• Title/Summary/Keyword: Moving Condition

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Optimal path planning for the capturing of a moving object

  • Hwang, Cheol-Ho;Lee, Sang-Hun;Ko, Jae-Pyung;Lee, Jang-Myung
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.186-190
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    • 2003
  • In this paper, we propose an algorithm for planning an optimal path to capture a moving object by a mobile robot in real-time. The direction and rotational angular velocity of the moving object are estimated using the Kalman filter, a state estimator. It is demonstrated that the moving object is tracked by using a 2-DOF active camera mounted on the mobile robot and then captured by a mobile manipulator. The optimal path to capture the moving object is dependent on the initial conditions of the mobile robot, and the real-time planning of the robot trajectory is definitely required for the successful capturing of the moving object. Therefore the algorithm that determines the optimal path to capture a moving object depending on the initial conditions of the mobile robot and the conditions of a moving object is proposed in this paper. For real-time implementation, the optimal representative blocks have been utilized for the experiments to show the effectiveness of the proposed algorithm.

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Search for Ground Moving Targets Using Dynamic Probability Maps (동적 확률지도를 이용한 지상 이동표적 탐색)

  • Kim, Eun-Kyu;Choi, Bong-Wan;Yim, Dong-Soon
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.38 no.4
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    • pp.11-21
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    • 2015
  • In order to achieve success in ground operations, searching for moving targets is one of critical factors. Usually, the system of searching for adversary ground moving targets has complex properties which includes target's moving characteristics, camouflage level, terrain, weather, available search time window, distance between target and searcher, moving speed, target's tactics, etc. The purpose of this paper is to present a practical quantitative method for effectively searching for infiltrated moving targets considering aforementioned complex properties. Based upon search theories, this paper consists of two parts. One is infiltration route analysis, through terrain and mobility analysis. The other is building dynamic probability maps through Monte Carlo simulation to determine the prioritized searching area for moving targets. This study primarily considers ground moving targets' moving pattern. These move by foot and because terrain has a great effect on the target's movement, they generally travel along a constrained path. With the ideas based on the terrain's effect, this study deliberately performed terrain and mobility analysis and built a constrained path. In addition, dynamic probability maps taking terrain condition and a target's moving speed into consideration is proposed. This analysis is considerably distinct from other existing studies using supposed transition probability for searching moving targets. A case study is performed to validate the effectiveness and usefulness of our methodology. Also, this study suggests that the proposed approach can be used for searching for infiltrated ground moving target within critical time window. The proposed method could be used not only to assist a searcher's mission planning, but also to support the tactical commander's timely decision making ability and ensure the operations' success.

Intelligent Optimal Route Planning Based on Context Awareness (상황인식 기반 지능형 최적 경로계획)

