imp_stiff_high — cocarry_partners@v2

Set. cocarry_partners@v2 (task cocarry@v1) · Stratum. scripted · Split. public · Role. partner_arm

Identity. partner_id 4d0ae9868c4c10c8 · parameter digest 212f054214340e8e69849cf63594c71bf92fdf026cddaf37c8e4f67e3999e8ff · weights_uri member://cocarry_impedance/212f054214340e8e69849cf63594c71bf92fdf026cddaf37c8e4f67e3999e8ff

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)). Public member: the exact values below were drawn from the committed box under the maintainer-held derivation seed and are committed next to their digest.

parameter	committed box	value
damping	[0.035, 0.045]	0.0364
ki	[0.5, 0.7]	0.6856
kp	[3.5, 4.3]	3.6431
lag_steps	[0, 0] (int)	0
step_max	[0.028, 0.032]	0.029

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-v2/imp_stiff_high/, 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	0.3177
action_abs_p90	1
action_std	0.4274
n_episodes	20
stress_max	109.6
stress_mean	80.4
stress_p50	80.4
stress_p90	94.67
success_rate	1

Competence floor. floor probe fingerprint — success 1 vs committed floor 0.75 → PASS