imp_fast — cocarry_partners@v1
Set. cocarry_partners@v1 (task cocarry@v1) · Stratum. scripted · Split. private · Role. partner_arm
Identity. partner_id bfa69a8aa3979220 · parameter digest 0fe7eb258c8ed441e0f3e302684d2aa0f0de539cb921bc931401b3846ae0fed8 · weights_uri member://cocarry_impedance/0fe7eb258c8ed441e0f3e302684d2aa0f0de539cb921bc931401b3846ae0fed8
What this partner does
A deterministic end-effector-space PI impedance controller for one co-carry arm (ADR-026 §Decision 1): it drives its bar-end toward the cooperative goal along a straight Cartesian path through a damped pseudo-inverse Jacobian, sharing the bar load compliantly with the ego arm. kp/ki set the Cartesian PI gains, step_max the per-step command clip (response speed), damping the pseudo-inverse regularisation, and lag_steps a bounded transport delay (a sluggish-but-competent member: delayed but convergent tracking).
Construction provenance
Built from registry class cocarry_impedance (PartnerSpec(seed=0, checkpoint_step=None)). Private member: the exact values are withheld (ADR-009 as amended — published hashes, withheld parameters). They were drawn from the committed box under the maintainer-held seed; the digest below verifies any authorised local re-derivation.
| parameter | committed box | value |
|---|---|---|
damping |
[0.035, 0.045] | withheld |
ki |
[0.5, 0.7] | withheld |
kp |
[2.3, 2.7] | withheld |
lag_steps |
[0, 0] (int) | withheld |
step_max |
[0.04, 0.047] | withheld |
Behavioural fingerprint
Committed probe suite: seeds [7000, 7001, 7002, 7003] x 5 episodes against the task's reference ego (archive: spikes/results/partner-fingerprints/cocarry_partners-v1/imp_fast/, an ADR-028 v3 bundle). Summary statistics of the member's action distribution and the dyad's stress channel — enough to tell members apart without policy access (ADR-018/I3).
| statistic | value |
|---|---|
action_abs_mean |
0.3906 |
action_abs_p90 |
1 |
action_std |
0.4899 |
n_episodes |
20 |
stress_max |
125.1 |
stress_mean |
104.1 |
stress_p50 |
117.2 |
stress_p90 |
121.4 |
success_rate |
1 |
Competence floor. floor probe fingerprint — success 1 vs committed floor 0.75 → PASS