  • Lee, Hyun-Jung;Chang, Yong-Sik
    • Asia pacific journal of information systems
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    • v.19 no.2
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    • pp.117-137
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    • 2009
  • Recently, intelligent traffic information systems have enabled people to forecast traffic conditions before hitting the road. These convenient systems operate on the basis of data reflecting current road and traffic conditions as well as distance-based data between locations. Thanks to the rapid development of ubiquitous computing, tremendous context data have become readily available making vehicle route planning easier than ever. Previous research in relation to optimization of vehicle route planning merely focused on finding the optimal distance between locations. Contexts reflecting the road and traffic conditions were then not seriously treated as a way to resolve the optimal routing problems based on distance-based route planning, because this kind of information does not have much significant impact on traffic routing until a a complex traffic situation arises. Further, it was also not easy to take into full account the traffic contexts for resolving optimal routing problems because predicting the dynamic traffic situations was regarded a daunting task. However, with rapid increase in traffic complexity the importance of developing contexts reflecting data related to moving costs has emerged. Hence, this research proposes a framework designed to resolve an optimal route planning problem by taking full account of additional moving cost such as road traffic cost and weather cost, among others. Recent technological development particularly in the ubiquitous computing environment has facilitated the collection of such data. This framework is based on the contexts of time, traffic, and environment, which addresses the following issues. First, we clarify and classify the diverse contexts that affect a vehicle's velocity and estimates the optimization of moving cost based on dynamic programming that accounts for the context cost according to the variance of contexts. Second, the velocity reduction rate is applied to find the optimal route (shortest path) using the context data on the current traffic condition. The velocity reduction rate infers to the degree of possible velocity including moving vehicles' considerable road and traffic contexts, indicating the statistical or experimental data. Knowledge generated in this papercan be referenced by several organizations which deal with road and traffic data. Third, in experimentation, we evaluate the effectiveness of the proposed context-based optimal route (shortest path) between locations by comparing it to the previously used distance-based shortest path. A vehicles' optimal route might change due to its diverse velocity caused by unexpected but potential dynamic situations depending on the road condition. This study includes such context variables as 'road congestion', 'work', 'accident', and 'weather' which can alter the traffic condition. The contexts can affect moving vehicle's velocity on the road. Since these context variables except for 'weather' are related to road conditions, relevant data were provided by the Korea Expressway Corporation. The 'weather'-related data were attained from the Korea Meteorological Administration. The aware contexts are classified contexts causing reduction of vehicles' velocity which determines the velocity reduction rate. To find the optimal route (shortest path), we introduced the velocity reduction rate in the context for calculating a vehicle's velocity reflecting composite contexts when one event synchronizes with another. We then proposed a context-based optimal route (shortest path) algorithm based on the dynamic programming. The algorithm is composed of three steps. In the first initialization step, departure and destination locations are given, and the path step is initialized as 0. In the second step, moving costs including composite contexts into account between locations on path are estimated using the velocity reduction rate by context as increasing path steps. In the third step, the optimal route (shortest path) is retrieved through back-tracking. In the provided research model, we designed a framework to account for context awareness, moving cost estimation (taking both composite and single contexts into account), and optimal route (shortest path) algorithm (based on dynamic programming). Through illustrative experimentation using the Wilcoxon signed rank test, we proved that context-based route planning is much more effective than distance-based route planning., In addition, we found that the optimal solution (shortest paths) through the distance-based route planning might not be optimized in real situation because road condition is very dynamic and unpredictable while affecting most vehicles' moving costs. For further study, while more information is needed for a more accurate estimation of moving vehicles' costs, this study still stands viable in the applications to reduce moving costs by effective route planning. For instance, it could be applied to deliverers' decision making to enhance their decision satisfaction when they meet unpredictable dynamic situations in moving vehicles on the road. Overall, we conclude that taking into account the contexts as a part of costs is a meaningful and sensible approach to in resolving the optimal route problem.

The perceptual span during reading Korean sentences (우리글 읽기에서 지각 폭 연구)

  • Choi, So-Young;Koh, Sung-Yrong
    • Korean Journal of Cognitive Science
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    • v.20 no.4
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    • pp.573-601
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    • 2009
  • The present study investigated the perceptual span during reading Korean, using the moving-window display change technique introduced by McConkie and Rayner(1975). Eight different window sizes were used in Experiment 1. They were 3, 5, 7, 9, 11, 13, 15 characters in size and the full line. Reading rate, number of fixation, saccadic distance, fixation duration were compared between each window-size condition and the full line condition. The reading rate was no higher in the full line condition than in the 15 character condition but was higher than in the other conditions. The number of fixations was no larger in the full line condition than in the 15 character condition, had a tendency to be larger than in the 13 characters condition, and was more than in the other conditions. The result pattern of the saccadic distance based on character was the same as that of the reading rate, and the saccadic distance based on the pixel was the same as that of the number of fixation. Similarly, for fixation duration, there was no differences between whole line condition and 15, 13, and 11 characters condition. The fixation duration had a tendency to be shorter in the 9 characters, and was shorter in the 7, 5, and 3 characters conditions than whole line condition. In Experiment 2, based on asymmetry of perceptual span, the 6 different window sizes(0, 1, 2, 3, 4 characters in size and the full line) were used. There was a difference only between the 0 condition and the other conditions in the reading rate, number of fixations, fixation duration. Considering the pattern of eye-movement measures above, the perceptual span of Korean readers extends about 6-7 characters to the right of fixation and 1 character to the left of fixation.

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Radial Basis Hybrid Neural Network Modeling for On-line Detection of Machine Condition Change (기계상태의 변화를 온라인으로 탐지하기 위한 Radial Basis 하이브리드 뉴럴네트워크 모델링)

  • Wang, Gi-Nam;Kim, Gwang-Sub;Jeong, Yoon-Seong
    • Journal of Korean Institute of Industrial Engineers
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    • v.20 no.4
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    • pp.113-134
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    • 1994
  • A radial basis hybrid neural network (RHNN) is presented for an on-line detection of machine condition change. Two-phase modeling by RHNN is designed for describing a machine condition process and for predicting future signal. A moving block procedure is also designed for detecting a process change. A fast on-line learning algorithm, the recursive least square estimation, is introduced. Experimental results showed the RHNN could be utilized efficiently for on-line machine condition monitoring.

