contact_radius_fit_pixelwise — DRIVE `tacsim` op

• Data kinds: normalmap × matrix × matrix × scalar × scalar → table

• Call: import fullseye as fs; fs.ledger.contact_radius_fit_pixelwise(normals, X, Y, R: 'float', a0: 'float', centre_xy=(0.0, 0.0), r_max_over_a: 'float' = 2.5, excl_px: 'float' = 1.5) -> 'dict' (to call the implementation directly, import tacsim; tacsim.contact_radius_fit_pixelwise(normals, X, Y, R: 'float', a0: 'float', centre_xy=(0.0, 0.0), r_max_over_a: 'float' = 2.5, excl_px: 'float' = 1.5) -> 'dict'; from the registry, opsdrive.get("contact_radius_fit_pixelwise"))

Usage

Reads the contact radius by fitting the Hertz slope model dh/dr(r; a), with continuous a, to the per-pixel radial slopes (the bin-free version of contact_radius_fit; a0 is its coarse value).

> The detailed description below is the original text — the summary and the headings are translated.

contact_radius_fit は半径ビン(幅 = 画素ピッチ)の平均に当てるので、a が画素ピッチをまたぐたびに偏りの符号が変わる(P = 3.5 / 4.0 / 4.5 N で −0.04 / +0.31 / −0.02 %)。P の値そのものは 0.3 % で十分でも、2 枚の差(把持の 2 本指の F_x = P_L − P_R) では P̂ の傾き dP̂/dP が効き、ビン版は傾きを 40 % 狂わせた(pegtactile の PoC で測った)。ここでは r < r_max_over_a·a0 の画素をそのまま使い、縁 r ≈ a0 の ±excl_px 画素は捨てる —— スロープは r = a で微分が不連続(外側に平方根の尖り)で、画素と縁の位置関係で値が揺れ、残すと a が画素ピッチの周期で揺れる。SSE(a) を黄金分割(初期区間 [0.8, 1.2]·a0、40 回)で最小化。centre_xy は既知の中心 (x, y)、単位 m。返り a・delta = a²/R・rms(スロープの残差)・n(使った画素数)。Raises ValueError: R, a0 ≤ 0、形が合わない、使える画素が 16 未満。

References (sample data, literature)

• 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.

Runnable examples (verified samples that actually call this op)

• poc_peg_insertion_tactile — py -3.11 examples/poc_peg_insertion_tactile.py

Ops the type connects to (they accept `table` as input)

course_layout · course_occupancy · course_contains · world_build · world_camera · world_move · lidar_scan · rss_longitudinal_same

Same category (`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).*

contact_radius_fit_pixelwise — DRIVE tacsim op