ball op• Data kinds: signal × points × table → table
• Call: import fullseye as fs; fs.ledger.fit_spin(t, p, bp: 'dict', *, omega0=None, omega_max: 'float' = 1000.0, iters: 'int' = 20, dt: 'float' = 0.001) -> 'dict' (to call the implementation directly, import ballistics; ballistics.fit_spin(t, p, bp: 'dict', *, omega0=None, omega_max: 'float' = 1000.0, iters: 'int' = 20, dt: 'float' = 0.001) -> 'dict'; from the registry, opsdrive.get("fit_spin"))
Reads the spin from how the ball curves: fits the equations of motion with drag + Magnus to a trajectory (t_i, p_i) (an interval without bounces) with the 9 parameters (p₀, v₀, ω) by Gauss–Newton (the aerodynamic coefficients are the values in bp = assumed known).
> The detailed description below is the original text — the summary and the headings are translated.
マグヌスの力は ω × v なので、ω の v に平行な成分は力を生まず、軌跡からは決まらない(進行方向を軸にした回転 = 横回転の一部)。飛ぶうちに v の向きが変わるので完全に不定ではないが弱い。返り値の omega_perp = 初速に垂直な成分(読める部分)、cond = ヤコビアンの条件数、omega_axial_sensitivity = 平行成分を 1 rad/s 動かしたときの軌跡の変化の rms [m] (小さいほど読めない)。返り値 {"p0", "v0", "omega", "omega_perp", "rms", "cond", "omega_axial_sensitivity", "iters", "t0"}。真値の軌跡を入れると 1e-3 rad/s で戻る(門)。模様から測った角速度(balltrack.spin_from_markers)と独立な第 2 の測り方になる。
omega_max [rad/s] = 回転の大きさの上限(各歩の後にこの球へ射影する)。★スピン比の模型 C_L = 1/(2 + 1/S) は回転が大きいと 0.5 で頭打ちになるので、力が足りないと見た当てはめは |ω| を際限なく大きくできる(大きさが決まらない)。軌跡が短く雑音が勝つと 1e5 rad/s へ走った(2026-09-30)。既定 1000 rad/s ≈ 160 回転/秒(強打の上限より上)。返り値の at_bound が True なら上限に張り付いた = 大きさは読めていない。
• 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_table_tennis_spin — py -3.11 examples/poc_table_tennis_spin.py
table as input)course_layout · course_occupancy · course_contains · world_build · world_camera · world_move · lidar_scan · rss_longitudinal_same
ball)ball_params · impact_params · flight_vacuum · flight_ode · flight_simulate · flight_state_at · magnus_lift_coefficient · drag_coefficient_sphere
*Provenance: ballistics.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.