Files
scanengine-3/tests/fakes.py
T
Thomas Ales 6e8c1cb7a2 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>
2026-09-04 14:00:36 -05:00

389 lines
14 KiB
Python

"""Recording fake hardware for headless ScanEngine tests.
Each fake records an ordered call trace, so a test can assert the exact
command sequence the engine issues — the property that matters when the
real rig isn't available.
The stage and scope are wired together the way the rig is: an X move at scan
velocity with the trigger gate armed feeds frames into a running acquisition,
at the real 20 kHz / 100 mm/s rate. Per-row and burst acquisition therefore
get their frame counts from the same model, which is what makes a
byte-identity comparison between the two paths meaningful — and it means a
gate the engine forgets to drop shows up as extra frames instead of passing
silently.
"""
from __future__ import annotations
from core.scan_engine import (
AXIS_X, LASER_FREQ_HZ, SCAN_RAMP_BUFFER_MM, SCAN_RAMP_MM,
SCAN_VELOCITY_MM_S,
)
RAMP_TOTAL_MM = SCAN_RAMP_MM + SCAN_RAMP_BUFFER_MM
class Trace:
"""Ordered record of hardware calls, shared by all fakes in one test."""
def __init__(self):
self.calls: list[tuple] = []
def record(self, *entry):
self.calls.append(entry)
def names(self) -> list[str]:
return [c[0] for c in self.calls]
def of(self, name: str) -> list[tuple]:
return [c for c in self.calls if c[0] == name]
def count(self, name: str) -> int:
return len(self.of(name))
class FakeStage:
"""Stands in for ThorlabsServoDriver."""
def __init__(self, trace: Trace, homed=(True, True), enabled=(True, True),
scope=None):
self._t = trace
self.am_homed = list(homed)
self.am_enabled = list(enabled)
self.positions = [0.0, 0.0]
self._scope = scope
self.gate_armed = False
def attach_scope(self, scope):
"""Route gated motion into `scope`, as the TRIGOUT pin does on the rig."""
self._scope = scope
def enable_axis(self, axis):
self._t.record("enable_axis", axis)
self.am_enabled[0 if axis == AXIS_X else 1] = True
def home_axis(self, axis, timeout=0.0):
self._t.record("home_axis", axis)
self.am_homed[0 if axis == AXIS_X else 1] = True
def set_velocity_params(self, axis, max_velocity=None, acceleration=None):
self._t.record("set_velocity_params", axis, max_velocity, acceleration)
def set_trigger_trigout_maxv(self, axis):
self._t.record("set_trigger_trigout_maxv", axis)
if axis == AXIS_X:
self.gate_armed = True
def set_trigger_gate_off(self, axis):
self._t.record("set_trigger_gate_off", axis)
if axis == AXIS_X:
self.gate_armed = False
def arm_scan_gate(self, axis, armed, verify=True):
self._t.record("arm_scan_gate", axis, bool(armed))
if axis == AXIS_X:
self.gate_armed = bool(armed)
def move_axis_absolute(self, axis, pos, timeout=0.0):
idx = 0 if axis == AXIS_X else 1
prev = self.positions[idx]
self._t.record("move_axis_absolute", axis, round(pos, 6))
self.positions[idx] = pos
# The gate is high only at max velocity, i.e. over the move minus its
# two ramps — direction-agnostic, so a flyback the engine failed to
# gate off produces frames instead of quietly producing none.
if axis == AXIS_X and self.gate_armed and self._scope is not None:
at_speed_mm = abs(pos - prev) - 2 * RAMP_TOTAL_MM
if at_speed_mm > 0:
self._scope.acquire_frames(
round(at_speed_mm * LASER_FREQ_HZ / SCAN_VELOCITY_MM_S))
def background_record(n: int, samples_per_frame: int) -> bytes:
"""The waveform FakeScope returns from its n-th background capture.
Every angle captures its own, so the tests need to tell one from the
next: a background that landed under the wrong angle would otherwise
look exactly like the right one.
"""
return bytes((n * 17 + s) % 256 for s in range(samples_per_frame))
class FakeScope:
"""Stands in for TektronixOscilloscopeBase.
Returns deterministic frame bytes so the written file can be compared
against an expected byte pattern.
