http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
미터링 오리피스 압력 진폭을 이용한 방향제어밸브 대역폭 주파수에 관한 연구
김성동(Sungdong Kim),전세형(Sehyeong Jeon),신대영(Daeyoung Shin) 유공압건설기계학회 2017 드라이브·컨트롤 Vol.14 No.2
The spool displacement of a directional control valve can be considered as the standard signal for the measurement of its bandwidth frequency. When the spool displacement is not available, the metering-orifice system is suggested in this study as an alternative way to measure the - 3 dB amplitude-ratio bandwidth frequency of the hydraulic directional-control valve. The amplitude ratio of the metering-orifice pressure can be adjusted to equal that of the spool displacement through the controlling of the metering-orifice opening area. A series of experiments were conducted to verify the effectiveness of the metering-orifice system. The metering orifice was confirmed as adequate for the measurement of the - 3 dB amplitude-ratio bandwidth frequency.
배관 압력을 이용한 방향제어밸브 위상각 대역폭 주파수 측정에 관한 연구
김성동(Sungdong Kim),이정은(Jung-eun Lee),신대영(Daeyoung Shin) 유공압건설기계학회 2018 드라이브·컨트롤 Vol.15 No.4
Spool displacement of a direction control valve is the standard signal to measure the bandwidth frequency of the direction control valve. When the spool displacement signal is not available, it is suggested in this study to use the metering hydraulic line as an alternative way to measure – 90 degree phase bandwidth frequency of the hydraulic direction control valve. Dynamics of the hydraulic line is composed of inertia, capacitance, and friction effects. The effect of oil inertia is dominant in common hydraulic line dynamics and the line dynamics is close to a derivative action in a range of high frequency; such as a range of bandwidth frequency of common directional control valves. Phase difference between spool displacement and line load pressure is nearly constant as a valve close to 90 degree. If phase difference is compensated from the phase between valve input and pressure, compensated phase may be almost same as the phase of spool displacement that is a standard signal to measure phase bandwidth frequency of the directional control valve. A series of experiments were conducted to examine the possibility of using line pressure in to measure phase bandwidth frequency of a directional control valve. Phase bandwidth frequency could be measured with relatively high precision based on metering hydraulic line technique and it reveals consistent results even when valve input, oil temperature, and supply pressure change.
김성동(Sungdong Kim),전세형(Sehyeong Jeon),신대영(Daeyoung Shin) 유공압건설기계학회 2017 유공압건설기계학회 학술대회논문집 Vol.2017 No.5
The spool displacement of a servo valve can be considered to be the standard signal to measure the bandwidth frequency of servo valves. When the spool displacement is not available, the metering orifice system is suggested as an alternative way to measure the – 3 dB amplitude ratio bandwidth frequency of the hydraulic servo valve in this study. The amplitude ratio of the metering orifice pressure can be adjusted to be the same as that of the spool displacement by controling the opening area of the metering orifice. A series of experiments were conducted to verify the effectiveness of the metering orifice system. The metering orifice was found to be good enough to measure the – 3 dB amplitude ratio bandwidth frequency.
딥러닝 기반 장애물 인식을 위한 가상환경 및 데이터베이스 구축
이재인(JaeIn Lee),곽기성(Gisung Gwak),김경수(KyongSu Kim),강원율(WonYul Kang),신대영(DaeYoung Shin),황성호(Sung-Ho Hwang) 유공압건설기계학회 2021 드라이브·컨트롤 Vol.18 No.4
This study proposes a method for creating learning datasets to recognize obstacles using deep learning algorithms in automated construction machinery or an autonomous vehicle. Recently, many researchers and engineers have developed various recognition algorithms based on deep learning following an increase in computing power. In particular, the image classification technology and image segmentation technology represent deep learning recognition algorithms. They are used to identify obstacles that interfere with the driving situation of an autonomous vehicle. Therefore, various organizations and companies have started distributing open datasets, but there is a remote possibility that they will perfectly match the user"s desired environment. In this study, we created an interface of the virtual simulator such that users can easily create their desired training dataset. In addition, the customized dataset was further advanced by using the RDBMS system, and the recognition rate was improved.