ORBIT: A Modular Multi-finger Robotic Hand Platform with Rotational Finger Reconfiguration

Overview & Synopsis

Despite the popularity of multi-fingered robotic hands for dexterous manipulation, there is no systematic platform to compare different hand morphologies against one another. We present ORBIT (Orbital Reconfigurable Base-actuated Integrated Theta-motion Hand), a modular platform designed to enable principled exploration of multi-fingered hand morphology. The core contribution of ORBIT is a rotating knuckle mechanism, where independent fingers travel around a cylindrical palm via a belt drive. This enables ORBIT to perform quick recon- figuration (< 1 s) of finger layout without hand disassembly. ORBITs a robust system, with finger average angular velocity of 1.57 rad / s1 and a root finger force resistance of 50 N. Using a three fingers instantiation of ORBIT, we demonstrate an initial pilot grasping study, comparing anthropomorphic, isometric, and Barrett-style finger layouts across eleven objects of varied size, shape, and texture. We further demonstrate how ORBITs nonanthropomorphic orbital DOF enables the achievement of tasks that would be difficult to perform with fixed-knuckle designs, such as cube face reorientation, lid threading, and precision pinching of sub-centimeter objects. These results establish ORBIT as a viable platform for direct apples to apples comparison of multi-fingered hand morphologies for specific manipulation tasks