• Proceedings of the KSME Conference
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• 2004.04a
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• pp.870-874
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• 2004

This paper presents a three dimensional modeling and simulations of operation and running of a wheel loader using the ADAMS program. A wheel loader consists of a bucket, a boom, a crank, a front frame, a rear frame, a bucket cylinder, two boom cylinders, two steering cylinders, nine spherical joints, six universal joints, five translation joints, three inline joints, a revolute and a fixed joint. Judging from the actual degrees of freedom of the wheel loader, proper kinematic joints are selected to exclude redundant constraints in the modeling. Through the running simulation over a bump with the three dimensional modeling, the joint reaction forces are calculated.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.3
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• pp.109-119
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• 2018

The purpose of this study is to evaluate the structural safety of the front-end loader for the 90 kW class of agricultural tractors in impact test conditions. Deformation and stress on the loader under the impact test conditions are analyzed using the commercial finite element analysis software ANSYS. In previous research dealing with the initial design of the loader, the maximum stress occurred in the mount and exceeded the yield strength of the material. In this paper, an improved design of the mount of the loader was proposed to reduce the stress concentration in the initial design. The safety of the improved design was verified by performing rigid-body dynamics analysis, transient structural analysis, and static structural analysis under three impact test conditions: a drop and catch test, a corner pull test, a corner push test. It was found that the local stress concentration in the mount that appeared in the initial design was greatly reduced in the improved design, and that the maximum stresses occurred in the three impact test conditions are smaller than the yield strength. It is expected that the design improvement of the mount proposed in this study and the method of analysis may be effectively used to enhance structural safety in the development of new model front loaders in the future.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.387-390
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• 2012

In this paper, we propose a fast booting solution with embedded linux-based smart devices. We have divided the fast boot process into six steps, such as boot loader, kernel, file system, the init-scripts, shared libraries, and applications for an embedded linux-based boot process to improve the fast booting. Improvements for the fast boot are made in the boot loader phase, which is the first phase at power-up, and the init-script that runs the boot loader phase. To improve the fast booting, standby time from the boot loader and unnecessary initialization routine have been removed, and uncompressed kernel image loading as well as optimized copy routine have been applied. Further, a technology that replaces binary scripts in init-script phase and light-weight init process have been utilized to improve the boot.

• Journal of Korea Multimedia Society
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• v.10 no.11
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• pp.1472-1482
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• 2007

The integrated loader/linker plays a very important role in creating all types of information and ensuring information integrity needed for substantial executions by receiving a PE input file, an intermediate representation of a java class file or a .NET environment, thereby allowing for saving information optimized for verification, resolution, initialization, and execution. This paper proposes a loader/linker system for integrating a java class file and .NET-based PE file. As a means of implementing the loader/linker system, a new execution file format(*.evm) and a memory format were designed to save all information of Java class files and .NET-based PE files, and enable the information in those files to be executed in a JVM or .NET environment through the use of saved execution information.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.5
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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.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.6
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• pp.693-699
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• 2011

In this study, a hydraulic system of a mini-loader is modeled, and the model is validated by comparing the simulation results to the experimental results. A load force acting on the structure of the mini-loader is obtained from the simulation of the hydraulic system, and the structural analysis via finite element method is performed using the obtained load force to evaluate the structural safety of the loader. For the mainframe that requires additional strengthening according to the structural analysis, the optimum design parameters are proposed using the design of experiments to improve strength without additional mass.

• Journal of Drive and Control
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• v.11 no.2
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• pp.22-29
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• 2014

This paper presents simulation-based analysis of energy flow of a wheel loader. The objective of this study is to analyze the energy flow of a wheel loader during driving and working. Because the wheel loader powertrain consists of a mechanical and hydraulic powertrain, the generated power from the engine is divided into 2 powertrains. Further, a virtual prediction of energy flow in the powertrains is a key factor in terms of optimal design. Accordingly, the simulation model that is able to predict the virtual energy flow is developed and analyzed in this study. The proposed wheel loader simulation model has been constructed in the Matlab/Simulink environment. It is expected that the developed simulation model will analyze the energy flow and efficiency in the design stage.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1998.11a
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• pp.414-419
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• 1998

1996년에 3판이 발행된 S-57 표준은 디지틀 수로데이터의 국제적인 교환 표준형식이며 ENC는 S-57을 기본형식으로 하고 특정 상품을 위한 생산품 규약에 의해 만들어진 것이다. ECDIS에 사용되기 위해 만들어진 디지틀 해도 데이터 상품이지만 앞으로 예상되는 ENC 데이터의 일반적 목적을 갖고 있는 사용자들이 모두 S-57과 ENC 생산품 규약을 이해하고 데이터를 읽기 위해 시간과 노력을 투자하는 것은 무척 소비적인 일이 될 것이다. 즉 사용자의 요구는 데이터의 형식이 아니라 데이터의 사용에 집중된다. 그러므로 사용자가 데이터의 내부형식을 알지 못하더라도 사용하고자 하는 의도에 맞게 데이터의 내용을 보여주고 필요한 형식으로 재가공하여 사용할 수 있도록 데이터를 제공하는 프로그램이 필요하며 이는 ENC의 보급 및 활용도를 높이는데 매우 중요하다고 할 수 있다. 본 논문에서는 Data Loader 개발의 기초 단계로 ENC 데이터를 텍스트 형태로 전환하여 ENC에 담긴 내용을 파악할 수 있도록 하는 ENC Data Loader의 기능과 프로그램 개발과정에 대하여 기술하고 텍스트가 아닌 그림으로 보여주며 일반적인 데이터 교환형식으로 변환하는 둥의 새로운 모듈 개발과정을 설명한다. 이를 위해 ENC 데이터의 형식과 내용을 분석하고 GIS 측면에서의 데이터 해석을 시도한다. 또한 이러한 프로그램을 이용한 향후 ENC 데이터의 활용방안에 대하여 기술한다.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.4
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• pp.24-29
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• 2020

Measuring the torque of the wheel loader of a driving device is a preemptive task to ensure its performance. In this study, wireless torque measurements were successfully conducted. Moreover, based on the experimental results and the adopted design method, the key factor of torque generation, which is the main load in driving devices, was analyzed. Other data not analyzed in this paper will be the basis for the logical design of wheel loader-based driving devices.

• Journal of the Ergonomics Society of Korea
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• v.29 no.2
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• pp.249-255
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• 2010

The visibility evaluation is significant for the development of construction equipment. The visibility evaluation follows the standards of ISO 5006, ISO 14401-1, and ISO 14401-2. The evaluation contains the operator's visibility and the visibility of rear-view mirrors. The operator's visibility includes the visibility test which requires the recognition of the rectangular line surrounding the machine by one meter and the circle with a 12 meter radius. This study describes the two evaluation processes for the development of the wheel loader. The first process is the light bulb shadow test by using a prototype wheel loader. The second process is based on computer simulation in virtual space. The advantages and disadvantages of computer simulation process are investigated.