capture_margin — DRIVE locomotion op

• Data kinds: vector × vector × scalar × points → measurement

• Call: import fullseye as fs; fs.ledger.capture_margin(com, com_vel, com_height, contacts, gravity: 'float' = 9.81, ground=None, contact_tol: 'float' = 0.02) -> 'float' (to call the implementation directly, import locomotion; locomotion.capture_margin(com, com_vel, com_height, contacts, gravity: 'float' = 9.81, ground=None, contact_tol: 'float' = 0.02) -> 'float'; from the registry, opsdrive.get("capture_margin"))

• GPU: none (CPU reference implementation only)

Usage

Signed distance of the LIPM capture point to the support set (0-step capturability).

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

捕捉点 ξ(lipm_capture_point)の、支持の形(support_line_margin と同じ規則) までの符号つき余裕。正 = ξ が支持多角形の内側で、踏み出さずに止まれる(足圧中心を ξ に置ける。Koolen ほか 2012 の 0 歩捕捉可能)。負 = どこに足圧中心を置いても重心は止まらない

ので、踏み出すか倒れる。静的な com_support_margin は速度を見ないので、前へ走っている重心を「安定」と読む ―― この op はそれを負にする。

com / com_vel は 1 時刻の (3,) か (2,)。com_height [m] は正の有限値。足が 1 つも無いときは ValueError。空の入力(com が 0 要素)も ValueError で拒否する。

English: positive = the capture point lies inside the support polygon, so the robot can stop without stepping (0-step capturable); negative = it must step. Segment / single-foot support follows support_line_margin (never positive).

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)

• walking_ops_tour — py -3.11 examples/walking_ops_tour.py

Ops the type connects to (they accept measurement as input)

spin_from_marker_sequence · carla_transform_matrix · carla_pose_to_world · carla_camera_pose · carla_xy_yaw · carla_scene_load · town_chain · osm_parse

Same category (locomotion)

contact_points · com_from_silhouette · support_polygon · com_support_margin · gait_phase · support_line_margin · lipm_capture_point · gait_step_events


*Provenance: locomotion.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.