• Title/Summary/Keyword: motion planning

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G2 Continuity Smooth Path Planning using Cubic Polynomial Interpolation with Membership Function

  • Chang, Seong-Ryong;Huh, Uk-Youl
    • Journal of Electrical Engineering and Technology
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    • v.10 no.2
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    • pp.676-687
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    • 2015
  • Path planning algorithms are used to allow mobile robots to avoid obstacles and find ways from a start point to a target point. The general path planning algorithm focused on constructing of collision free path. However, a high continuous path can make smooth and efficiently movements. To improve the continuity of the path, the searched waypoints are connected by the proposed polynomial interpolation. The existing polynomial interpolation methods connect two points. In this paper, point groups are created with three points. The point groups have each polynomial. Polynomials are made by matching the differential values and simple matrix calculation. Membership functions are used to distribute the weight of each polynomial at overlapped sections. As a result, the path has $G^2$ continuity. In addition, the proposed method can analyze path numerically to obtain curvature and heading angle. Moreover, it does not require complex calculation and databases to save the created path.

A New Technique to Escape Local Minimum in Artificial Potential Field Based Path Planning

  • Park, Min-Gyu;Lee, Min-Cheol
    • Journal of Mechanical Science and Technology
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    • v.17 no.12
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    • pp.1876-1885
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    • 2003
  • The artificial potential field (APF) methods provide simple and efficient motion planners for practical purposes. However, these methods have a local minimum problem, which can trap an object before reaching its goal. The local minimum problem is sometimes inevitable when an object moves in unknown environments, because the object cannot predict local minima before it detects obstacles forming the local minima. The avoidance of local minima has been an active research topic in the potential field based path planing. In this study, we propose a new concept using a virtual obstacle to escape local minima that occur in local path planning. A virtual obstacle is located around local minima to repel an object from local minima. We also propose the discrete modeling method for the modeling of arbitrary shaped objects used in this approach. This modeling method is adaptable for real-time path planning because it is reliable and provides lower complexity.

A collision-free path planning for multiple mobile robots by using hopfield neural net with local range information (국소 거리정보를 얻을 수 있는 다중 이동로보트 환경에서의 Hopfield 신경회로 모델을 이용한 충돌회피 경로계획)

  • 권호열;변증남
    • 제어로봇시스템학회:학술대회논문집
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    • 1990.10a
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    • pp.726-730
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    • 1990
  • In this paper, assuming that local range information is available, a collision-free path planning algorithm for multiple mobile robots is presented by using Hopfield neural optimization network. The energy function of the network is built using the present position and the goal position of each robot as well as its local range information. The proposed algorithm has several advantages such as the effective passing around obstacles with the directional safety distance, the easy implementation of robot motion planning including its rotation, the real-time path planning capability from the totally localized computations of path for each robot, and the adaptivity on arbitrary environment since any special shape of obstacles is not assumed.

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Collision-Free Path Planning of Articulated Robot using Configuration Space (형상 공간을 이용한 다관절 로보트의 충돌 회피 경로 계획)

  • Kim, J.H.;Choi, J.S.;Kang, H.Y.;Kim, Dong-Won;Yang, S.M.
    • Transactions of the Korean Society of Automotive Engineers
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    • v.2 no.6
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    • pp.57-65
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    • 1994
  • A collision-free path planning algorithm between an articulated robot and polyhedral obstacles using configuration space is presented. In configuration space, a robot is treated as a point and obstacles are treated as grown forbidden regions. Hence path planning problem is transformed into moving a point from start position to goal position without entering forbidden regions. For mapping to 3D joint space, slice projection method is used for first revolute joint and inverse kinematics is used for second and third revolute joint considering kinematic characteristics of industrial robot. Also, three projected 2D joint spaces are used in search of collision-free path. A proper example is provided to illustrate the proposed algorithm.

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Automated initial process planning system for three-axis NC machining of sculptured surfaces (자유 곡면의 3축 NC 가공을 위한 초기 공정 계획 기능의 자동화)

  • Kang, Jae-Kwan
    • Journal of the Korean Society for Precision Engineering
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    • v.14 no.3
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    • pp.114-121
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    • 1997
  • In this paper, the automated initial process planning for 3-axis NC machining of sculptured surfaces is persented. The solution algorithms determining three process planning functions, i.e. machining feasibility, setup orientation and feasible machine selection are developed. The machining feasibility is determined by means of BSM(Binary Spherical Map) which derives its solution quickly in algebraic form, and the setup orientation is determined so that the cutting force is minimized. Finally, the feasible machine is determined by computing the minimum motion ranges of each control axisl. The developed algorithms are tested by numerical simulations, convincing they can by readily implemented on the CAD/CAM system as a process planner.

