Development of a spherical amphibious mother robot

A variety kinds of underwater robots have been developed for the uses of underwater investigation and underwater operation. For those tasks in complicated or tiny underwater environments, some kinds of underwater microrobots have been developed. Thanks to the developments of smart actuators, microrobots realized relatively high performance within a compact structure. But problems in velocity and sustainable time limited their application. To solve this problem, we proposed a mother-son robot system, which include several microrobots as son robots, and an amphibious spherical robot as the mother robot. In this paper, a mother robot was proposed. It was designed to be able to walk on land, as well as move in water using a vectored water-jet mechanism. As the mother robot in the under-developing system, it also contained the space for transporting microrobots, and two openable hulls to protect the microrobots from the water currents and obstacles in water. A pressure sensor was used to determine whether robot was on land or in water, and measure the depth while in the underwater situation. To avoid obstacles, eight infrared distance sensors were used to detect obstacles in all the directions around the robot. In order to evaluate the robot's underwater performance, some experiments were conducted.