Does sweeping the planned centre of pressure from heel to toe let a stock humanoid carry faster?

What it found

A follow-up to buildbot-carrycop, which held the planned centre of pressure (CoP) at a constant offset. Here the CoP moves linearly along the sole during single support (the linear inverted pendulum with a ramped CoP has a closed-form orbit) and the Menagerie G1 and H1 are re-scored over 1,680 cases (payload, step length, step time, eight sweeps) with the carryphase inverse kinematics and joint-torque limits. Result: the G1's ceiling does not move except the known one-cell gain at 4 kg (0.10 to 0.13 m/s, also reached by a constant 6 cm-behind CoP); the H1 gains one cell unloaded (0.15 to 0.20 m/s) with a −3 to +3 cm sweep but loses all cases when the sweep starts 6 cm behind the sole point. Torque, not the sole, remains the wall. Prescribed gait, no falls or energy scored, no trunk or arm motion, not a safety case.

A figure from its own output

Paper, code and results

• README and method
• Experiments and results
• Code
• Tests

More in Robots on the building site

• Can a stock Unitree G1 or H1 humanoid hold one end of a sheet while a person lifts the other?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).
• Does a stock humanoid pay for itself on a house site, and how much of a new home's price could it remove?Does a stock humanoid pay for itself on a house site? The break-even slowdown against a $38/h loaded carpenter is about 2.4 for a $16k Unitree G1 and 1.1 for a $90k H1; over a sweep the G1 saves money in 15% of draws, the H1 in 0.4%, and a perfect H1 would remove 0.19% of an average home's price on the taskbook scope (inputs swept, not measured).
• Does a purpose-built nailing gantry beat a stock humanoid at fastening sheathing, and at what house volume does it pay?Does a purpose-built nailing gantry beat a stock humanoid at fastening sheathing? A modelled two-axis bridge nails a 62-nail sheet in 61 s (6.1x hand nailing); a $100k machine needs about 150 houses a year to break even on walls (50 with roof cassettes), where the H1 saves money in 0.4% of draws (price and times swept, not sourced).
• Can a stock Unitree G1 or H1 humanoid push a nailer into a wall and place nails inside a stud face?Can a stock Unitree G1 or H1 push a nailer into a wall and place nails inside a stud face? One 4x8 sheet is 62 nails, 34 with a +-3.9 mm window; the tip needs 1.24 mm scatter for a 95% sheet. The G1 pushes up to 142 N and reaches 18 of 62 nails from one stance, the H1 up to 276 N and 36 of 62 (static, peak torque, no policy).
• Can a G1 humanoid nail a 4x8 sheet lying flat on a table?Can a G1 humanoid nail a 4x8 sheet lying flat on a table? Not better than on a wall: pushing down at 50 N with its feet planted it holds only 30 of 693 reach cells, reaching 48 of the sheet's 62 nails in 16 stances (13 stances for all 62 on a wall), and matching hand nailing (372 s) only if each re-stance takes under 23-24 s (push, standoff and re-stance time are swept, not sourced; static IK, no walking).
• With the simulated carry and nailing results in place of a swept slowdown, does a stock humanoid pay on a house site?With simulated carry and nailing results in place of a swept slowdown, does a stock humanoid pay on a house site? The H1's carry slowdown is 0.41 to 1.70 against a one-stud labourer (pays in 72% of cells) and 1.63 to 6.82 against a bundle carrier (never pays), against a break-even of 1.07; the dollars are tens per house.

All 27 Robots on the building site projects →

Other research topics

Proper scoring & elicitation28Effort & peer prediction9Verification games & slashing19Detection & tolerances14Markets as routers13Prediction-market design9Paying contributors8Decentralised training systems23Digital twins & sim-to-real164LLM chip design loops40Robot manufacturing loops53Ambient AI assistant46Self-replicating manufacturing34Simulation-first design64Engineered clothing45Task-specific AI accelerators40Algorithmic chip-design loops42Open-source purpose-built robots44The software-engineering loop43Adversarial human imitation41Open-source residential construction41Autonomous multi-angle capture34Sensing, imaging and 3D31Energy supply and dense energy storage39Robot societies among people31Agentic co-design of low-cost robots27Laundry-hanging robots25Machine learning on qualitative data23Robots on the building site27Civilizations & group psychology1History & human sciences1

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.