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A Study on the Maneuvering Area of Ship in Moving at Single Point Mooring (SPM 이안 선박의 조종영역에 관한 기초 연구)

  • Kim Jin-Soo;Jong Jae-Yong;Kim Kung-Tae;Kim Jong-Rok
    • Proceedings of KOSOMES biannual meeting
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    • 2005.11a
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    • pp.21-26
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    • 2005
  • The work of VLCC SPM mainly is accomplished on the open sea On the open sea as a result of meteorological condition and the ocean wave influence, When the weather condition is get bed, peremptorily moving to the safety place, because of the gale and the billow, almost happened frequently, the pilot is unable to go on board and the tug is also unable to be used Now bemuse of the bad weather the VLCC SPM moving to the other safety place frequently happened in the ulsan port. the construction of new harbor, it constructed many break water around SPM. So that it is necessary to propose the new standard about how to maneuvering area actually. Now our country is at the blank stage about the establishment of SPM research Most of the situations are refer to overseas standard But these standards lack of consistency and clarity. So when moving to the other safety place from SPM, we must carry through the researching and study on the ships using by sailing data of AIS. we must put forward a new standard about maneuvering area of ship in moving at SPM.

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A Study on the Maneuvering Area of Ship in Moving at Single Point Mooring (SPM 이안 선박의 조종영역에 관한 기초 연구)

  • Kim Jin-Soo;Jong Jae-Yong;Kim Kyung-Tae
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.11 no.2 s.23
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    • pp.19-25
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    • 2005
  • The work of VLCC SPM mainly is accomplished on the open sea. On the open sea as a result of meteorological condition and the ocean wave influence, When the weather condition is get bed, peremptorily moving to the safety place, bemuse of the gale and the billow, almost happened frequently, the pilot is unable to go on board and the tug is also unable to be used Now bemuse of the bad weather the VLCC SPM moving to the other safety place frequently happened in the ulsan port. the construction of new harbor, it constructed many break water around SPM. So that it is necessary to propose the new standard about how to maneuvering area actually. Now our country is at the blank stage about the establishment of SPM research Most of the situations refer to overseas standards. But these standards lack consistency and clarity. So when moving to the another safe place from SPM, we must Carry through the research and study on the ships using sailing through AIS Data We must put forward a new standard about maneuvering area of ships moving at SPM.

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The Flow Analysis of Jeju Harbor using Moving Boundary Technique (이동경계기법을 이용한 제주항의 유동해석)

  • Kim, Nam-Hyeong;Park, Ji-Hun
    • Journal of Navigation and Port Research
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    • v.27 no.5
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    • pp.539-546
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    • 2003
  • The numerical model of the flow analysis by finite element technique is described. The Galerkin method is employed for spatial discretization Two step explicit finite element scheme is used to discretize the time function, which has advantage in problems treating large numbers of elements and unsteady state. Two dimensional hydrodynamic model considering moving boundary condition is developed. Also it applied flow model which develop on flow portion of ideal fluid in the model flume and verified, and the results of this study confirm the efficiency of moving boundary treatment in Jeju harbor. The computed results have shown the good adaptability of moving boundary condition From these studies, it can be concluded that the present method is a useful and effective tool in tidal flow analysis.

Noise Visualization of Moving Vehicles Using Microphone Line Array (선형 마이크로폰 어레이를 이용한 이동 차량의 음장 가시화)

  • 김시문;권휴상;박순홍;김양한
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1996.04a
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    • pp.291-297
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    • 1996
  • To visualize sound field or to identify noise sources, we can use many methods such as intensity method, acoustic holographic method, source identification method using line array, etc. Conventionally all these methods are performed with the assumption of stationary condition in space and time. But for moving source, spatial characteristics and frequency components are changing, so we need another processing algorithm. This paper shows some experimental results - sound field by moving noise sources. In the experiment cross type microphone line array is used for sensing pressure and cars and a motorcycle are used as moving sources that are assumed to have constant speed. The processing methods are acoustic holographic method, spherical beamforming and spectrogram.

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