• Title/Summary/Keyword: collision technique

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초음파 스캐닝을 활용한 지능형 건설기계 충돌방지 기술 (Intelligent Collision Prevention Technique for Construction Equipment using Ultrasound Scanning)

  • 이재훈;황영서;양강혁
    • 한국건설관리학회논문집
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    • 제22권5호
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    • pp.48-54
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    • 2021
  • 고용노동부의 2020년 산업재해 사고 사망 통계 발표에 따르면 최근 5년간 발생한 업무상 사고 사망 재해의 절반 이상이 건설업에서 발생하고 있다. 그중 건설기계와 관련된 충돌 및 협착 사고가 사망 재해의 큰 부분을 차지하고 있다는 것을 알 수 있다. 정부는 건설 현장에서 발생하는 사고를 예방하기 위해 "건설안전특별법" 발의, 사고 예방을 위한 새로운 기술의 도입 장려 등 큰 노력을 기울이고 있지만, 여전히 건설 현장에서 수많은 안전사고가 발생하고 있다. 이에 본 연구는 초음파 스캐닝 기술을 통해 반경 내 대상의 종류와 위치를 인식하여 건설기계와 작업자 간의 충돌사고를 예방할 수 있는 기술을 개발했다. 본 연구는 파일럿 실험을 수행하였으며, 결과 분석을 통해 대상 인식과 위치 추정 모두에서 높은 정확도로 기술의 실현 가능성을 증명하였다. 개발한 기술은 건설 현장에서 발생하는 충돌사고를 예방하고, 자동화된 건설기계 충돌사고 예방 기술 개발에 이바지할 수 있을 것으로 기대된다.

파올로 포르토게시 건축에 나타난 바로크적 특성 연구 (A Study on the characteristics of baroque in Architecture of Paolo Portogheshi)

  • 한명식
    • 한국실내디자인학회논문집
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    • 제18권6호
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    • pp.52-59
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    • 2009
  • In the study will look into how Baroque concepts are expressed in architectural space by analyzing the concepts of Baroque formative vocabularies applied in his architecture through a Spanish architect Paolo Portoghesi. Baroque is regarded as the philosophical thought that means enlargement toward diversity of a firm and fixed trend beyond the concept of a certain epochal form of 16th and 17th century architecture. In addition, it is from the free attitude and the intelligent and formal stereotype, and signifies common conditions more than one style in architecture history. Paolo Portoghesi proposes to express gestalt approach by Baroque precedent in his architecture through plasticity and geometric collision technique. Here, the expression of plasticity means the effect that gives formative rhythm to Baroque curved structures. That is the method to expand the formative possibility by changing various materials such as bricks, concrete, and timbers. Second, the geometric collision technique is the technique to constitute the flat form of overall space through the juxtaposition technique, Baroque symmetrical and homogeneous geometric manipulation technique. Accordingly, this study will overcome Inlimitation of formative monotony and expression of abstraction that modernism architecture has, and examine formative waste and conflicts which may be derived from impractical architectural languages of the concept of excessive disorder or the minimum form. This discussion is considered as the first step to tune balance between productivity and formativeness in modern architecture.

A robust collision prediction and detection method based on neural network for autonomous delivery robots

  • Seonghun Seo;Hoon Jung
    • ETRI Journal
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    • 제45권2호
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    • pp.329-337
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    • 2023
  • For safe last-mile autonomous robot delivery services in complex environments, rapid and accurate collision prediction and detection is vital. This study proposes a suitable neural network model that relies on multiple navigation sensors. A light detection and ranging technique is used to measure the relative distances to potential collision obstacles along the robot's path of motion, and an accelerometer is used to detect impacts. The proposed method tightly couples relative distance and acceleration time-series data in a complementary fashion to minimize errors. A long short-term memory, fully connected layer, and SoftMax function are integrated to train and classify the rapidly changing collision countermeasure state during robot motion. Simulation results show that the proposed method effectively performs collision prediction and detection for various obstacles.

충돌 회피를 위한 로봇 시뮬레이터의 개발에 관한 연구 (A Study on Development of Robot Simulator for Collision Avoidance)

  • 이주형
    • 수산해양기술연구
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    • 제32권3호
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    • pp.321-328
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    • 1996
  • This paper presents a robot simulator which can automatically generate a smooth collision free path. This simulator has the characterstisc of the object - oriented programming which is coded in Borland C+ +. Using General Inverse Algorithm, the inverse kinematics solutions of any kind of robots can be found generally. This simulator also uses Bezier Functions for the description of a smooth collision - free path. In addition, GUI(Graphic User Interface)technique is employed for user's convenience.

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물리 엔진을 이용한 3차원 게임 객체의 충돌 처리 (Using the Physics engine to collision detection of 3D Game Object)

  • 강정훈
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2009년도 추계학술대회
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    • pp.711-712
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    • 2009
  • 본 논문은 3차원 게임 내에서 물리 엔진을 이용하여 다양한 객체들의 충돌 처리를 구현하는 방법과 그에 따른 문제점에 대해 설명한다. 특히, 3D 게임콘텐츠에서 실시간으로 유용하게 사용될 수 있는 알고리즘을 제안한다.

