free-humanoid-wheeled

Free Humanoid Wheeled

An open hardware, open firmware, open data wheeled-base humanoid reference design — sibling morphology to the bipedal Free Humanoid Platform and the deployment partner of the shoal water-remediation fleet. Targeted at the shoal dock-B service mission: urban stormwater outfalls, harbor docks, and industrial discharge points where shoal docks are deployed. Shielded by the Free Humanoid Corpus.

Status: scaffold (v0.1). This repository establishes the project’s positioning, governance, and architectural commitments. It is not yet a buildable robot. The architectural decisions are resolved in ARCHITECTURE.md §9; each commitment is shielded by a corpus-cited prior-art chain. Detailed CAD, vendor-pinned BOM, and physical-build documentation are the next deliverables.


What this is

Free Humanoid Wheeled is the wheeled sibling to the Free Humanoid Platform. It inherits the platform’s torso, arms, hands, head, sensing, compute, and safety supervisor architecture verbatim. It replaces the bipedal legs with a wheeled differential-drive base for paved and concrete urban service environments. The design domain is intentionally narrower than the bipedal sibling — no stair climbing, no rough-terrain ambition — and the resulting mass, payload, and runtime budgets are correspondingly more generous.

The project sits at the intersection of four projects:

  1. OpenLoco — the substrate. The platform compiles from a single UDD JSON file to URDF, MJCF, STL, BOM, and assembly through OpenLoco. Free Humanoid Wheeled is a humanoid_wheeled morphology family in the same compiler.

  2. Free Humanoid Corpus — the prior-art commons. Every non-trivial design choice cites a specific corpus entry, the same governance posture as the bipedal platform.

  3. Free Humanoid Platform — the bipedal sibling. The upper body of this morphology is the upper body of the platform; this repo cross-links rather than duplicates that work.

  4. shoal — the deployment partner. Free Humanoid Wheeled is designed to integrate with the shoal cartridge-swap protocol and waste-handling logistics at shoal dock-B sites. See shoal ARCHITECTURE §3 for the dock spec, especially shoal-dock-B (shore-tethered).

These are tenants of one another. The wheeled morphology is one of many possible service-environment tenants of the bipedal upper body and one of many possible service tenants of the shoal fleet.


Design domain

Paved and concrete urban service environments. Stormwater outfalls. Harbor docks. Industrial discharge sites. Wastewater treatment plant grounds. Municipal water-utility yards.

The platform deliberately does not target stair climbing, off-road traversal, or unstructured outdoor terrain. Where stairs are required, the bipedal sibling is the correct platform. Where terrain is rough but flat (gravel, dirt access roads), the wheeled-balancing variant suggested by ascento shielding remains a future-track option.


Headline numbers

Quantity Target Notes
Total system mass ~70 kg 30 kg base (battery + drive + casters + tower stand) + 40 kg upper body (inherited from the bipedal platform’s 50 kg minus its leg mass)
Battery capacity 2 kWh primary + 0.2 kWh UPS Doubled from the bipedal’s 1 kWh; no leg cavity constraint
Sustained payload at extended reach 30 kg Six times the bipedal’s 5 kg; possible because the wide wheeled base gives a much larger support polygon and the lower-mounted battery lowers the COM
Peak ground speed ~1.5 m/s Half-again the bipedal’s 1.0 m/s; safe upper bound for service-environment shared-space operation
Base footprint ~600 mm × 800 mm × 350 mm tall Wide stance for stability under upper-body manipulation loads; clears standard 800 mm doorways
Drive wheels 2× 15” diameter pneumatic Sized for outdoor curb tolerance at dock-B sites
Caster wheels 2× passive swivel Positioned for differential-drive geometry; specifics flagged TBD in ARCHITECTURE §2.2

These numbers are scaffold targets, not validated specifications. Iterating them against physical CAD, the actuator-distribution architectural call, and the shoal dock-B protocol is the Phase 1 deliverable.


