{
  "generator": "twm.force_recovery.export_force_columns",
  "stiffness_n_per_mm": 2.0,
  "penetration": "penetration_mm = force_normal_n / stiffness_n_per_mm  (ASSUMED stiffness)",
  "press_direction": "R(q_row) @ gel_axis_in_rigid from calibration/*/T_gel_to_rigid_<side>.json",
  "no_contact_rule": "force == 0 -> penetration 0 and target_pose is a copy of sensor_<side>_pose",
  "duplicate_rows": "tactile_<side>_is_new == False rows reuse the previous estimate (forward fill, asserted exact)",
  "source_release": "/media/yxma/Disk1/twm/release/motherboard/meta/2026-05-10/episode_002.parquet",
  "force_calibration": [
    "react_calib (calibration-free recon + gain field + clip correction)"
  ],
  "supersedes": "Exports before 2026-08-07 used a calibration that applied pixel-unit weights to mm-unit features (end-to-end rho 0.143, peak force 18.3 N). Those newton values are void; these come from react_calib (held-out rho 0.739, MAE 1.23 N, split by press position).",
  "task": "motherboard",
  "date": "2026-05-10",
  "episode": "episode_002",
  "rows": 10475,
  "sides": [
    {
      "side": "left",
      "rows": 10475,
      "npz": "/media/yxma/Disk1/twm/force_recovery/motherboard/2026-05-10/episode_002_left.npz",
      "force_calibration": "react_calib (calibration-free recon + gain field + clip correction)",
      "pipeline_version": 5,
      "n_contact_rows": 3646,
      "no_contact_frac": 0.6519331742243437,
      "is_new_frac": 0.28992840095465394,
      "duplicate_rows_forward_filled": 7438,
      "force_p50_n": 0.0,
      "force_p95_n": 5.145384788513184,
      "force_max_n": 7.293181896209717,
      "force_p50_contact_n": 2.9424359798431396,
      "penetration_p50_mm": 0.0,
      "penetration_p95_mm": 2.572692394256592,
      "penetration_max_mm": 3.6465909481048584,
      "gel_max_depth_p95_mm": 0.987415146827696,
      "gel_max_depth_max_mm": 2.5124549865722656,
      "identity_max_abs_dev": 0.0,
      "direction": {
        "usable": true,
        "v_dot_n_rise_mm": 17.353876757240776,
        "v_dot_n_fall_mm": 7.143570223529609,
        "corr_dforce_vdotn": 0.2914760563516624,
        "n_rise": 1192,
        "n_fall": 1124
      }
    },
    {
      "side": "right",
      "rows": 10475,
      "npz": "/media/yxma/Disk1/twm/force_recovery/motherboard/2026-05-10/episode_002_right.npz",
      "force_calibration": "react_calib (calibration-free recon + gain field + clip correction)",
      "pipeline_version": 5,
      "n_contact_rows": 2829,
      "no_contact_frac": 0.7299284009546539,
      "is_new_frac": 0.28878281622911695,
      "duplicate_rows_forward_filled": 7450,
      "force_p50_n": 0.0,
      "force_p95_n": 5.259615421295166,
      "force_max_n": 7.869999885559082,
      "force_p50_contact_n": 2.9424359798431396,
      "penetration_p50_mm": 0.0,
      "penetration_p95_mm": 2.629807710647583,
      "penetration_max_mm": 3.934999942779541,
      "gel_max_depth_p95_mm": 0.9458164691925007,
      "gel_max_depth_max_mm": 2.131033182144165,
      "identity_max_abs_dev": 0.0,
      "direction": {
        "usable": true,
        "v_dot_n_rise_mm": 10.64731797745946,
        "v_dot_n_fall_mm": -0.5853754667810747,
        "corr_dforce_vdotn": 0.28042243071430834,
        "n_rise": 1005,
        "n_fall": 880
      }
    }
  ],
  "columns": [
    "force_left_normal_n",
    "force_left_penetration_mm",
    "force_left_target_pose",
    "force_right_normal_n",
    "force_right_penetration_mm",
    "force_right_target_pose"
  ]
}