Experimental evaluation of gripping characteristics based on frictional theory for ground grip locomotive robot on an asteroid

Owing to the irregular terrain and microgravity environment of an asteroid, an appropriate locomotion mechanism is required for exploring the asteroid by a robot. In this paper, a ground grip locomotive robot is proposed. One of the most important requirements of the robot is the development of the finger gripping mechanism that can be attached on an uneven surface. To meet this requirement, grip condition and friction characteristics between the finger and the surface need to be understood. Therefore, we conducted an experimental evaluation of gripping characteristics by measuring the coefficients of friction between several types of fingers and simulated grounds. Moreover, the range of possible gripping angles for simulated ground was determined by conditional equations and confirmed by an experiment of gripping the ground using an air-floating system. In this paper, conical shape is shown to be effective for ground grip locomotive robot.