Spherical Amphibian Robot Design with Novel Driving Principle

Abstract

The advantage of spherical robots is utilized in the development of amphibian robots. It leverages the spherical advantage in terms of mobility and concealment to operate underwater. The main issue when developing the robot is that the robot is not conceal properly. Mainly when travel underwater. Robot that applied propeller as the actuator capable to conceal the equipment but different actuator needed for terrestrial locomotion. Therefore, a suitable combination of both terrestrial and underwater actuators that capable to perform multiple motion axis with minimal energy consumption is crucially needed. The objective of this paper is to represent a novel amphibian spherical robot design with its driving principle in terrestrial and underwater motion. The proposed spherical robot consists of 4 motor and 1 water pump. Terrestrial motion applied servo motor to roll the sphere in surge while yawing motion was control by a pendulum that rotates around the x-axis controlled by another servo motor. When travel underwater, surge motion was achieved by using the propeller and ballast will maintain the depth. To change the thrust direction, servo motor will rotate the sphere body to a certain degree which makes it possible to perform heave and surge motion at the same time. Diving and floating motion utilized the variable ballast and the propeller to optimize the robot energy usage and performance. The flow test shows that the resistance is higher when the size is bigger. The hydrodynamic forces act to the robot is the same in all directions. Therefore, the proposed robot should experience the same magnitude of noise in all directions when traveling underwater.