Assistive robotic systems face a fundamental trade-off: fully autonomous sys- tems 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 it’s own ”mind” and operates with variable autonomy levels. A learning-from-demonstration vi- suomotor 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 bottles, lighter, 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 23.3% across trials ( 𝒑 < 0.001, Cohen’s 𝒅 = 0.82), task success reached 93.6%, and acceptance ratings were high (5.70/7 overall impression, 5.52/7 daily use willing- ness). This work establishes co-embodiment with variable autonomy as a viable approach for assistive robotics, enabling human-robot collaboration through co- embodiment.