http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
구오흥(Hung, Nguyen Quoc),최민규(Choi, Min-Kyu),윤보영(Yoon, Bo-Young),최승복(Choi, Seung-Bok) 한국소음진동공학회 2006 한국소음진동공학회 논문집 Vol.16 No.7
This paper presents a novel type of hybrid dispensing head for IC fabrication and surface mount technology. The proposed mechanism consists of solenoid valve and piezoelectric stack as actuators, and provides positive-displacement and jet dispensing. The positive-displacement dispensing can produce desired adhesive amount without viscosity effect, while the jet dispensing can produce high precision adhesive amount. In order to determine the relationship between required voltage of the piezoelectric actuator and needle displacement, both static and dynamic analysis are undertaken, In addition, finite element analysis is performed in order to find optimal design parameters. Dispensing flow rate and pressure in the chamber are evaluated through fluid dynamic model.
하우징 위에 전자석코일을 갖고 있는 MR 브레이크의 최적설계
구오흥(Quoc Hung Nguyen),한철희(Chulhee Han),이태훈(Tae-Hoon Lee),안진희(Jin-Hee An),최승복(Seung-Bok Choi) 한국소음진동공학회 2019 한국소음진동공학회 논문집 Vol.29 No.1
This work presents a new design structure for a magneto-rheological brake (MRB) with magnetic coils located on either side of the housing. With this structural configuration, the designed MRB is expected to provide higher braking torque at a more compact brake unit size than can be offered by conventional MRBs in which the magnetic wire coils are wound onto the non-magnetic bobbin. The working principle underlying MRBs is briefly outlined, and thereafter, the Bingham-plastic rheological model of MR fluid braking torque is used to calculate the braking torque of the MRBs under consideration. To determine the principal design parameters, an optimization is undertaken by considering the minimum mass of the new brake necessary to meet the torque requirement. To demonstrate some of the intended merits of the proposed design configuration, a comparison between the proposed MRB and the existing conventional MRBs is drawn. It is shown that the proposed MRB can provide both a much higher torque level and a wider torque control range than can be achieved by conventional MRBs.
구오흥(Nguyen, Quoc-Hung),오종석(Oh, Jong-Seok),최승복(Choi, Seung-Bok) 한국소음진동공학회 2012 한국소음진동공학회 논문집 Vol.22 No.5
In this work, the configuration of a haptic gripper featuring magnetorheological(MR) brakes is proposed and an optimal design of the MR brakes for the haptic griper is performed considering the required braking torque, the uncontrollable torque(zero-field friction torque) and mass of the brakes. Several configurations of MR brake is proposed such as disc-type, serpentine-type and hybrid-type. After the configurations of the MR brakes are proposed, braking torque of the brakes is analyzed based on Bingham rheological model of the MR fluid. The zero-field friction torque of the MR brakes is also analyzed. An optimization procedure based on finite element analysis integrated with an optimization toolbox is developed for the MR brakes. The purpose of the optimal design is to find optimal geometric dimensions of the MR brake structure that can produce the required braking torque and minimize the mass of the MR brakes. In addition, the uncontrollable torque of the MR brakes is constrained to be much smaller than the required braking torque. Based on the developed optimization procedure, optimal solution of the proposed MR brakes are achieved and the best MR brake is determined. The working performance of the optimized MR brake is then investigated.
압전작동기를 이용한 고속 토출 젯팅 디스펜서의 성능 특성
윤보영(Yun, Bo-Young),구오흥(Nguyen, Quoc-Hung),손정우(Sohn, Jung-Woo),최승복(Choi, Seung-Bok) 한국소음진동공학회 2008 한국소음진동공학회 논문집 Vol.18 No.4
This paper presents a new jetting dispenser driven by a piezoelectric actuator at high operating frequency to provide very small dispensing dot size of adhesive in modern semiconductor packaging processes. After describing the mechanism and operational principle of the dispenser, a mathematical model of the structured system is derived by considering behavior of each component such as piezostack and dispensing needle. In the fluid modeling, a lumped parameter method is applied to model the adhesive whose rheological property is expressed by Bingham model. The governing equations are then derived by integrating the structural model with the fluid model. Based on the proposed model, dispensing performances such as dispensing amount are investigated with respect to various input trajectories.
최민규(Choi, Min-Kyu),구오흥(Nguyen, Quoc-Hung),윤보영(Yun, Bo-Young),최승복(Choi, Seung-Bok) 한국소음진동공학회 2006 한국소음진동공학회 논문집 Vol.16 No.11
This paper presents a new type of jetting dispenser for the integrated circuit (IC) fabrication and surface mount technology The proposed system is featured by the piezoelectric actuator and hydraulic magnification device. After describing structural component of the dispensing mechanism and its operation principle, both the fluid modeling and the hydraulic magnification modeling are undertaken with a lumped-parameter method based on the analogy of the fluid system and mechanical system. A mathematical governing equation is then derived by integrating the fluid model with the mechanical model of the driving piston and piezoelectric actuator. Subsequently, in order to achieve a desired dispensing amount, control algorithm adjusting duty cycle of the driving voltage is synthesized and control responses are presented in time domain.
압전 작동기를 이용한 방향 제어 밸브의 동적 모델링 및 제어
전준철(Juncheol Jeon),한영민(Young-Min Han),구오흥(Quoc Hung Nguyen),한승훈(Seung-Hun Han),최승복(Seung-Bok Choi) 한국소음진동공학회 2012 한국소음진동공학회 학술대회논문집 Vol.2012 No.10
This paper proposes a new type of high-frequency directional valve controlled by the piezostack actuator associated with displacement amplifier. As a first step, a dynamic model of directional valve which can operate at 200 Hz with a flow rate of 12 l/min is derived by considering pressure drop and flow force. As a second step, an appropriate piezostack is selected by considering actuation force as well as field-dependent displacement. Subsequently, in order to control spool displacement and flow rate a proportional-derivative (PD) controller is designed based on the 3<SUP>rd</SUP>-order valve system. Control performances such as sinusoidal trajectory tracking of the spool displacement in time domain are evaluated. In addition, the field-dependent flow rate is also presented to verify the required performance of the valve system.
압전 작동기를 이용한 방향 제어 밸브의 동적 모델링 및 제어
전준철(Jeon, Jun-Cheol),한영민(Han, Young-Min),구오흥(Nguyen, Quoc Hung),최승복(Choi, Seung-Bok) 한국소음진동공학회 2012 한국소음진동공학회 논문집 Vol.22 No.10
This paper proposes a new type of high-frequency directional valve controlled by the piezostack actuator associated with displacement amplifier. As a first step, a dynamic model of directional valve which can operate at 200 Hz with a flow rate of 12 litter/min is derived by considering pressure drop and flow force. As a second step, an appropriate piezostack is selected by considering actuation force as well as field-dependent displacement. Subsequently, in order to control spool displacement and flow rate a proportional-derivative(PD) controller is designed based on the 3rd-order valve system. Control performances such as sinusoidal trajectory tracking of the spool displacement in time domain are evaluated. In addition, the field-dependent flow rate is also presented to verify the required performance of the valve system.