• Journal of Electrical Engineering and Technology
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• 제11권4호
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• pp.829-838
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• 2016

This paper focuses on the engineering trade-offs in designing capacitor voltage balancing schemes for modular multilevel converters (MMC) HVDC: regulation performance and switching loss. MMC is driven by the on/off switch operation of numerous submodules and the key design concern is balancing submodule capacitor voltages minimizing switching transition among submodules because it represents the voltage regulation performance and system loss. This paper first introduces the state-of-the-art MMC-HVDC submodule capacitor voltage balancing methods reported in the literatures and discusses the trade-offs in designing these methods for HVDC application. This paper further proposes a submodule capacitor balancing scheme exploiting a control signal to flexibly interchange between the on-state and the off-state submodules. The proposed scheme enables desired performance-based voltage regulation and avoids unnecessary switching transitions among submodules, consequently reducing the switching loss. The flexibility and controllability particularly fit in high-level MMC HVDC applications where the aforementioned design trade-offs become more crucial. Simulation studies for MMC HVDC are performed to demonstrate the validity and effectiveness of the proposed capacitor voltage balancing algorithm.

• 제어로봇시스템학회논문지
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• 제22권5호
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• pp.353-360
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• 2016

In this paper, a DOB (disturbance observer) is designed for the steering stabilization of one-wheeled balancing robot. Based on the simple stick model of the single-wheeled robot, DOBs and the corresponding Q filters are designed. Although the proposed models are simple, DOBs are desired to deal with model uncertainties for the enhanced balancing performance. Experimental studies of two different cases of Q filter design are conducted to evaluate the performances of DOBs. Their performances are compared through balancing control experiments.

• 제어로봇시스템학회논문지
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• 제17권10호
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• pp.1037-1043
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• 2011

Two-wheeled balancing mobile robots are currently controlled in terms of linear control methods without considering the nonlinear dynamical characteristics. However, in the high maneuvering situations such as fast turn and abrupt start and stop, such neglected terms become dominant and greatly influence the overall driving performance. This paper addresses the SDRE nonlinear optimal control method to take advantage of the exact nonlinear dynamics of the balancing robot. Simulation results indicate that the SDRE control outperforms LQR in the respect of transient performance and required wheel torques. A design example is suggested for the state matrix that provides design flexibility in the SDRE control. It is shown that a well-planned state matrix by reflecting the physics of a balancing robot greatly contributes to the driving performance and stability.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2009년도 춘계학술대회 논문집
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• pp.133-134
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• 2009

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2001년도 춘계학술대회 논문집(한국공작기계학회)
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• pp.309-314
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• 2001

The balance of high speed spindle system with high precision rotation like grinding machine is very important. Traditionally, we use trial and error method to balance the spindle. It takes much time. So we are developing the automatic balancing equipment being used in the grinding machine. The balancing head we develop is wireless. It will be used high-speed grinding machine. We use influence coefficient method to control the automatic balancer. Experiments are based on automatic and manual balancing. We perform test of the vibration filter. It helps to remove noise. The filter and experiments with automatic balancing controller show that automatic balancing control can be successfully achieved with the quick response and good stability characteristics.

• 대한기계학회논문집
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• 제12권5호
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• pp.1026-1034
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• 1988

본 연구에서는 실제적인 평형스프링을 비교적 단순한 계산에 의해 설계할 수 있는 방법의 하나로서, 선형스프링의 근사법을 제시하였으며, 이 근사법을 4절 기구의 입력토오크 특성의 향상문제에 적용하여 유용한 결과가 얻어짐을 보였다.

• 한국소음진동공학회논문집
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• 제15권11호
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• pp.1268-1275
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• 2005

Vibration in Engine module could be reduced by introducing a balance shaft module which has one or more unbalanced rotors. Since the unbalanced rotor is installed in an opposite direction of the free force or unbalance moment by engine component, the unexpected vibration could be decreased kinematically. The essential equation of the unbalanced rotor was Presented for two cases, 3 in-line and 4 in-line cylinder engine type, And the efficiency of the balance shaft is investigated by the vehicle testing that is focused on measuring the reduced vibration level when adapting a balancing module. With the signal processing of measured signals, some important issues on design the balancing shaft could be derived and the overall design process is explained in the final part including the peripheral component, i.e. housing and bush.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1992년도 춘계공동학술대회 발표논문 및 초록집; 울산대학교, 울산; 01월 02일 May 1992
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• pp.159-168
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• 1992

생산라인의 line balancing이 흐름생산에 있어서 일관된 생산을 하기 위한 필수조건이다. 여러 다양한 제품을 생산하는 printed circuit board(PCB) 공장에서의 line balancing을 얻기 위해서는 mixed model line balancing절차를 설명하고자 한다.

• 제어로봇시스템학회논문지
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• 제19권3호
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• pp.233-239
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• 2013

This paper presents the analysis and control of the position of the COG (Center of Gravity) for a two-wheel balancing robot. The two-wheel balancing robot is required to maintain balance by driving two wheels only. Since the robot is not exactly symmetrical and its dynamics is changing with respect to moving parts, robust balancing control is difficult. Balancing performance becomes difficult when two arms hold a heavy object since the center of gravity is shifted out of the wheel axis. Novel design of a sliding waist mechanism allows the robot to react against the shift of the COG by moving the whole upper body to compensate for the imbalance of the mass as a counter balancer. To relocate the COG position accurately, the COG is analyzed by force data measured from two force sensors. Then the sliding COG mechanism is utilized to control the sliding waist position. Experimental studies are conducted to confirm the proposed design and method.

• 한국정보통신학회논문지
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• 제6권8호
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• pp.1259-1268
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• 2002

분산 시스템에서 전체 시스템의 부하 균형을 이루어 시스템의 성능을 향상시키는 것이 주요 목표 중 하나이다. 시스템간의 부하를 균등하게 함으로써 처리기의 가동률을 높이고 작업 반환 시간도 줄일 수 있다. 본 논문은 지식 기반 메카니즘을 이용하여 각 노드에서 과거 및 현재의 정보를 기반으로 추론한 미래 부하상태 정보를 서로 공유하여 최적의 부하 균등화를 이루는 의사 결정 규칙과 정보 교환 규칙을 설계하였다. 성능 평가 결과 각 노드의 가동률이 균등해지고 처리 속도의 향상을 보였으며, 시스템의 신뢰성과 가용성이 향상되었다. 본 논문에서 제안한 기법은 분산 운영 체제의 부하 조절 알고리즘 설계에 활용될 수 있다.