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선박의 충돌회피를 위한 자동제어에 관한 기초적 연구 (A Study on the Automatic Control for Collision Avoidance of the Ships)

  • 이승건;권배준
    • 한국항해항만학회지
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    • 제26권1호
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    • pp.8-14
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    • 2002
  • 해난사고에 있어 어선의 사고율은 높은 비율을 차지한다. 특히, 소형어선의 사고율이 가장 높아, 이러한 사고를 예방할 수 있는 기술들이 필요한 실정이다. 본 논문에서는 충돌회피를 위한 자동제어를 두 가지 과정으로 구성하고 있다. 하나는 퍼지추론을 이용한 위험도의 추론이며 나머지는 첫 번째 과정에서 계산된 위험도를 토대로 선박을 조종하는 과정이다. 위험도를 평가하기 위해서 선박의 위치와 충돌예상시점에 의한 정보(DCPA and TCPA)를 이용하였다. 이 방법의 실효성을 검증하기 위해 어선의 충돌회피운동을 MMG 수학모델에 의해 시뮬레이션 하였다. 시뮬레이션 결과는 선박의 충돌회피에 유효함을 알아다.

충돌 비트 위치를 활용한 RFID 다중 태그 인식 알고리즘 (A New RFID Tag Anti-Collision Algorithm Using Collision-Bit Positioning)

  • 이현지;김종덕
    • 한국통신학회논문지
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    • 제31권4A호
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    • pp.431-439
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    • 2006
  • RFID 다중 태그 인식이란 하나의 RFID 리더 영역 내에 있는 다수의 태그를 태그 간의 통신 간섭에 의한 충돌을 피하며 고속으로 인식하는 기술이다. 다중 태그 인식 기술은 RFID 시스템의 성능과 안정성을 결정하는 핵심 기술로 중요성이 높다. 논문은 대표적 다중 태그 인식 기술인 QT(Query Tree) 알고리즘의 충돌 비트 위치를 활용하여 개선된 QT-CBP(Query Tree with Collision-Bit Positioning) 알고리즘을 제안한다. 시뮬레이션을 통한 검증 결과 QT-CBP는 태그 정보 비트의 중복성이 높고, 태그 수가 많을 때 QT에 비해 뚜렷한 성능 개선이 있었다.

다이나믹 프로그래밍에 의한 두 대의 로보트를 위한 최소시간 경로계획 (A Near Minimum-Time Trajectory Planning for Two Robots Using Dynamic Programming Technique)

  • 이지홍;오영석
    • 전자공학회논문지B
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    • 제29B권11호
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    • pp.36-45
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    • 1992
  • A numerical trajectory planning method for path-constrained trajectory planning is proposed which ensures collision-free and time-optimal motions for two robotic manipulators with limited actuator torques and velocities. For each robot, physical constraints of the robots such as limited torques or limited rotational velocities of the actuators are converted to the constraints on velocity and acceleration along the path, which is described by a scalar variable denoting the traveled distance from starting point. Collision region is determined on the coordination space according to the kinematic structures and the geometry of the paths of the robots. An Extended Coordination Space is then constructed` an element of the space determines the postures and the velocities of the robots, and all the constraints described before are transformed to some constraints on the behaviour of the coordination-velocity curves in the space. A dynamic programming technique is them provided with on the discretized Extended Coordination Space to derive a collision-free and time-optimal trajectory pair. Numerical example is included.

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Delay Time Optimal Coordination Planning for Two Robot Systems

  • Lee, Ji-Hong;Nam, Heon-Seong;Joon Lyou
    • Journal of Electrical Engineering and information Science
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    • 제2권3호
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    • pp.51-60
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    • 1997
  • A practically applicable collision free trajectory planning technique for tow robot systems is proposed. The robot trajectories considered in this work are composed of many segments, an at the intersection points between segments robots stop to assemble, weld, ordo other jobs by the attached a end-effectors. The proposed method is based on the Planning-Coordination Decomposition where planning is to find a trajectory of each robot independently according to their tasks and coordination is to find a velocity modification profile to avoid collision with each other. To fully utilize the independently planned trajectories and to ensure no geometrical path deviation after coordination, we develop a simple technique added the minimal delay time to avoid collision just before moving along path segments. We determine the least delay time by the graphical method in the Coordination space where collisions and coordinations are easily visualized. We classify all possible cases into 3 group and derive the optimal solution for each group.

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Direct-contact heat transfer of single droplets in dispersed flow film boiling: Experiment and model assessment

  • Park, Junseok;Kim, Hyungdae
    • Nuclear Engineering and Technology
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    • 제53권8호
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    • pp.2464-2476
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    • 2021
  • Direct-contact heat transfer of a single saturated droplet upon colliding with a heated wall in the regime of film boiling was experimentally investigated using high-resolution infrared thermometry technique. This technique provides transient local wall heat flux distributions during the entire collision period. In addition, various physical parameters relevant to the mechanistic modelling of these phenomena can be measured. The obtained results show that when single droplets dynamically collide with a heated surface during film boiling above the Leidenfrost point temperature, typically determined by droplet collision dynamics without considering thermal interactions, small spots of high heat flux due to localized wetting during the collision appear as increasing Wen. A systematic comparison revealed that existing theoretical models do not consider these observed physical phenomena and have lacks in accurately predicting the amount of direct-contact heat transfer. The necessity of developing an improved model to account for the effects of local wetting during the direct-contact heat transfer process is emphasized.