spin_from_marker_sequence — DRIVE balltrack op

• Data kinds: any → table

• Call: import fullseye as fs; fs.ledger.spin_from_marker_sequence(dirs, dt: 'float', *, lag: 'int' = 4, max_angle: 'float' = 0.5) -> 'dict' (to call the implementation directly, import balltrack; balltrack.spin_from_marker_sequence(dirs, dt: 'float', *, lag: 'int' = 4, max_angle: 'float' = 0.5) -> 'dict'; from the registry, opsdrive.get("spin_from_marker_sequence"))

Usage

Reads the angular velocity from the marker directions dirs[k] over a sequence of frames ((M_k, 3) unit vectors; None for frames where none is found) (2 stages).

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

1 段目: 隣のコマ同士で、向きが max_angle [rad] 以内で最も近い模様を組にして Kabsch(spin_from_markers)、その中央値を ω₁ とする。2 段目: lag コマ離れた組を、前のコマを ω₁ で回した予測に最も近い模様(max_angle/2 以内)と組んで当て直す —— 回転角が lag 倍になるので、模様の位置の誤差が効く割合は 1/lag。★1 コマの回転角は max_angle より十分小さいこと(模様の取り違え)、lag コマの回転は π より小さいこと(Kabsch は最短の回転を返す)。返り値 {"omega", "omega_stage1", "n_pairs", "per_pair" (N, 3)}(ω は dirs と同じ座標系)。組が 1 つも無ければ ω は NaN。模様が見えた向きの組が要るので、各コマ 2 個以上の模様が要る。

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_table_tennis_bounce — py -3.11 examples/poc_table_tennis_bounce.py

• poc_table_tennis_spin — py -3.11 examples/poc_table_tennis_spin.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 (balltrack)

ball_detect · ball_track · kalman_ca · triangulate_dlt · track_triangulate · bounce_detect · marker_direction · spin_from_markers


*Provenance: balltrack.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.