Same pose stream, new safety axis: musculoskeletal-load prevention. This is an
honest 2D reduction of REBA - band exposure TIME, not a precise REBA score.
Edge:
- geometry: arm_elevation_deg (shoulder->elbow vs vertical-down, best of both
arms) and knee_flexion_deg (hip-knee-ankle interior angle, worst of both
legs). Both return None when no confident side exists - "unmeasurable" must
never read as "0 deg / straight".
- detectors/ergonomics.py: per-frame dt accumulation into bands (trunk 20-60
and 60+ deg via the existing torso angle, arm 90+ deg, knee <110 deg), gated
on confident core keypoints; detection gaps are dt-capped (2s) so a dropout
never counts as exposure. Hourly per-camera report, skipped when nothing was
observed (an empty-workshop report is noise).
- Engine: tracks in an incident state (FALLING/FALLEN/NO_MOTION) are excluded
- a fallen worker's 90-deg trunk is an incident, not an ergonomic exposure.
The report event (ergo_report/INFO) carries no track_id and no spatial:
a camera-level anonymous aggregate, per the PIPA-first product stance.
- run_once: NO snapshots on ergo_report (a frame would turn a statistic into
surveillance imagery); capture is skipped entirely when only ergo fired.
Server/UI: ergo_report accepted (validator + chk_events_type, edited in the
still-undeployed heatmap migration); detail view now renders event metrics
with Korean labels and seconds humanized - the ergo report's whole value IS
its metrics. Korean type label in list + detail.
Verified: pytest 232 pass (10 new) / PHPUnit 135 pass. NOTE: the detail-view
visual check is pending - the Chrome extension disconnected mid-verification;
harness is staged under the session scratchpad (events/1/view).
