• Title/Summary/Keyword: Back-tracking

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An Intelligent Control of Mobile Robot Using Genetic Algorithm (유전자 알고리즘을 이용한 이동로봇의 지능제어)

  • 한성현
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.13 no.3
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    • pp.126-132
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    • 2004
  • This paper proposed trajectory tracking control based on genetic algorithm. Trajectory tracking control scheme are real coding genetic algorithm(RCGA) and back-propagation algorithm(BPA). Control scheme ability experience proposed simulation. Stable tracking control problem of mobile robots have been studied in recent years. These studies have guaranteed stability of controller, but the performance of transient state has not been guaranteed. In some situations, constant gain controller shows overshoots and oscillations. So we introduce better control scheme using real coding genetic algorithm and neural network. Using RCGA, we can find proper gains in several situations and these gains are generalized by neural network. The generalization power of neural network will give proper gain in untrained situation. Performance of proposed controller will verity numerical simulations and the results show better performance than constant gain controller.

A Point-to-Multipoint Routing Path Selection Algorithm for Dynamic Routing Based ATM Network (동적 라우팅기반의 점대다중점 라우팅 경로 선택)

  • 신현순;이상호;이경호;박권철
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.8A
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    • pp.581-590
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    • 2003
  • This paper proposes the routing path selection mechanism for source routing-based PtMP (Point-to-Multipoint) call in ATM switching system. Especially, it suggests PtMP routing path selection method that can share the maximum resource prior to the optimal path selection, guarantee the reduction of path calculation time and cycle prevention. The searching for the nearest branch point from destination node to make the maximum share of resource is the purpose of this algorithm. Therefore among neighbor nodes from destination node by back-tracking, this algorithm fixes the node crossing first the node on existing path having the same Call ID as branch node, constructs the optimal PtMP routing path. The optimal node to be selected by back-tracking is selected by the use of Dijkstra algorithm. That is to say, PtMP routing path selection performs the step of cross node selection among neighboring nodes by back-tracking and the step of optimal node selection(optimal path calculation) among neighboring nodes by back-tracking. This technique reduces the process of search of routing information table for path selection and path calculation, also solves the cycle prevention easily during path establishment.

Using play-back image sequence to detect a vehicle cutting in a line automatically (역방향 영상재생을 이용한 끼어들기 차량 자동추적)

  • Rheu, Jee-Hyung;Kim, Young-Mo
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.2
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    • pp.95-101
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    • 2014
  • This paper explains effective tracking method for a vehicle cutting in a line on the road automatically. The method employs KLT based on optical flow using play-back image sequence. Main contribution of this paper is play-back image sequence that is in order image frames for rewind direction from a reference point in time. The moment when recognizing camera can read a license plate very well can usually be the reference point in time. The biggest images of object traced can usually be obtained at this moment also. When optic flow is applied, the bigger image of the object traced can be obtained, the more feature points can be obtained. More many feature points bring good result of tracking object. After the recognizing cameras read a license plate on the vehicle suspected of cut-in-line violation, and then the system extracts the play-back image sequence from the tracking cameras for watching wide range. This paper compares using play-back image sequence as normal method for tracking to using play-forward image sequence as suggested method on the results of the experiment and also shows the suggested algorithm has a good performance that can be applied to the unmanned system for watching cut-in-line violation.

Comparison of Eye Movement and Fit Rating Criteria in Judging Pants Fit Between Experts and Novices - Using Eye Tracking Technology - (바지 맞음새 평가 시 전문가와 초보자의 시선추적 및 맞음새 평가 항목의 중요도 비교분석 - Eye Tracking 기법을 이용하여 -)

  • Kim, Youngsook;Song, Hwa Kyung;Jang, Hyowoong
    • Fashion & Textile Research Journal
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    • v.19 no.2
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    • pp.230-239
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    • 2017
  • In the clothes industry, there are lack of experts including technical designers who can analyze the fit of clothes. This study is to provide practical data available for fit analysis education by distinguishing the differences in standards and aspects of garment fit between experts and novices, through the eye-tracking technology to quantify the sense of fit. For this study, two groups were organized; one composed of 7 experts with over 15 year-experience including technical designers and patternmakers, and the other composed of 7 novices who are students majoring in clothing. Wearing the goggle type eye-tracker Tobii Pro Glasses 2, the participants in the experiments were required to conduct fit analyses for a pair of pants on a live model. After those experiments, they were required to check the items for fit analysis and assess the importance level of them on a questionnaire. The differences between the two groups in the ratios of total visit count and total visit duration by each AIO(Area of Interest) of clothes were analyzed through non-parametric statistical test. The results of eye tracking experiments showed that experts focused on center front and back line, crotch area, and side seam, while novice's fixation points were dispersed around the pants. The survey results showed that the experts put importance on the center line position and its verticality, front-back proportion of side seam line, and front-back proportion of waist line, 71.4~100% of whom checked them, while 14.3% of the novices checked them.

