• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2004.10a
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• pp.201-204
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• 2004

감속기가 사용되어지는 경우 부하의 변동이나 구동부의 상태변화에 따라 모터의 토크, 회전수 등이 변하는데 이러한 값들을 모니터링 하면 부하의 변동이나 구동부를 진단할 수 있다. 본 논문은 유성기어를 이용한 기어드 모터를 제작하고, LCD를 포함하는 간단한 사용자 인터페이스를 통해 전달 Torque, 전달회전수(rpm), 전달동력을 확인할 수 있는 소형의 표시기가 있는 감속기에 관한 것이다. 일반적으로 전달 토크를 측정하는 장비는 크기가 크고 고가이며 계측기를 연결하고 측정하는 과정이 매우 번거로울 뿐만 아니라 지속적인 유지보수가 필요한 단점이 있다. 본 논문에서 제안하는 유성기어를 사용하면 간단히 모터의 토크 및 회전수를 측정할 수 있고 측정값을 표시하는 표시기를 모터에 부착할 수 있다. 측정 및 표시기는 기존 가격에 비해 매우 값싸게 제작할 수 있고 유지보수가 필요 없으며 검출 값을 시스템 제어부에 피드백 시키면 자기진단이 가능해진다. 특히 블루투스를 이용한 무선 통신기능을 부과하면 원격 모니터링이 가능하고 복수 모터유닛의 네트워크 구성이 용이하며 인터넷을 통한 데이터 통신으로의 확장이 가능하다.

• Proceedings of the KIPE Conference
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• 2017.07a
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• pp.62-63
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• 2017

본 논문에서는 휠체어의 탑승자의 구동력과 BLDCM(Brushless DC Motor) 에서 출력되는 보조력인 전기적인 구동력을 동시에 사용하는 탈부착형 하이브리드 휠체어의 동작제어방식을 제안한다. 기존에는 휠체어에 토크센서를 부착하여, 토크센서 신호의 피이드백을 통하여 보조력을 발생하는 방식이 적용되고 있지만, 제안된 방식에서는 토크센서의 사용없이 사용자의 동작을 간접적으로 검출하는 방식을 제안한다. 사용자가 휠체어의 핸드림을 조작할 때, 발생하는 휠체어의 동작을 3축 가속도 센서를 통해 모션을 예측하고, 이에 대응하는 구동력을 보조하는 PAS(Power Assist System)을 설계하였다. 사용자의 동작 예측을 위해, 3축 가속도 센서의 신호를 조합하여 전진과 후진 및 정지 상태 신호를 예측하는 방식을 시뮬레이션과 실험을 통해 증명하였다.

• Proceedings of the KIEE Conference
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• 2005.10c
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• pp.44-46
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• 2005

대용량 유도전동기가 정지상태에서 기동할때 매우 큰 돌입전류에 의해 Voltage Sag를 유발하게 되며 유도전동기에 걸리는 기계적 토크보다 큰 전기적 토크가 가해지지 않으면 유도전동기는 기동에 실패하게 된다. 따라서 대용량 유도전동기의 기동을 위해서는 Voltage Sag를 줄이고 전동기의 가속에 필요한 기동토크를 인가할 수 있는 기동법이 필요하다. 본 논문에서는 유도전동기의 기동특성을 모의할 수 있는 모델링 기법을 제안하고 시뮬레이션에 의한 기동특성을 모의하여 적절한 기동법을 적용한다. 본 논문에서 사용한 대상 유도전동기는 한국수자원공사 취수장에서 운영하는 2500KVA 대용량 유도전동기를 사용하였으며 PSCAD/EMTDC 소프트웨어를 사용하여 시뮬레이션을 수행하였다.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.7
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• pp.722-728
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• 2015

The demand for shipboard energy management is expected to gradually increase based on ship energy efficiency management plans (SEEMPs), which have been in use since January 1, 2013. Therefore, the fuel consumption of the main engine, which occupies the greatest portion of the energy used, along with elements related to the engine power, should be strictly monitored. There are many different methods for indicating the engine power. However, this study performed an experiment to monitor the status of a ship's engine power in real time using an encoder and a proximate switch, which are economical to purchase and easy to install. In the experiment, the angular velocity during one cycle of a two-stroke low-speed engine was measured, and the measured data were converted to the torque fluctuation. The angular velocity during an abnormal firing condition in the cylinder was also measured, and the torque fluctuation as a result of a misfire was considered. The results were compared with sea trial data to determine the reliability. In this study, the status of the engine power was determined using the torque fluctuation of the main engine in an operating ship.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.3
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• pp.514-521
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• 2009

The current control for Interior-mounted Permanent Magnet Motor(IPM Motor) is more complicate than Surface-mounted Permanent magnet Motor(SPM Motor) because of its torque characteristic depending on the reluctance. For high performance torque control, it requirs state decoupling between d-axis current and q-axis current dynamics. However the variation of the inductances, which couples the state dynamics of the currents, makes the state decoupling difficult. So some decoupling methods have developed to cope this variation and each current can be regulated independently. This paper proposes a novel approach for fully decoupling the states cross-coupling using sliding mode control with virtual state for IPM Motor. As a result, in spite of the parameter uncertainty and disturbance, the proposed sliding surface can have the dynamics of nominal system controlled by PI controller.

