著者

田窪 朋仁 吉岡 健伸 新井 健生 前 泰志 大原 賢一

出版者

一般社団法人日本機械学会

雑誌

日本機械学會論文集. C編 (ISSN:03875024)

巻号頁・発行日

vol.75, no.759, pp.2996-3004, 2009-11-25

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Leg-wheel hybrid locomotion on rough terrain for a hexapod robot is realized by continuous transition between wheeled and legged locomotion based on sensor feedback. In basic positioning on a flat surface, the robot is supported by three legs and moves using its wheels. Upon sensing an obstacle, the robot's support and swing legs change as a tripod gait to cross over the obstacle. We define the three dimensional model of the motion on a slope for stability estimation, and its analysis indicates that the maximum obstacle height depends on the robot's height and the slope gradient. Even if the slope is steep, the robot can climb over a higher step on it by moving the robot's center of gravity (COG) based on the analysis. The experimental results on ASTERISK H confirm the advantage of proposed motion by comparing to the fixed COG motion.

著者

田窪 朋仁 上撫 琢也 前 泰志 新井 健生 大原 賢一

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集C編 (ISSN:18848354)

巻号頁・発行日

vol.78, no.793, pp.3186-3201, 2012 (Released:2012-09-25)

参考文献数

12

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A new convergence calculation method of the Normal Distributions Transform (NDT) scan matching for high resolution of grid maps is proposed. NDT scan matching algorithm usually has a good effect on large grids, so it is difficult to generate the detailed map with small grids. The proposed method employs Interactive Closest Point(ICP) algorithm to find corresponding point, and it also enlarges the convergence area by modifying the eigenvalue of normal distribution so that the evaluation value is driven effectively for the pairing data. In addition, outlier elimination process is implemented to the scanning for sub-grid scale objects. The scanning data from Laser Range Finder(LRF) have error but its set of detected small objects can be clustered to determine the Center of Mass(CoM) and the outlier data. The outlier commonly locates behind true points and it can be eliminated when the robot observes from other points. Experimental result shows the effectiveness of the proposed convergence algorithm and the outlier elimination method.