1. (2) T. Kanda, H. Ishiguro, T. Ono, M. Imai, T. Maeda, and R. Nakatsu: “Development of “Robovie” as Platform of Everyday-Robot Research”, IEICE, Vol. J85-D-1, No. 4, pp. 380-389 (2002) (in Jananese)
2. Ultrasonic Range Finder with Cross-Correlation for Outdoor Mobile Robots.