• Title, Summary, Keyword: obstacle avoidance

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Mobile Robot Obstacle Avoidance using Visual Detection of a Moving Object (동적 물체의 비전 검출을 통한 이동로봇의 장애물 회피)

  • Kim, In-Kwen;Song, Jae-Bok
    • The Journal of Korea Robotics Society
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    • v.3 no.3
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    • pp.212-218
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    • 2008
  • Collision avoidance is a fundamental and important task of an autonomous mobile robot for safe navigation in real environments with high uncertainty. Obstacles are classified into static and dynamic obstacles. It is difficult to avoid dynamic obstacles because the positions of dynamic obstacles are likely to change at any time. This paper proposes a scheme for vision-based avoidance of dynamic obstacles. This approach extracts object candidates that can be considered moving objects based on the labeling algorithm using depth information. Then it detects moving objects among object candidates using motion vectors. In case the motion vectors are not extracted, it can still detect the moving objects stably through their color information. A robot avoids the dynamic obstacle using the dynamic window approach (DWA) with the object path estimated from the information of the detected obstacles. The DWA is a well known technique for reactive collision avoidance. This paper also proposes an algorithm which autonomously registers the obstacle color. Therefore, a robot can navigate more safely and efficiently with the proposed scheme.

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ELA: Real-time Obstacle Avoidance for Autonomous Navigation of Variable Configuration Rescue Robots (ELA: 가변 형상 구조로봇의 자율주행을 위한 실시간 장애물 회피 기법)

  • Jeong, Hae-Kwan;Hyun, Kyung-Hak;Kim, Soo-Hyun;Kwak, Yoon-Keun
    • The Journal of Korea Robotics Society
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    • v.3 no.3
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    • pp.186-193
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    • 2008
  • We propose a novel real-time obstacle avoidance method for rescue robots. This method, named the ELA(Emergency Level Around), permits the detection of unknown obstacles and avoids collisions while simultaneously steering the mobile robot toward safe position. In the ELA, we consider two sensor modules, PSD(Position Sensitive Detector) infrared sensors taking charge of obstacle detection in short distance and LMS(Laser Measurement System) in long distance respectively. Hence if a robot recognizes an obstacle ahead by PSD infrared sensors first, and judges impossibility to overcome the obstacle based on driving mode decision process, the order of priority is transferred to LMS which collects data of radial distance centered on the robot to avoid the confronted obstacle. After gathering radial information, the ELA algorithm estimates emergency level around a robot and generates a polar histogram based on the emergency level to judge where the optimal free space is. Finally, steering angle is determined to guarantee rotation to randomly direction as well as robot width for safe avoidance. Simulation results from wandering in closed local area which includes various obstacles and different conditions demonstrate the power of the ELA.

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Obstacle Recognition and Avoidance of the Bio-mimetic Underwater Robot using IR and Compass Senso (IR 센서 및 Compass 센서를 이용한 생체 모방형 수중 로봇의 장애물 인식 및 회피)

  • Lee, Dong-Hyuk;Kim, Hyun-Woo;Lee, Jang-Myung
    • Journal of Institute of Control, Robotics and Systems
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    • v.18 no.10
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    • pp.928-933
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    • 2012
  • In this paper, the IR and compass sensors for the underwater system were used. The walls of the water tank have been recognized and avoided treating the walls as obstacles by the bio-mimetic underwater robot. This paper is consists of two parts: 1.The hardware part for the IR and compass sensors and 2.The software part for obstacle avoidance algorithm while the bio-mimetic robot is swimming with the obstacle recognition. Firstly, the hardware part controls through the RS-485 communications between a microcontroller and the bio-mimetic underwater robot. The software part is simulated for obstacle recognition and collision avoidance based upon the data from IR and compass sensors. Actually, the bio-mimetic underwater robot recognizes where is the obstacle as well as where is the bio-mimetic robot itself while it is moving in the water. While the underwater robot is moving at a constant speed recognizing the wall of water tank as an obstacle, an obstacle avoidance algorithm is applied for the wall following swimming based upon the IR and compass sensor data. As the results of this research, it is concluded that the bio-mimetic underwater robot can follow the wall of the water tank efficiently, while it is avoiding collision to the wall.

Intelligent Obstacle Avoidance Algorithm for Autonomous Control of Underwater Flight Vehicle (수중비행체의 자율제어를 위한 지능형 장애물회피 알고리즘)

  • Kim, Hyun-Sik;Jin, Tae-Seok
    • Journal of the Korean Institute of Intelligent Systems
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    • v.19 no.5
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    • pp.635-640
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    • 2009
  • In real system application, the obstacle avoidance system for the autonomous control of the underwater flight vehicle (UFV) operates with the following problems: it has local information because the sonar can only offer the obstacle information in a local detection area, it requires a continuous control input because the system that has reduced acoustic noise and power consumption is necessary, and further, it requires an easy design procedure in terms of its structures and parameters. To solve these problems, an intelligent obstacle avoidance algorithm using the evolution strategy (ES) and the fuzzy logic controller (FLC), is proposed. To verify the performance of the proposed algorithm, the obstacle avoidance of UFV is performed. Simulation results show that the proposed algorithm effectively solves the problems in the real system application.

