• 한국공작기계학회논문집
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• 제13권3호
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• pp.76-83
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• 2004

The purpose of this paper is to find an effective control system for a hydraulic motor-load system using matlab. The Hydraulic control system consists of a hydraulic pump, a hydraulic proportional control valve, hydraulic pipelines, a hydraulic motor and a load system. The simulation models were verified by comparing the simulation results with measured data from the real hydraulic proportional position control system. In order to compensate the nonlinear friction characteristics in a hydraulic motor-load system, a discrete time PD controller and Friction torque observer has been applied.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1999년도 추계학술대회 논문집 - 한국공작기계학회
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• pp.387-392
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• 1999

The micro electronic control technology with developing microcomputers make great contribution to electrohydraulic control systems. The electrohydraulic pulse control simplifies in conjunction with power electronic amplifier and high speed operated solenoid valves. It is necessary to valves to convert electronic pulse signal to hydraulic pulse flow as fast as possible. This study deals with the speed control of an oil hydraulic motor operated by two way high speed solenoid valves. The valves acts as converters of electronic-pulse signals to hydraulic power. By constructing systems in which a hydraulic motor is operated by two solenoid valves, the pulse with modulation method (PWM) has adopted as the speed control of hydraulic motor systems. The static and dynamic characteristics of the systems are investigated by the experiment. It is clarify that a hydraulic motor operated PWM show good performance as a control component, achieving accurate velocity control.

• 한국자동차공학회논문집
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• 제21권4호
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• pp.188-194
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• 2013

Hydrostatic pumps and motors occupy an important position in hydraulic system. There are a lot of researches on characteristics of hydraulic pumps, but not hydraulic motors. So in order to know the characteristics of hydraulic motors we had this research. The purpose of this study is to derive and analyze the theoretical calculation of hydraulic axial piston motor torque and torque ripples. Then, analyzed the differences between torque ripples with dead place and without dead place on the valve plate, and modeling a hydraulic motor with AMESim software. Finally, theoretical calculation of hydraulic motor torque ripples was verified from the viewpoint of simulation.

• 항공우주기술
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• 제4권1호
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• pp.162-170
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• 2005

KSLV-I의 킥모터의 추력벡터제어용 구동장치 시스템은 전기-유압식 서보 구동장치 형상으로 설계되었으며 가동노즐을 구동하는 구동장치, 유압동력을 생성하는 유압동력 생성장치, 유압동력을 구동장치에 전달해 주는 유압동력분배장치와 관성항법장치에서 입력되는 제어신호에 따라 구동장치를 제어하는 제어장치 등으로 구성되어있다. 그중에서 유압동력을 생성하는 장치는 전기모터를 이용하여 유압펌프를 구동하는 EMDP(Electric Motor Driven Pump) 방식을 채택하고 있다. 일반적으로 전기모터는 구동이 편리한 브러시 방식의 직류모터(BDC 모터)를 사용하는데 일정 고도이상에서는 사용이 용이하지 않다. 그래서 고고도에서 사용하기 위해 브러시없는 직류모터(BLDC 모터)를 이용하여 유압펌프를 구동하는 시스템을 개발하고 있다. 본 논문에서는 브러시없는 직류모터를 구동하기 위한 제어기 설계에 대하여 자세히 설명하고자 한다.

• 한국산업융합학회 논문집
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• 제4권3호
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• pp.305-310
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• 2001

Hydraulic power shifting systems of hydraulic travel motor may be far safer than mechanical power transmission systems. Thus, hydraulic power shifting systems are widely used for speed control on the hydraulic equipments. In the case of liquid shifting lines, the rapid change of area, such as valve closing, can result in a large pressure transient. It is necessary to assure proper control method in order to obtain the smallest shift shock. This study conducts the shock characteristics of hydraulic power shifting system of the hydraulic travel motor. Experimental results show that shock pressure depends on the operating pressure, flow rate and pipe line area. The shock characteristics can be applied for reducing shocks.

