An Underactuated Rigid-Soft Hybrid Gripper Prototype for Conforming Free-Flying Manipulation

Astrobee is a free-flying robot that is used to perform zero-gravity manipulation tasks, such as perching onto the handrails of the International Space Station. The complexity of future space station subsystems will require free-flying manipulation to be more adaptive, dexterous, and conforming. This article presents a rigid-soft hybrid gripper prototype for conforming manipulation in zero-gravity environments. This proof-of-concept prototype is a three-finger underactuated tendon-driven gripper with rigid joints and hinges equipped with inflatable soft padding and soft distal joints. Integrated into Astrobee's perching arm payload, this prototype is capable of grasping spherical geometries with reduced actuation and payload volume stowage. This gripper prototype is a step towards increased conforming manipulation capabilities for free-flying robots.