pegfail op• Data kinds: table × scalar → table
• Call: import fullseye as fs; fs.ledger.jamming_parallelogram_planar(kp, depth: 'float') -> 'dict' (to call the implementation directly, import pegfail; pegfail.jamming_parallelogram_planar(kp, depth: 'float') -> 'dict'; from the registry, opsdrive.get("jamming_parallelogram_planar"))
Derives the jamming parallelogram from the planar statics of two-point contact (a 2nd path checked against the vertices of pegsim.jamming_diagram = the values of OCW p.34).
In the plane (x right, z up), the tip's rim touches the wall on the −x side at depth l (normal force f₁ ≥ 0, toward +x), and the rim of the mouth on the +x side touches the body (f₂ ≥ 0, toward −x). With Coulomb friction in which both points slide downward (μf upward), the equilibrium of (F_x, F_z positive downward, M positive counter-clockwise) applied at the tip is
F_x = f₂ − f₁, F_z = μ(f₁ + f₂), M = μ r f₁ − (μ r + l) f₂
→ M/(rF_z) = −λ − μ(λ + 1)·(F_x/F_z), λ = l/(2rμ). The mirrored configuration (tip on the +x wall) is +λ − μ(λ+1)x. f₁ = 0 / f₂ = 0 give the vertical edges |F_x/F_z| = 1/μ (friction limit of one-point contact). 4 vertices = intersections of 2 oblique edges × 2 vertical edges = (−1/μ, 2λ+1), (1/μ, −1), (1/μ, −(2λ+1)), (−1/μ, 1) (OCW order). Returns: lambda, slope = −μ(λ+1), vertices (4, 2), line_minus, line_plus (intercepts). Raises ValueError: l < 0, μ ≤ 0.
• 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_peg_failure_recovery — py -3.11 examples/poc_peg_failure_recovery.py
table as input)course_layout · course_occupancy · course_contains · world_build · world_camera · world_move · lidar_scan · rss_longitudinal_same
pegfail)insertion_failure_table · insertion_failure_validate · insertion_signature · insertion_failure_classify · insertion_recovery_primitive · jamming_force_check · wedging_risk · insertion_stall_detect
*Provenance: pegfail.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.