A Self-Organizing Fuzzy Control Approach to the Driving Control of a Mobile Robot (자기구성 퍼지제어기를 이용한 이동로봇의 구동제어)

  • Bae, Kang-Yul
    • Journal of the Korean Society for Precision Engineering
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    • v.23 no.12 s.189
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    • pp.46-55
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    • 2006
  • A robust motion controller based on self-organizing fuzzy control(SOFC) and feed-back tracking control technique is proposed for a two-wheel driven mobile robot. The feed-back control technique of the controller guarantees the robot follows a desired trajectory. The SOFC technique of the controller deals with unmodelled dynamics of the vehicle and uncertainties. The computer simulations are carried out to verify the tracking ability of the proposed controller with various driving situations. The results of the simulations reveal the effectiveness and stability of the proposed controller to compensate the unmodelled dynamics and uncertainties.

Direct Power Control Scheme of Improved Command Tracking Capability for PMSG MV Wind turbines

  • Kwon, Gookmin;Suh, Yongsug
    • Proceedings of the KIPE Conference
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    • 2015.07a
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    • pp.361-362
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    • 2015
  • This paper proposes a Direct Power Control (DPC) scheme of improved command tracking capability for Permanent Magnet Synchronous Generator (PMSG) Medium Voltage (MV) Wind Turbines. Benchmarking is performed based on a neutral point clamped three-level back-to-back type voltage source converter. It is introduced to design the DPC modeling and propose DPC scheme of a three-level NPC (3L-NPC) converter. During the fault condition in wind farms, the proposed control scheme directly controls the generated output power to the command value from the hierarchical wind farm controller. The proposed control scheme is compared with conventional control scheme as respect to loss and thermal analysis. The DPC scheme of improved command tracking capability is confirmed through PLECS simulations. Simulation result shows that proposed control scheme achieves a much shorter transient time in a step response of generated output power. The proposed control scheme makes it possible to provide a good dynamic performance for PMSG MV wind turbine to generate a high quality output power under grid fault condition.

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Efficiency analysis of PV tracking system with PSA algorithm (PSA 알고리즘에 의한 태양광 추적시스템의 효율분석)

  • Back, Jung-Woo;Ko, Jae-Sub;Choi, Jung-Sik;Jang, Mi-Geum;Kang, Sung-Jun;Chung, Dong-Hwa
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2009.05a
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    • pp.412-415
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    • 2009
  • This paper analyzes efficiency of photovoltaic(PV) tracking system using position solar algorithm(PSA). Solar location tracking system is needed for efficiently and intensively using PV system independent of environmental condition. PV tracking system of program method is presented a high tracking accuracy without the wrong operating in rapidly changed insolation by the clouds and atmospheric condition. Therefore, this paper analyzes efficiency of PV system using PSA algorithm for more correct position tracking of solar. Also, controlled altitude angle and azimuth angle by applied algorithm is compared with data of korea astronomy observatory. And this paper analyzes the tracking error and roves the validity of applied algorithm.

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Evaluation of Tool Paths and NC Codes Generation for PCB Drilling Operations (PCB 홀 천공순서의 평가 및 NC 코드의 생성)

  • Choi, Hoo-Gon;Lee, Ho-Chan;Seo, Jun-Sung
    • IE interfaces
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    • v.10 no.1
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    • pp.223-235
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    • 1997
  • The process of determining the optimal tool path in PCB(printed circuit board) drilling operations is identical with that of solving a TSP(traveling salesman problem). However, the optimal solution will be ruined when a drill bit needs tracking back in its tool paths. The back tracking occurrences shorten a life of the main spindle and result in inaccurate mechanical movements. In this study, the performances of four heuristics(Nearest Neighbor, Convex Hull, Greatest Angle and Most Eccentric Ellipse) are evaluated to obtain feasible tool paths along with less number of back trackings for a large number of holes(more than 2000holes/bit) and to generate corresponding NC codes for a given CNC drill. Also, the operations of these algorithms are visualized to show a user the graphic image of tool visitation with PCB holes on a computer screen.

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Coupling Analysis of Slim Type Optical Pick-up using Back Electromotive Force, and Decoupling Control for It (역기전력을 이용한 슬림형 광 픽업의 연성 해석 및 비연성 제어기 설계)

  • Choi, Jin-Young;Lee, Kwang-Hyun;Lee, Jae-Sung;Kim, Sang-Hoon;Yang, Hyun-Seok;Park, No-Cheol;Park, Young-Pil
    • Transactions of the Society of Information Storage Systems
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    • v.2 no.2
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    • pp.117-122
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    • 2006
  • A novel method to find interaction dynamics between focusing direction and tracking direction in an optical pick-up is proposed. and the decoupling control to reduce the interaction effect is discussed. First, the basic principle to detect dynamic interaction analysis using back electromotive force is introduced. Second, the interaction analysis between focusing and tracking direction of is analyzed for a commercial slim type optical pick-up. Finally. decoupling control process and its simulation results are shown.

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The Real-time Neural Network Control of Mobile Robot Based-on Genetic Algorithm (유전 알고리즘을 이용한 이동로봇의 실시간 신경회로망 제어)

  • 정경규;김종수;이우송;이명재;한성현
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2002.04a
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    • pp.561-566
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    • 2002
  • This paper proposed trajectory tracking control of Mobile Robot. Trajectory tracking control scheme are Real coding Genetic-Algorithm and Back-propergation Algorithm. Control scheme ability experience proposed simulation.

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