• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 D
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• pp.2397-2399
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• 2004

This paper deals with the messages scheduling of a CAN (Controller Area Network), based on the distributed control scheme to integrate actuators and sensors in a humanoid robot. In order to supply the distributed processing for a humanoid robot, each control unit should have the efficient control method, fast calculation and valid data exchange. The preliminary study has concluded that the performance of CAN is better and easier to implement than other network such as FIP (Factory Instrumentation Protocol), VAN (Vehicle Area Network), etc. Since humanoid robot has to treat the significant control signals from many actuators and sensors, the communication time limitation could be critical according to the transmission speed and data length of CAN specification. In this paper, the CAN message scheduling in humanoid robot was suggested under the presence of Jitter in the message group, the existence of high load of messages over the network and the presence of transmission errors. In addition, the response time under the worst case is compared with the simulation by using the simulation algorithm. As a result, the suggested messages scheduling can guarantee our CAN limitation, and utilized to generate the walking patterns for the humanoid.

• 한국생산제조학회지
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• 제20권5호
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• pp.639-645
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• 2011

Wheel-loader is a construction vehicle for uploading soil or sand into truck and transportation of materials, which requires large driving power and high rotational speed. To improve the working efficiency, the operator has to shift gears and control levers for bucket & boom simultaneously. Therefore, the automatic transmission has been introduced to enhance operator's convenience and enable effective operation. To develop the automatic transmission for the wheel-loader, technologies such as gears and a clutch-pack design and shift algorithm are required for improvement of shift quality. In this paper, the shift algorithm for the wheel-loader was developed and its shift pattern was analyzed. As the shift control is affected by the pressure profile for the clutch control, the shift quality depending on the pressure profile has been evaluated using experiment and simulation model analysis.

• 한국화재소방학회논문지
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• 제22권4호
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• pp.70-75
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• 2008

최근 들어 철도차량 안전과 관련하여 국내에서 다양한 연구가 진행되고 있다. 하지만 대부분의 연구는 여객을 수송하는 일반 객차, 전동차, 고속열차 등을 중심으로 행해지고 있으며, 화물 특히 위험물 수송 화물차량에 대한 연구는 전무한 실정이다. 본 연구에서는 위험물질을 수송하는 탱크차의 안전기준을 개발하기 위하여 유류를 중심으로 국내외 관련된 안전기준을 비교 분석하여 국내 위험물 수송 탱크차 안전기준 개발의 기초를 마련하고자 한다.

• 한국ITS학회 논문지
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• 제14권4호
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• pp.80-85
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• 2015

ICT기술이 차량 교통 시스템에 적용되면서 스마트한 도로 교통 시대(ITS)가 열리고 있다. 이러한 기술적 진보를 가져온 요소 중 하나는 고속으로 이동하는 차량과 인프라 간의 통신기술이다. IEEE802.11p기반의 WAVE 통신기술을 적용하여 도로교통의 다양한 안전서비스들과 운전자 편의 서비스들이 개발되고 있다. 본 논문에서는 이러한 ITS 서비스들의 품질을 보장하기 위해 필요한 link budget 분석을 수행하였다. 고속도로 환경에 적합한 경로손실 모델로 자유공간 모델과 two-ray모델을 통한 비교 분석을 통해 안정적인 통신 서비스가 가능한 셀 커버리지를 분석하였다.

• 대한조선학회논문집
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• 제52권4호
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• pp.305-314
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• 2015

In this paper, a numerical analysis is carried out to study the drag of conical cavitators, supercavity generation devices for the high-speed underwater vehicle. The realizable k-∊ turbulence model and the Schnerr-Sauer cavitation model are applied to calculate steady-state supercavitating flows around cones of various cone angles. The calculated drags of the cones are decomposed of the pressure and the friction parts and their dependency on the geometry and the flow conditions have been analyzed. It is confirmed that the pressure drag coefficients of the cones can be estimated by a simple function of both the cone angle and the cavitation number while the friction drag coefficients approximately by well-known empirical formulas, e.g., Schults-Grunow's for the drag of the flat plate. Finally a practical method for estimating the total drags of supercavitating cones is suggested, which can be useful consequently for the design of conical cavitaors.

