• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.6
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• pp.1374-1381
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• 1994

This study suggests a new type shaft generating system driven by hydrostatic transmission suitable for small size vessels. In this system, the hydraulic motor speed is controlled by displacement adjustment using a 3-way high speed on/off valve. The 3-way high speed valve is operated by PWM control signal. In this study, a digital robust servo control algorithm is applied to the controller design of the system. By experiments and numerical computations, the frequency variation characteristics of the generating system under various disturbances are investigated. Conclusively, it is said that the shaft generating system proposed in this study shows excellent control performances.

• Journal of Industrial Technology
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• v.16
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• pp.113-121
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• 1996

In the early developmental stages of robotics,hydraulics played an important role. As the power-to-weight ratio of electric motors increased, they eventually replaced hydraulic actuators in robot manipulators. Recently, however, task requirements have dictated that the manipulator payload capacity increase to accomodate greater payload, greater length, greater reaction forces, and hydraulic actusators are being studied as an effective form of robot actuation again. For efficient control of hydraulic actuators, the knowledge of its dynamic equation is essential. However, the dynamic equation of hydraulic actuators are nonlinear, and the dynamic coefficients are time varying. In this paper, an estimation algorithm of the dynamic coefficients of the hydraulic piston dynamics are formulated. Simulation results are presented to show the possibility of the parameter estimation.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.2
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• pp.201-211
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• 2002

In this research, we are trying to research about hydraulic system design and vehicle dynamic modeling far the development of the tire roller. The reason why we would like develop it is that tire roller is one of the most useful machine for the road construction site and application other construction equipments. Here, we conceptualize the new hydraulic system and derive the equations of motion fur dynamic analysis and also investigate system modeling by using a DAQ board. We design the hydraulic circuit of steering and traction mechanism system. This design can be used to create virtual prototypes of construction equipment. So, we studied tire roller to integrate development technology. In system analysis, we formulate hydraulic traction system model and hydraulic steering system model. Also, we integrate DAQ system to acquire experimental results in real tire roller equipment.

• Journal of Drive and Control
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• v.20 no.2
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• pp.1-6
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• 2023

This study aims to develop a Korean dental chair hydraulic circuit by improving the existing equipment in order to localize foreign leading companies' products. The suggested Hydraulic circuit can be applicable to varied sectors where height and backrest angle control of chair-type equipment are required. The study followed the steps below. First, three kinds of foreign hydraulic circuits were analyzed and three kinds of Korean dental chair hydraulic circuits were suggested. Second, it was determined whether the three kinds of Korean hydraulic circuits operate normally through SimulationX, a software specialized in multi domain analysis, and the effectiveness of each circuit was examined.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.184-184
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• 2004

볼 나사는 반도체ㆍLCDㆍPDP 등 전자제품 조립장비 제조업체와 CNC 공작기계, 정밀측정기계, 직교좌표로봇, 반송장치, 항공기용 유압구동장치 대체품, 전동공구, 파워 steering, 테이블 개폐장치 등에서 구동 장치 및 물품의 이송을 위해 대부분 사용되는 중요한 기계요소 중의 하나이다. 그것은 회전운동을 직선운동으로 전환해주는 기구부에 들어가는 가장 중요한 부품이며, 원통형의 봉에 나선형의 그루브를 가공한 장축의 나사와 단축의 너트 사이에 볼을 게재시켜 축의 회전 시 적은 구름마찰로 인해, 너트부가 직선 운동하는데 원활 하게 만들어진 기계요소이다.(중략)

• Convergence Security Journal
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• v.7 no.2
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• pp.145-154
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• 2007

In this paper, a study on the actuator device technology in guided weapon system development. Hydraulic and pressure, electric motor device had been mostly used, but recently due to high output to weight ratio, pressure actuator device is widely used except for small tactical guided ammunition which needed small power. And now the actuator design concept and technical level is changed because of high mobility of guided ammunition, development of magnetic materials which used new material for requirement of despondence, progress of control and electrodynamics technology, and digitalize and integrity. In this paper we clearly proposed the actuator design criteria and detailed technology development trend for next generation guided weapon system.

• Transactions of the Korean Society of Mechanical Engineers
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• v.13 no.2
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• pp.213-220
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• 1989

This paper describes the application of the variable structure control(VSC) concept for the position control of an electro-hydraulic servomotor system. The basic philosopy of VSC is that the structure of the feedback control is altered as the state crosses discontinuity surfaces in the state space with the result that certain desirable properties are achieved. The switching of the control function yields total(or selective) invariance to system parameter variations and disturbances, and closed loop eigen value placement in time-varing and uncertain systems. The control scheme is derived, implemented and tested in the laboratory where analog controller have been used to control the representive servosystem. The control system schematics are given and simple results are shown for illustration. And the results of variable structure system for the electro-hydraulic servomotor were compared to that of the fixed structure system when load disturbance and system parameter variation exists.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.10
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• pp.162-169
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• 2000

A Direct Drive Valve(DDV) hydraulic actuation system which is commonly used as an aircraft's control surface driving actuator has multi-loop control structure to ensure its safety operation. However, because of not perfect matching of one self channel characteristics with the others, the servo valve driving current of each channel can be widely different. Therefore, the long-time use of DDV actuator without any correction of these channel current offsets will cause the problem of performance or life expectancy degradation due to unwanted heats in the linear motor. A current equalization loop structure which can minimizes current offsets between channels is introduced and designed. The performance of the current equalization loop is investigated and verified through the analytic and experimental ways.

• Journal of Drive and Control
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• v.13 no.4
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• pp.102-107
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• 2016

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.10a
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• pp.291-292
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• 2012