• 한국정밀공학회지
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• 제24권12호
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• pp.74-81
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• 2007

This paper focuses on improvement of the reliability for endurance test to serve military automobiles. The driving loads have been measured by use of the wireless telemetry system for the drive shaft of the 4-wheel drive car. In order to analyze the transmission input torque and engine revolution of loads of the test courses and unpaved road have been made use of the revolution counting and cumulative damage by miner's rule. This paper presents the evaluated result for quantified damage about the test courses and roads.

• 대한의용생체공학회:의공학회지
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• 제38권4호
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• pp.197-204
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• 2017

The aim of this study was to evaluate driving performance of normal subjects for controlling the steering wheel by using foot operated steering devices in the driving simulator. Many people with complete bilateral loss or loss of use of upper limbs but with normal lower limbs are frequently left without use and/ or control of their hands, arms, or the upper extremities of their bodies. As a result, persons disabled in this manner have problems in operation an automobile because they cannot grasp and manipulate a conventional steering wheel. Therefore, if foot operated steering devices are used for controlling the vehicle on in people with disabilities, the disabled people could improve their community mobility by driving a car safely. Ten normal subjects were involved in this research to evaluate steering performance by using three types of steering devices(conventional steering wheel, pedal type foot steering, circular type foot steering) in driving simulator. STISim Drive 3 program was used for testing the driving performance in two road scenarios: straight road and curved road at low and high speed of vehicle (40 km/h and 80 km/h). This study used two-way ANOVA to compare the influences of two factors(type of foot steering device and road scenario) in the three dependent variables of steering performance(standard deviation of lateral position, the lateral position of vehicle and the number of line crossing). The average values of the three dependent variables(standard deviation of lateral position, lateral position and the number of line crossing) of driving performance were significantly smaller for conventional steering wheel or pedal type foot steering than circular type foot steering.

• 동력기계공학회지
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• 제8권4호
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• pp.57-63
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• 2004

Conventionally, 2WS is used for vehicle steering, which can only steering front wheel. In case of trying to high speed lane change or cornering through this kind of vehicle equipped 2WS, it may occur much of Yaw moment. On the other hand, 4WS makes decreasing of Yawing Moment, outstandingly, so it is possible to support vehicle movement stable. And conventional ABS and TCS can only possible to control the longitudinal movement of braking equipment and drive which can only available to control of longitudinal direction. There after new braking system ESP was developed, which controls both of longitudinal and lateral, with adding of the function of controlling Active Yaw Moment. On this paper, we show about not only designing of improved braking and steering system through establishing of the integrated control system design of 4WS and ESP but also designing of the system contribute to precautious for advanced vehicle stability problem.

• 자동차안전학회지
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• 제5권1호
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• pp.62-68
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• 2013

This paper describes development of 4 Wheel Drive (4WD) Electric Vehicle (EV) based driving control algorithm for severe driving situation such as icy road or disturbance. The proposed control algorithm consists three parts : a supervisory controller, an upper-level controller and optimal torque vectoring controller. The supervisory controller determines desired dynamics with cornering stiffness estimator using recursive least square. The upper-level controller determines longitudinal force and yaw moment using sliding mode control. The yaw moment, particularly, is calculated by integration of a side-slip angle and yaw rate for the performance and robustness benefits. The optimal torque vectoring controller determines the optimal torques each wheel using control allocation method. The numerical simulation studies have been conducted to evaluated the proposed driving control algorithm. It has been shown from simulation studies that vehicle maneuverability and lateral stability performance can be significantly improved by the proposed driving controller in severe driving situations.

• 한국산학기술학회논문지
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• 제11권1호
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• pp.159-165
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• 2010

본 논문에서는 원격제어기반 이동체 감지 및 변형 퍼스널 로봇시스템을 설계 및 구현하고 성능을 분석하였다. 설계에 있어서 중점적으로 고려한 사항은 퍼스널 로봇의 버튼기반 및 원격제어방식 설계, 휠 주행모드/보행모드/자동 주행모드/감시모드의 동작모드 설계, 원격제어기능 설계, 주변환경 변화감지 기능 설계, 모션데이터 추출기법 설계, 장애물 탐지기법 설계이다. 개발한 퍼스널 로봇은 언제 어디서나 원격지에서 인터넷과 접속하여 로봇의 동작 및 영상인식을 제어하여 주변 환경변화를 감지하는 이동체 감지 및 4가지의 변형이 가능하다. 또한 실험결과, 실내의 문턱이나 전선등으로 이루어진 지형의 요철을 다리 관절로 이동 가능하며, 자동 주행모드로 진행 할 경우 30cm*30cm 공간의 장애물 환경에서 3개의 적외선 센서를 이용하여 장애물을 성공적으로 벗어남을 확인하였다.

