- P2-6 tracking: global greedy IoU matching (all pairs, best overlap first)
replaces track-iteration-order greedy, so a crossing worker's box can no
longer be stolen by whichever track came first. Any track in a contended
match (person overlapping 2 tracks, or track overlapping 2 persons) is
reported via tracker.ambiguous(); run_once resets its detector + smoother
state so FALLEN/baseline/immobility never ride an id swap onto the wrong
person. A genuinely fallen worker re-confirms within prone_confirm_s.
- P2-7 fall: STANDING -> FALLING now requires sustained prone
(falling_confirm_s, 1.0s). One prone-looking frame (a bend, a bbox glitch)
no longer arms the ghost detector's CRITICAL if the person then leaves.
FALLEN / no_motion timing is unchanged (keyed off prone_since).
- P2-8 app: run_once feeds the engine and smoothers only tracks re-detected
this tick; a track coasting inside max_age with a frozen frame is no-data,
so prone-confirm / no-motion / immobility timers cannot accrue on stale
data. Re-detection still confirms the fall (dropout pauses evidence).
TDD: 7 new tests verified failing on the pre-fix code (git stash), then
203 passed / 2 skipped (hardware) with the fixes.
- Split clocks: detector timers/cooldowns run on a MONOTONIC clock (immune to an
NTP step on an RTC-less Pi); wall time is used only for the HMAC X-Timestamp
and Event.occurred_at. Fixes false IMMOBILITY / dropped tracks after a clock jump.
- Heartbeat is time-based (30s, predictable regardless of load) and now carries
temp/throttle/queue_pending/config_version telemetry.
- A dead (no-frame) camera counts as erroring instead of a healthy frame, so a
silent monitoring outage no longer looks green.
- Offline queue: isolate one undecodable row instead of wedging every event behind
it; classify 401 (stale clock) as transient, never a poison-drop.
- New edge/health.py: vcgencmd temp/throttle parsing, None off-Pi (no fake 0).
edge/app.py run_once used ONE shared KeypointSmoother across all persons
BEFORE tracking assigned IDs. The smoother holds per-joint-index One-Euro
filter state, so with >1 person in frame the filter state was shared and
corrupted across different people, and same-timestamp calls within a frame
would pass through unsmoothed while still clobbering the shared state.
Multi-person scenes could get corrupted torso angles -> missed/false falls.
Add TrackSmootherPool (edge/smoothing.py) that lazily allocates one
KeypointSmoother per track_id. run_once now: tracks raw keypoints first,
then smooths each track's latest frame in place using its own pooled
smoother, and forgets a track's smoother when the track is lost (ties into
FIX 5 lost-track cleanup).
BEHAVIOR CHANGE: keypoints are now smoothed after tracking instead of
before. Single-person pipelines are unaffected (still one smoother, one
identity). Multi-person pipelines get correct, non-cross-contaminated
smoothing.
run_once signature: smoother param replaced with pool: TrackSmootherPool.
build_pipeline now constructs "pool" instead of "smoother".
Tests: tests/test_smoothing.py adds TrackSmootherPool identity/forget
coverage; tests/test_app.py adds test_two_persons_get_independent_smoothing
demonstrating each track's smoothed keypoints stay on its own side instead
of being pulled toward the other person.