"""
def __init__(self, trace: Trace, samples_per_frame=8, max_frames=4096):
self._t = trace
self.samples_per_frame = samples_per_frame
self.max_frames = max_frames
self._acq_polls = 0
self._running = False
self._acquired = 0
self._backgrounds_taken = 0
# Per-channel running frame index. Frame content is a function of
# (channel, index) alone, so the same total frame sequence yields the
# same bytes however it is chopped into transfers.
self._next_frame: dict[int, int] = {}
# -- driven by FakeStage ------------------------------------------------
def acquire_frames(self, n):
if self._running:
self._acquired += n
# -- writes / queries ---------------------------------------------------
def write(self, cmd):
self._t.record("write", cmd)
if cmd == "ACQuire:STATE RUN":
self._running = True
self._acquired = 0
elif cmd == "ACQuire:STATE STOP":
self._running = False
def query(self, cmd):
self._t.record("query", cmd)
if cmd == "ACQuire:STATE?":
self._acq_polls += 1
# STOPAfter SEQuence self-stops when the sequence completes, so
# reporting "stopped" and staying armed would be inconsistent.
self._running = False
return "0" # background average finished
if cmd == "ACQuire:NUMFRAMESACQuired?":
return str(self._acquired)
return ""
# -- typed setters used by core.scope_sras ------------------------------
def set_trigger_source(self, ch):
self._t.record("set_trigger_source", ch)
def set_trigger_slope(self, slope):
self._t.record("set_trigger_slope", slope)
def set_trigger_level(self, ch, level):
self._t.record("set_trigger_level", ch, level)
def set_trigger_mode(self, mode):
self._t.record("set_trigger_mode", mode)
def set_acquire_mode(self, mode):
self._t.record("set_acquire_mode", mode)
def set_fastframe_state(self, on):
self._t.record("set_fastframe_state", on)
def set_fastframe_count(self, n):
self._t.record("set_fastframe_count", n)
def get_fastframe_state(self):
return 1
def get_fastframe_max_frames(self):
self._t.record("get_fastframe_max_frames")
return self.max_frames
def set_sample_rate(self, sr):
self._t.record("set_sample_rate", sr)
def get_record_length(self):
return self.samples_per_frame
def set_data_source(self, ch):
self._t.record("set_data_source", ch)
self._source = ch
def set_data_encoding(self, encoding):
self._t.record("set_data_encoding", encoding)
def set_data_width(self, width):
self._t.record("set_data_width", width)
def query_wfmoutpre(self):
return f"WFMOUTPRE:CH{self._source};YMULT 1.5625E-3;YOFF -87.04;YZERO 0.0"
def transfer_curve(self):
self._t.record("transfer_curve")
n = self._backgrounds_taken
self._backgrounds_taken += 1
return background_record(n, self.samples_per_frame)
def _frames(self, ch, count):
spf = self.samples_per_frame
start = self._next_frame.get(ch, 0)
self._next_frame[ch] = start + count
return [bytes((ch * 31 + g + s) % 256 for s in range(spf))
for g in range(start, start + count)]
def transfer_fastframe(self, parse=True, byte_count=1, signed=True,
byte_order='MSB'):
self._t.record("transfer_fastframe", self._source)
return self._frames(self._source, self._acquired)
def transfer_fastframe_bulk(self, frame_count, samples_per_frame,
bytes_per_sample=1):
self._t.record("transfer_fastframe_bulk", self._source, frame_count)
return bytearray(b"".join(self._frames(self._source, frame_count)))
# channel config (only used by configure_channels)
def set_channel_label_name(self, ch, name):
self._t.record("set_channel_label_name", ch, name)
def set_channel_scale(self, ch, v):
self._t.record("set_channel_scale", ch, v)
def set_channel_position(self, ch, v):
self._t.record("set_channel_position", ch, v)
def set_channel_termination(self, ch, v):
self._t.record("set_channel_termination", ch, v)
def set_channel_coupling(self, ch, v):
self._t.record("set_channel_coupling", ch, v)
def set_channel_bandwidth(self, ch, v):
self._t.record("set_channel_bandwidth", ch, v)
class FakeT3R:
"""Stands in for the (Qt-free) T3RDriver, for RotationAxis."""
GR_AXIS_CH = 3
MOTOR_FULL_STEPS_PER_REV = 200
GEAR_TEETH_MOTOR = 10
GEAR_TEETH_STAGE = 125
def __init__(self, trace: Trace, is_open=True, motion_completes=True):
self._t = trace
self.is_open = is_open
self._motion_completes = motion_completes
# Microsteps commanded per channel, so a test can read the tilt the
# platform ended up at rather than replaying the move trace.
self.positions = {ch: 0 for ch in range(4)}
def set_microstep(self, ch, micro):
self._t.record("t3r_set_microstep", ch, micro)
def set_current(self, ch, run_ma, hold_ma, ihold):
self._t.record("t3r_set_current", ch, run_ma, hold_ma, ihold)
def enable(self, ch):
self._t.record("t3r_enable", ch)
def steps_for_angle(self, angle_deg, microsteps):
ratio = self.GEAR_TEETH_STAGE / self.GEAR_TEETH_MOTOR
return round(self.MOTOR_FULL_STEPS_PER_REV * microsteps * ratio
* angle_deg / 360.0)
def move(self, ch, steps, velocity, accel):
self._t.record("t3r_move", ch, steps)
self.positions[ch] += steps
def rotate_stage(self, angle_deg, microsteps, velocity, accel):
self._t.record("t3r_rotate", round(angle_deg, 6))
def wait_motion_done(self, ch, timeout):
self._t.record("t3r_wait_motion_done", ch)
return self._motion_completes
class FakeAlignRig:
"""A tilted sample on the tilt platform, as the DC levels would read it.