Obstacle Avoidance Using Velocity Dipole Field Method

  • Munasinghe, Sudath R.;Oh, Chang-Mok;Lee, Ju-Jang;Khatib, Oussama
    • 제어로봇시스템학회:학술대회논문집
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    • pp.1657-1661
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    • 2005
  • The velocity dipole field method is presented for real-time collision avoidance of mobile robots. The direction of motion of the obstacle is used as the axis of the dipole field, and the speed of the obstacle is used to proportionally strengthen the dipole field. The elliptical field lines of the dipole field are useful to skillfully guide the robot around obstacles, quite similar to the way humans avoid moving obstacles. Field modulation coefficient is also introduced to weaken the field effect as the obstacle recedes. The real-time algorithm of the velocity dipole field has been devised and experimentally tested on the robot soccer test-bed. The results show the capability of the new real-time collision avoidance strategy and how it can overcome the weaknesses in the conventional potential field method. The new method makes an explicit and proactive action of collision avoidance, unlike the conventional method, which forces the robot merely away from the obstacle aimlessly. The proposed method delivers greater capability with no considerable computational overhead

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A Study on Orientation and Position Control of Mobile Robot Based on Multi-Sensors Fusion for Implimentation of Smart FA (스마트팩토리 실현을 위한 다중센서기반 모바일로봇의 위치 및 자세제어에 관한 연구)

  • Dong, G.H;Kim, D.B.;Kim, H.J;Kim, S.H;Baek, Y.T;Han, S.H
    • Journal of the Korean Society of Industry Convergence
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    • v.22 no.2
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    • pp.209-218
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    • 2019
  • This study proposes a new approach to Control the Orientation and position based on obstacle avoidance technology by multi sensors fusion and autonomous travelling control of mobile robot system for implimentation of Smart FA. The important focus is to control mobile robot based on by the multiple sensor module for autonomous travelling and obstacle avoidance of proposed mobile robot system, and the multiple sensor module is consit with sonar sensors, psd sensors, color recognition sensors, and position recognition sensors. Especially, it is proposed two points for the real time implementation of autonomous travelling control of mobile robot in limited manufacturing environments. One is on the development of the travelling trajectory control algorithm which obtain accurate and fast in considering any constraints. such as uncertain nonlinear dynamic effects. The other is on the real time implementation of obstacle avoidance and autonomous travelling control of mobile robot based on multiple sensors. The reliability of this study has been illustrated by the computer simulation and experiments for autonomous travelling control and obstacle avoidance.

Automatic Ship Collision Avoidance Algorithm based on Probabilistic Velocity Obstacle with Consideration of COLREGs (국제해상충돌예방규칙을 고려한 확률적 속도 장애물 기반의 선박 충돌회피 알고리즘)

  • Cho, Yonghoon;Han, Jungwook;Kim, Jinwhan;Lee, Philyeob
    • Journal of the Society of Naval Architects of Korea
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    • v.56 no.1
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    • pp.75-81
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    • 2019
  • This study presents an automatic collision avoidance algorithm for autonomous navigation of unmanned surface vessels. The performance of the collision avoidance algorithm is heavily dependent on the estimation quality of the course and speed of traffic ships because collision avoidance maneuvers should be determined based on the predicted motions of the traffic ships and their trajectory uncertainties. In this study, the collision avoidance algorithm is implemented based on the Probabilistic Velocity Obstacle (PVO) approach considering the maritime collision regulations (COLREGs). In order to demonstrate the performance of the proposed algorithm, an extensive set of simulations was conducted and the results are discussed.

Obstacle Avoidance and Path Planning for a Mobile Robot Using Single Vision System and Fuzzy Rule (모노비전과 퍼지규칙을 이용한 이동로봇의 경로계획과 장애물회피)

  • 배봉규;이원창;강근택
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • pp.274-277
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    • 2000
  • In this paper we propose new algorithms of path planning and obstacle avoidance for an autonomous mobile robot with vision system. Distance variation is included in path planning to approach the target point and avoid obstacles well. The fuzzy rules are also applied to both trajectory planning and obstacle avoidance to improve the autonomy of mobile robot. It is shown by computer simulation that the proposed algorithm is working well.

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Obstacle Avoidance for AUV using CAPM (CAPM을 이용한 AUV의 장애물 회피)

  • 양승윤
    • Journal of the Korea Institute of Military Science and Technology
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    • v.4 no.2
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    • pp.17-29
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    • 2001
  • In this paper, we designed the hybrid path generation method which is named CAPM(Continuous path generation method based on artificial Potential field) that is able to be used in the obstacles environment. This CAPM was designed so that it puts together two obstacle avoidance algorithm-the continuous path generation method(CPGM) and the artificial potential field method(APFM). Here, the CAPM generate the safety path using continuous path curvature. But, this method has demerits when used in obstacles environment in which are closely located. Another method which is named the APFM generates the path with the artificial potential field in the obstacles environment. But, It has local minima in certain places and unnecessarily calculates the path in which obstacles are not located. So, the CAPM was designed for autonomous underwater vehicle(AUV) obstacle avoidance. As the result of simulation, it was confirmed that the CAPM can be applied to a safe path generation for AUV.

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Improving on the Obstacle Avoidance Method for a Mobile Robot (mobile robot의 장애물 회피방법 개선)

  • Park, Jong-Hun;Lee, Woo-Young;Huh, Dei-Jeung;Huh, Uk-Youl
    • Proceedings of the KIEE Conference
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    • pp.146-149
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    • 2002
  • This paper presents collision avoidance for mobile robots equipped with synchro-drive using curvature trajectory by the obstacle type. he new real-time obstacle avoidance method presents how to create a curvature trajectory in which dynamics of a mobile robot is considered we controlled translation and rotational velocity of the mobile robot. Using these two speeds with curvature trajectory, the mobile robot navigates to target point without collision. We consider that the robot going to curvature trajectory by obstacle size towards a goal location. The collision avoidance has been implemented and tested using pioneer2-dxe mobile robot.

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