`co_hold_secure@v1` — Co-hold-and-secure (Gate-0 candidate)

A fixation-tooling task: one robot holds a part under continuous contact while the other pushes a plug home against a seat-click detent — a fastening or connector seat, never a zero-clearance peg (the co-insert correction, enforced by the wedge-inverted design rule in code). Gate-0 is in progress under ADR-029: the env is runnable, the stress channel is pinned as the holder workpiece-wrench under process load, and success requires the part to stay in pose under the securing load. The tier moves only via the admission protocol once a founder-signed Gate-0 pre-registration exists.

Tier 3 — documented candidates and closures · Status: CANDIDATE · Suite: CHAMBER-Bench v1.0 (adr/ADR-027-chamber-bench-v1-protocol.md)

Spaces

Action space. Two Panda arms, pd_joint_delta_pos at 20 Hz: the holder presents a part (fixed-link grip); the securing operator pushes a welded plug to seat against a 40 N detent over the final 2 mm.
Observation. state_dict: per-arm proprioception + plug pose + part pose (the co-insert controller obs contract) + goal.
Simulator backend. maniskill3 · Agents. 2

Stress channel

Holder workpiece-wrench under process load — the friction-inclusive wrist incoming joint force (ADR-029 §Consequences)

Axis validity

Per-cell status under the validity matrix (adr/ADR-027-chamber-bench-v1-protocol.md):

AS	OM	CR	CM	PF	SA
`untested`	`untested`	`untested`	`untested`	`untested`	`untested`

Industrial analogue

Fixtureless welding and robotic machining or finishing: one robot holds the workpiece in place of a dedicated fixture while another welds, drills, or fastens — the settings where high process force makes the inter-robot coupling strongest. The specific public tolerance citation attaches at the Gate-0 pre-registration.

Committed falsifier

If a passive fixture — a single robot plus static tooling — matches the two-robot team under the same tolerances, the task is fixture-design-plus-single-arm and is not admitted (the A2 two-robot-infeasibility gate applied to fixation tooling). The v1 posture is application-grounded (route i): the fixtureless setting is the industrial anchor and the C-fixture control is reported honestly; the in-episode multi-pose securing sequence (route ii) is a designed-but-dormant escape hatch.

Evidence

How to run one episode

import chamber.tasks

env = chamber.tasks.make("co_hold_secure", render_backend="none")
obs, _ = env.reset(seed=0)

Notes

Gate-0 in progress (ADR-029; the second-discriminating-task pivot after the handover learned-ladder NO-GO, PR #309). The geometry is the wedge-inverted design rule: engagement depth 10 mm, per-side clearance band {1.5, 2.5, 3.5} mm, >=2 mm 45-deg lead-in chamfer, so the wedge-limit tilt (8.5/14.0/19.3 deg) clears 2x the measured achievable-control ceiling (2.8 deg) on every cell — a fastening / connector seat, never a zero-clearance peg (the co-insert correction, now enforced in code). The securing axis is deliberately non-vertical (60 deg from vertical) so no passive support can react the process load. Success adds the pose_held conjunct (the part stays within 5 mm / 5 deg under load). A2 posture (ADR-029): route (i) application-grounded (fixtureless high-mix cells; the C-fixture control is reported honestly beside the team cells); route (ii), an in-episode multi-pose securing sequence, is a designed-but-dormant hook. The specific public industrial-tolerance citation attaches at the Gate-0 pre-registration, not before. Committed falsifier (the A2 gate applied to fixation tooling): if a passive fixture — single robot plus static tooling — matches the two-robot team under the same tolerances, the task is fixture-design-plus-single-arm and is not admitted. Tier moves only via the ADR-027 admission protocol under a founder-signed Gate-0 prereg tag; no leaderboard cells exist for this task.

co_hold_secure@v1 — Co-hold-and-secure (Gate-0 candidate)