• 한국생산제조학회지
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• 제26권4호
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• pp.418-424
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• 2017

A wheel dynamometer was installed between the rim and axle hub to measure the forces and moments applied to a vehicle. The wheel dynamometer was composed of sensing and signal processing components. Because the sensing component contained a complex structure to sense the six components of the forces and moments and the wheel rotated along with the vehicle movement, sophisticated signal processing hardware and a software algorithm were used. The strains and the calibration matrices of the wheel dynamometer along the wheel rotation angle were investigated using FEM. From the analysis, the calibration matrices were simplified using a spline interpolation. Based upon these results, the signal processing component could be effectively designed and the firmware software could be simplified.

• 한국자동차공학회논문집
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• 제24권3호
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• pp.294-301
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• 2016

This paper discusses about analyzing in-wheel vehicle's dynamic motion and load torque. Since in-wheel vehicle controls each left and right driving wheels, it is dangerous if vehicle's wheels are not in a cooperative control. First, this study builds the main wheel control logic using PID control theory and evaluates the stability. Using Carsim-Matlab/Simulink, vehicle dynamic motion is simulated in virtual 3D driving road. Through this, in-wheel vehicle's driving performance can be analyzed. The target vehicle is a rear-wheel drive in D-class sedan. Second, by using the first In-wheel vehicle's performance results, it derivate the drive motor's dynamic load torque for applying the dynamometer. Extracted load torque impute to dynamometer's load motor, linear experiment in dynamometer can replicated the 3-D road driving status. Also it, will be able to evaluate the more accurate performance analysis and stability, as a previous step of actual vehicle experiment.

• 대한기계학회논문집A
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• 제40권1호
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• pp.53-63
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• 2016

자동차 주행 중 도로면으로부터 차량 바퀴에 전달되는 동하중을 측정하기 위해 휠 동력계가 사용된다. 본 논문에서는 전단 변형과 굽힘 변형을 이용한 두 가지 타입의 6축 휠 동력계를 설계하고 비교 평가하였다. 유한요소해석을 이용하여 휠 동력계 기본 구조에 대한 전단 변형 거동과 굽힘 변형 거동을 분석하였으며 이로부터 전단형 휠 동력계와 굽힘형 휠 동력계를 설계하였다. 변형률 해석을 반복 수행하여 각 하중에 대한 출력변형률이 미리 결정된 비슷한 값이 되도록 하고 상호간섭 변형률이 최소화 되도록 설계를 수정하고 브리지 회로를 구성하였다. 전단형 휠 동력계는 균일한 변형률 분포를 얻을 수 있어 제작시 안정된 특성치를 얻을 수 있는 반면에, 굽힘형 휠 동력계는 각 하중에 대한 출력 변형률 값이 더 일정하여 균일한 감도의 좋은 성능을 얻을 수 있을 것으로 예측된다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.548-552
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• 2003

In the braking system, the friction force is the most important factor of the design. For long time, many researchers have been strived for getting the exact friction coefficients. But the friction coefficients are affected by the road condition and changed by lots of parameters, such as normal force and characteristics between two contacted materials, temperature, etc. For the development of ABS of the aircraft, HILS(Hardware-In-the-Loop-Simulation) test and dynamometer test was carried out. For the calculation of the friction coefficients, the wheel moments were measured using the load cell mounted on the housing of the wheel. The test conditions were dry and greasy, as the 0.7 and 0.4 in friction coefficient, respectively. In this paper, the test results of the friction coefficients were represented and the improvement method was suggested.

• 한국기계가공학회지
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• 제1권1호
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• pp.29-37
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• 2002

The wavelet transform is a popular tool for studying intermittent and localized phenomena in signals. In this study the wavelet transform of cutting force signals was conducted for the diagnosis of grinding conditions in grinding process. We used the Daubechies wavelet analyzing function to detect a sudden change in cutting signal level. STD11 workpiece was 85 times of machined pieces cut by the WA wheel and a tool dynamometer obtained cutting force signals. From the results of the wavelet transform, the obtained signals were divided into approximation terms and detailed terms. At dressing time, the approximation signals were slowly increased and 45 machined times noticed dressing time.

