• Title/Summary/Keyword: Relative electrical distance

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Distance Transform Path Planning using DEM and Obstacle Map (DEM과 장애물 지도를 이용한 거리변환 경로계획)

  • Choe, Tok-Son;Jee, Tae-Young;Kim, Jun;Park, Yong-Woon;Ryu, Chul-Hyung
    • Proceedings of the KIEE Conference
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    • 2005.10b
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    • pp.92-94
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    • 2005
  • Unmanned ground vehicles(UGVs) are expected to play a key role in the future army. These UGVs would be used for weapons platforms. logistics carriers, reconnaissance, surveillance, and target acquisition in the rough terrain. Most of path planning methodologies for UGVs offer an optimal or sub-optimal shortest-path in a 20 space. However, those methodologies do not consider increment and reduction effects of relative distance when a UGV climbs up or goes down in the slope of rough terrain. In this paper, we propose a novel path planning methodology using the modified distance transform algorithm. Our proposed path planning methodology employs two kinds of map. One is binary obstacle map. The other is the DEM. With these two maps, the modified distance transform algorithm in which distance between cells is increased or decreased by weighting function of slope is suggested. The proposed methodology is verified by various simulations on the randomly generated DEM and obstacle map.

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Effective Route Decision of an Automatic Moving Robot(AMR) using a 2D Spatial Map of the Stereo Camera System

  • Lee, Jae-Soo;Han, Kwang-Sik;Ko, Jung-Hwan
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.20 no.9
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    • pp.45-53
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    • 2006
  • This paper proposes a method for an effective intelligent route decision for automatic moving robots(AMR) using a 2D spatial map of a stereo camera system. In this method, information about depth and disparity map are detected in the inputting images of a parallel stereo camera. The distance between the automatic moving robot and the obstacle is detected, and a 2D spatial map is obtained from the location coordinates. Then the relative distances between the obstacle and other objects are deduced. The robot move automatically by effective and intelligent route decision using the obtained 2D spatial map. From experiments on robot driving with 240 frames of stereo images, it was found that the error ratio of the calculated distance to the measured distance between objects was very low, 1.52[%] on average.

Metric Defined by Wavelets and Integra-Normalizer (웨이브렛과 인테그라-노말라이저를 이용한 메트릭)

  • Kim, Sung-Soo;Park, Byoung-Seob
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.50 no.7
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    • pp.350-353
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    • 2001
  • In general, the Least Square Error method is used for signal classification to measure distance in the $l^2$ metric or the $L^2$ metric space. A defect of the Least Square Error method is that it does not classify properly some waveforms, which is due to the property of the Least Square Error method: the global analysis. This paper proposes a new linear operator, the Integra-Normalizer, that removes the problem. The Integra-Normalizer possesses excellent property that measures the degree of relative similarity between signals by expanding the functional space with removing the restriction on the functional space inherited by the Least Square Error method. The Integra-Normalizer shows superiority to the Least Square Error method in measuring the relative similarity among one dimensional waveforms.

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Longitudinal Motion Control of Vehicles Using Adaptive Sliding Mode Cascade Observer (적응 슬라이딩 모드 축차 관측기를 이용한 직진 주행 차량 제어)

  • Kim Eung-Seok;Kim Cheol-Jin;Rhee Hyung-Chan
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.52 no.1
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    • pp.1-8
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    • 2003
  • In this paper, an observer-based adaptive controller is proposed to control the longitudinal motion of vehicles. The standard gradient method is used to estimate the vehicle parameters, mass, time constant, etc. The inter-vehicle spacing and its derivatives are estimated by using the sliding mode cascade observer introduced in this paper. It is shown that the proposed adaptive controller is uniformly ultimately bounded. It is also shown that the errors of the relative distance, the relative velocity and the relative acceleration asymptotically converge to zero. The simulation results are presented to investigate the effectiveness of the proposed method.

Breakdown Characteristics of Air in the Gap between Line Conductor and Plane Electrode in Case of Combustion Flame on the Plane Electrode (선도체 대 평면전극 갭에서 평면전극에 연소화염 존재시 대기의 절연파괴 특성)

  • Kim, In-Sik
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.27 no.4
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    • pp.73-80
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    • 2013
  • Breakdown characteristics of air in the vertical arrangement of line conductor and plane electrode in case of combustion flame on the plane electrode are examined by the application of AC. and DC voltages to the gap. In order to investigate the effect of paraffin flame on the breakdown characteristics of air, flashover voltages are measured according to the variation of the gap length and the horizontal distance between the flame and the line conductor. As the result of the experiment, flashover voltages are substantially lowered down to 29.8% in case of the AC voltage, and 16.1% in case of the negative DC voltage, when in the presence of the flame. from 100% when in the absence of flame. Flashover voltages of air in the range of smaller than 3㎝ at the horizontal distance are increased in the proportion of the gap length and the horizontal distance in case of both AC and negative DC voltages. But before the flashover occurs, the flame is extinguished by such corona wind that is produced from the line conductor when the gap length and the horizontal distance reach to a certain degree. The effect of relative air density and the phenomenon of thermal ionization are analysed as the reduction factors of flashover voltages, due to high temperature of the flame.

