• Journal of the Korean Institute of Intelligent Systems
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• v.10 no.6
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• pp.597-604
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• 2000

본 연구에서는 전기자동차에 사용되는 전자식 차동 시스템의 신경망 모델을 제안한다. 차량이 곡선도로를 따라 주행할 경우 내측 바퀴와 외측 바퀴의 회전속도가 서로 달라야 진동이나 뒤틀림 없이 완만한 선회 주행을 할 수 있다. 전기자동차는 그 구조적 특성상 각각의 바퀴가 독립된 구동원을 갖는다. 이 때문에 일반 엔진 차량의 기어식 차동장치를 대신할 전자식 차동장치가 요구된다. 이러한 차동장치는 차량의 구조뿐만 아니라 차량의 주요 파라미터인 조향각 및 속도에 따라서 비선형적인 관계를 가지고 있어서 해석하기가 쉽지 않다. 따라서 이와 같은 비선형적인 관계 모델을 학습 능력을 가진 신경망에 의하여 모델링 함으로써 제어에 적용할 수 있다. 이를 실현하기 위해 제작한 전기자동차로 곡선도로를 주행하여 다양한 곡률과 주행속도에 따른 내측 외측 바퀴의 회전속도 데이터를 획득하고, 데이터의 비선형 특성을 고려한 차동 속도 제어기의 구조를 설계한다. 이 제어기에 적합한 모델은 신경망을 이용하여 실측 데이터를 학습시킴으로써 차동기능을 수행할 수 있는 제어기를 구현한다.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1142-1147
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• 2004

The tooth profile of helical gear that is manufactured by the rack cutter consists of the involute curve and the trochoid curve. However, gear designers are very hard to calculate the exact profile because it needs very complex information about the gear manufacturing. Therefore, the purpose of this study is to develop the automatic generation program for the helical gear using the Solid Works API. First, involute and trochoide coordinates by the rack cutter are calculated. Using the data, Visual Basic program for the helical gear model is coded. This work gives us the quick helical gear modeling and can be used as the modeling for the finite element analysis.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.2
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• pp.32-37
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• 2011

This study developed Gear Automatic Design Program that users with the basic knowledge about mechanical engineering can easily model spur gears and helical gears. The Gear Automatic Design Program used Visual LISP which is an user program based on Auto CAD and made it model the gears with involute tooth by the exact mathematic definition. Also, to verify these, the reliability was secured by comparing it with a gear generated in commercial software. And we will develop nitrocarburising process and solve problems which had been caused of SCM440's dimensional changing.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.1
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• pp.151-159
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• 2008

The parameter-based cardiovascular impedance simulator that is able to overcome the limits of conventional mock circulatory systems is critical for the development and test of biomedical devices including artificial heart. The concept of impedance simulator was validated mathematically in a previous study using high-gain feedback linearization control which, however, may cause serious difficulties and limits for practical implementation. In this study, therefore, practical applicability of the impedance simulator is investigated considering the physical limits such as motor speed and torque. Simple PID controller which do not require complex model of the simulator is used considering the practical implementation. Design guidelines of the impedance simulator are also provided based on the results.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.12
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• pp.1718-1723
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• 2015

The diameter of the rotor of 2MW wind turbine is being developed by a number of companies with more than 80m, reliability and economic efficiency of the wind power generator has been improved. The need for large-scale wind turbine with excellent economy has been attracting attention because the new orders and the location of the wind turbine market has reached a limit. Technology development for enlargement of wind turbine is possible not only the improvement of energy efficiency but also reduce the construction costs per unit capacity. However, mechanical gearboxes used in wind generators have problems of wear, damage, need for lubrication oil and maintenance. Therefore, we want to configure the gearbox of a large-scale wind turbine using a magnetic gear in order to solve these problems of mechanical gearbox.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.12
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• pp.857-862
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• 2014

In this paper, we designed and fabricated electromagnetic induction based scaffold type energy harvester. For energy harvesting, mechanical energy of vertical motion is transferred to rotational energy using rack gear and multiplying gear was used to maximize energy transfer. To optimize design parameters, physical structure of energy harvester was modeled using finite element method. The effect of multiplying gear ratio and frequency levels of applied mechanical energy on energy generation efficiency are analyzed by computer simulation and experimental test. Experimental results showed that maximum 25.36 W of electric power can be achieved at the frequency of 2 Hz and 1:77 of gear ratio with only 5 mm of vertical changes on scaffold structure.

• Tribology and Lubricants
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• v.24 no.5
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• pp.221-227
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• 2008

This paper presents a step-by-step design of noncircular gears. From the diagram of angular velocity ratio of a noncircular gear pair, the pitch curves of the two mating gears are determined, and the perimeter of the pitch curve has been divided into equal-length segments by the number of teeth. A master tooth profile, which is a composite curve of circular arcs that represents involute, has been introduced. A noncircular gear pair has been designed by imposing the master tooth on the divided points of the pitch curve, and a full fillet has been achieved between neighbour teeth. Thus, the whole profile of the noncircular gear is a composite curve of arcs only, and consequently NC codes for wire EDM can be easily generated.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.11
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• pp.140-148
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• 2004

Tight integration of product design and process planning in the early design stage would make bigger impact as wider spectrum of design and manufacturing alternatives can be pursued and evaluated. Thus the development of systematic computer-based supporting for this integration if desirable. For this integration and process planning in the early design stage, the systematic method to synthesize shape of part from functional requirements is crucial. This research presents the methods of functional decomposition from overall function of product and synthesizing shape of part based on functional relations extracted from functional decomposition using planetary gear transmission system as an example.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.319-322
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• 2006

Under the national project for the development of 2MW wind energy convert system, we are under development of the prototype of 2MW wind turbine with low speed gearbox. This system adopts low speed gear box with planetary and spur gear and is pitch regulated variable speed type with the synchronous permanent magnet generator. The compromised size of generator in diameter and width are adopted to meet the structural design requirements. In this paper, the concept study for the type, the aerodynamic design for the blade and the details of load calculation will be presented. The detailed characteristics of the system will also be introduced.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1997.10a
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• pp.50-57
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• 1997

A 600HP class high-speed gear driven 3-stage turbo-compressor (IGCC : Integrally Geared Centrifugal Compressor) driven by a 3600 rpm AC induction motor has been designed, of which low speed pinion runs at 35000 rpm and high speed pinion at 50000 rpm nominally. Due to its high speed operation, the system requires very reliable bearing selection and design as well as accurate rotordynamic analysis and prediction of its dynamic behavior to secure the operating reliability. Rotordaynamic analyses of the IGCC rotor-bearing system predicted that the low speed pinion rotor mounted on 5-pad tilting pad bearings has two critical speeds before its design speed and high speed pinion rotor only one critical speed, and estimated critical speeds of both pinion shafts are away from the continuous operating speed enough to satisfy the corresponding API requirement. The forced response analysis with API specified maximum allowable unbalances also showed that unbalance responses are small enough for smooth operation of the system.