• 한국자동차공학회논문집
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• 제14권6호
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• pp.95-103
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• 2006

Wheel treads of E.M.U. are usually under a heavy thermal load by brake frictional heat between wheel and brake shoe and damaged by repeated thermal and mechanical loads. To examine the cause of wheel tread damage of E.M.U.'s in service running, a systematic approach has been used. This study is composed of three parts. Frictional heat analysis was conducted in the first part by finite element method. Two kinds of brake shoes in service were considered. In the second part, experimental study was carried out on a brake dynamometer. Temperatures were measured for the two brake shoes. And experimental study in service running E.M.U.'s was performed. Wheel and brake shoe temperatures were measured by using thermocouples and temperature indicating strips. Finally metallurgical characteristics were examined by a SEM/EDS and the cause of the wheel damage was analyzed. It seems that aggregated ferrous component is a main cause of the wheel tread damage.

• 오토저널
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• 제8권4호
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• pp.56-65
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• 1986

This paper theoretically analyzed the relations between the out-put braking torque and the wheel cylinder pressure in the leading-trailing drum brake for heavy duty truck as the characteristics of friction in break lining, comparing with the results derived from full-scale inertial brake dynamometer test in actual braking condition to develop reliable brake system in extensive using conditions. The main results obtained are as follows; 1) The characteristic curve representing the relations between BEF (Brake Effectiveness Factor) and Friction coefficient derived from theoretical analysis are consistent with the experimental results of dynamometer test. 2) According to the results of dynamometer test, the friction coefficient of brake lining is subject to initial brake speed and the actual using temperature in brake system.

• 대한기계학회논문집A
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• 제38권1호
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• pp.37-44
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• 2014

본 연구에서는 전기이륜차의 1회충전주행거리를 알아보기 위해 도로 주행시험과 차대동력계(Chassis Dynamometer) 주행시험을 하였다. 도로주행시험은 대전시(Daejeon Metropolitan City)의 도로 중 대표적인 3가지 루트에서 주행시험을 하였다. 차대동력계를 이용한 CVS-40모드 주행시험의 경우 도로 부하조건을 다양하게 설정하여 CVS-40 모드주행을 실시하였다. 본 연구를 통하여 도로에서의 전기이륜차의 1회 충전주행거리(Per-Charge Range Testing)를 확인하고, 차대동력계 도로부하 설정방법에 따른 주행거리 및 에너지소비효율을 측정하였다. 이를 통해 실도로 주행시험과 차대동력계 주행시험을 비교하여, 차대동력계 실험에서도 전기이륜차 1회충전주행거리시험이 실도로에서의 주행조건과 근접한 결과를 갖는 도로부하 설정에 대해 연구하였다.

• 대한기계학회논문집A
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• 제35권5호
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• pp.525-531
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• 2011

최근 지구환경에 대한 전 세계적인 관심증가에 따른 친환경 이동수단에 대한 수요가 늘고 있다. 휘발유를 에너지원으로 하는 내연기관 이륜차의 경우 소음 공해와 배기가스 배출로 인해 국제적으로 전기이륜차로의 보급을 추진하고 있다. 이에 정확한 전기이륜차 성능평가의 필요성이 증가하고 있다. 전기이륜차의 성능을 평가하는 방법은 도로에서 주행 시험하는 방법과 실내에서 차대동력계를 이용한 시험방법이 있다. 차대동력계는 전기이륜차가 도로에서 주행하는데 받는 주행 저항을 전기모터에 의해 재현시켜 준다. 이때 도로부하 설정은 차대동력계에 의한 시험의 결과에 영향을 준다. 본 논문에서는 차대동력계를 이용한 성능평가의 중요한 설정 값인 도로부하 설정에 대한 방법인 테이블법과 타력주행 시험에 의한 도로부하 설정의 차이에 대해 비교 분석하였다.

• 한국자동차공학회논문집
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• 제24권6호
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• pp.635-641
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• 2016

Regenerative braking performance of an electrically powered vehicle is closely related to driving distance per battery charge. An electric vehicle uses appropriate amounts of mechanical braking force and electromagnetic regenerative braking force to recover energy and increase driving efficiency. In particular, when it drives on a downhill road, energy recovery rate is maximized through regenerative braking during coasting based on the mass inertia of the vehicle. Since an electric two-wheeled vehicle covered in this paper is lighter than an electric four-wheeled vehicle, the improvement of its driving distance per battery charge through regenerative braking is different from an electric four-wheeled vehicle. This study compared the driving characteristics of an electric two-wheeled vehicle based on regenerative braking. Two driving test modes were simulated with a chassis dynamometer system. By analyzing the measurement of a chassis dynamometer, the driving characteristics of a two-wheel electric vehicle, such as driving efficiency, were analyzed. In addition, test results were reviewed to draw the limitations of conventional test methods for regenerative braking performance of an electric two-wheel vehicle.