• Journal of Navigation and Port Research
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• v.34 no.3
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• pp.195-203
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• 2010

This paper concerns about total dynamic analysis of integrated mining system. This system consists of vertical steel pipe, intermediate buffer station, flexible pipe and self-propelled miner. The self-propelled miner and buffer are assumed as rigid-body of 6-dof. Discrete models of vertical steel pipe and flexible pipe are adopted, which are obtained by means of lumped-parameter method. The motion of mining vessel is not considered. Instead, the motion of mining vessel is taken into account in form of various boundary conditions (e.g. forced excitation in slow motion and/or fast oscillation and so on). A terramechanics model of extremely cohesive soft soil is applied to the self-propelled miner. Hinged and ball constraints are used to define the connections between sub-systems (vertical steel pipe, buffer, flexible pipe, self-propelled miner). Equations of motion of the coupled model are derived with respect to the each local coordinates system. Four Euler parameters are used to express the orientations of the sub-systems. To solve the equations of motion of the total dynamic model, an incremental-iterative formulation is employed. Newmark-${\beta}$ method is used for time-domain integration. The total dynamic responses of integrated mining system are investigated.

• Proceedings of the KIPE Conference
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• 2011.11a
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• pp.241-242
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• 2011

교통 약자 승객의 편의성 증대, 도심의 매연 감소 및 온실가스 저감 등 대중 교통 선진화를 위해 친환경 초저상 전기버스의 개발이 필요하다. 초저상 전기버스는 초저상 액슬 일체형 휠모터 구동시스템을 탑재한 형태로 구현이 가능하며, 초저상 액슬 일체형 휠모터 구동시스템은 구동 모터를 액슬 허브에 일체화 시킴으로써 기존 구동시스템 대비 무게 및 사이즈가 대폭 줄어들고, 동력 전달 매커니즘을 획기적으로 개선하여 효율 향상 및 차량 연비 개선이 가능하다. 특히 바퀴 중심과 액슬 출력 중심에 단차를 둠으로써 차량의 전방 바닥 뿐만 아니라 후방바닥을 평평하게 유지할 수 있어 실내 공간이 획기적으로 개선되어 교통 약자를 포함한 승객의 편의성을 향상시킬 수 있다. 또한, 액슬 일체형 휠모터 구동시스템은 각 휠의 분산 구동이 가능하므로 동특성 및 구동제어성이 뛰어나고, ESP(Electronic Stability Program), VDC(Vehicle Dynamic Control) 등과 연계하여 통합적인 지능형 시스템을 구현할 수 있다. 액슬 일체형 휠모터 구동시스템은 휠모터와 감속기 및 휠모터제어기 등으로 구성되며, 본 논문에서는 초저상 액슬 일체형 구동시스템용 120kW급 휠모터 및 휠모터제어기의 개발 및 다이나모 환경에서 T-N 특성 및 최대 출력 시험, 효율 시험을 통해 전기버스 등 대형 차량(Heavy Duty Vehicle)에 적용 가능한 전기동력시스템의 성능을 확인하였다.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.4
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• pp.504-510
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• 2019

Practical test items were analyzed to extend the existing scoring method for boat operator licenses to an electronic scoring method. We have attempted to digitize the method within the current practical test system scope and have developed an electronic scoring system using LiDAR sensors and WAVE communication. The results of the study are as follows; the first, the scoring data entered into the LiDAR and examiner score device on the boat were transferred from an integrated processing unit to a land control center through WAVE communication. The system was constructed and verified to store and manage examinee data. Second, when testing the meandering task, accurate distance measurement was achieved by using LiDAR instead of visually observing the stick (3 m), and an accurate distance was displayed through the examiner score device quickly. Finally, we confirmed that it is possible to smoothly transmit and process the WAVE communication used to transfer the score data acquired from the boat to the monitoring center at a high speed without loss.

• Journal of Power System Engineering
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• v.4 no.4
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• pp.92-98
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• 2000

Modern manufacturing systems should cope with the frequent changes in a product model and disturbances in manufacturing process. The control system of such systems must cover a constant adaptation and high flexibility. Holonic Flexible Manufacturing Cell(HFMC) is introduced to handle these issues more successfully. It is based on the concept of autonomous co-operating agent, called 'Holon', which is a building block of a manufacturing system for transforming, transporting, storing and/or validating information and physical objects. In this paper the basic structure of the HFMC is represented by using Unified Modeling Language and Open architecture cell controller is developed for effective integration components of a manufacturing system. Also a new control model, called MuLOM(Multi-Layered Operation Model), is suggested to represent the control behaviour for a holonic flexible manufacturing cell control system.

