Characteristic evaluation on land for a novel amphibious spherical robot

In recent years, people have attached great importance to the development of amphibious robots that are used to develop marine resources and implement marine missions. This paper presents a new type of amphibious spherical robots. The robot includes four drive units. Each drive unit consists of two servo motors, a water-jet propeller, a DC motor and a wheel. The robot can constitute 3 movement structure ways according to the environment. When the robot enters water, it adopts water jet propulsion. According to different land conditions, there are two movement patterns to switch. One is a quadruped movement pattern which is available to climb over obstacles; the other is a driving wheel movement pattern which is used to speed up the movement of robot under the flat terrain. The paper focuses on characteristic evaluation on land for a novel amphibious spherical robot. Based on two movement patterns, experiments were conducted under the condition of different terrains and different loads on land. From the results, the robot moving speed decreases with the load increasing in the same terrain. Without load, the maximum velocity of the robot is 8cm/s at the frequency of 1.25Hz on the title floor under quadruped movement pattern. Without load, the maximum velocity of the robot is 36.7cm/s at the duty of 100% on the title floor under wheel movement pattern. So compared with the quadruped movement speed, wheel movement speed of the amphibious spherical robot has greatly improved.