• 한국정밀공학회지
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• 제16권6호
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• pp.66-76
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• 1999

Vehicle driving simulators have been used in the development and modification of models. A simulator can reduce cost and time through a variety of driving simulations in the laboratory. Recently, driving simulators have begun to proliferate in the automotive industry and the associated research community. This paper presents the hardware and software developed for a driving simulator of construction vehicles. This effor involves the real-time dynamic analysis of wheel-type excavator, the design and manufacturing of the Stewart platform, an integrated control system of the platform, and three-dimensional graphic modeling of the driving environments.

• International Journal of Precision Engineering and Manufacturing
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• 제4권3호
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• pp.62-67
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• 2003

The grinding force generated during the grinding process causes an elastic deformation of the workpiece, grinding wheel, and machine system. Thus, the true depth of cut is always smaller than the apparent depth of cut. This is known as machining elasticity phenomenon. The machining elasticity parameter is defined as a ratio between the true depth of cut and the apparent depth of cut. It is an important factor to understand the material removal mechanism of the grinding process. To increase productivity, the value of this machining elasticity parameter must be large. Therefore, it is essential to know the characteristics of this parameter. The objective of this research is to study the effect of the major grinding conditions, such as table speed, depth of cut, on this parameter experimentally, Through this research, it is found that this parameter value is increasing when the table speed is decreasing or the depth of cut is increasing. Also, this parameter value depends on the grinding mode (up grinding, down grinding).

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2005년도 추계학술대회 논문집
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• pp.156-159
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• 2005

The outer race of CV(constant velocity) joint is an important load-supporting automotive put that transmits torque between the transmission gear box and driving wheel. The outer race is difficult to forge because its shape is very complicated and the required dimensional tolerances are very small. To guarantee the dimensional accuracy of the forged CV Joint, the quick and precise measurement is required to increase the inspection speed of forged products. Therefore in this study, PP(Pre-Position) Device to decrease the inspection time of measuring system has been developed to cope with forging cycle time. The measured inspection time confirms that the PPD is very effective in decreasing inspection time.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2005년도 추계학술대회 논문집
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• pp.160-163
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• 2005

The cute. race of CV(constant velocity) Joint is an important load-supporting automotive part, which transmits torque between the transmission gear box and driving wheel. The outer race is difficult to forge because its shape is very complicated and the required dimensional tolerances are very small. The forged CV Joint investigated in this study has six inner ball grooves requiring high operational accuracy. Therefore, the precise measurement of forged CV Joint is very important to guarantee the sound operation without noise and abnormal wear. In this study, unique in-situ measuring system designed specifically to measure the dimensional accuracy of six inner ball grooves of CV joint has been developed and implemented in shop environments. Newly developed system shows high measurement accuracy with simple operational sequence.

• 한국정밀공학회지
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• 제15권10호
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• pp.41-50
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• 1998

In this study, to investigate a characteristics of slip ratio control of H.C.U for ABS, half car model tester were developed and a new H.C.U. was compactly designed comparing to the commercical H.C.U. for ABS. In half car model tester, variable inertia wheel has been used to load the car weights and braking forces according to the road surface conditions which were realized by pneumatic cylinder. And solenoid valves using P.W.M. (Pulse Width Modulation) method were installed in the new H.C.U The slip ratio characteristics of tire had been measured using half car model tester and the results were used in the control simulation for a new H.C.U.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.474-478
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• 2004

A bushing is a device used in automotive suspension systems to reduce the load transmitted from the wheel to the frame of the vehicle. A bushing is a hollow cylinder, which is bonded to a solid steel shaft at its inner surface and a steel sleeve at its outer surface. The relation between the force applied to the shaft and the relative deformation of a bushing is nonlinear and exhibits features of viscoelasticity. A force-displacement relation for bushings is important for multibody dynamics numerical simulations. For the nonlinear viscoelastic axial response, Pipkin-Rogers model, the direct relation of force and displacement, has been derived from Lianis model and the sinusoidal input was used for Pipkin-Rogers model, and the affection of displacement with frequency change was studied with Pipkin-Rogers model.