• Proceedings of the KIPE Conference
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• 2011.11a
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• pp.159-160
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• 2011

일반적인 엘리베이터 시스템에서는 로드셀이라고 하는 센서가 설치되어 탑승자를 포함한 모터에 걸리는 전체부하를 측정한다. 그리고 이 무게 정보는 브레이크가 풀리고 엘리베이터가 움직이기 시작하기 전에 토크 전향보상을 하는데 사용되고, 엘리베이터는 브레이크 개방 과정에서 정지상태를 유지하여 엘리베이터가 부드럽게 출발하도록 한다. 안티롤백은 로드셀없이 브레이크가 열리는 동안에 위치 편차를 억제하는 기능이다. 다른 회사에서는 이 기능을 기존의 PI 제어기를 사용하여 개발하였다. 반면에 이 논문에서는 안티롤백 기능을 위하여 상태궤환 위치제어기를 사용하였으며 그 적절성을 논의한다.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.1
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• pp.59-65
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• 2013

In this study, the effects of the compressor for the air conditioning system on the fuel economy were experimentally investigated in an actual automobile. This study aims to analyze the level of contribution of the driving torque of the compressor to the fuel economy. A torque sensor, which is directly set on the clutch of the compressor, is developed to obtain data about the compressor load, which influences the fuel efficiency, and then, the reliability of the torque sensor is verified by comparing the results with those of a torque meter in a bench test. An actual automobile equipped with the compressor and torque sensor is operated in a climate wind tunnel in which appropriate facilities are set up to evaluate the fuel efficiency. The compressor driving torque resulting from the difference in the compressor displacement is found to influence the fuel economy, and the fuel economy is found to be worsened by up to 2~3% with an around 11% increase in the compressor displacement under the same conditions.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.2
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• pp.123-128
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• 2022

The torque of the SRM((Switched Reluctance Motor)) is proportional to the inductance slope, so it has a non-linear torque characteristic, and has a disadvantage in that the torque pulsation is large and noise is severe. In particular, the biggest obstacle to the commercialization of SRM is the pulsating torque generated from the rotating shaft, which has various adverse effects not only on the device itself but also on the peripheral devices. Therefore, various methods for reducing the pulsating torque have been published by domestic and foreign researchers, and there is a study result that the hysteresis controller has an advantage in that it can flow a smooth current compared to the chopping control. However, in determining the hysteresis band, if the band is too small, it has a disadvantage in that it may cause a switching loss due to many switching and an unstable initial start when the encoder is used. Therefore, in this paper, a variable hysteresis controller that can reduce torque ripple in a steady state while having a more stable and fast speed response through the change of the hysteresis band according to the speed error.

• Journal of Bio-Environment Control
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• v.6 no.3
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• pp.133-142
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• 1997

Most of the greenhouses employ the roll-up type ventilation control system. Torque required to roll-up and down might be theoretically expressed with the weight times radius of the ventilation roll; however, measured torques were two times of the theoretically estimated values. As the window film of roll-up vent is used over the periods of time, the warping and crumpling of the material caused the increase of the torque in addition to a span deformation. Therefore, this study was performed to develop an empirical torque formulae to present basic torque data and to assist the development of roll-up type ventilation control system. The empirically adjusted rolling radius (r＋a) exponentially increased at the maximum span deformation. The coefficient of rolling resistance (Cr) was about 0.7―0.8 depending upon the wrinkle status of film material.

• Journal of the Korean Society of Marine Environment & Safety
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• v.17 no.1
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• pp.83-88
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• 2011

There are various environmental conditions under which ship may navigate over ocean or in harbor. Ship's torque and speed change frequently under the voyage conditions. In this case, harmonics is created in the electrical power systems. The major adverse impacts of voltage and current harmonics in the electrical power systems on generator, transformer, converter, inverter and propulsion motor lead to the increase of machine heating caused by iron and copper losses which are dependent on frequency. In this paper, an analysis of THD(total harmonic distortion) for currents and voltages in the propulsion equipment was carried out. The THD and torque ripple in the input currents of the propulsion motor have been confirmed by the simulation results.