Design and Simulation of an Adaptive Underactuated Gripper for Grasping Lunar Rock

Robotic grasping by grippers is a representative operation conducting scientific activities in space, such as on-orbit construction, on-orbit maintenance, and planetary exploration. The underactuated gripper is an emerging research direction of space robots. This paper proposes a new configuration of the adaptive underactuated gripper for grasping lunar rocks. In this paper, based on the contact conditions of different stages under ideal conditions, the kinematic analysis of the equivalent mechanism at each stage is carried out. The gripper adopts static equilibrium and dynamics calculation and can successfully secure a spherical object with a diameter of 100 mm to 200 mm. According to the analysis, the numerical simulation shows that the underactuated gripper has a good accessible space and a stable grasping process. This underactuated gripper is proved numerically to have the adaptative morphing capacity to tighten on the target with multiple advantages, such as few actuation units, low cost, good load capacity, and wide grasping range.