Can a stock Unitree G1 or H1 humanoid hold one end of a sheet while a person lifts the other?
research/buildbot-cohold
Can a stock Unitree G1 or H1 hold one end of a sheet while a person lifts the other? For a 22 kg sheet the person carries 11.1-11.5 kg-equivalent in a 2-4 s lift; the G1 manages up to 8 kg, the H1 a 23 kg drywall sheet; lag sets the tilt (2-6 degrees at 0.2-0.5 s).
What it found
A person lifts one end of a 4x8 sheet 0.3 m; a Menagerie G1 or H1 holds the other under impedance control that copies the person's motion after a lag. Planar rigid-sheet dynamics (108 control settings), static whole-body torque checks along the lift, and ISO/TS 15066 speed limits. For a 22 kg sheet the person's load stays at 11.1–11.5 kg-equivalent in a 2–4 s lift (NIOSH constant 23.1 kg) and reaches 15.5–20.4 kg in a 0.5 s snatch. Peak tilt is about hand speed × lag ÷ sheet length: 2.2° at 0.2 s lag, 3–6° at 0.5 s. The G1's waist limits it to an 8 kg sheet (6 kg in a fast lead); the H1 holds half of a 23.2 kg drywall sheet at 0.77 of its elbow limit. The standard's body-region formula gives 0.13 m/s for the face and 0.29 m/s for the chest at the robot's end, against 0.28 m/s hand speed in a 2 s lift. Simulated and preliminary: the standard's values come from a secondary source (arXiv:2311.13814), the hand controller and lift are my own choices, the robot stays in one stance, and nothing is a safety case.
A figure from its own output

Paper, code and results
More in Robots on the building site
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Produced with AI assistance (Claude). Results are from the code in this repository and are simulated or stylised unless the abstract says otherwise; nothing here implies affiliation with or endorsement by any lab, researcher or company cited. MIT licensed.