Conceptual Design of High-Speed Semi-Low-Floor Bogie for Train-Tram

Maosen Wang,Nak-Tak Jeong,Sehoon Yoo,Hoyong Lee,Myung-Won Suh 한국자동차공학회 2015 한국자동차공학회 부문종합 학술대회 Vol.2015 No.5

Train-tram railway vehicles implement the connection between urban tramlines and the surrounding railway network. Train-tram railway vehicles, which use existing infrastructure, can help to avoid large investments in new railways or tramlines and make interchanges between city center and surrounding cities unnecessary. However, present train-tram rail vehicle cannot continuously carry out the integration of operating by means of high speed in intercity railways with operating on small radius of curvature in inner city tramlines. This paper aims to develop a new model for solid wheelsets train-tram railway vehicles, which will not only pass the curve of 25mR radius of curvature traveling on inner city tramlines with the speed of 18km/h, but also can travel on straight railway with 200km/h high speed between intercity. As a result, a new train-tram model, including five car-body and five motor bogies with ten traction motors, is addressed. Expect as a real rail vehicle testing, this study prefer virtual simulation, which is an effective way to show the rail vehicle performance, such as ride stability, ride comfort, and ride safety, by means of evaluating the dynamic characteristics of rail vehicle. Finally, passengers comfort indexes and vehicle derailment coefficients are obtained. The analysis results show that this new train-tram model is reliable and practical enough to be applied on real rail vehicle design

CONCEPTUAL DESIGN OF HIGH-SPEED SEMI-LOW-FLOOR BOGIE FOR TRAIN-TRAM

정낙택,Maosen Wang,유세훈,김원경,한석윤,이호용,서명원 한국자동차공학회 2017 International journal of automotive technology Vol.18 No.3

Train-tram railway vehicles implement the connection between urban tramlines and the surrounding railway network. Train-tram railway vehicles, which use existing infrastructure, can help to avoid large investments in new railways or tramlines and make interchanges between city center and surrounding cities unnecessary. However, present train-tram rail vehicle cannot carry out the integration of operating by means of high speed in intercity railways with operating on small radius of curvature in inner city tramlines. This paper aims to develop a new model for solid wheelsets train-tram railway vehicles, which will not only pass the curve of 25mR radius of curvature traveling on inner city tramlines with the speed of 18 km/h, but also can travel on straight railway with 200 km/h high speed between intercity. In this paper, a new train-tram model, including five car-body and five motor bogies with ten traction motors, is addressed. Expect as a real rail vehicle testing, this study prefer virtual simulation, which is an effective way to show the rail vehicle performance, such as ride stability, ride comfort and ride safety, by means of evaluating the dynamic characteristics of rail vehicle. Moreover, Design of Experiment (DOE) method is used to optimize solid wheelsets bogie system on improving passenger comfort, safety and stability of train-tram. Parameters of components of bogie system are tuned to minimize the derailment coefficient and the ride comfort index. The results shows that the best comfort index for passenger and minimum derailment coefficient are found. The results also show that this optimized new train-tram model is reliable and practical enough to be applied on real rail vehicle design.

System Control Methods for Energy Efficiency Improvement of Parallel Pump Systems: A Review

Chenchen Hua,Maosen Xu,Jiegang Mou,Junlei Wang,Peijian Zhou,Xuelong Yang 한국유체기계학회 2023 International journal of fluid machinery and syste Vol.16 No.4

With the consistent pursuit of global countries for the goal of carbon neutrality, the urgency of energy saving and emission reduction is self-evident. Considering the critical proportion of pump consumption in the total energy consumption, improving its energy efficiency is significant to energy saving and emission reduction. Recently, many researches have aimed to improve parallel pump systems' energy efficiency. Due to the inflexibility of the existing parallel pump systems structure and the difficulty of equipment modification, the research methods mainly focus on improving the system control methods to enhance the system performance further. This paper introduces the latest research progress in modeling and control methods for parallel pump systems, firstly analyzing the energy consumption of existing parallel pump systems and proposing the possibility of energy saving in parallel pump systems. Then the system modeling and control methods are discussed in detail, comparing the traditional control methods with the emerging control optimization methods and discussing the parallel pump systems structure and monitoring. This review is expected to provide insights for future research on improving the performance of parallel pump systems.