Mission profile

The platform exists to handle the human-equivalent service tasks at shoal dock-B sites:

  1. Cartridge rotation. Retrieve spent gut cartridges from the dock’s cartridge port; deliver fresh cartridges from the dock’s biology reservoir. See shoal ARCHITECTURE §2.2 for the cartridge spec.
  2. Waste hopper retrieval. Empty the dock’s collected-pollutant hoppers into transport bins or municipal waste-stream containers.
  3. Dock-side maintenance. Visual and tactile inspection of dock-B mechanical components (mooring, fluid manifolds, biology-reservoir seals).
  4. Biology-reservoir status. Confirm reservoir handshake; report nutrient-feed status; flag anomalies upstream to shoal-fleet.
  5. Municipal water-utility EAM integration. The platform is designed to be a node in a municipal water utility’s enterprise asset management workflow — work orders in, status updates out.

The deployment unit is the platform plus a transport vehicle that moves it between dock-B sites; the platform itself is not road-going.


License posture

Same as the bipedal sibling, with the same release-blocker note on canonical license-text inlining:

Artifact class License Files
Hardware (CAD, schematics, PCB layouts, mechanical designs) CERN-OHL-S 2.0 LICENSE-HARDWARE
Firmware, control software, simulation, tools Apache 2.0 LICENSE-SOFTWARE
Documentation CC-BY-SA 4.0 LICENSE-DOCS
Descriptors (UDD JSON), datasets, BOM data CC0 1.0 LICENSE-DATA

CC0 on the descriptor is the load-bearing license choice. The license files in this repo currently contain SPDX-tagged headers; inlining the canonical text is a release-blocker before any public push.


Governance posture

Inherits verbatim from Free Humanoid Platform: defensive-publication norms, examiner-citeable design rationale, no-patent-aggression contributor norm, reference-design-not-product, fail-safe-to-inert. See CONTRIBUTING.md for the full text of the contributor contract.


Eventual hosting

Per the OpenIE hosting split, OSS projects live at openie-dev.github.io/<project>/. The wheeled morphology’s eventual home:

Local-only at v0.1; no public push until the canonical license text inlining and the architectural-call resolution gates pass.


Repository layout

free-humanoid-wheeled/
  README.md                  this file
  ARCHITECTURE.md            canonical full-system spec, prior-art-cited
  CONTRIBUTING.md            quality bar, defensive-publication norms
  LICENSE-HARDWARE           CERN-OHL-S 2.0 (canonical text inlining is a release blocker)
  LICENSE-SOFTWARE           Apache-2.0
  LICENSE-DOCS               CC-BY-SA-4.0
  LICENSE-DATA               CC0-1.0

  descriptor/                UDD descriptor — source of truth
    free-humanoid-wheeled.udd.json
    README.md

  base/                      wheeled-base subsystem (the morphology-distinguishing work)
    README.md

  upper-body/                inherited from free-humanoid-platform
    README.md

  electronics/               PCB pointers, power tree, Joule SOM integration
  firmware/                  HAL, behaviors, MathGround safety supervisor, comms
  control/                   differential-drive MPC, manipulation policy
  sim/                       MuJoCo / Gazebo / Drake model pointers
  docs/                      design notes beyond root README/ARCHITECTURE

  prior-art/
    INDEX.md                 corpus entries this morphology depends on, by subsystem

Each subdirectory has its own README.md scoped to its concern.


Reading order

  1. ARCHITECTURE.md — canonical full-system spec.
  2. descriptor/free-humanoid-wheeled.udd.json — UDD source of truth.
  3. prior-art/INDEX.md — corpus citation map.
  4. Free Humanoid Platform ARCHITECTURE.md — for everything inherited (upper body, sensing, compute, safety, manipulation, learning policy).
  5. shoal ARCHITECTURE.md — for the dock-B mission integration target.

Status and roadmap

Current state is scaffold (v0.1). The morphology’s shape, governance, architectural commitments, and prior-art chain are in place. Phase 1 is OpenLoco-compiler-buildable simulation (descriptor → MuJoCo → differential-drive controller → dock approach). Phase 2 is dock-side prototype. Phase 3 is the first municipal-utility pilot at a real shoal dock-B site. See ARCHITECTURE.md §6 for the full roadmap.