Сортировочная ячейка Isaac Sim: CV-пайплайн и меши товаров

Замкнутый контур "поток -> CV -> механика": товары идут по конвейеру с шагом 700 мм,
класс определяется стереопайплайном во время движения, пушер и плуг реагируют физически.

Состав:
* control_test/ - ячейка и CV. run_sorting_cv.py + cv_worker.py (два процесса, потому что
  torch внутри Isaac роняет сцену), cell.py (физика лент, плуга, пушера), measure_plane.py
  (замер габаритов), README.md и .memory.md с замерами, проблемами и ловушками
* robozon_sorter/ - модули симуляции, scripts/ - утилиты, scene/ - сцены
* assets/ - меши товаров, плуг, объекты Objaverse

Бейзлайн CV: DEFOM-Stereo vitl, вход 480, iters 24, кроп зоны осмотра, без сегментации.
На потоке 700 мм - классы 8/9, габариты MAE 32.8 мм, 469 мс на товар при такте 700 мс.

Веса моделей (4.5 ГБ) и пропсы конвейера NVIDIA (274 МБ) не включены - источники и
команды скачивания в MODELS.md. Выход прогонов (captures/, runtime/) не включён:
воспроизводится.

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

scripts/lower_plow_to_belt.py

@@ -0,0 +1,81 @@
+#!/usr/bin/env python3
+"""Drop the plow so its blade sweeps at belt level instead of over the goods.
+
+    /home/whatevenif/isaacsim/python.sh scripts/lower_plow_to_belt.py
+
+Measured on the built scene:
+
+    blade   z 1.810 .. 1.890
+    belt    top z 1.781
+    gap under the blade = 29 mm
+
+29 mm is enough for flat goods to pass straight under the blade, and tall ones get caught
+near their top edge and tipped rather than led across. It is the reason items reached only
+y ~ 0.24 while the arm was correctly holding 42 deg with 402 mm of reach: the blade was not
+touching them at all, so no amount of angle or lane geometry could have helped.
+
+The whole ``DiverterEnd`` is moved, not just the arm: base and arm keep their relative
+placement, so the hinge stays consistent whether the arm is driven kinematically or by its
+joint. The pedestal sinks the same 27 mm, which is invisible - it stands on the floor.
+
+Target clearance is 2 mm: enough that the blade is not grinding on the belt collider,
+little enough that nothing rides under it.
+"""
+from __future__ import annotations
+
+import sys
+from pathlib import Path
+
+from pxr import Gf, Usd, UsdGeom
+
+SCENE = Path(__file__).resolve().parent.parent / "scene" / "plow_cell.usd"
+DIVERTER = "/World/Diverters/DiverterEnd"
+ARM = DIVERTER + "/Arm"
+BELT = "/World/ConveyorTrack_04/Belt"
+CLEARANCE = 0.002
+
+
+def _range(stage, path):
+    return UsdGeom.BBoxCache(0, ["default"]).ComputeWorldBound(
+        stage.GetPrimAtPath(path)).ComputeAlignedRange()
+
+
+def main():
+    if not SCENE.exists():
+        sys.exit(f"{SCENE} not found")
+    stage = Usd.Stage.Open(str(SCENE))
+
+    arm = _range(stage, ARM)
+    belt = _range(stage, BELT)
+    if arm.IsEmpty() or belt.IsEmpty():
+        sys.exit("arm or belt has no bounds - wrong scene?")
+
+    blade_bottom, belt_top = arm.GetMin()[2], belt.GetMax()[2]
+    gap = blade_bottom - belt_top
+    drop = gap - CLEARANCE
+    print(f"blade bottom z {blade_bottom:.4f} | belt top z {belt_top:.4f}")
+    print(f"gap {gap * 1000:.0f} mm -> target {CLEARANCE * 1000:.0f} mm, dropping {drop * 1000:.0f} mm")
+
+    if abs(drop) < 1e-4:
+        print("already at height, nothing to do")
+        return
+
+    prim = stage.GetPrimAtPath(DIVERTER)
+    xf = UsdGeom.Xformable(prim)
+    for op in xf.GetOrderedXformOps():
+        if op.GetOpType() == UsdGeom.XformOp.TypeTranslate:
+            t = op.Get()
+            op.Set(Gf.Vec3d(t[0], t[1], t[2] - drop))
+            break
+    else:
+        sys.exit(f"{DIVERTER} has no translate op to move")
+
+    stage.GetRootLayer().Save()
+    after = _range(stage, ARM)
+    print(f"blade now z[{after.GetMin()[2]:.4f}, {after.GetMax()[2]:.4f}] "
+          f"-> clearance {(after.GetMin()[2] - belt_top) * 1000:.0f} mm")
+    print(f"saved {SCENE}")
+
+
+if __name__ == "__main__":
+    main()