Concrete strength monitoring based on the variation of ultrasonic waveform acquired by piezoelectric aggregates

Li Wei,Zijian Wang,Maosen Cao,Ronghua Fu 국제구조공학회 2020 Structural Engineering and Mechanics, An Int'l Jou Vol.76 No.5

Ultrasonic waves provide a non-destructive and sensitive way to monitor the concrete hydration. However, limited works are reported to monitor the evolution of the mechanical parameter at early ages. In this study, modified piezoelectric aggregates are embedded inside a concrete beam to excite and receive primary waves. A hydration index, namely, the variation of ultrasonic waveform (VUW) is developed to characterize the variation of the transmitted waves during the hydration process. The recorded hydration indices are compared with the compressive strength measured by destructive test at different ages. The results show that the VUW is closer to the compressive strength than the other two traditional hydration indices, ultrasonic velocity and wave packet energy. The proposed VUW provides a simple and accurate way to monitor the concrete hydration at early ages.

차량 정보를 이용한 졸음 운전 예측 연구

김광섭(Kwangseub Kim),Wang Maosen,정낙탁(Naktak Jung),양성모(Seongmo Yang),유세훈(Sehoon Yoo),기대성(Daeseong Gi),서명원(Myungwon Suh) 한국자동차공학회 2015 한국자동차공학회 부문종합 학술대회 Vol.2015 No.5

Drowsy behavior is more likely to occur in sleep-deprived drivers. The accident rate is higher driver of drowsiness. Individuals’ drowsy behavior detection technology should be developed to prevent drowsiness related crashes. Driving information such as accelerations, steering angles and velocity, and physiological signals of drivers such as electroencephalogram (EEG), and eye tracking were adopted in present drowsy behavior detection technologies. However, it is difficult to measure physiological signal, as a result, driving information becomes more popular for drowsy driving detection. In this paper, vehicle information including lateral accelerations, longitudinal acceleration and steering angles, was combined into various cases to detect drowsy driving behavior. In order to increase the accuracy, it is defined the data set and predicted drowsy driving prediction using the Random Forest algorithm. As the result, the case of lateral and longitudinal of acceleration showed the best.

Analysis of the muzzle dynamic response interval based on the bond space method

Fu He,Jinsong Dai,Shengye Lin,Maosen Wang 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.10

Accurate analysis of the dynamic response of the muzzle shows a vital role in improving the accuracy of small-caliber artillery burst fire. However, the complex small-caliber artillery system and the uncertainty of parameters make the muzzle dynamic response analysis more difficult. To solve the problem that it is difficult to analyze the dynamic response of smallcaliber artillery containing uncertain parameters by traditional methods, the critical uncertain parameters are regarded as interval variables, and the bonded space theory is used to establish the muzzle dynamic response model of small-caliber artillery with continuous firing, and combined with Chebyshev polynomial expansion method to solve it, and finally the muzzle dynamic response interval is obtained. Through computational analysis and experimental testing, 84.6 % and 95 % of the tested muzzle dynamic response curves in the horizontal and vertical directions fall into the simulation interval, respectively. Meanwhile, the error of the mean, the variance, the most value, and the amplitude of the test and simulation are less than 10 %, which verifies the method’s accuracy. In addition, by adjusting the optimized parameters, the amplitude of the dynamic response of the muzzle was reduced by 78.67 %. We conclude that the muzzle dynamic response interval method works well for analyzing and controlling the muzzle dynamic response problem with the desired accuracy.

