• Title, Summary, Keyword: obstacle avoidance

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Performance Enhancement of an Obstacle Avoidance Algorithm using a Network Delay Compensationfor a Network-based Autonomous Mobile Robot (네트워크 기반 자율이동 로봇을 위한 시간지연 보상을 통한 장애물 회피 알고리즘의 성능 개선)

  • Kim, Joo-Min;Kim, Jin-Woo;Kim, Dae-Won
    • Proceedings of the KIEE Conference
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    • pp.1898-1899
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    • 2011
  • In this paper, we propose an obstacle avoidance algorithm for a network-based autonomous mobile robot. The obstacle avoidance algorithm is based on the VFH (Vector Field Histogram) algorithm and delay-compensative methods with the VFH algorithm are proposed for the network-based robot that is a unified system composed of distributed environmental sensors, mobile actuators, and the VFH controller. Firstly, the compensated readings of the sensors are used for building the polar histogram of the VFH algorithm. Secondly, a sensory fusion using the Kalman filter is proposed for the localization of the robot to compensate both the delay of the readings of an odometry sensor and the delay of the readings of the environmental sensors. The performance enhancements of the proposed obstacle avoidance algorithm from the viewpoint of efficient path generation and accurate goal positioning are also shown in this paper through some simulation experiments by the Marilou Robotics Studio Simulator.

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Obstacle Avoidance Method for UAVs using Polar Grid

  • Pant, Sudarshan;Lee, Sangdon
    • Journal of Korea Multimedia Society
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    • v.23 no.8
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    • pp.1088-1098
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    • 2020
  • This paper proposes an obstacle avoidance method using a depth polar grid. Depth information is a crucial factor for determining the safe path for collision-free navigation of unmanned aerial vehicles (UAVs) as it can perceive the distance to the obstacles effectively. However, the existing depth-camera-based approaches for obstacle avoidance require computational y expensive path planning algorithms. We propose a simple navigation method using the polar-grid of the depth information obtained from the camera with narrow field-of-view(FOV). The effectiveness of the approach was validated by a series of experiments using software-in-the-loop simulation in a realistic outdoor environment. The experimental results show that the proposed approach successfully avoids obstacles using a single depth camera with limited FOV.

An Obstacle-Avoidance Algorithm for a Redundant Robot Arm Using Fuzzy Control and Performance-Function Optimization (퍼지제어와 성능함수 최적화를 이용한 여유자유도 로봇 팔의 장애물 우회 알고리즘)

  • Lee, Byung-Ryong;Hwang, Jae-Suk;Park, Chan-Ho;Yang, Soon-Yong;Ahn, Kyung-Kwan
    • Journal of the Korean Society for Precision Engineering
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    • v.19 no.4
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    • pp.187-194
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    • 2002
  • In this paper, a motion control algorithm is developed using a fuzzy control and the optimization of performance function, which makes a robot arm avoid an unexpected obstacle when the end-effector of the robot arm is moving to the goal position. During talc motion, if there exists no obstacle, the end-effector of the robot arm moves along the predefined path. But if these exists an obstacle and close to talc robot arm, the fuzzy motion controller is activated to adjust the path of the end-effector of the robot arm. Then, the robot arm takes the optimal posture far collision avoidance with the obstacle. To show the feasibility of the developed algorithm, numerical simulations are carried out with changing both the positions and sites of obstacles. It was concluded that the proposed algorithm gives a good performance for obstacle avoidance.

Dynamic Obstacle Avoidance of a Mobile Robot Using a Collision Vector (충돌 벡터를 이용한 이동로봇의 동적 장애물 회피)

  • Seo, Dae-Geun;Lyu, Eun-Tae;Lee, Jang-Myung
    • Journal of Institute of Control, Robotics and Systems
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    • v.13 no.7
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    • pp.631-636
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    • 2007
  • An efficient obstacle avoidance algorithm is proposed in this paper to avoid dynamic obstacles using a collision vector while a tele-operated mobile robot is moving. For the verification of the algorithm, an operator watches through a monitor and controls the mobile robot with a force-reflection joystick. The force-reflection joystick transmits a virtual force to the operator through the Inter-net, which is generated by an adaptive impedance algorithm. To keep the mobile robot safe from collisions in an uncertain environment, the adaptive impedance algorithm generates the virtual force which changes the command of the operator by pushing the operator's hand to a direction to avoid the obstacle. In the conventional virtual force algorithm, the avoidance of moving obstacles was not solved since the operator cannot recognize the environment realistically by the limited communication bandwidth and the narrow view-angle of the camera. To achieve the dynamic obstacle avoidance, the adaptive virtual force algorithm is proposed based on the collision vector that is a normal vector from the obstacle to the mobile robot. To verify the effectiveness of the proposed algorithm, mobile robot navigation experiments with multiple moving obstacles have been performed, and the results are demonstrated.

VFH+ based Obstacle Avoidance using Monocular Vision of Unmanned Surface Vehicle (무인수상선의 단일 카메라를 이용한 VFH+ 기반 장애물 회피 기법)

  • Kim, Taejin;Choi, Jinwoo;Lee, Yeongjun;Choi, Hyun-Taek
    • Journal of Ocean Engineering and Technology
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    • v.30 no.5
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    • pp.426-430
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    • 2016
  • Recently, many unmanned surface vehicles (USVs) have been developed and researched for various fields such as the military, environment, and robotics. In order to perform purpose specific tasks, common autonomous navigation technologies are needed. Obstacle avoidance is important for safe autonomous navigation. This paper describes a vector field histogram+ (VFH+) based obstacle avoidance method that uses the monocular vision of an unmanned surface vehicle. After creating a polar histogram using VFH+, an open space without the histogram is selected in the moving direction. Instead of distance sensor data, monocular vision data are used for make the polar histogram, which includes obstacle information. An object on the water is recognized as an obstacle because this method is for USV. The results of a simulation with sea images showed that we can verify a change in the moving direction according to the position of objects.

