lateral 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.offtracking_circle(front_radius: 'float', wheelbase: 'float', arc_length, *, track: 'float' = 0.0, gamma0: 'float' = 0.0) -> 'Dict[str, np.ndarray]' (to call the implementation directly, import drivelateral; drivelateral.offtracking_circle(front_radius: 'float', wheelbase: 'float', arc_length, *, track: 'float' = 0.0, gamma0: 'float' = 0.0) -> 'Dict[str, np.ndarray]'; from the registry, opsdrive.get("offtracking_circle"))
Off-tracking transient (closed form): the vehicle pose and the radius of the inner wheel after the front-axle center has traveled arc length s since entering a circle of radius R.
The centre of the rear axle is towed by the centre of the front axle with a bar of length L (no slip). The angle γ between the bar and the front velocity obeys dγ/ds = 1/R − sin γ / L. With a = 1/R, b = 1/L, k = √(b² − a²), t± = (b ± k)/a (t− = tan(γ*/2), sin γ* = L/R), Q = ((t+ − t₀)/(t− − t₀)) e^{k s}, tan(γ/2) = (Q t− − t+)/(Q − 1).
arc_length: s ≥ 0 (array allowed). track: track width t (used for the position of the inner wheels). gamma0: γ when entering the circle (0 = entering straight from a straight line, 0 ≤ γ₀ < γ*). Return values (same shape as s): gamma, rear_radius (radius of the rear-axle centre √(R² + L² − 2RL sin γ)), front_inner_wheel_radius, rear_inner_wheel_radius (distance of the inner wheels from the turning centre), offtracking (front inner wheel − rear inner wheel), steady (dict of the values as s → ∞).
Raises ValueError: R ≤ L (no steady state), s < 0, γ₀ out of range, t/2 ≥ radius of the rear wheel.
• 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_driving_lateral — py -3.11 examples/poc_driving_lateral.py
table as input)course_layout · course_occupancy · course_contains · world_build · world_camera · world_move · lidar_scan · rss_longitudinal_same
lateral)friction_circle_usage · curve_speed_limit · design_min_radius · understeer_gradient · steady_cornering · bicycle_model_step · ackermann_steer_angles · rear_axle_path
*Provenance: drivelateral.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.