A study of the microstructure modification of a space crawling robot adhesive feet based on discrete element method

According to the on-orbit maintenance mission requirements of a proposed space cooperative spacecraft, a new type of space crawling robot, which can be mounted on a grasping manipulator, is proposed. After the active spacecraft and the faulty target form a connection, the crawling robot can move to the spot on the faulty target that requires maintenance to be performed using fine operations. In this paper, the adhesion technology of space crawling robots was studied, and an adhesive microarray structure, which imitates gecko setae, was proposed. The simulation model was established using the discrete element software EDEM. 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 using simulation. Based on the simulation results, a plasma deep etching process was used to process the microarray specimens. The desorption process was tested in the ground environment using the water droplet method, and the tangential desorption force was tested. The experimental data show that the tangential adhesion decreases with an increase in the spacing and the length–diameter ratio. The experimental results are very consistent with the simulation results, which further demonstrated the correctness of the discrete element simulation with respect to the desorption process and the rationality of the optimal design of the microarray structure.