• Title/Summary/Keyword: multi-linkage kinematics

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Optimized design of Jansen mechanism based on target trajectory tracking method using multi-objective genetic algorithm (Multi-objective Genetic Algorithm 을 이용한 얀센 메커니즘의 목표 궤적 트래킹 기반 최적 설계)

  • Heo, Joon;Hur, Youngkun
    • Proceeding of EDISON Challenge
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    • 2016.03a
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    • pp.455-462
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    • 2016
  • Recently, followed by rapid growth of robotics field, multi-linkage mechanism which can even pass by rough road is getting lots of attention. In this paper, I focused on Jansen mechanism. It's a kinematics object which is named after Dutch artist Theo jansen. Jansen mechanism embraces structure and mechanism which creates locomotion with the combination of the power and simple structure. Theo jansen suggests a 'Holy number'. It's an ideal ratio of leg components length. However, if there's desired gait locomotion, you have to adjust the ratio and the length. But even slight change of the length could cause a big change at the end-point. To solve this problem, I suggest a reverse engineering method to get a ratio of each links by nonlinear optimization with pre-set desired trajectory. First, we converted a movement of the joint of Jansen mechanism to vectors by kinematics analysis of multi-linkage structure. And we showed the trajectory at the end-point. After that, we set desired trajectory which we found most ideal. Then we got the length of the leg components which draws a trajectory as same as trajectory we set, using Multi-objective genetic algorithm toolbox in MATLAB. Result is verified by Edison designer and mSketch. And we analyzed if it could pass through the obstruction which is set dynamically.

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A Kinematic Approach to Answering Similarity Queries on Complex Human Motion Data (운동학적 접근 방법을 사용한 복잡한 인간 동작 질의 시스템)

  • Han, Hyuck;Kim, Shin-Gyu;Jung, Hyung-Soo;Yeom, Heon-Y.
    • Journal of Internet Computing and Services
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    • v.10 no.4
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    • pp.1-11
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    • 2009
  • Recently there has arisen concern in both the database community and the graphics society about data retrieval from large motion databases because the high dimensionality of motion data implies high costs. In this circumstance, finding an effective distance measure and an efficient query processing method for such data is a challenging problem. This paper presents an elaborate motion query processing system, SMoFinder (Similar Motion Finder), which incorporates a novel kinematic distance measure and an efficient indexing strategy via adaptive frame segmentation. To this end, we regard human motions as multi-linkage kinematics and propose the weighted Minkowski distance metric. For efficient indexing, we devise a new adaptive segmentation method that chooses representative frames among similar frames and stores chosen frames instead of all frames. For efficient search, we propose a new search method that processes k-nearest neighbors queries over only representative frames. Our experimental results show that the size of motion databases is reduced greatly (${\times}1/25$) but the search capability of SMoFinder is equal to or superior to that of other systems.

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Kinematic Analysis of a Legged Walking Robot Based on Four-bar Linkage and Jansen Mechanism (4절 링크 이론과 얀센 메커니즘을 기반으로 한 보행 로봇의 운동학 해석)

  • Kim, Sun-Wook;Kim, Dong-Hun
    • Journal of the Korean Institute of Intelligent Systems
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    • v.21 no.2
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    • pp.159-164
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    • 2011
  • In this study, a crab robot is implemented in H/W based on four-bar linkage mechanism and Jansen mechanism, and its kinematics is analysed. A vision camera is attached to the mechanism, which makes the proposed robot a kind of biologically inspired robot for image acquisition. Three ultrasonic sensors are adopted for obstacle avoidance. In addition, the biologically inspired robot can achieve the mission appointed by a programmer outside, based on RF and Blue-tooth communication module. For the design and implementation of a crab robot, it is need to get joint variable, a foot point, and their relation. Thus, the proposed kinematic analysis is very important process for the design and implementation of legged robots.