Longitudinal robotics project · C-1N // 02 · STAND

C-1N

A six-legged MuJoCo robot whose checkpoints preserve failed behavior, the measurements that expose it, and the physical models used to interpret it.

Current checkpoint

02 · STAND

The deterministic 10-second native baseline keeps six foot-ground contacts declared, a COM-projection margin to the support polygon of at least 0.2346 m, torso height of at least 0.4495 m, and numerically zero torso angular speed.

Closed loop, bounded claim

Closed-loop stationary stance controller

The controller maps Cartesian foot-position error into bounded joint-space corrections with a Jacobian transpose, gated by declared six-foot contact and positive COM-projection margin. It helps C-1N remain vertical; stationary stance is not yet robust disturbance rejection.

Next capability

Learned locomotion toward 03 · STRIDE

The eight declared 1 mg force-pulse cases remain a failed recovery boundary for STAND. That evidence stays frozen rather than becoming a blocking robustness phase. The next planned capability is learned locomotion: train a policy, preserve the first understandable failure, and require reproducibly better sustained locomotion before claiming STRIDE.

Live browser simulation

Inspect C-1N checkpoint evidence

Loading MuJoCo WebAssembly…

Current playback: the simplified visual STAND controller begins from the deterministic six-contact reset. Switching checkpoints creates a fresh physics state.

Current model mass
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Gravity
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Loading current force pulse…

Your browser does not support canvas. See the canonical C-1N repository below.

20 s history · time →

Torso x
Torso x position trace.
Forward v
Forward velocity trace.
Roll / pitch
Body attitude trace.

Drag to orbit. Right-drag or use two fingers to pan. Scroll or pinch to zoom. Follow C-1N tracks the live torso until you move the camera yourself.

Simulation time
Torso x
Torso y
Torso height
Contacts
Roll / pitch
Joint-speed RMS
Actuator-force RMS

STAND force-pulse suite

33 declared external-disturbance cases

STAND loops through all 33 cases by default. Each nonzero case applies a 200 ms horizontal force pulse at reset, then gets 1 second of observation before the next case. Pause the suite or use the compact controls to inspect one case directly.

Loading perturbation case…

Coverage map: one control and four force-magnitude rows across eight bearings. The highlight shows the case now in view; the map is not interactive.

The eight declared 1 mg force-pulse cases are the current recovery frontier; the canonical record retains 1 mg recovery as failed. Browser playback uses the canonical STAND model, reset, and 33-case definition. Its simplified visual controller is not a parity port of native contact/support-margin gating or Jacobian-transpose control.

Live telemetry

Signals from the selected checkpoint

Each graph keeps the latest 20 seconds of MuJoCo state. The horizontal axis is time. Reset or checkpoint selection clears the sample history.

Ground-plane positionx y · meters
Live torso ground-plane position graph.
Torso heightmeters
Live torso height graph.
Body attituderoll pitch · radians
Live body attitude graph.

Runtime: first-party MuJoCo JavaScript bindings ↗, pinned to v3.11.0. The STAND model, deterministic reset, 33-case force-pulse definition, and Googly Surveyor visual layer are pinned to C-1N commit a6cf1cb ↗. The browser visualizes a simplified bounded controller; the native rollout remains the evidence record.

Checkpoint lineage

The robot should make its own evolution inspectable.

C-1N is the integration point. The Robotics Test Bench isolates the physical questions that make a checkpoint legible. A checkpoint advances only for a demonstrated capability or an understood failure worth preserving and comparing.

  • C-1N // 00 · SPAWN — historical deterministic six-foot spawn baseline. It does not claim stance stabilization or locomotion.
  • C-1N // 01 · SHUFFLE — preserved coordinated-gait failure. Motion is not controlled locomotion.
  • C-1N // 02 · STAND — reproducible stationary-stance baseline. Its closed-loop controller maps Cartesian foot-position error into bounded joint-space corrections through a Jacobian transpose, gated by declared six-foot contact and positive COM-projection margin. This is not robust disturbance rejection.
  • C-1N // 03 · STRIDE — next capability target, not yet earned. Train the first learned locomotion policy, preserve its failure modes, and require materially better sustained locomotion under fixed evaluation before promoting the checkpoint.