• Title/Summary/Keyword: Obstacle-avoiding

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Development of an Autonomous Mobile Robot with the Function of Teaching a Moving Path by Speech and Avoiding a Collision (음성에 의한 경로교시 기능과 충돌회피 기능을 갖춘 자율이동로봇의 개발)

  • Park, Min-Gyu;Lee, Min-Cheol;Lee, Suk
    • Journal of the Korean Society for Precision Engineering
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    • v.17 no.8
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    • pp.189-197
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    • 2000
  • This paper addresses that the autonomous mobile robot with the function of teaching a moving path by speech and avoiding a collision is developed. The use of human speech as the teaching method provides more convenient user-interface for a mobile robot. In speech recognition system a speech recognition algorithm using neural is proposed to recognize Korean syllable. For the safe navigation the autonomous mobile robot needs abilities to recognize a surrounding environment and to avoid collision with obstacles. To obtain the distance from the mobile robot to the various obstacles in surrounding environment ultrasonic sensors is used. By the navigation algorithm the robot forecasts the collision possibility with obstacles and modifies a moving path if it detects a dangerous obstacle.

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A Dynamic Path-Finding Method Avoiding Moving Obstacles in 3D Game Environment (3D게임에서 이동 장애물을 고려한 동적 경로 탐색 기법)

  • Kwon, Oh-Ik;WhangBo, Teag-Keun
    • Journal of Korea Game Society
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    • v.6 no.3
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    • pp.3-12
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    • 2006
  • Path-finding, one of the traditional Game A.I. problems, becomes an important issue to make games more realistic. Due to the limited resources in the computer system, path-finding systems sometimes produce a simplified and unrealistic path. The most relent researches have been focused on the path-finding avoiding only static obstacles. Various moving obstacles are however deployed in real games, a method avoiding those obstacles and producing a smooth path is necessary. In this paper, navigation mesh is used to represent 3D space and its topological characteristics are used for path-finding. Intellectual repulser and attractor are also used to avoid moving obstacles and to find an optimal path. We have evaluated the path produced by the method proposed in this paper and verified its usability in real game.

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Strategies of Collision Avoidance with Moving and Stationary Human Obstacles during Walking (보행 시 인간 장애물의 동적·정적 상태에 따른 충돌회피전략)

  • Lee, Yeon-Jong;Kim, Joo-Nyeon
    • Korean Journal of Applied Biomechanics
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    • v.29 no.2
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    • pp.97-104
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    • 2019
  • Objective: The aim of this study was to investigate the strategies for avoiding moving and stationary walker using body segments during walking. Method: Ten healthy young adults (10 males, age: $24.40{\pm}0.49yrs$, height: $175.80{\pm}5.22cm$, body mass: $70.30{\pm}5.22kg$) participated in this study. Each participant was asked to perform a task to avoid collisions with another walker who was moving or stationary during walking on the 10 m walkway. Both walkers were performed at natural self-selected walking speed. Results: Medio-lateral avoidance displacement of the trunk and the pelvis were significantly increased when avoiding a stationary walker (p<.05). There were no significant differences in medio-lateral center of mass trajectory. Rotation angle of trunk, pelvis and foot on the vertical axis were significantly increased when avoiding a stationary walker (p<.05). Conclusion: Based on our results, when another walker moves continuously, the walker recognizes another walker as the object of social interaction and performs the avoidance strategies while expecting the cooperative distance. On the other hand, when another walker is stopped, it is determined that the walker has an obligation to avoid, and the walker performs a relatively safer avoidance strategy.

Optimal Path Planning of Autonomous Mobile Robot Utilizing Potential Field and Fuzzy Logic (퍼지로직과 포텐셜 필드를 이용한 자율이동로봇의 최적경로계획법)

  • Park, Jong-Hoon;Lee, Jae-Kwang;Huh, Uk-Youl
    • Proceedings of the KIEE Conference
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    • 2003.11b
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    • pp.11-14
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    • 2003
  • In this paper, we use Fuzzy Logic and Potential field method for optimal path planning of an autonomous mobile robot and apply to navigation for real-time mobile robot in 2D dynamic environment. For safe navigation of the robot, we use both Global and Local path planning. Global path planning is computed off-line using sell-decomposition and Dijkstra algorithm and Local path planning is computed on-line with sensor information using potential field method and Fuzzy Logic. We can get gravitation between two feature points and repulsive force between obstacle and robot through potential field. It is described as a summation of the result of repulsive force between obstacle and robot which is considered as an input through Fuzzy Logic and gravitation to a feature point. With this force, the robot fan get to desired target point safely and fast avoiding obstacles. We Implemented the proposed algorithm with Pioneer-DXE robot in this paper.

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Hierarchical Fuzzy Logic Controller Design for Obstacle Avoidance of a Mobile Robot (이동로봇의 장애물 회피를 위한 계층적 퍼지 제어기 설계)

  • Kim, Ki-Woong;Lee, Suk
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1995.10a
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    • pp.319-322
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    • 1995
  • This paper addresses that through the use of Fuzzy Logic Control, a reactiv behavior (e.g. avoiding obstacles on the way) are smoothly blended into one sequence of control action. In this classical problem, the aim is to guide a mobile robot along its path to avoid any static obstacles in front of it. This controller presented here uses three sub-controllers. This fuzzy controller was apply to a miniature mobile robot. This robot follows a left wall, maintining a minimum distance.

