One Body, Two Minds: Variable Autonomy Approach for a Co-embodied Robotic Hand

2026-06-24

AI Summary

This work addresses the inherent tension between user autonomy and cognitive load in assistive robotics by proposing a novel "co-embodied variable autonomy" approach. It introduces an innovative "one-body, two-brains" paradigm, wherein the human and robot share a single physical embodiment and dynamically adjust autonomy levels across task phases. The system integrates a vision-based visuomotor diffusion policy learned from demonstrations to enable autonomous grasping, while a hands-free, head-gesture-driven interface allows users to seamlessly reclaim control at any moment. User studies demonstrate that this method reduces task completion time by 23.3%, achieves a peak success rate of 93.6%, and yields a high overall impression score of 5.70 out of 7, significantly enhancing task efficiency, reliability, and user acceptance.

Abstract

Assistive robotic systems face a fundamental trade-off: fully autonomous systems lack user agency, while fully user-controlled systems demand continuous cognitive effort. Existing shared autonomy approaches blend human and robot commands but are mostly deployed in separate physical bodies. We introduce co-embodiment with variable autonomy, where human and robot share a single physical body and operate at different autonomy levels across task phases, from mutual autonomy during object search and grasping to human-dominant control during actuation. We present a co-embodied, wearable robotic hand that has its own ``mind'' and operates with variable autonomy levels. A learning-from-demonstration visuomotor diffusion policy enables autonomous grasping when the user positions the hand near known objects. Once grasped, the system signals completion and the human can actuate the grasped tool (drill, spray bottle, infrared thermometer, lighter, and ice-cream scoop) via hands-free head gestures. The human retains veto authority at all times through a release gesture that returns the system to the initial phase. Unlike blended autonomy, where control is continuously negotiated, our co-embodied approach consists of variable autonomy from full human control to full independent actions while maintaining physical coupling, realizing a one body, two minds paradigm. In a user study with 44 participants performing five bimanual tasks, users rapidly adapted to this ``two minds'' paradigm: completion times improved by 23.3% across trials ($p < 0.001$, Cohen's $d = 0.94$), the best-performing policy variant reached a 93.6% task success rate, and acceptance ratings were high (5.70/7 overall impression, 5.52/7 daily use willingness). This work establishes co-embodiment with variable autonomy as a viable approach for assistive robotics, enabling human-robot collaboration through co-embodiment.

Problem

• assistive robotics
• shared autonomy
• co-embodiment
• variable autonomy
• human-robot collaboration

Innovation

• co-embodiment
• variable autonomy
• shared autonomy
• visuomotor diffusion policy
• wearable robotic hand