• 유공압시스템학회:학술대회논문집
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• 유공압시스템학회 2010년도 춘계학술대회
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• pp.39-43
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• 2010

It is hard and complex to analytically derive a volumetric displacement formula of a gerotor hydraulic motor because geometric shape of its rotors is complicate. An analytical method about the volumetric displacement is proposed in this work, which is relatively easy and based upon two physical concepts. The first one is energy conservation between hydraulic input energy of the motor and mechanical output energy. The second concept is torque equilibrium with respect to inner and outer rotors. The proposed formula about the volumetric displacement is verified by comparing an analytical displacement and a numerical displacement for an example specification of the motor. The numerical displacement is calculated through a kind of CAD technology. The analytical formula can be utilized in analysis and design of hydraulic gerotor motors.

• 전기학회논문지
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• 제60권7호
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• pp.1360-1365
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• 2011

Electro-hydraulic servo motor is used to a lot of in the field of industrial equipment which requires one of the control functions among pressure, flow, and power output. In this paper, linear discrete reference model of the electro-hydraulic servo motor system are made for 1-step ahead predictive control. The parameters of electro-hydraulic servo motor system are estimated using the recursive least square method. 1-step ahead predictive model output of electro-hydraulic servo motor system corresponded to reference model output in spite of estimated parameters are not meet real parameters. Control performance affections are studied due to the forgetting factors variation.

• 드라이브 ㆍ 컨트롤
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• 제12권4호
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• pp.28-34
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• 2015

Because heavy-duty construction vehicles such as excavators are required for good engine-room cooling capacity, a hydraulic gear motor is adopted in the cooling fan drive mechanism to actively control the output speed, instead of adopting the conventional ON/OFF type belt drive. While gear motors are normally limited to 140bars of operating pressure, those for the cooling fan are capable of operating at continuous pressures of up to 220bars. After assembly, all gear motors for high pressure must pass an aging test which is a kind of the wearing process between the gear teeth and motor housing. During the aging process with gradual pressure increments, gear sticking sometimes occurs due to abnormal wear, resulting in defects. This paper focuses on a gear-sticking free aging test controller that is designed together with the knowledge of an experienced operator and the analysis results of experimental data of the gear jamming phenomenon. From the aging experiment, it is demonstrated that the developed controller that can alter the setting pressure of the load pump is effective for stabilizing the abrupt increase in the motor input pressure, thus preventing the hydraulic motor from stopping. This is expected to be helpful for the reduction of defects and increase in productivity.

• Tribology and Lubricants
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• 제15권2호
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• pp.164-170
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• 1999

Gerotor is widely used as a hydraulic pump or motor, by virtue of its volume changing ability. Performance deterioration of a gerotor hydraulic motor mainly due to the wear come from the contact between inner rotor with trochoidal curve and outer rotor with circular arc profile. This research covers the basic investigation about the contact forces of a gerotor hydraulic motor using analytic method. The influence of the eccentricity and the radius of circular arc teeth on the contact stress was evaluated.

• 대한기계학회논문집A
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• 제39권2호
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• pp.195-201
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• 2015

전기굴삭기는 배터리에 저장된 에너지로 전동기-유압펌프를 구동해서 유압 에너지를 생성하고 이를 작업에 활용한다. 기존 유압굴삭기의 유압펌프는 디젤 엔진의 운전 효율에 최적화된 레귤레이터에 의해 제어되고, 유압펌프 자체의 효율은 고려되지 않았다. 전기굴삭기는 배터리를 에너지원으로 사용하기 때문에 전동기의 효율뿐 아니라 유압펌프의 효율을 함께 고려한 제어가 요구된다. 통합 제어를 위해서 유압펌프와 전동기의 출력과 효율 특성을 분석하여 효율맵을 작성하였고, 이를 바탕으로 최적동작맵을 구성하고 통합 제어 알고리즘을 개발했다. 알고리즘의 효과를 확인하기 위해 전기굴삭기 MILS 를 구성해서 통합 제어 알고리즘을 적용했다. 굴삭기 작업 시뮬레이션 결과는 통합 제어 알고리즘이 시스템 효율을 향상 시켰음을 보여준다.