The detection beam is fixed and the stage carries the sample under it, so
the height error under the beam is the sample's slope times how far the
stage has moved off the reference point. The T-axes tilt the sample the
other way: their three heights define a plane, and its slope adds to the
sample's. Nulling the split-detector difference therefore means cancelling
the sample slope — which is exactly what an aligner has to work out.
The plane is fitted by least squares here, rather than reusing
core.auto_align's closed form, so the two are independent statements of
the same geometry.
``curvature_mv_per_mm2`` bends the surface: a curved sample needs opposite
corrections at +1.5 mm and -1.5 mm, which is the disagreement the
procedure is supposed to report instead of averaging away.
"""
# Actuator azimuths on the platform, in degrees from stage +X.
AZIMUTH_DEG = {0: 120.0, 1: 0.0, 2: 240.0}
def __init__(self, stage, t3r, ref_mm=(50.0, 40.0),
x_slope_mv_per_mm=40.0, y_slope_mv_per_mm=-25.0,
tilt_gain_mv_per_mm=0.2, base_mv=400.0,
curvature_mv_per_mm2=0.0, jitter_mv=0.0):
self._stage = stage
self._t3r = t3r
self.ref_mm = ref_mm
self.x_slope_mv_per_mm = x_slope_mv_per_mm
self.y_slope_mv_per_mm = y_slope_mv_per_mm
self.tilt_gain_mv_per_mm = tilt_gain_mv_per_mm
self.base_mv = base_mv
self.curvature_mv_per_mm2 = curvature_mv_per_mm2
self.jitter_mv = jitter_mv
self._reads = 0
# -- geometry -----------------------------------------------------------
def platform_tilt(self):
"""(x_tilt, y_tilt) of the plane through the three actuator heights."""
import numpy as np
rows, heights = [], []
for ch, azimuth in self.AZIMUTH_DEG.items():
theta = np.radians(azimuth)
rows.append([1.0, np.cos(theta), np.sin(theta)])
heights.append(float(self._t3r.positions[ch]))
_, x_tilt, y_tilt = np.linalg.lstsq(np.array(rows), np.array(heights),
rcond=None)[0]
return float(x_tilt), float(y_tilt)
def slopes_mv_per_mm(self):
"""The residual sample slope the beam sees, after the platform tilt."""
x_tilt, y_tilt = self.platform_tilt()
return (self.x_slope_mv_per_mm + self.tilt_gain_mv_per_mm * x_tilt,
self.y_slope_mv_per_mm + self.tilt_gain_mv_per_mm * y_tilt)
def difference_mv(self):
x_off = self._stage.positions[0] - self.ref_mm[0]
y_off = self._stage.positions[1] - self.ref_mm[1]
slope_x, slope_y = self.slopes_mv_per_mm()
return (slope_x * x_off + slope_y * y_off
+ self.curvature_mv_per_mm2 * (x_off ** 2 + y_off ** 2))
# -- what the scope reports ---------------------------------------------
def level_v(self, channel):
"""CH3 and CH4 as volts: the difference straddling a constant sum.
The sum is fixed because tilt steers the beam across the detector
rather than changing how much light comes back — so a nulled
difference does put both levels back where they were.
"""
self._reads += 1
# A deterministic alternating wobble, so a test can check the median
# of several reads is what keeps the loop stable.
jitter = self.jitter_mv * (1 if self._reads % 2 else -1)
half = 0.5 * self.difference_mv()
mv = self.base_mv + (half if channel == 3 else -half) + jitter
return mv / 1000.0
class FakeAlignScope(FakeScope):
"""FakeScope that also answers the DC measurements auto-align reads."""
def __init__(self, trace: Trace, rig: FakeAlignRig, samples_per_frame=8,
acquisitions_advance=True):
super().__init__(trace, samples_per_frame=samples_per_frame)
self._rig = rig
self._acq = 0
self._advance = acquisitions_advance
def measure_immediate(self, channel, measurement_type="MEAN"):
self._t.record("measure_immediate", channel, measurement_type)
return self._rig.level_v(channel)
def get_acquisition_count(self):
if self._advance:
self._acq += 1
return self._acq