Underwater robot with a buoyancy control system based on the spermaceti oil hypothesis development of the depth control system

The goal of this paper is to develop a robot control system using a microcomputer for an underwater robot with a buoyancy control system based on the spermaceti oil hypothesis. Sperm whales have a spermaceti organ in their head that is filled with spermaceti oil. It is said that sperm whales control their buoyancy by melting or coagulating spermaceti oil. In the previous papers proposed an underwater robot with a buoyancy control device using its theory. The robot was radio controlled and it had no sensor. Therefore, the robot could not detect water depth. Also, it was not able to control its own depth. In addition, the robot could not dive because it had no cooling system. In this paper, we built a depth control circuit using a microcomputer and pressure sensor. The pressure sensor detected the robot´s depth, and the microcomputer controlled the robot´s position. And, we made a new buoyancy control device using a peltier element. A peltier element was used for heating and cooling systems of the paraffin wax. Then, we experimented with the robot control. As a result, we confirmed that when we ordered a target water depth, the robot dived, floated and maintained the depth itself by detecting its own position. In addition, we confirmed that when a disturbance occurs, the robot returned to the former depth.