• 제어로봇시스템학회논문지
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• 제4권4호
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• pp.441-447
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• 1998

Motivated by a recent work, a fuzzy-power-controller(FPC) is designed for the relieving-horsepower control of output variable pump with electrical proportional valve and actually implemented on the industrial excavator. In order to calculate the output power of pump with input of FPC, a linear discrete time model of load system to pump is obtained and the result is applied to control the engine-pump coupled system by software without pressure and flow sensor. The FPC controls the engine and pump coupled system by relieving horsepower control according to the change of load and the running conditions in relieving horsepower control are selected by fuzzy inference engine. A case study is peformed through the construction of the control device and installation on the excavator. It shows that the relieving-horsepower control system with the FPC, as suggested in this paper, is superior to the conventional PID controllers. And also, the excavator, with the FPC, shows that the power-loss of the coupled system is reduced and the running speed of the hydraulic actuator is enhanced.

• 대한기계학회논문집A
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• 제24권10호
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• pp.2535-2542
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• 2000

The regulator system has been modeled and combined to a swashplate type axial piston pump. Linear approximation has been performed for nonlinear coefficient terms of an axial piston pump-regulator model without significantly affecting accuracy. Based on the mathematical model of an axial piston pump-regulator system, a couple of characteristic curves of negative flow control and horsepower control are drawn, which show a good correlation with those of experimental results. So the simplified axial piston pump-regulator model in this paper is expected to be utilized not only for the design and analysis of hydraulic circuit of excavator but also for prevention of engine overload.

• 한국정밀공학회지
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• 제15권2호
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• pp.134-145
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• 1998

The purpose of this paper is to construct a computer simulation system which can analyze and design the hydraulic excavator Theoretical analyses are performed on the hydraulic circuit and attachment of excavator with load sensing system. Databases are constructed for control valve opening areas, horsepower control and for load sensing regulator. For hydraulic components modularized programming techniques are applied which is expected to be utilized for software development of fluid power system. Through simulation an information of any point in hydraulic circuit can be obtained.

• KSTLE International Journal
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• 제1권2호
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• pp.101-106
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• 2000

Variable displacement axial piston pumps are widely used for raising the energy level of the fluid in hydraulic systems. And the regulator is the device which regulates the discharge flow of the piston pump by controlling the swivel angle. The regulator receives the hydraulic pilot pressure and controls the pump output flow depending on the machine load and engine speed. This work deals with constant power control (horsepower control) in the design of a regulator by using a bent-axis type piston pump. In order to effectively use engine power, we must keep the horsepower from the engine to the pump constant. Therefore the regulator operates the constant power control. As a result, optimum power usage is obtained by accurately following the power hyperbola. This study focused on developing a simulation model of a regulator. First, the governing equations of the regulator are derived, and analysis is performed by computer simulation, which can identify significant parameters of regulator. As a result, the variation of the swivel angle, flow rate, hyperbolic curve, inner leakage and responsibility are simulated, and significant parameters of a regulator are identified.

• 한국항공우주학회지
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• 제34권7호
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• pp.105-111
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• 2006

항공기 엔진은 항공기가 각종 기동을 수행하도록 추력을 발생하는 것 외에 기동 수행을 위해 작동되는 조종면에 공급될 유압계통의 동력과 각종 항전장비 작동을 위한 전기계통의 동력을 공급한다. 엔진으로부터 제공되는 동력은 엔진의 고압압축기로부터 추출되기 때문에 축마력(Horsepower Extraction, HPX)이라하며, 추출되어 제공되는 엔진 축마력이 유압계통과 전기계통에서 요구하는 요구 축마력보다 작게 되면 엔진에 과도한 부하가 걸려 엔진회전수 감소(Rollback) 및 심한 경우 실속(stall)등이 발생할 수 있다. T/A-50체계개발 동안 요구 축마력과 엔진의 공급 축마력에 대한 비교 해석을 수행하였고, 해석 결과 엔진 축마력이 요구 축마력보다 작은 것을 확인하였다. 엔진 축마력 증가를 위한 엔진 제어 스케쥴 변경이 수행되었으며, 변경된 제어 스케쥴이 장착된 엔진을 이용하여 T/A-50비행시험을 수행하였다. 비행시험 결과를 통해 해석 결과 및 변경된 제어 스케쥴의 타당성을 검증하였다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.994-999
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• 2007

The particulate matters emitted by diesel locomotives cause serious air pollution in stations and railroad. There have been various attempt to reduce the air pollution from diesel bus or trucks. However, the air pollution from the diesel locomotives has been out of control because there has not any adaptable technology. In this study, a diesel particulate filter was developed and applied to the diesel locomotives. A 3,000 horsepower large-scale locomotive and a 1,500 horsepower middle-scale locomotive were used for the test of the filter. The particulate matter emissions before and after the treatment was monitored by a scanning mobility particle sizer and a dust monitor. As a result, it was observed that the particulate matters could be successfully removed from the emission gases by using the filter.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 B
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• pp.923-924
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• 2006

For the interior permanent magnet synchronous motor(IPMSM) drive to operate above the base speed in the constant horsepower region, field weakening control is applied. However, the field weakening control was not almost applied to sensorless control of the interior permanent magnet synchronous motor. In this parer, field weakening control is applied to the sensorless control of IPMSM based on an instantaneos reactive power. The effectiveness of the Proposed system is verified by the experimental results.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.881-882
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• 2008

For the interior permanent magnet synchronous motor(IPMSM) drive to operate above the base speed in the constant horsepower region, the field weakening control is applied. However, the field weakening control was not almost applied to sensorless control of the interior permanent magnet synchronous motor. In this paper, the field weakening control is applied to the sensorless control of IPMSM based on the fuzzy controller. The effectiveness of the proposed system is verified by the experimental results.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 B
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• pp.926-928
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• 2004

For the permanent magnet synchronous motor(PMSM) drive to operate above the base speed in the constant horsepower region, field weakening control is applied. But field weakening control was not almost applied to sensorless control of the permanent magnet synchronous motor. In this paper, field weakening control is applied to the sensorless control of PMSM based on an instantaneos reactive power. And the effectiveness of the proposed system is verified by the experimental results.

• 전기의세계
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• 제19권4호
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• pp.1-11
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• 1970

It is well known that solid-state devices like inverter and converter made by transistor and other semi-conductors are widely used for the purpose of motor speed control in industrial fields. This paper is devoted primarily to a study of Trial Manufacturing of Solid-state Frequency Converter by means of single-phase bridge-type SCR inverter. The principle of the trial product belongs to AC-DC-AC conversion system. The voltage to be impressed to the motor in case of speed control by frequency conversion method is necessary to be proportional to frequency. It also requires the frequency and voltage are independent to hte load variation. In order to meet above requests required to motor speed control., the trial product introduced the open loop system in the frequency setting and closed loop system in the voltage setting. The trial product showed the favorable performance characteristics in speed control of singlephase fractional horsepower motor from 45HZ through 80HZ.