• Proceedings of the KIPE Conference
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• 2011.11a
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• pp.241-242
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• 2011

교통 약자 승객의 편의성 증대, 도심의 매연 감소 및 온실가스 저감 등 대중 교통 선진화를 위해 친환경 초저상 전기버스의 개발이 필요하다. 초저상 전기버스는 초저상 액슬 일체형 휠모터 구동시스템을 탑재한 형태로 구현이 가능하며, 초저상 액슬 일체형 휠모터 구동시스템은 구동 모터를 액슬 허브에 일체화 시킴으로써 기존 구동시스템 대비 무게 및 사이즈가 대폭 줄어들고, 동력 전달 매커니즘을 획기적으로 개선하여 효율 향상 및 차량 연비 개선이 가능하다. 특히 바퀴 중심과 액슬 출력 중심에 단차를 둠으로써 차량의 전방 바닥 뿐만 아니라 후방바닥을 평평하게 유지할 수 있어 실내 공간이 획기적으로 개선되어 교통 약자를 포함한 승객의 편의성을 향상시킬 수 있다. 또한, 액슬 일체형 휠모터 구동시스템은 각 휠의 분산 구동이 가능하므로 동특성 및 구동제어성이 뛰어나고, ESP(Electronic Stability Program), VDC(Vehicle Dynamic Control) 등과 연계하여 통합적인 지능형 시스템을 구현할 수 있다. 액슬 일체형 휠모터 구동시스템은 휠모터와 감속기 및 휠모터제어기 등으로 구성되며, 본 논문에서는 초저상 액슬 일체형 구동시스템용 120kW급 휠모터 및 휠모터제어기의 개발 및 다이나모 환경에서 T-N 특성 및 최대 출력 시험, 효율 시험을 통해 전기버스 등 대형 차량(Heavy Duty Vehicle)에 적용 가능한 전기동력시스템의 성능을 확인하였다.

• The Transactions of the Korean Institute of Power Electronics
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• v.14 no.6
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• pp.481-487
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• 2009

This paper proposes a regulation method of DC line voltage for urban transit system fluctuated during the acceleration or deceleration by using supercapacitor. Supercapacitor is modelled electrically under the assumption of three different time constants of RC circuits with variable capacitances depending on the voltage. And its parameters are determined by the experimental measurements. The energy storage system using supercapacitors is installed based on this model, and the proposed model is tested through the simulations and experiments, and the controller for charging and discharging is designed. Finally, it is tested at Kyoungsan test site for the urban light rail road system and the energy saving effect is evaluated economically.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.11
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• pp.965-972
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• 2016

This paper presents results of flight experiments on a navigation algorithm including multiplicative extended Kalman filter for estimating attitude of the guided munition. The filter describes orientation of aircraft by data fusion with low-cost sensors where measurement update is done by multiplication, rather than addition, which is suitable for quaternion representation. In determining attitude from vector observations, the existing approach utilizes a 3-axis accelerometer as a 2-axis inclinometer by measuring gravity to estimate pitch and roll angles, while GNSS velocity is used to derive heading of the vehicle. However, during accelerated maneuvers such as coordinated flight, the accelerometer provides inadequate inclinometer measurements. In this paper, the measurement update process is newly defined to complement the vulnerability by using different vector observations. The acceleration measurement is considered as a result of a centrifugal force and gravity during turning maneuvers and used to estimate roll angle. The effectiveness of the proposed method is verified through flight experiments.

• Journal of Korean Society of Transportation
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• v.21 no.1
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• pp.91-102
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• 2003

There are two goals in this paper. The one is development of existing CA(Cellular Automata) model to explain more realistic deceleration process to stop. The other is the application of the updated CA model to forecasting simulation to predict short term link travel time that takes a key rule in finding the shortest path of route guidance system of ITS. Car following theory of CA models don't makes not response to leading vehicle's velocity but gap or distance between leading vehicles and following vehicles. So a following vehicle running at free flow speed must meet steeply sudden deceleration to avoid back collision within unrealistic braking distance. To tackle above unrealistic deceleration rule, “Slow-to-stop” rule is integrated into NaSch model. For application to interrupted traffic flow, this paper applies “Slow-to-stop” rule to both normal traffic light and random traffic light. And vehicle packet method is used to simulate a large-scale network on the desktop. Generally, time series data analysis methods such as neural network, ARIMA, and Kalman filtering are used for short term link travel time prediction that is crucial to find an optimal dynamic shortest path. But those methods have time-lag problems and are hard to capture traffic flow mechanism such as spill over and spill back etc. To address above problems. the CA model built in this study is used for forecasting simulation to predict short term link travel time in Kangnam district network And it's turned out that short term prediction simulation method generates novel results, taking a crack of time lag problems and considering interrupted traffic flow mechanism.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.10
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• pp.415-424
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• 2019

In this paper, a minimum rotation radius was designed and fabricated to overcome the threshold so that elderly or disabled people who have difficulty moving can move and transfer safely and conveniently in a narrow room. In the indoor environment, where the sedentary culture develops, this study aimed to provide convenience for passengers with fracture diseases, geriatric diseases, and other knee and waist diseases. First, links, seats, armrests, covers, motors, batteries, chargers, controllers, etc. were attached to the frame so that they could be moved and lifted indoors. The product design and structure were designed considering the user's environment and physical characteristics, and IoT functions were added. A driving experiment was performed to confirm the operating performance of the manufactured indoor moving and lifting wheelchair. The performance tests, such as continuous running time, turning radius, maximum actuator load, maximum lift height, sound pressure level, minimum sensing distance of the driving aid sensor, interworking of server and app programs, device compatibility, and duty cycle error rate, were performed. As a result of the test, the built-in wheelchair could achieve the performance test target of each item and operate successfully.