• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2004년도 추계학술대회
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• pp.41-46
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• 2004

본 논문에서는 속도 구속조건을 갖는 수중이동체를 초기위치로부터 목적위치에 접안하는 제어기법에 대해서 논의한다. 단, 수중이동 체는 일정방향으로 속도성분을 갖지 않는 즉, 속도구속조건을 가지는 것으로 가정한다. 본 논문에서는 이러한 시스템에 대하여 비 홀로노믹적인 관점에서 시스템을 해석하고 수중이동체를 체인드폼으로 변환한 후 Multi-rate 디지털 제어기법을 적용하여 자세제어를 행하고 수치시뮬레이션을 통하여 제어기법의 유용성을 평가하였다.

• Journal of Welding and Joining
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• 제17권6호
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• pp.90-99
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• 1999

Significant portion of the total manufacturing time for a pipe fabrication process is spent on the welding following primary machining and fit-up processes. To achieve a reliable weld bead appearance, automatic seam tracking and adaptive control to fill the groove are urgently needed. For the seam tracking in welding processes, the vision sensors have been successfully applied. However, the adaptive filling control of the multi-torches system for the appropriate welded area has not been implemented in the area of SAW(submerged arc welding) by now. The term adaptive control is often used to describe recent advances in welding process control by strictly this only applies to a system which is able to cope with dynamic changes in system performance. In welding applications, the term adaptive control may not imply the conventional control theory definition but may be used in the more descriptive sense to explain the need for the process to adapt to the changing welding conditions. This paper proposed various types of methodologies for obtaining a good bead appearance based on multi-torches welding system with the vision system in SAW. The methodologies for adaptive filling control used welding current/voltage, arc voltage/welding current/wire feed speed combination and welding speed by using vision sensor. It was shown that the algorithm for welding current/voltage combination and welding speed revealed sound weld bead appearance compared with that of voltage/current combination.

• International Journal of Control, Automation, and Systems
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• 제4권1호
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• pp.1-9
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• 2006

This paper presents the modeling and multivariable feedback control of a novel high-precision multi-dimensional positioning stage. This integrated 6-degree-of-freedom. (DOF) motion stage is levitated by three aerostatic bearings and actuated by 3 three-phase synchronous permanent-magnet planar motors (SPMPMs). It can generate all 6-DOF motions with only a single moving part. With the DQ decomposition theory, this positioning stage is modeled as a multi-input multi-output (MIMO) electromechanical system with six inputs (currents) and six outputs (displacements). To achieve high-precision positioning capability, discrete-time integrator-augmented linear-quadratic-regulator (LQR) and reduced-order linearquadratic-Gaussian (LQG) control methodologies are applied. Digital multivariable controllers are designed and implemented on the positioning system, and experimental results are also presented in this paper to demonstrate the stage's dynamic performance.

• Journal of Electrical Engineering and Technology
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• 제7권2호
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• pp.240-245
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• 2012

A 160 MW drum-type boiler-turbine system is developed in the present research through a multi-multivariable dynamic matrix control (DMC) scheme and a multi-multivariable model approach. A novel intelligence-based decision mechanism (IBDM) is realized to support both model approach and control scheme. In such case, the responsibility of the proposed IBDM is to identify the best multivariable model of the system and the corresponding multivariable DMC scheme to cope with the system at each instant of time in an appropriate manner.

• 한국정보기술응용학회:학술대회논문집
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• 한국정보기술응용학회 2005년도 6th 2005 International Conference on Computers, Communications and System
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• pp.335-338
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• 2005

In this paper, we propose a downlink power control scheme to apply in the unequal error protection multi-code CDMA mobile medicine system. The mobile medicine system contains (i) blood pressure and body temperature measurement value, (ii) ECG medical signals measured by the electrocardiogram device, (iii) mobile patient's history, (iv) G.729 audio signal, MPEG-4 CCD sensor video signal, and JPEG2000 medical image. By the help of the multi-code CDMA spread spectrum communication system with downlink power control scheme and unequal error protection strategy, it is possible to transmit mobile medicine media and meet the quality of service. Numerical analysis and simulation results show that the system is a well transmission platform in mobile medicine.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.1091-1097
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• 1991

