2016 Volume 136 Issue 9 Pages 606-614
In this paper' we describe an underwater robot with three movement functions: 1) swimming, 2) crawling on a floor and 3) climbing on a wall. These functions help the robot avoid obstacles and thus improve its ability to access narrow spaces. The swimming stability of the robot is also improved by increasing the distance between the center of gravity and the center of buoyancy. We propose a simple attitude control technique for making the robot adhere to a wall after it is rotated by thrusters. Attitude control is realized by sequence control, and appropriate control parameters are determined by considering the control disturbance and stability of the robot. We confirm experimentally that the robot swims stably and adheres to a vertical wall by virtue of the simple sequence control.