A Dexterous and Compliant Gripper With Soft Hydraulic Actuation for Microgravity Manipulation

William Su, Jordan Kam, Yixiao Wang, Jianshu Zhou

Keywords: Astrobee, DexCoHand, in-hand manipulation, gripper prototype, free-flying robot

TL;DR: We propose the integration of a dexterous and compliant DexCoHand with the free flying robot Astrobee to enable expanded dexterous in-hand manipulation in space.

Abstract: Astrobee’s existing one-degree-of-freedom (DOF) underactuated compliant claw gripper enables perching on the International Space Station (ISS), but provides limited capability for continuous dexterous manipulation. More complex microgravity tasks require an end-effector that can maintain stable contact while limiting disturbance to the free-flying base, since contact forces directly couple into base motion. This article presents the integration of DexCoHand, a dexterous and compliant two-finger, 6-DOF gripper, with the Astrobee free-flying robot for microgravity manipulation. The system is evaluated in MuJoCo using Astrobee’s standard handrail perching sequence, including approach, perching, and subsequent pan and tilt motions. Compared with Astrobee’s existing gripper, DexCoHand preserves the commanded pan and tilt motions while reducing unintended cross-axis base motion. Hardware experiments on Earth further demonstrate DexCoHand’s dexterous manipulation capabilities and its potential for more adaptable intelligent manipulation tasks.

Submission Number: 32