Abstract
The final goal of this study is to develop a buoyancy control device for underwater robot utilizing phase change of material. A conventional underwater robot and submarine adjust buoyancy by discarding a set of iron balls or seawater in other place, which is harmful to the environment. Therefore, we proposed new buoyancy control method utilizing phase change of material. In this paper, we report the improvement of the buoyancy control device that utilizes expansion and contraction of metal bellows, which we proposed in the previous paper. Paraffin wax filled in the device was cooled by peltier devices and heated by them and a nichrome wire, resulting in volume change. We designed a new device with a new mechanism to reduce the mass of the device and to improve the insulation characteristic and the heating speed of the device. As a result, the mass of the new device is two sevenths that of the previous one. Also we confirmed that the new device has high insulation characteristics compared with the previous one.
