Testing the windup-fix rework live against sude/sud_0030.json surfaced a
distinct bug: a HOLD overshoot from grain-fill-in cooling never decayed -
process_pid()'s pid_outer_y floor clamped to exactly 0.0, so pid_inner
fought the pot's own ambient loss to hold the overshot temperature flat
instead of declining back to setpoint (see docs/overshoot2.png).
Replace the hardcoded 0.0 floor with a configurable Outer.y_hold_min
(default 0.0, backward compatible), set to -0.1 in config.json, both
.tpl templates, and the demo scripts - small enough to avoid
reintroducing the bb5af3c limit cycle while letting HOLD request a
gentle decline matching passive ambient cooling.
Adds TestHoldOvershootRecoversToSetpoint and documents the finding in
docs/overshoot_hold_windup.md's Follow-up section and
components/pid/TODO.md. Confirmed against a live sud_0030 re-run, not
just the unit test.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01M2ierBoxW3v7nUbDw3M2pE
Renames pid_hold/pid_heat/pid_cool to pid_outer/pid_inner/pid_inner_cool
to match what actually runs when, and splits inner-loop config into
Inner.Heat/Inner.Hold/Inner.Cool so the same PID instance gets a tight
yi_max ceiling only while HOLD drives it, without capping legitimate
1.5 K/min ramps. Fixes the overshoot from docs/overshoot_hold_windup.md
where a cold-water disturbance during HOLD wound up pid_heat's integral
term with no anti-windup engagement, taking ~35s+ to unwind naturally.
Breaking config change: Hold/Heat/Cool -> Outer/Inner.{Heat,Hold,Cool}
in config.json, both .tpl templates, the pid/sud demo scripts, and
replay_sim.py's CLI flags. Adds tests/components/pid/ (stdlib unittest)
covering the Pid clamp/recovery behavior and closed-loop disturbance,
ramp, and HOLD<->HEAT transition cases.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DGQhVQ2Y3yXAQTXhrxVd5u
jensandClaude Sonnet 5