Seabottom roughness measurement by aquatic walking robot

Port construction works in Japan are now being done in deeper sea areas than before. Flattening of the rubble mound foundation in these deeper areas are carried out by machines because human divers' working time is very short at these depths. The authors developed a six-legged aquatic walking robot for underwater inspection. The robot named "AQUAROBOT" is navigated by an LBL ultrasonic transponder on the machine-leveled rubble mound foundation at up to 50 m depth. AQUAROBOT is able to walk on the uneven surface of the mound autonomously with its several sensors. Roughness is measured by the foot motion and pressure gauge during walking. The measured data is compensated for the tide.