• Journal of Digital Convergence
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• v.12 no.6
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• pp.349-354
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• 2014

A maze-escaping method with cooperating work of robots alongside one another will be proposed in this paper. Educational robots can communicate each other using Zigbee; however, they can't solve problems together due to their lack of arithmetic function. The robots walk upright controlled by a motion program; furthermore, they recognize an intersection or a dead-end in the use of distant sensors with sending data and receiving commands from the central control system. The maze-search algorithms were modified so that all robots can effectively navigate the maze.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.66-66
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• 2000

In this parer, we introduce an algorithm to control flows of the traffic in multi-intersections. It is pointed out that the main problem in traffic control is how to resolve the congested situations for the particular time-durations and directions. The heavy load to a certain direction usually leads the intersection to congested situations, and the adjacent intersections are affected. We control and analyze the traffic flow of multi-intersections consisting of five intersections, in which four intersections are linked to the four directions of the central one. The entrance of vehicles of each direction is described using the concept of probability. We compare the performance of the pretimed signal controls to the traffic adaptive signal controller using a Petri Net simulation tool, Exspect.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.1003-1006
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• 2002

In machining free-form curves with a machine tool equipped with parallel device, improving contouring accuracy is very important. In this paper, we present contouring control algorithm far parallel machine tool. The relation between the error in Joint space and the error in catesian space is evaluated, and we estimate contouring error vector which efficiently determines the variable gains for the cross coupled control. To show the validity of the algorithm, the contouring control is simulated for free form contour trajectory in cubic parallel machine tool model.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.11
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• pp.948-953
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• 2002

The electronic expansion valve (EEV) may be used to control the refrigerant flow rate for the multi-type heat pump. Stepping motor driven EEV may precisely control the refrigerant flow rate to meet each internal load requirement. To control the EEV, PI algorithm may be used. But the hysteresis of EEV deteriorates the performance of superheat control. To reduce the performance degradation, the PI algorithm along with the dither signal may be used. The dither signal, with about 10 times higher frequency than the system crossover frequency and about 10 times larger magnitude than the deadband of hysteresis, was selected for the superheat control of EEV. Experimental results showed the improvement of EEV control by adding the dither signal to the PI algorithm.

• Proceedings of the KIPE Conference
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• 2012.07a
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• pp.588-589
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• 2012

최근 LED 드라이버의 효율 향상에 집중될수록 LED의 특성을 고려한 정전류 제어가 더욱 중요해지고 있다. 본 논문에서는 LED 모듈과 같은 정전류 제어가 필요한 부하에 플라이백 컨버터의 병렬구조 연결에 의한 정전류 공급법에 대해 제안한다. 플라이백 컨버터를 병렬구조로 연결하고 전류 불연속 모드 상태에서 스위칭 소자에 PWM 신호를 교차 인가하고, 또한 싱글 스테이지의 전력변환을 함으로써 시스템 효율을 개선하였다. 더불어 병렬구조로 연결된 플라이백 컨버터의 변압기를 통합하여 설계함으로써 코어의 부피, 비용 및 출력 리플 저감의 효과를 가능하게 하였다. 제안된 알고리즘 및 시스템에 대해서 시뮬레이션을 통해 그 타당성을 검증하였다.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.8
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• pp.65-72
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• 1997

An asymmetrical cross-coupled compensator to improve the contouring performance is proposed. This is a refinement of the structure suggested by Koren. The position loop is closed with a proportional controller as in the uncoupled system. An additional input term proportional to the component of the contour error along the corresponding axis is included. The controller gains are chosen to give an appropriate frequency response and an optimum range for the damping ratio. The effectiveness of the proposed controller is studied by means of digital simulations of the dynamics of the drives and the controller for 4 types of command trajectories: straight line contour, cornering contour, circular contour, elliptic contour. Substantial improvement in contouring performance is obtained for a range of contouring conditions.

• Annual Conference of KIPS
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• 2021.11a
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• pp.367-370
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• 2021

스마트 시티에서 교차로의 통행을 관리하는 교통신호 시스템 분야의 목표는 교통 혼잡 최소화 및 처리량 최대화이다. 현재, 신호 제어 시스템은 고정형 시스템을 사용하고 있으며, 효율적이고 유동적으로 교통을 제어하기 위해 적응형 방식의 교통신호 제어 연구가 활발히 진행 중이다. 적응형 방식의 교통신호 방식 중에서 고정된 신호 순서에 상황에 맞는 신호시간을 할당하는 방법이 있다. 본 논문은 고정된 신호 순서가 교통 신호 성능에 미치는 영향을 분석하였다. 그 결과, 신호 순서가 교통신호 성능에 미치는 영향도가 크지 않다는 것을 확인할 수 있었다.

• Journal of the Society of Disaster Information
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• v.11 no.4
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• pp.570-580
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• 2015

In the study, planning indicator that should be considered in applying traffic calming technique was derived, and it was intended to analyze the importance of indicator that should most considered in planning traffic calming technique through AHP analysis on the basis of it. The result of planning indicator may be summarized by dividing into road section and crossing section. In road section, hump (0.35) for equipment stimulating reduction of speed, hump image/fort (0.31) for visual control equipment, and slalom type road (0.52) for chicane, and bollard (0.47) for blocking passing route are shown to be the most important and come before anything. In crossing section, signal indicator (0.33) for visual control equipment, rumble strip (0.44) for equipment stimulating reduction of speed, zigzag type road (0.65) for chicane, and blocking going straight at crossing (0.45) for blocking passing route are shown to be the most important and come before anything. The result of the study is judged to be used for basic material in applying traffic calming technique and establishing policy hereafter.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.2
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• pp.77-92
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• 2019

TPCLT is a advanced signal system that serves twice left turn phases during the same cycle. TPCLT can be a useful where the left turn traffic volume is high and the length of the left turn lane is short. This study examined the effectiveness of TPCLT in reducing delay for a signalized three-Leg intersection and proposed the application of TPCLT signal system. 108 scenarios with different traffic volumes were created. This study analyzed the control delay of the three-Leg intersection in case TPCLT is operated and non-TPCLT is operated. As a result of analysis, it was shown that TPCLT was effective in most of the scenarios. When traffic volume ratio of the left turn is 30~40%, TPCLT was more effective at reducing the control delay. The study result shows significant delay reduction for the left turning traffic and it is approximately 50 seconds. The opposing movement's average control delay increased 2 seconds. The effect of TPCLT on the length of left turn lane was analyzed. As a result, it is found that TPCLT is effective when the length of left turn lane is 30%~60% compared to that of conventional three leg intersection operations.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.4
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• pp.897-905
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• 2015

This research suggested the traffic signal calculation model of active transit signal priority using a shockwave model. Using this signal priority timing optimization model, the shockwave area is computed under the condition of Early Green and Green Extension among active transit signal priority techniques. This study suggested the speed estimation method of backward shockwave using average travel time and intersection passing time. A shockwave area change is calculated according to signal timing change of transit signal priority. Moreover, this signal timing calculation model could determine the optimal signal priority timings to minimize intersection delay of general vehicles. A micro simulation analysis using VISSIM and its user application model ComInterface was applied. This study checked that this model could calculate the signal timings to minimize intersection delay considering saturation condition of traffic flow. In case studies using an isolated intersection, this study checked that this model could improve general vehicle delay of more over ten percentage as compared with equality reduction strategy of non-priority phases. Recently, transit priority facilities are spreading such as tram, BRT and median bus lane in Korea. This research has an important significance in that the proposed priority model is a new methodology that improve operation efficiency of signal intersection.