cooperative guidance method is validated through the simulation with a stationary target and a moving target, respectively.

• 한국산업융합학회 논문집
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• 제25권1호
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• pp.87-99
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• 2022

We propoes a study on the dynamic characteristics analysis and position control of 5-degree multi-joint manipulators for untact remote working at construction sites and manufacturing plants. The main frame of freedom multi-joint manipulator consists of five elements, boom cylinder, boom cylinder, arm cylinder, bucket cylinder, and rotation joint and link. In addition, the main purpose of the proposed system is to realize the work of the manufacturing process or construction site by remote control. Motion control of the entire system is a servo valve control method by hydraulic servo cylinders for one to four joints, and a servo motor control method is applied for five joints. The reliability of the proposed method was verified through performance experiments by computer simulation.

• 문화기술의 융합
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• 제4권4호
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• pp.419-427
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• 2018

본 연구에서는 하나의 제어보드로 여러 대의 제어 시스템을 동시에 제어 가능하도록 하는 다중채널 제어기능을 갖는 오토튜닝 온도제어기를 설계하고 구현한다. 제어기 보드는 다중채널 입력 및 출력 기능을 가지고 있으며, 여러 개의 제어 알고리듬이 서로 독립적이지만 동시에 동작하는 멀티채널 제어기이다. 먼저 다중채널 제어기능을 갖는 온도제어기 설계방법을 나타내고. 이를 구현하는 센서입력부 회로, 제어신호 출력부 회로, 파워제어부 회로 등의 하드웨어 회로를 설계한다. 또한 다중채널 온도 제어기의 성능을 모니터링 하기 위하여 온도 제어 출력신호의 직렬 통신 데이터 프로토콜을 설계하고, 구현된 다채널 온도제어기의 실제 시험을 통한 성능을 평가한다.

• 조명전기설비학회논문지
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• 제25권9호
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• pp.50-55
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• 2011

This research is to apply the adaptive control of neuron networks for the real-time attitude control of Multi-articulated robot. Multi-articulated robot is expressed with a complicated mathematical model on account of the mechanic, electric non-linearity which each articulation of mechanism has, and includes an unstable factor in time of attitude control. If such a complex expression is included in control operation, it leads to the disadvantage that operation time is lengthened. Thus, if the rapid change of the load or the disturbance is given, it is difficult to fulfill the control of desired performance. In this research we used the response property curve of the robot instead of the activation function of neural network algorithms, so the adaptive control system of neural networks constructed without the information of modeling can perform a real-time control. The proposed adaptive control algorithm generated control signs corresponding to the non-linearity of Multi-articulated robot, which could generate desired motion in real time.