SPACE CLIMBING ROBOT FEET WITH MICROARRAY STRUCTURE BASED ON DISCRETE ELEMENT METHOD

摘要

Aiming at the on-orbit maintenance requirements of spacecraft, this paper proposed an updated type of space climbing robot that can climb onto the target spacecraft in space environment for repairing and rescuing. The robot's movement system consists of piezoelectric driving legs and micro-adhesive feet. The robot leg and body connection have two degrees of freedom, the knee joint has one degree of freedom, and the ankle joint has two degrees of freedom. In space environment with no gravity, the climbing robot can over obstacles by crawling movement and flipping movement. The clamping force of the robot is provided by the adhesion of the robot feet with microarray structure. The robot foot-end microarray adhesion structure was designed based on the multi-scale microstructure of the gecko's sole. The effects of the structural parameters, such as the contact area, length-diameter ratio, length, diameter, and density, on the adhesion characteristics of the microarrays in zero-gravity space environment were analysed. The simulation model was established using the discrete element software EDEM. The normal and tangential adhesion of the microarray in different motion modes is obtained by simulation. The simulation results demonstrate that using different ways of movement can achieve different adhesive abilities. The above conclusion supports the theory of the later achievement regarding robot feet's strong attaching and rapid detaching ability.