Design of Navigation Algorithm for Mobile Robot using Sensor fusion (센서 합성을 이용한 자율이동로봇의 주행 알고리즘 설계)

  • Kim Jung-Hoon;Kim young-Joong;Lim Myo-Teag
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.53 no.10
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    • pp.703-713
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    • 2004
  • This paper presents the new obstacle avoidance method that is composed of vision and sonar sensors, also a navigation algorithm is proposed. Sonar sensors provide poor information because the angular resolution of each sonar sensor is not exact. So they are not suitable to detect relative direction of obstacles. In addition, it is not easy to detect the obstacle by vision sensors because of an image disturbance. In This paper, the new obstacle direction measurement method that is composed of sonar sensors for exact distance information and vision sensors for abundance information. The modified splitting/merging algorithm is proposed, and it is robuster for an image disturbance than the edge detecting algorithm, and it is efficient for grouping of the obstacle. In order to verify our proposed algorithm, we compare the proposed algorithm with the edge detecting algorithm via experiments. The direction of obstacle and the relative distance are used for the inputs of the fuzzy controller. We design the angular velocity controllers for obstacle avoidance and for navigation to center in corridor, respectively. In order to verify stability and effectiveness of our proposed method, it is apply to a vision and sonar based mobile robot navigation system.

Flashover Characteristics of Vertical-type Model Power Line in the Presence of Combustion Flame (연소화염 존재 시 수직형 모델 전력선의 섬락 특성)

  • Kim, In-Sik
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.23 no.5
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    • pp.58-65
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    • 2009
  • A forest fire in the area of power line installations may be caused by flashover disturbances in power systems. In this study, experiments were conducted so as to investigate the reduction in dielectric strength caused by combustion flame, and flashover characteristics in the simulated condition of vertical-type model power lines were examined by making shorter and longer the horizontal distance(s) between combustion flame and high-voltage conductors under the application of 60[Hz] a.c. and d.c. high-voltages. As the results of the experimental investigation it is demonstrated that flame can reduce flashover voltages of the model air-gap in shorter range of the horizontal distance(s). Relative air density is considered in order to analyze the reduction causes of the flashover voltages, and it can be seen that the relative air density has a great influence on the flashover characteristics under the presence of combustion flame.

A Finite Element Analysis on the Influence of Floating Shield of a Vacuum Interrupter to the Insulation (진공 인터럽터의 차폐판이 절연에 미치는 영향의 유한요소해석)

  • 최승길;심재학;강형부
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1998.11a
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    • pp.113-116
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    • 1998
  • This study should investigate to what extent the electric field of a vacuum interrupter might be influenced by the electric potential of floating arc shield. The electric potentials of floating shield and electric fields of a vacuum interrupter are analysed by a finite element method against variation of gap distances from 1mm to 12mm. The electric potentials of floating shield was increased with the gap distance, which is because the relative position of shield is closer to fixed contact so that the capacitance distribution inside interrupter is varied. The calculated results show that the maximum value of electric field of a vacuum interrupter with floating shield is nearly same to that without shield at shorter gap distance(below 5mm), however at larger gaps a significant increment of electric field is achieved in interrupter with shield companying with model without shield, which is due to the influence of charged floating shield.

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A Relative Position Estimation System using Digital Beam Forming and ToA for Automatic Formation Flight of UAV (UAV 자동 편대비행을 위한 디지털 빔포밍 및 ToA 기반의 상대위치 추정 시스템)

  • Kim, Jae-Wan;Yoon, Jun-Yong;Joo, Yang-Ick
    • Journal of Korea Multimedia Society
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    • v.17 no.9
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    • pp.1092-1097
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    • 2014
  • It is difficult to perform automatic formation flight of UAV (Unmanned Aerial vehicle) when GPS (Global Positionig System) is out of order or has a system error, since the relative position estimation in the flight group is impossible in that case. In this paper, we design a relative localization system for the automatic formation flight of UAV. For this purpose, we adopt digital beam forming (DBF) to estimate the angle with the central controller of the flight group and Particle Filtering scheme to compensate the estimation error of ToA (time of arrival) method. Computer simulation results present a proper distance between the central controller and a following unit to maintain the automatic formation flight.

Novel Method of ACO and Its Application to Rotor Position Estimation in a SRM under Normal and Faulty Conditions

  • Torkaman, Hossein;Afjei, Ebrahim;Babaee, Hossein;Yadegari, Peyman
    • Journal of Power Electronics
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    • v.11 no.6
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    • pp.856-863
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    • 2011
  • In this paper a novel method of the Ant Colony Optimization algorithm for rotor position estimation in Switched Reluctance Motors is presented. The data provided by the initial assumptions is one of the important aspects used to solve the problems relative to an Ant Colony algorithm. Considering the nature of a real ant colony, it was found that the ants have no primary data for deducing which is the shortest path in their initial iteration. They also do not have the ability to see the food sources at a distance. According to this point of view, a novel method is presented in which the rotor pole position relative to the corresponding stator pole in a switched reluctance motor is estimated with high accuracy using the active and inactive phase parameters. This new method gives acceptable results such as a desirable convergence together with an optimized and stable response. To the best knowledge of the authors, such an analysis has not been carried out previously.