Auto-align: level the sample on the DC bias levels from the camera window

The operator frames a good spot, confirms the two DC levels the detector
reads there, and the rig then measures its own tilt: step 1.5 mm either side
on X and then on Y, and tilt the platform until those levels come back.  The
correction that fixes an offset point is the correction that levels the whole
travel — height error and tilt effect are both proportional to the offset —
so the procedure ends by applying it and leaving it applied.

Both directions are measured from the same starting tilt and averaged, which
makes their disagreement a flatness read-out rather than something averaged
away silently.

core/auto_align.py holds the geometry and the search, Qt-free.  The three
T-axes' azimuths are the whole geometry: T1 lies along +X so it alone tilts
along X, and T0/T2 move as an equal-and-opposite pair to tilt along Y without
touching X (tilt_response derives that, and the tests pin it — an axis map
that drifts would still converge, on the wrong axis).  The search is a secant
null on the split-detector difference: probe once to learn what a microstep
is worth, sign included, then step at the null.  It refuses to servo on a
scope that has not re-triggered, escalates a probe that reads as no response
before calling an axis dead, and stops at a per-axis travel limit.

gui/align_bridge.py runs it on a worker thread; stopping is a threading.Event
rather than a queued command, because the worker is inside a long handler for
the whole run.  The camera window carries the button and the progress window,
and locks the scan panel and the jog pads while a run owns the stage.

Adds immediate MEAN measurements and an acquisition count to the scope
driver, and read_bias_mv to core/scope_inspect — the one scalar the
inspection state was missing.

KNOWN_ISSUES.md records what only the rig can settle: the probe step, the
travel limit, the hold current, and whether the piston the X phase applies
alongside its tilt matters.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

This commit is contained in:

Thomas Ales

2026-09-04 14:00:36 -05:00

parent 083cbdaa34

commit 6e8c1cb7a2

13 changed files with 1868 additions and 19 deletions

sc3-aui-camera.ui

+10

View File

@@ -78,6 +78,16 @@
        </item>
       </layout>
      </item>
      <item>
       <widget class="QPushButton" name="uc480_auto_align_btn">
        <property name="text">
         <string>Auto-Align…</string>
        </property>
        <property name="toolTip">
         <string>Level the sample: step the stage 1.5 mm each way and re-tilt the T-axes until the DC bias levels read what they read here.</string>
        </property>
       </widget>
      </item>
      <item>
       <widget class="QPushButton" name="uc480_close_window_btn">
        <property name="text">