Multi-legged mobile robots possess high mobility performance in rough terrain environments, stemming from their high postural stability, joint flexibility, and the redundancy provided by multiple legs. In prior research on navigating between different environments such as land and water, the primary strategy employed involves switching to a controller that generates an appropriate gait for the new environment upon entering it. However, designing appropriate gaits for each complex and diverse environment and accurately determining controller switching for each environment is challenging. Therefore, this research develops a centipede-type mobile robot that navigates both aquatic and terrestrial environments with a simple, unified control scheme, based on the implicit-explicit control philosophy and by ingeniously designing the robot's body structure. In this research, we developed the robot featuring flexible joints and left and right legs on each body segment and focused on the leg structure which has extensive contact with the environment. This paper evaluates the locomotion performance on land and water using the three developed leg structures, using the robot's leg slip rate and actuator energy consumption as evaluation metrics. The experimental results confirmed the existence of an appropriate leg structure capable of navigating both aquatic and terrestrial environments under identical control.

In one of the weirdest scientific experiments yet, goldfish have been trained to'drive' a robotic tank around a room. Scientists in Israel constructed a'fish operated vehicle' consisting of a water-filled tank, a camera and a computer on top of a set of wheels. In tests, the onboard camera and computer were able to detect the fish's position in real time and activate the vehicle motors to move the vehicle in the same direction. Six goldfish were successfully trained to use the bizarre device and managed to find their way around the small room towards a food reward. The results suggest that fish can adjust their navigation skills'to a wholly different terrestrial environment', according to the researchers.