• 한국컴퓨터정보학회논문지
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• 제25권6호
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• pp.91-98
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• 2020

급제동 시 추돌사고를 방지하기 위하여 비상등 자동작동 기능이 없는 기존 차량에 손쉽게 추가장착이 가능한 비상등 자동작동 시스템을 제안하였다. 급제동을 인식하기 위해서는 몇 가지 방법이 있지만 GPS를 사용하면 시스템이 터널에서 작동하지 않으며 차량 속도 센서를 사용하면 기존 차량에 시스템을 추가로 설치하기 어렵다. 따라서 제안한 시스템은 가속도 센서를 사용하여 이러한 문제점들을 제거하고 차량의 급회전 및 급바운스도 인식 할 수 있도록 하였다.

• 대한기계학회논문집A
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• 제35권10호
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• pp.1315-1321
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• 2011

제품 생산과 실험에 앞서 설계 단계에서의 강도 평가가 이루어져야 하며, 이 단계에서 범용 프로그램인 ANSYS 의 도입 및 활용은 제품의 생산과 강도 평가에 있어서 시간과 비용의 절감 등 여러 가지 이점을 갖게 한다. 본 연구에서는 ANSYS 를 이용하여 승용차용 디쉬 타입과 스포크 타입의 휠을 3 차원 형상으로 모델링하고 구조해석과 피로해석을 수행하였다. 디쉬 타입과 스포크 타입에 대한 해석 결과를 비교해 보면, 디쉬 타입이 스포크 타입보다 변형이 적게 일어나고 최대등가응력도 작음을 알 수 있다. 그럼에도 불구하고, 스포크 타입이 경량과 우수한 냉각성능으로 인해 자주 사용되고 있다. 수명에 대한 피로 해석 결과, 알루미늄 휠이 스틸 휠보다 피로 저항력이 우수함을 보였다.

• 한국컴퓨터정보학회논문지
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• 제16권7호
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• pp.157-163
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• 2011

본 논문에서는 ARS(Attitude Refrence System)를 이용하여 모바일 역진자 로봇의 수평유지와 주행을 위한 자세 제어를 연구하였다. 현재 미국 및 여러 나라에서는 모바일 역진자 로봇에 대한 많은 연구가 진행되고 있으며 이를 이용한 세그 웨이 등을 개발하고 있다. 이러한 2자유도를 이용한 모바일 역진자 로봇은 다양한 모드로 움직일 수 있다. 모바일 역진자 로봇이 2바퀴로 수직 자세를 취하면 시스템이 안정을 취하기 위하여 항상 앞, 또는 뒤로 넘어지려는 성질을 가진다. 현재 자이로센서와 가속도센서를 혼합하는 알고리즘은 칼만필터가 일반적으로 이용되고있으며 많은 연구가 진행되고 있다. 본 연구에서 ARS는 2축의 자이로 각(roll, pitch)과 3축의 가속도계 값(x, y, z)값으로 자세를 계산하도록 하였다. 본 논문은 자율주행시스템인 2발 로봇 시스템으로 간단하지만 원하는 성능을 발휘할 수 있는 ARS와 PID 알고리즘을 이용한 자세 제어를 실현하였다.

• 한국안전학회지
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• 제26권1호
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• pp.58-64
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• 2011

This study evaluated the effects of the handle width(shoulder width, 1.25${\times}$shoulder width, 1.5${\times}$shoulder width), height(3 levels : knee, medium, knuckle) and horizontal angle($0^{\circ}$, $10^{\circ}$) on the pushing, lifting, and twisting strengths which were required for carrying single or two wheel barrows. Twelve healthy college students(male) participated in the experiment. In each experimental condition($3{\times}3{\times}2$=18), the subjects exerted three forces(pushing, lifting, and twisting clockwise). The experimental conditions and three forces were tested in random order, and a minimum 2 minutes of rest was provided between exertions. Results showed that the mean and maximum pushing forces showed greater values when the horizontal angle was $0^{\circ}$ than $10^{\circ}$(p=0.016). However, the three independent variables had no statistically significant effects on the lifting forces(p>0.1). The mean and maximum twisting forces increased as the handle width became larger(p<0.05). Also, there was a marginal effect of the horizontal angle(p=0.065) on the twisting force. From the results of this study, the horizontal angle of $0^{\circ}$ and the wider handle width were suggested for the design of single-wheel barrows.