pad_params — DRIVE pegtactile op

• Data kinds: none → table (an op determined by its arguments alone — it takes no image or data input)

• Call: import fullseye as fs; fs.ledger.pad_params(R: 'float' = 0.02, E: 'float' = 3000000.0, nu: 'float' = 0.48, mu: 'float' = 1.0, grip: 'float' = 4.0, w: 'float' = 0.005, grasp_below_top: 'float' = 0.008, fov: 'float' = 0.016, n: 'int' = 256, marker_pitch: 'float' = 0.0005, marker_r_px: 'float' = 2.5, dark: 'float' = 0.85, peg_mass: 'float' = 0.04, com_below_top: 'float' = 0.01425) -> 'dict' (to call the implementation directly, import pegtactile; pegtactile.pad_params(R: 'float' = 0.02, E: 'float' = 3000000.0, nu: 'float' = 0.48, mu: 'float' = 1.0, grip: 'float' = 4.0, w: 'float' = 0.005, grasp_below_top: 'float' = 0.008, fov: 'float' = 0.016, n: 'int' = 256, marker_pitch: 'float' = 0.0005, marker_r_px: 'float' = 2.5, dark: 'float' = 0.85, peg_mass: 'float' = 0.04, com_below_top: 'float' = 0.01425) -> 'dict'; from the registry, opsdrive.get("pad_params"))

Usage

Fingertip pad table: dome radius R, gel E and ν, pad-peg friction μ, grip force G₀ [N], finger half-spacing w (half-width of the peg's flats), distance of the grasp point from the peg top, field of view and pixel count of the membrane camera, markers (pitch, radius [px], darkness), peg mass and center of mass (same as the pegfail defaults).

Rationale for the dimensions: at G₀ = 4 N, a ≈ 2.5 mm (a/R 0.13, within the Hertz range); field of view 16 mm ≥ 5a (tacsim's window condition); marker 0.5 mm = 8 px. The return adds the Hertz composite modulus Es, the shear modulus G, the pixel pitch pitch, and the contact radius under grip alone a_grip. Raises ValueError: a quantity that must be positive is not; ν outside [0, 0.5]; n < 64; marker spacing below 4 px; the field of view falls short of 5a at 1.5 times the grip force.

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)

• gallery_drive_soil_tactile — py -3.11 examples/gallery_drive_soil_tactile.py

• poc_knife_tactile_toughness — py -3.11 examples/poc_knife_tactile_toughness.py

• poc_peg_insertion_tactile — py -3.11 examples/poc_peg_insertion_tactile.py

• poc_tactile_dipole_torque — py -3.11 examples/poc_tactile_dipole_torque.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 (pegtactile)

pad_context · peg_wrench_to_pad_loads · pad_loads_to_peg_wrench · pad_shear_asymmetry · pad_marker_displacement · pad_tactile_frame · pad_tactile_read · contact_candidates


*Provenance: pegtactile.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.