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An Efficient 3D Visualization Method of AUV Motion Using Interpolation of Position Data (보간법을 이용한 무인잠수정 3차원 운동의 효율적인 가시화 기법)

  • Lee, Hee-Suk;Jun, Bong-Huan;Kim, Ki-Hun;Kim, Sang-Bong
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2006.11a
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    • pp.327-330
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    • 2006
  • With the increasing requirements for the survey and development of the ocean, the demands on the of AUV(Autonomous Underwater Vehicle) technologies have been increased. Reconstruction and replay of the AUV motion on the basis of the data stored during the execution of mission, can help the development of control strategies for AUVs such as mission planning and control algorithms. While an AUV cruises for her mission, her attitude and position data are is recorded. The data can be used for visualization of the motion in off-line. However, because most of the position data gathered from acoustic sensors have long time-interval and include intermittent faulty signal, the replayed motion by the graphic simulator can not demonstrate the motion as a smooth movie. In this paper, interpolation methods are surveyed to reconstruct the AUV position data. Then, an efficient 3D visualization method for AUV motion using the interpolation method is proposed. Simulation results arc also included to verify the proposed method.

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Patient Respiratory Motion Tracking Using Visual Coded Markers (시각 부호화 마커를 이용한 환자의 호흡 추적)

  • Wijenayake, Udaya;Park, Soon-Yong
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.12
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    • pp.111-122
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    • 2014
  • As radiotherapy has become one of the widely used techniques in cancer treatment, accurate tracking of patient's respiratory motion is considered to be more important in treatment planning and dose calculations. Inaccurate motion tracking can cause severe issues such as errors in target/normal tissue delineation and increasing the volume of healthy tissues exposed to high doses. Different methods have been introduced to estimate the respiratory motion, but most of them require some electronic devices or expensive materials. As an inexpensive and easy to use alternative to the previous methods, we propose a new 3D respiratory motion tracking method by using stereo vision techniques of detecting and decoding visual coded markers.

Minimum-Time Trajectory Planning Ensuring Collision-Free Motion for Two Robots : Neural Optimization Network Approach (신경 최적화 회로망을 이용한 두 대의 로보트를 위한 최소시간 충돌회피 경로 계획)

  • Lee, Ji-Hong;Bien, Zeung-Nam
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.27 no.10
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    • pp.44-52
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    • 1990
  • A collision-free trajectory planning for two robots with designated paths is considered. The proposed method is based on the concept of decomposing the planning problem into two steps: one is determining coordination of two robots, and the other is velocity planning with determined coordination. Dynamics and maximum allowable joint velocities are also taken into consideration in the whole planning process. The proposed algorithm is converted into numerical calculation version based on neural optimization network. To show the usefulness of proposed method, an example of trajectory planning for 2 SCARA type robot in common workspace is illustrated.

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A Study on the Working Clothes in the Changwon National Industrial Complex -Considering Clothing Performance and Motion Factors in Work Places- (창원국가산업공단 근로자들 작업복 착용실태에 관한 연구 -작업분야별 작업복 기능성 및 동작요인 중심으로-)

  • Park, Gin-Ah;Bae, Hyun-Sook
    • Journal of the Korean Society of Clothing and Textiles
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    • v.32 no.10
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    • pp.1571-1583
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    • 2008
  • The study aimed to investigate the actual condition of working clothes in the Changwon National Industrial Complex and to analyze the industrial workers' satisfaction with and preference to the working clothes in terms of the clothing performance and work motion factors. 1 major companies in machinery, automotive, industrial engineering, shipbuilding and rolling stock industries located in the industrial complex were selected as the subject firms. Approximately 900 workers responded to the questionnaire designed for the research and the results derived from the research were as follows. (1) The subject employees were divided into 4 work groups, i.e. the $1^{st}$ work group: managerial, general affairs, sales, production planning; the $2^{nd}$ group: quality assurance, material planning and distribution, product inspection; the $3^{rd}$ group: electric, facilities, machinery, vehicles; and the $4^{th}$ group: cutting, pressing, rolling, welding and coating. (2) The significant work environmental factors considered by all work groups were air ventilation, noise and dust factors and in particular, the most dissatisfied factors evaluated by manufacture workers were insulation, noise, dust and vibration. (3) According to the employees' work motion evaluation, the work motion diversity and frequency increased in proportion to the degree of work intensity. Besides, manufacture workers more frequently wore the working clothes even during the off-duty hours comparing to the evaluation of the other work groups. (4) The most important clothing performance factors considered by manufacture work groups were perspiration absorption, stretch, air permeability, tactile sense softness, soil proof in order.

Design of Hybrid Wheeled and Legged Mobile Robot with a Waist Joint (허리 구조를 갖는 복합 바퀴-다리 이동형 로봇의 설계)

  • Choi, Dae-Gyu;Jeong, Dong-Hyuk;Kim, Yong-Tae
    • Journal of the Korean Institute of Intelligent Systems
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    • v.24 no.3
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    • pp.304-309
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    • 2014
  • In this paper, we design a hybrid wheeled and legged mobile robot with a waist joint. The proposed hybrid mobile robot is designed to have a hybrid structure with leg and wheel for the efficient movement in flat and uneven surfaces. The proposed robot have a waist joint that is used to stably transform from wheeled driving to legged walking of the robot and to overcome non-flat surface. In order to recognize various environments we use LRF sensor, PSD sensor, CCD camera. Also, a motion planning method for hybrid mobile robot with a waist joint is proposed to select wheeled driving motion and legged walking motion of the robot based the environment types. We verify the efficient mobility of the developed hybrid mobile robot through navigation experiments using the proposed motion planning method in various environments.