Collision Avoidance Algorithm of an Intelligent Wheelchair Considering the User's Safety with a Moving Obstacle (탑승자의 안전을 고려한 지능형 휠체어의 단일 이동 장애물 충돌회피 알고리즘)

  • Kim, Yong Hwi;Yoon, Tae Sung;Park, Jin Bae
    • Journal of Institute of Control, Robotics and Systems
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    • v.19 no.10
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    • pp.936-940
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    • 2013
  • As the ageing population grows around the world, the demand for electric wheelchairs, an important mobility assistance device for the disabled and elderly, is gradually increasing. Therefore, a number of studies related to intelligent wheelchairs are actively underway to improve safety and comfort for wheelchair users. However, previous collision avoidance studies for intelligent wheelchairs have concentrated on collision avoidance methods with the shortest distance and by only changing either velocity or heading angle, rather than considering the forces exerted on the user. If a collision avoidance algorithm that does not consider these forces is applied to an intelligent wheelchair, there is a possibility of an accident due to falling as wheelchair users are generally disabled and elderly people. In this paper, we propose a collision avoidance algorithm which minimizes the forces exerted on a wheelchair user by minimizing the variation of the wheelchair's velocity and heading angle when the sizes, positions, velocities, and heading angles of a wheelchair and a moving obstacle are known.

Intelligent 3-D Obstacle Avoidance Algorithm for Autonomous Control of Underwater Flight Vehicle (수중비행체의 자율제어를 위한 지능형 3-D 장애물회피 알고리즘)

  • Kim, Hyun-Sik;Jin, Tae-Seok;Sur, Joo-No
    • Journal of the Korean Institute of Intelligent Systems
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    • v.21 no.3
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    • pp.323-328
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    • 2011
  • In real system application, the 3-D obstacle avoidance system for the autonomous control of the underwater flight vehicle (UFV) operates with the following problems: the sonar offers the range/bearing information of obstacles in a local detection area, it requires the system that has reduced acoustic noise and power consumption in terms of the autonomous underwater vehicle (AUV), it has the UFV operation constraints such as maximum pitch and depth, and it requires an easy design procedure in terms of its structures and parameters. To solve these problems, an intelligent 3-D 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 3-D obstacle avoidance of UFV is performed. Simulation results show that the proposed algorithm effectively solves the problems in the real system application.

Obstacle Avoidance for Mobile Robot using Focus of a Camera Lens (카메라 렌즈의 초점을 이용한 이동로봇의 장애물 회피)

  • Yoon, Ki-Don;Oh, Sung-Nam;Han, Chul-Wan;Kim, Kab-Il;Son, Young-Ik
    • Proceedings of the KIEE Conference
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    • pp.255-257
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    • 2005
  • This paper describes a method for obstacle avoidance and map building for mobile robots using one CCD camera. The captured image from one camera has the feature that some parts where focused look fine but the other parts look blear (this is the out-focusing effect). Using this feature a mobile robot can find obstacles in his way from the captured image. After Processing the image, a robot can not only determine whether an obstacle is in front of him or not, but also calculate the distance from obstacles based on image data and the focal distance of its camera lens. Finally, robots can avoid the obstacle and build the map using this calculated data.

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An obstacle avoidance system of an unmanned aerial vehicle using a laser range finder

  • Kim, Hyun;Miwa, Masafumi;Shim, Joonhwan
    • Journal of Advanced Marine Engineering and Technology
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    • v.37 no.7
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    • pp.737-742
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    • 2013
  • Recently, unmanned aircrafts for safe measurement in hazardous locations have been developed. In a method of operation of unmanned aircraft vehicles (UAV), there are two methods of manual control and automatic control. Small UAVs are used for low altitude surveillance flights where unknown obstacles can be encountered. Obstacle avoidance is one of the most challenging tasks which the UAV has to perform with high level of accuracy. In this study, we used a laser range finder as an obstacle detector in automatic navigation of unmanned aircraft to patrol the destination automatically. We proposed a system to avoid obstacles automatically by measuring the angle and distance of the obstacle using the laser range finder.

A Data Fusion Method of Odometry Information and Distance Sensor for Effective Obstacle Avoidance of a Autonomous Mobile Robot (자율이동로봇의 효율적인 충돌회피를 위한 오도메트리 정보와 거리센서 데이터 융합기법)

  • Seo, Dong-Jin;Ko, Nak-Yong
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.4
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    • pp.686-691
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    • 2008
  • This paper proposes the concept of "virtual sensor data" and its application for real time obstacle avoidance. The virtual sensor data is virtual distance which takes care of the movement of the obstacle as well as that of the robot. In practical application, the virtual sensor data is calculated from the odometry data and the range sensor data. The virtual sensor data can be used in all the methods which use distance data for collision avoidance. Since the virtual sensor data considers the movement of the robot and the obstacle, the methods utilizing the virtual sensor data results in more smooth and safer collision-free motion.