This paper proposes a light-weight sensor plat form that consists of gyro-assisted odometry and a 3D laser scanner for localization of human-scale robots. The gyro assisted odometry provides highly accurate positioning only by dead-reckoning. The 3D laser scanner has a wide field of view and uniform measuring-point distribution. Robust and computationally inexpensive localization is implemented on the sensor platform using a particle filter on a 2D grid map generated by proj ecting 3D points on to the ground. The system uses small and low-cost sensors, and can be applied to a variety of mobile robots in human-scale environments. Outdoor navi gation experiments were performed at the Tsukuba Challenge 2009, which is an open proving ground for human-scale robots.Our robot successfully navigated the assigned I-km course in a fully autonomous mode multiple times.

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We proposed a new procedure for evaluating the parameters of the asperity models for predicting strong ground motions from inland earthquakes caused by long strike-slip faults. The evaluation formula of averaged dynamic stress drops obtained by Irie et al. (2010) 1) for surface ruptured faults 15 to 100 km long was adopted in our procedure, because the evaluation formula of the averaged static stress drops for circular cracks, commonly adopted in existing procedures, could not be applied to surface ruptured faults or long faults. The dynamic stress drop averaged on the entire fault was estimated to be 34 bars from the data of the rupture areas and the seismic moments of actual earthquakes, and the dynamic stress drop on the asperity was estimated to be 122 bars from the data of the short-period levels and the seismic moments of actual earthquakes. These results led to the conclusions that the asperity areas were 23 % of the entire ruptured areas.

Irie et al.

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