tacsim op• Data kinds: image2d × scalar → table
• Call: import fullseye as fs; fs.ledger.contact_radius_ring(h, pitch: 'float', n_az: 'int' = 72, step_px: 'float' = 0.25, r_max_px: 'float | None' = None) -> 'dict' (to call the implementation directly, import tacsim; tacsim.contact_radius_ring(h, pitch: 'float', n_az: 'int' = 72, step_px: 'float' = 0.25, r_max_px: 'float | None' = None) -> 'dict'; from the registry, opsdrive.get("contact_radius_ring"))
Reads the contact radius a from the height field without a model: the contact edge r = a is the ring where the radial slope |∂h/∂r| is maximal (in Hertz it grows as r/R inside and drops sharply as √ outside, a cusp). |∇h| is bilinearly interpolated in step_px steps along n_az radial lines in azimuth, each line's peak is refined to subpixel by parabolic interpolation → measure.fit_circle on the 72 points (2nd implementation) and the median of the radii.
> The detailed description below is the original text — the summary and the headings are translated.
返り: a(中央値 × pitch)[m]、a_circle(円当てはめの半径 × pitch)、r_px・cy・cx・rms_px(円)、radii_px(方位角ごとのピーク半径)、centre(重心 (cy, cx))、bias_px_per_a(分解能の限界の目安 = −0.7 px / a、双線形補間がカスプを約 1 px 平滑するので a が 14 px なら −5 %、21 px なら −3 % 内側に出る —— 実測値、模型なしの代償)。しきい値の帯の重心(試作 v1)が 9 % 内側に寄った反省から、帯でなくピーク位置を使い、半径方向の傾きは h の双線形標本の 1 px スパン差分(np.gradient の 2 px より平滑が少ない)で取る。既定(r_max_px=None)は窓の縁 − 2 px まで探す。膜の裾の外側に別のピーク(隣の接触・縁の影)がある実機の画像では r_max_px を明示すること。Raises ValueError: へこみが無い、pitch ≤ 0、探索半径が 2 px 未満(へこみが窓の縁に寄りすぎ)。
• Sample-data catalog (download URLs / licences) — 2-D uses skimage.data (BSD/public domain) plus synthetic images; 3-D lists download URLs for real data sources (Stanford, PDS, …).
• Operator provenance and references — the sources of the research/methods this op family came from.
• The canonical algorithm (author, year) and its uses are named in the family usage guide above.
• poc_tacscalib_sphere_lut — py -3.11 examples/poc_tacscalib_sphere_lut.py
• poc_tacsim_elastic_membrane — py -3.11 examples/poc_tacsim_elastic_membrane.py
table as input)course_layout · course_occupancy · course_contains · world_build · world_camera · world_move · lidar_scan · rss_longitudinal_same
tacsim)combined_modulus · hertz_sphere · hertz_force · hertz_cylinder · hertz_surface_uz · hertz_pressure · membrane_indent_sphere · membrane_indent_shape
*Provenance: tacsim.py — DRIVE operator registry. This per-op note is generated by tools/opdocs.py md (do not hand-edit).*
© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.