A logical and systematic procedure to derive a mathematical model for magnetically levitation(maglev) systems with a combined lift and guidance is developed by using and graph. First, bond graph is constructed for the energy-feeding system with magnetic leakage flux. And, the overall maglev system in which lift and guidance dynamics are coupled is modeled by using the concept of multi-port field in bond notations. Finally, the LQG/LTR control systems are designed for single-input single-output and for multi-input multi-output maglev systems. In this paper, it has been shown that the bond graph is an excellent method for modeling multi-energy domain systems such as maglev systems and the multivariable control system is required to improve the performance of the maglev system with a combined lift and guidance.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2003년도 유체기계 연구개발 발표회 논문집
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• pp.535-540
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• 2003

In this Paper, a LON based distributed control system for HVAC is described. We developed multi-protocol converter based on SoC, Neuron Chip, embedded Linux. It utilizes the network environment and therefore requires an appropriate operating system for handling protocols and an advanced development environment. The open source licensing, reliability, and broad hardware support are key reasons for use of embedded Linux in embedded industry. The multi-prootocol converter integrates LonWorks devices to a client with Java applet. The system consists of three-tier architecture, such as clients, multi-protocol converter, and LonWorks devices. The experiment result show that multi-protocol converter using embedded Linux is a flexible and effective way to build a Web-based monitoring and control system.

• 한국산학기술학회논문지
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• 제19권5호
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• pp.139-145
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• 2018

아웃리거 시스템은 지진이나 풍하중에 의한 동적 응답을 줄이기 위하여 고층 건물의 횡방향 강성을 증가시키는데 널리 사용되고 있다. 풍하중과 지진하중의 동적 특성은 매우 다르기 때문에 스마트 진동 제어 시스템이 아웃리거 시스템과 함께 사용된다면 두 가지 동적 하중에 대해서 효과적으로 사용될 수 있을 것이다. 본 논문에서는 아웃리거 댐퍼 시스템 기반 멀티 해저드 적응형 스마트 구조 제어 시스템에 대한 연구를 수행하였다. 스마트 아웃리거 댐퍼 시스템을 개발하기 위하여 MR 댐퍼를 사용하였다. 수치 해석을 위해 미국에 있는 LA, 찰스턴, 앵커리지의 세 도시에 대한 멀티 해저드 지진하중과 풍하중을 생성하였다. 스마트 아웃리거 댐퍼 시스템의 최적 설계를 위하여 MR 댐퍼 용량에 대한 파라메터 연구를 수행하였다. 유전자 알고리즘으로 최적화된 퍼지 논리 제어기를 이용하여 스마트 제어 알고리즘을 개발하였다. 해석결과를 통하여 아웃리거 댐퍼 시스템 기반 적응형 스마트 구조제어 시스템이 풍하중과 지진하중의 멀티 해저드에 대해서 우수한 제어성능을 나타내는 것을 확인할 수 있었다.

• Journal of Electrical Engineering and Technology
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• 제4권3호
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• pp.315-322
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• 2009

Penetration and installation of a new dynamic technology known as Flexible AC Transmission Systems (FACTS) in a practical and dynamic network requires and force expert engineer to develop robust and flexible strategy for planning and control. Unified Power Flow Controller (UPFC) is one of the recent and effective FACTS devices designed for multi control operation to enhance the power system security. This paper presents a dynamic strategy based on Particle Swarm Optimization (PSO) for optimal parameters setting of UPFC to enhance the system loadability. Firstly, we perform a multi power flow analysis with load incrementation to construct a global database to determine the initial efficient bounds associated to active power and reactive power target vector. Secondly a PSO technique applied to search the new parameters setting of the UPFC within the initial new active power and reactive power target bounds. The proposed approach is implemented with Matlab program and verified with IEEE 30-Bus test network. The results show that the proposed approach can converge to the near optimum solution with accuracy, and confirm that flexible multi-control of this device coordinated with efficient location enhance the system security of power system by eliminating the overloaded lines and the bus voltage violation.

• 대한기계학회논문집B
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• 제25권4호
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• pp.467-474
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• 2001

The mathematical model of a air-conditioning system is generally very complex and difficult to apply to controller design. In this paper, simple models applicable to the controller design are obtained by modeling the air-conditioning system by single-input single-output between compressor speed and indoor temperature, and by multi-input single-output between compressor speed, indoor fan speed and indoor temperature. Using these empirical models, model predictive control(MPC) technique was implemented for indoor temperature control of the air-conditioning system. It has been shown from various experiments that the indoor temperature control based on the MPC scheme yields reasonably good tracking performance with smooth changes in plant inputs. this multi-input multi-output MPC approach can be extended to multi air- conditioning systems where the conventional PID control scheme is very difficult to apply.