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Integrated Path Planning and Collision Avoidance for an Omni-directional Mobile Robot

  • Kim, Dong-Hun
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.10 no.3
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    • pp.210-217
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    • 2010
  • This paper presents integrated path planning and collision avoidance for an omni-directional mobile robot. In this scheme, the autonomous mobile robot finds the shortest path by the descendent gradient of a navigation function to reach a goal. In doing so, the robot based on the proposed approach attempts to overcome some of the typical problems that may pose to the conventional robot navigation. In particular, this paper presents a set of analysis for an omni-directional mobile robot to avoid trapped situations for two representative scenarios: 1) Ushaped deep narrow obstacle and 2) narrow passage problem between two obstacles. The proposed navigation scheme eliminates the nonfeasible area for the two cases by the help of the descendent gradient of the navigation function and the characteristics of an omni-directional mobile robot. The simulation results show that the proposed navigation scheme can effectively construct a path-planning system in the capability of reaching a goal and avoiding obstacles despite possible trapped situations under uncertain world knowledge.

Motion Planning of an Autonomous Mobile Robot in Flexible Manufacturing Systems

  • Kim, Yoo-Seok-;Lee, Jang-Gyu-
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1993.06a
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    • pp.1254-1257
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    • 1993
  • Presented in this paper is a newly developed motion planning method of an autonomous mobile robot(MAR) which can be applied to flexible manufacturing systems(FMS). The mobile robot is designed for transporting tools and workpieces between a set-up station and machines according to production schedules of the whole FMS. The proposed method is implemented based on an earlier developed real-time obstacle avoidance method which employs Kohonen network for pattern classification of sonar readings and fuzzy logic for local path planning. Particulary, a novel obstacle avoidance method for moving objects using a collision index, collision possibility measure, is described. Our method has been tested on the SNU mobile robot. The experimental results show that the robot successfully navigates to its target while avoiding moving objects.

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Command Fusion for Navigation of Mobile Robots in Dynamic Environments with Objects

  • Jin, Taeseok
    • Journal of information and communication convergence engineering
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    • v.11 no.1
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    • pp.24-29
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    • 2013
  • In this paper, we propose a fuzzy inference model for a navigation algorithm for a mobile robot that intelligently searches goal location in unknown dynamic environments. Our model uses sensor fusion based on situational commands using an ultrasonic sensor. Instead of using the "physical sensor fusion" method, which generates the trajectory of a robot based upon the environment model and sensory data, a "command fusion" method is used to govern the robot motions. The navigation strategy is based on a combination of fuzzy rules tuned for both goal-approach and obstacle-avoidance based on a hierarchical behavior-based control architecture. To identify the environments, a command fusion technique is introduced where the sensory data of the ultrasonic sensors and a vision sensor are fused into the identification process. The result of experiment has shown that highlights interesting aspects of the goal seeking, obstacle avoiding, decision making process that arise from navigation interaction.

A Study on AES Performance Assessment Protocol based on Car-to-car cut-out Scenario According to front Emergency Obstacle Avoidance of Preceding Vehicle during Highway Driving (고속도로 주행 시 선행차량의 전방 긴급 장애물 회피에 따른 Car-to-Car Cut-out 시나리오 기반 AES 성능평가 방법 연구)

  • Jinseok, Kim;Donghun, Lee
    • Journal of Auto-vehicle Safety Association
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    • v.14 no.4
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    • pp.84-90
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    • 2022
  • With the popularization of autonomous driving technology, safety has emerged as a more important criterion. However, there are no assessment protocol or methods for AES (Autonomous Emergency Steering). So, this study proposes AES assessment protocol and scenario corresponding to collision avoidance Car-to-Car scenario of Euro NCAP in order to prepare for obstacles that appear after the emergency steering of LV (Leading Vehicle) avoiding obstacles in front of. Autoware-based autonomous driving stack is developed to test and simulate scenario in CARLA. Using developed stack, it is confirmed that obstacle avoidance is successfully performed in CARLA, and the AES performance of VUT (Vehicle Under Test) is evaluated by applying the proposed assessment protocol and scenario.

A Homing and Obstacle Avoidance Algorithm for Nonholonomic Mobile Robots (Nonholonomic 이동로봇의 호밍과 장애물 회피 알고리즘)

  • Kong, Sung-Hak;Suh, Il-Hong
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.51 no.12
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    • pp.583-595
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    • 2002
  • Homing operation can be defined as a series of actions which are necessary for a mobile robot to move from the current position with any arbitrary orientation to a desired position with a specified orientation, while avoiding possible obstacles. In this paper, a homing and obstacle avoidance algorithm for nonholonomic mobile robots is proposed. The proposed algorithm consists of a local goal generator, a discrete state controller, and local path tracking controller based on Aicardi's path following algorithm. In the discrete state controller, 4 states are defined according to the environmental conditions and 4 desired high-level command for the states are given as follows: avoid, wander, home and homing zones. The proposed local goal generator is designed to generate the desired local path by using weighted distance transforms which are newly made to satisfy the nonholonomic constraints of mobile robots. Here, subgoals are also found as vertices of the desired local path. To demonstrate result effectiveness and applicability of the proposed algorithm, computer simulations are illustrated and experimental results for a real mobile robot system are also provided.