• Defense and Technology
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• no.11 s.129
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• pp.52-59
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• 1989

BAe사는 영국유수의 수출품제작회사로서 세계에서 손꼽히는 대규모 방산업체 가운데 하나이다. 이 회사는 군용 및 민간용 항공기, 유도무기, 방어용 장비, 우주시스템등 어느나라 보다도 더 많은 종류의 제품을 설계 및 제작하고 있다. 또한 자동차, 병기, 건설 및 전자산업에도 진출하여 세계 1백50개국에 고객을 확보하고 있고, 총 작업인원이 13만명을 상회하고 있다. 이 회사는 최근 고객에 대한 요구를 충족시키기 위해 전문성을 갖도록 독립적으로 회사를 재구성하였다. 방산분야를 볼 때 새로 통합된 조직은 영국 우주항공방산회사로서 3개회사(군용기회사, 동력학회사, 로얄병기회사 등)를 통해 광범위하고 복잡한 군사자원들을 결합시키고 있다

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.5
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• pp.601-607
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• 2013

This paper presents the development and validation of a wheel loader simulation model. The objective of doing so is to evaluate the performance of the wheel loader and improve its overall performance using Matlab/Simulink. The wheel loader simulation model consists of 4 parts: mechanical/hydraulic powertrain model and vehicle/working dynamic model. An integrated simulation model is required to evaluate and improve the performance of the wheel loader. It is expected that this model will be applied to fuel economizing, improving the pace of operation by using the hybrid system, and the intelligent wheel loader. The performance of the proposed simulation model has been validated by using Matlab/Simulink to compare the driving and the working experimental data.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.9
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• pp.833-841
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• 2016

The 200 W electrically powered unmanned aerial vehicle, which is studied in this research, uses solar cells, a fuel cell and batteries as the main power source simultaneously. The output of each power source performs power control for each power source by the active power control method so that an adequate capacity of the battery could be maintained while limiting the maximum output of the fuel cell. The output variation for each power source under the active power control method was identified through an integrated ground test. In addition, the effect of limiting the maximum output of the fuel cell on the output variation of the entire system was experimentally identified, and it was confirmed that the adequate maximum output value of the fuel cell for preventing the overdischarge of six series-connected, small size batteries for fuel cell systems is 150 W.

• Proceedings of the Korea Information Processing Society Conference
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• 2005.11a
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• pp.1259-1262
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• 2005

현재 디지털 기술의 핵심인 임베디드 시스템은 2010년 국민소득 2만불 달성이라는 국가 발전 목표의 실현을 위한 핵심 산업으로 2003년 8월 10개 신성장동력 산업의 핵심육성 분야로 선정되었다. 하지만, 특수한 목적을 위한 다양한 임베디드 시스템은 개발 및 유지 보수 비용과 개발 기간이 장기화 됨으로써 시장경쟁력 약화의 원인이 된다. 본 논문에서는 임베디드 시스템의 신뢰성 있는 개발을 위한 방법으로 가상프로토타이핑을 제안한다. 소프트웨어와 하드웨어로 각각 구현될 도메인을 선정하여 플랫폼 라이브러리에 등록되고 통합된 시뮬레이션을 통한 검증을 수행함으로써 제조 공정이 다른 여러 기능의 블록을 집적하는 기술을 가상플랫폼을 기반으로 가상프로토타이핑한다.

• Convergence Security Journal
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• v.13 no.6
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• pp.61-68
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• 2013

Needs for a new technologies of infrastructure systems arose, following the development of next generation EMU(Electric Multiple Unit) train with maximum speed over 400km/h. For high-speed operation tests of the new EMU, a high-speed railway infrastructure test-bed was constructed in a 28km long section of the Honam High-speed Railway. Diverse sensors and monitoring system was installed for continuous monitoring of the railway. Due to such effort, further demands and needs of the integrated monitoring system was derived in a more comprehensive and long-term perspective.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.12
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• pp.1011-1018
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• 2021

This numerical study conducts the modeling and the hover performance analyses of coaxial co-rotating rotor(or stacked rotor), using a rotorcraft comprehensive analysis code, CAMRAD II. The important design parameters such as the index angle and axial spacing for the coaxial co-rotating rotor are varied in this simulation study. The coaxial co-rotating rotor is trimmed using the torque value of the upper rotor of the previous coaxial counter-rotating rotor or the total thrust value of the previous coaxial counter-rotating rotor in hover. The maximum increases in the rotor thrust is 1.84% for the index angle of -10° when using the torque trim approach. In addition, the maximum decreases in the rotor power is 4.53% for the index angle of 20° with the thrust trim method. Thus, the present study shows that the hover performance of the coaxial co-rotating rotor for e-VTOL aircraft can be changed by the index angle.