The World robot summit disaster robotics category - achievements of the 2018 preliminary competition. - Satoshi Tadokoro; Tetsuya Kimura; Masayuki Okugawa; Katsuji Oogane; Hiroki Igarashi; Yoshikazu Ohtsubo; Noritaka Sato; Masaru Shimizu; Soichiro Suzuki; Tomoichi Takahashi; Shin'ichiro Nakaoka; Mika Murata; et al. (Adv. Robotics, 2019)