• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2016년도 추계학술대회
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• pp.668-669
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• 2016

상용차에 장착된 리타더(retarder)는 상용 브레이크를 보조하는 유압식 브레이크 시스템으로써 운전자의 자동모드 및 수동모드 선택에 의해 작동된다. 리타더 작동에 의해 발생된 열은 리타더 오일에 전달되며 리타더의 냉각기와 차량의 냉각시스템에 의해 열교환이 일어난다. 이때 리타더의 ECU는 자동모드와 수동모드, 리타더 오일/냉각수 온도, 엔진 냉각수 온도, 차량속도 등을 고려하여 제동토크를 조정하는 기능을 수행한다. 본 논문에서는 냉각 시스템 관련 리타더 제어로직 설계와 리타더 제동성능에 따른 시험결과를 제시하고자 한다.

• 산업경영시스템학회지
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• 제34권4호
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• pp.66-71
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• 2011

This article proposes a novel shift automation mechanism for an automated manual transmission (AMT). The development of an automated manual transmission is currently being paid considerable attention by vehicle manufacturers, with the prospects of combining the comfort of an automatic transmission and the high efficiency of a manual transmission. In order to automate the shift mechanism of a manual transmission, the proposed shift automation mechanism consists of two electric motors, cross shaped pinion gears, rack type shift rails, and a ball splined hollow shaft. First we describe the shift mechanism and operating principles of a manual transmission to investigate important design criteria for the shift automation device. And a new shift automation mechanism is described with its structure, elements, and operating principles in detail. Using a conventional manual transmission, we develop a full three-dimensional CAD model of an AMT which includes main components of the manual transmission and the designed shift automation mechanism. Finally we investigate the operating performances and feasibility of the designed AMT by a dynamic analysis.

• 한국자동차공학회논문집
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• 제12권4호
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• pp.146-153
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• 2004

This paper presents a discrete analysis approach to investigate the performance of dual mass flywheel (DMF). In the discrete analysis, arcspring installed between the flywheels is modeled as N- discrete elements. Each element consists of mass, spring and nonlinear friction element. LuGre friction model is used to describe nonlinear friction characteristic. Based on the dynamic models of the DMF, clutch, engine, manual transmission and vehicle, a DMF performance simulator is developed using MATLAB Simulink. Simulation results of the engine speed, driveshaft torque and vehicle velocity are compared with test results. It is found that the discrete DMF model describes the vehicle behavior closely, especially during the clutch actuation period.

• Tribology and Lubricants
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• 제24권6호
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• pp.285-290
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• 2008

The purpose of this paper is to present the case study of tribological failure analysis on the gear damages, oil leakage, and sealant sealing in a manual transmission of front engine and front wheel drive vehicle. The manual transmission is to change the speed range and direction of the engines depending on the driving conditions by friction driving forces with input and output gear system. The material property and surface roughness of the gears are strongly related to the gear noise and micro-vibration, oil leakage and wear, which may decrease the real contact area of the gear and the strength of the oil film thickness between the driving gear and driven one. The O-ring damage of speedometer driven gear and bad sealant sealing of oil pan may produce oil leakage through the contact surfaces, which cause the oil shortage and seizure on the sliding surfaces of the transaxle gears. In the failure case study, the proper repair working and good lubrication are very important for the long life of the transaxle without any tribological failures and oil leakage.

• 한국자동차공학회논문집
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• 제11권3호
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• pp.204-208
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• 2003

This study presents a clutch-by-wire system for automotive which can be utilized on a vehicle with a manual transmission real time while the vehicle is in motion. The system consists of air valve, spring, oil pressure control valve, oil pressure cylinder, switch, etc. In this study, commercial vehicle was studied on improvement of no clutch pedal system. Therefore the results obtained effective driveability, gear shiftability, convenience for driver.

