Design of a Hybrid Rigid-flexible Robotic Gripper for Grasping in Unstructured Environments during Space Operations

In recent years, with growing global interest in space technologies, numerous countries have intensified their research and development efforts for space operations. Space grasping plays an important role in space operations. This paper presents a novel hybrid rigid-flexible robotic gripper specifically designed for grasping objects in orbit, such as space junk, cubic satellite and so on. The gripping mechanism incorporates a simple cable- strut structure, ensuring seamless opening and closing of the rigid gripper. Additionally, a flexible folding mechanism is implemented to guarantee the closure of the gripper's internal space, so that the grasping target cannot escape from the space. The folding unit can be conceptualized as a spatial 6R linkage, with its motion characteristics analyzed by using the D- H method. The foldable unit is then expanded into a foldable array, while identifying and addressing potential issues that may arise during this process due to tailoring on the basis of a complete unit networking system. Dynamic simulation is conducted on the rigid part of the gripper, obtaining dynamic curves, which provides guidance for motor selection Finally, a prototype has been developed for experimental verification, and it has been demonstrated that the prototype meets the basic requirements and still needs improvements.