• 한국지능시스템학회논문지
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• 제23권4호
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• pp.332-340
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• 2013

본 논문은 실제 환경과 모의실험에서 이동 로봇의 위치 추정과 자율주행 구현을 위한 프로그래밍 툴킷에 대해 서술한다. 기존에 사용되고 있는 라이브러리들은 복잡성과 유용성의 결함으로 사용에 어려움이 있다. 제안된 툴킷은 추측항법, 운동 모델, 측정 모델, 그리고 방향 또는 지향각의 연산을 위한 툴킷들로 구성된다. 추측 항법과 운동 모델은 차륜 구동 로봇과 전, 후륜 속도에 의한 이륜차 로봇에 대해 다룬다. 툴킷들은 실제 환경과 모의실험에서의 자율주행을 위해 사용 가능하다. 툴킷의 사용가능성은 모의실험의 결과와 실제 실험의 결과를 보임으로써 증명한다. 제안된 툴킷은 이동 로봇의 위치추정, 지도 작성, 그리고 장애물 회피와 같은 자율주행의 구성 기술을 위한 알고리즘의 검사에 사용할 수 있을 것으로 기대된다.

• 한국철도학회논문집
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• 제11권4호
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• pp.398-403
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• 2008

전동차용 견인전동기 시스템은 저항 및 쵸퍼 제어에 의한 직류 전동기 방식에서 인버터 제어에 의한 유도전동기 방식으로 발전하였다. 오늘날 유도전동기 기술은 어느 정도 성숙기에 접어들었지만 최근에는 소음제거, 효율 극대화 및 유지보수 비용 절감 등의 이점이 있는 감속기를 제거한 직접 구동용 영구자석 전동기가 새로이 각광받고 있다. 특히 기계적으로 견고한 매입형 영구자석 동기전동기는 출력/토크 밀도가 높고 약계자 제어성이 우수하며 고효율 운전이 가능하다. 본 논문은 자기적 포화특성이 심한 영구자석 전동기를 대상으로 고급화된 비선형 수치해석 기법을 적용하여 설계된 전동기의 특성해석을 나타낸다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 추계학술대회 논문집 학회본부
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• pp.172-174
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• 1994

Due to the environmental considerations and the energy crisis, there has been a revival of electric vehicles since 1960s. Research and development work concerning with electric vehicles (EVs) was becoming more intense in last decade. As compared with conventional internal combustion engine (ICE) cars, EVs have the advantages of clean, quiet, better energy efficiency, less maintenance and improving the load factor of electric power systems. However, EVs usually have a snort running range, bad acceleration performance and high initial cost. The main reason for these shortcomings is the low figure of energy density and the high per energy cost of battery at present technology state. So it is very important to optimize the overall drive system design with respect to the maximum utilization of battery, energy, motor torque and inverter power. This paper describes a demonstration model of electric car which is driven by 4-wheel direct method using the vector control.

• Journal of Electrical Engineering and Technology
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• 제4권4호
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• pp.499-509
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• 2009

Electric vehicles (EV) are developing fast during this decade due to drastic issues on the protection of environment and the shortage of energy sources, so new technologies allow the development of electric vehicles (EV) by means of electric motors associated with static converters. The proposed propulsion system consists of two induction motors (IM) that ensure the drive of the two back driving wheels. The electronic differential system ensures the robust control of the vehicle behavior on the road. It also allows controlling, independently, every driving wheel to turn at different speeds in any curve. This paper presents the study of an hybrid Fuzzy-sliding mode control (SMC) strategy for the electric vehicle driving wheels, stability improvement, in which the fuzzy logic system replace the discontinuous control action of the classical SMC law. Our electric vehicle fuzzy-sliding mode control's simulated in Matlab SIMULINK environment, the results obtained present the efficiency of the proposed control with no overshoot, the rising time is perfected with good disturbances rejections comparing with the classical control law.

• 대한의용생체공학회:의공학회지
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• 제38권1호
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• pp.32-42
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• 2017

The aim of this study was to evaluate driving performance of Healthy and disabled groups (with or without driver's license) to control steering wheel by using steering assistive devices in the driving simulator. The persons with partial loss of use of all four limbs have problems in operation of the motor vehicle because of functional loss to operate steering wheel. Therefore, if steering assistive devices for grasping the steering wheel are used to control the vehicle on the road in persons with disabilities, the disabled persons can improve mobility in their community life by driving a motor vehicle safely. Ten healthy subjects (with or w/o driver's license) and ten subjects with physical disabilities (with or w/o driver's license) were involved in this study to evaluate driving performance to operate steering wheel by using four types of steering assistive devices (Single-pin, V-grip, Palm-grip, Tri-pin) in driving simulator. STISim Drive 3 software was used to test the steering performance in four scenarios: straight road at low and high speed of vehicle (40 km/h and 80 km/h), curved road at low and high speed of vehicle (40 km/h and 80 km/h). This study used two-way ANOVA in order to compare the effects of two factors (type of steering assistive device and subject group) in the three dependent variables of driving performance (the lateral position of vehicle, standard deviation of lateral position representing the variation of the left and right movement of the vehicle and the number of line crossing). The mean values of the three dependent variables (lateral position, standard deviation of lateral position, the number of line crossing) of steering performance were statistically significantly smaller for the healthy or disabled groups with driver's license than the other groups without driver's license on the curved road at high speed of vehicle compared to low speed of vehicle.