• 한국주거학회논문집
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• 제28권2호
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• pp.23-33
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• 2017

This study was aimed to assess accessibility situation of pedestrian environment of University-C focusing on accessibility of manual wheelchair users and to develop accessibility campus map. During March and April 2016, barrierfree design application situation of pedestrian environment and building entrances were investigated using a structured checklist and a digital distance and slope meter. Major findings are as follow. (1) Except one case, widths of all pedestrian routes (both sidewalk and non-sidewalk routes) exceeded 2 meters. (2) As for sidewalk and driveway contact point condition, there were many spots lacking curb ramp or alterative ramp that are accessible for manual wheelchair users. (3) More than half of non-sidewalk pedestrian routes did not have bollard to separate pedestrian and vehicle flows, and more than 92% of the bollards installed were too close for wheelchair users to pass or too far to prevent vehicle access. (4) More than 59 percent of the building entrances were found impossible for manual wheelchair users to access without any assistance, and one third of the buildings did not have any single accessible entrance. Based on the study findings, campus accessibility map was developed by the researchers and disseminated through university homepage. Using the campus accessibility map, users can plan their accessible paths ahead the trip.

• 동력기계공학회지
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• 제17권5호
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• pp.128-137
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• 2013

Modern transmission technologies such as automated manual transmission(AMT) and dual clutch transmission(DCT) are interested to all manufactures due to their fuel efficiency and driver's convenience, especially in a hybrid system. AMT has advantages in that they have a high efficiency of manual transmissions(MT) and offer operation convenience similar to automatic transmissions(AT), but it has some disadvantages in that they have torque gap during gear shift and shift time. To reduce disadvantages, it is necessary to evaluate errors and characteristics as a developing simulation model before experimental verification. The purpose of this study is to develop virtual components and simulate the transient response of AMT. A dynamic AMT model and a control logic for an integrated vehicle model have been developed using Matlab/Simulink as a simulation platform. In this paper, the clutch model to describe the stick-slip transition mode and the transmission model to describe the neutral gear shifting is introduced and compared with each other.

• 제어로봇시스템학회논문지
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• 제20권11호
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• pp.1112-1117
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• 2014

Unmanned aerial vehicles (UAVs) are a popular research topic because of a great ripple effect in the future. However, current UAV technologies cannot be applied to manual aerial vehicles without any modification. As an alternative to current UAV technology, humanoid robots are adopted as pilots. If a humanoid robot controls an aerial vehicle autonomously, not only could manual aerial vehicles be utilized as UAVs, but the humanoid robot would also be put into an environment created for humans and conduct some missions suitable for humans. Humanoid robots are also able to handle tools and equipment designed for humans. In order to prove that a humanoid robot can pilot an airplane, an experiment is performed and the results of this experiment are shown in this paper.

• ETRI Journal
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• 제45권1호
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• pp.75-92
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• 2023

Level 3 autonomous vehicles require conditional autonomous driving in which autonomous and manual driving are alternately performed; whether the driver can resume manual driving within a limited time should be examined. This study investigates whether the demographics and subjective driving tendencies of drivers affect the take-over performance. We measured and analyzed the reengagement and stabilization time after a take-over request from the autonomous driving system to manual driving using a vehicle simulator that supports the driver's take-over mechanism. We discovered that the driver's reengagement and stabilization time correlated with the speeding and wild driving tendency as well as driving workload questionnaires. To verify the efficiency of subjective questionnaire information, we tested whether the driver with slow or fast reengagement and stabilization time can be detected based on machine learning techniques and obtained results. We expect to apply these results to training programs for autonomous vehicles' users and personalized human-vehicle interfaces for future autonomous vehicles.

• 제어로봇시스템학회논문지
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• 제10권1호
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• pp.66-72
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• 2004

To assess tunnel safety, cracks in tunnel lining are measured by inspectors, who observe cracks with their naked eyes and record them. But manual inspection is slow, and measured crack data is subjective. Therefore, this study proposes inspection system fur measuring cracks in tunnel lining and providing objective crack data to be used in safety assessment. The system consists of On-vehicle system and Laboratory system. On-Vehicle system acquires image data with line CCD camera on scanning along the tunnel lining. Laboratory system extracts crack information from the acquired image using image processing. Measured crack information is crack thickness, length and orientation. To improve accuracy of crack recognition, the geometric properties and patterns of cracks in concrete structure were applied to image processing. The proposed system was verified with experiments in both laboratory environment and field environment such as subway tunnel.