• Journal of Electrical Engineering and Technology
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• 제11권3호
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• pp.639-643
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• 2016

This paper introduces the development process and investigation of a 60kW induction motor for electric vehicles. We present performance improvement in the induction motor of electric vehicle using copper die-casting based on a multi-gate process. Copper die-casting motors can reduce the size of the motor, the loss of the rotor, and material costs. We also introduce electromagnetic, thermal, mechanical design and analysis results that satisfy the design and the performance requirements. In order to analyze losses accurately of induction motor, commercial finite element analysis is done considering PWM voltage and thermal characteristics by using lumped-circuit parameters. Experimental tests are also carried out to validate the traction motor design.

• Advances in Automotive Engineering
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• 제1권1호
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• pp.61-77
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• 2018

In this study, the effects of sitting position of the driver on the whiplash neck injury have been analyzed experimentally by using hybrid III series 50 percentile male crash test dummy. A testing platform consisting of vehicle ground, driver foot rest, driver seat and a 3-point seatbelt has been prepared. This testing platform and the instrumented crash test dummy are prepared for tests according to the Euro NCAP whiplash testing protocol. The prepared test set-up has been exposed to 3 different acceleration-time loading curves defined in the Euro NCAP whiplash testing protocol by performing sled tests. 9 different sled tests have been performed with the combinations of 3 different seating positions of the crash test dummy and 3 different acceleration-time loading curves. The sensor data obtained from the crash test dummy and high-speed videos taken are analyzed according to the injury assessments criteria defined in the Euro NCAP whiplash testing protocol and the criticality of the whiplash injury is defined. It is seen that the backset distance of the driver head with the headrest and the height difference of the top of the head of the driver with the headrest have a great importance on whiplash injuries.

• 한국항행학회논문지
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• 제16권1호
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• pp.54-61
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• 2012

차세대 ITS 환경을 위한 차량용 무선 통신 규격인 WAVE 규격은 IEEE 802.11p와 IEEE P1609 규격을 통칭하며, IEEE 802.11p의 규격제정이 마무리됨에 따라 최근 많은 연구가 진행되고 있다. 고속 차량 환경과 실내 환경의 차이는 무선 통신 채널 모델이 훨씬 가혹하다는 것이다. 따라서, 무선 통신 시스템의 설계 시 온도, 잡음, 다중 경로 페이딩과 같은 시스템의 성능을 저하시킬 수 있는 사항들을 충분히 고려하여야 한다. 본 논문에서는 IEEE 802.11p PHY/MAC을 기반으로 하는 WAVE 무선 통신 시스템을 위한 RF 회로를 설계하고 실제로 구현하면서 나타나는 문제들을 보이고 이를 해결하는 과정을 보였다.

• 한국자동차공학회논문집
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• 제20권5호
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• pp.95-101
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• 2012

An electric water pump for engine cooling system has an advantage which particularly in the cold start, the use of the electric water pump saves fuel and leads to a corresponding reduction in emissions. The canned type electric water pump without mechanical sealing elements was selected to meet the requirements for operational reliability and life. However, the electric water pump for internal combustion engine generates much more heat loss than for hybrid electric vehicle since it is operated by the electric power of high current and low voltage. In this study, the fluid flow and thermal characteristics of the canned type electric water pump as an inverter integrated water pump has been investigated under the effects of heat generation. The analysis conditions such as outdoor air temperature of $125^{\circ}C$, water pump speed of 6000 rpm, coolant temperature of $106^{\circ}C$ and coolant flow rate of 120 L/min was used as a standard condition. Therefore, flow fields and temperature distribution inside the water pump were obtained. Also, we checked the feasibility of the canned type for the electric water pump in comparison with the mechanical seal type.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1994년도 추계학술대회 논문집
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• pp.472-477
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• 1994

The lockup clutch is embeded on torque converter of automatic transmission to prevent the efficiency deterioration of torque converter in high speed. For improving fuel consumption rate, it is desirable to engage the lockup clutch earlier. But, it results in degrading shift quality, due to the transient torque. The transient clutch pressure which affects the shifting quality, should be controlled properly. In this study, to solve the problem, it is analysed the hydraulic circuit of lockup system including line pressure regulating circuit, established the nonlinear model, and designed the PID controller. The line pressure is supplied to the lockup clutch through the lockup control valve by switching the lockup solenoid valve on. In order to control the transient pressure actively, it is needed to control the lockup solenoid valve by closed loop control. The lockup solenoid valve is 2-way on-off valve, and is adequate for PWM control. To reduce the pressure chattering, the carrier frequency is increased. Target pressure profile is computed from optimized velocity difference profile throuth dynamic equation of vehicle system.