Influence of prefabricated fragments projectile cabin opening attitude on damage probability and attitude optimization

Tian Tan,Jinsong Dai,Shengye Lin,Yongjie Cao,Maosen Wang 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.6

Cabin opening attitude of prefabricated fragment projectiles has a great impact on target damage probability. To address this issue, this study proposed a method for calculating damage probability based on gridding the target, which can estimate target damage probability under different cabin opening attitudes of projectile. To obtain the optimal cabin opening attitude of the projectile, an improved PSO algorithm named S-ACPSO was proposed, which has adaptive adjustment ability predicated on the sigmoid function and the particle diversity. To verify this method, a UAV target example was analyzed. The numerical result showed that the maximum target damage probability was 0.6847 under the optimal attitude. Following this, the influence of attitude parameters on the target damage probability was analyzed, which showed that the method in this study was feasible.

전기 자동차 성능 평가를 위한 도심 주행 모드 개발 Part Ⅰ

양성모(Seong-Mo Yang),정낙탁(Nak-Tak Jeong),김광섭(Kwang-Seup Kim),최수빈(Su-Bin Choi),Wang Maosen,김현수(Hyun-Soo Kim),서명원(Myung-Won Suh) 한국자동차공학회 2014 한국 자동차공학회논문집 Vol.22 No.7

Recently, due to various environmental problems such as global warming, increasing of international oil prices and exhaustion of resource, a paradigm of world automobile market is rapidly changing from vehicles using internal combustion engine to eco-friendly vehicles using electric power such as EV (Electric Vehicle), HEV (Hybrid Electric Vehicle), PHEV (Plug-in Hybrid electric Vehicle) and FCEV (Fuel Cell Electric Vehicle). There are many driving cycles for performance evaluation of conventional vehicles. However there is a lack of researches on driving cycle for EV. This study is composed of part 1 and part 2. In this paper part 1, in order to develop urban driving cycle for performance evaluation of electric vehicles, Gwacheon-city patrol route of police patrol car was selected. Actual driving test was performed using EV. The driving data such as velocity, time, GPS information etc. were recorded. GUDC-EV (Gwacheon-city Urban Driving Cycle for Electric Vehicles) including road gradient was developed through the results of analyzing recorded data. Reliability of the driving cycle development method was substantiated through comparison of electricity performance. In the second part of this study, the developed driving cycle was compared to simulation result of the existing urban driving cycle. Verification of the developed driving cycle for EV performance evaluation was described.

전기자동차 성능평가를 위한 도심 주행 모드 개발 Part Ⅱ

정낙탁(Nak-Tak Jeong),양성모(Seong-Mo Yang),김광섭(Kwang-Seup Kim),최수빈(Su-Bin Choi),Wang Maosen,유세훈(Sehoon You),김현수(Hyunsoo Kim),서명원(Myung-Won Suh) 한국자동차공학회 2015 한국 자동차공학회논문집 Vol.23 No.2

Recently, due to various environmental problems such as global warming, increases of international oil prices, exhaustion of resource, a paradigm of world automobile market is rapidly changing from conventional vehicles using internal combustion engine to eco-friendly vehicles using electric power such as EV, HEV, PHEV and FCEV. Generally, in order to measure fuel consumption and pollutant emissions of cars, chassis dynamometer tests are performed on various driving cycles before actual driving test. There are many driving cycles for performance evaluation of conventional vehicles. However, there is a lack of researches on driving cycle for EV. In this study, the urban driving cycle for performance evaluation of electric vehicles was developed. This study is composed of two parts. In the part 1, the urban driving cycle ’GUDC-EV(Gwacheon-city Urban Driving Cycle for Electric Vehicles)’ was developed by using driving data, which were obtained through actual driving experiment, and statistic analysis with chronological table. In this paper part 2, in order to verify the developed driving cycle GUDC-EV, virtual EV platforms were configured and simulations were performed with actual driving data using In addition, simulation results were compared with existing driving cycles such as FTP-72, NEDC and Japan 10-15.