4. Case Study — LSTM detection
Binary AnomalyLSTM: window → recurrent net → nominal / anomaly
Habitat sim
1 Hz telemetry
Input window
T=60 · F=68 · z-scored
t−59
…
t−1
t
x ∈ ℝ⁶⁸ each second
AnomalyLSTM (unrolled)
same cell · shared weights · H = 32
xₜ₋₅₉
…
xₜ₋₁
xₜ
LSTM
cell
···
LSTM
cell
LSTM
cell
h
h
h
hₜ ∈ ℝ³²
each step τ: (h_τ, c_τ) = LSTM(x_τ, h_{τ−1}, c_{τ−1})
only final h_t → binary head · gates: next slide
Binary head
two logits → softmax · true detection
⋮
hₜ (32)
z₀ nominal
z₁ anomaly
P = softmax(z)
· 2 classes
if P(anomaly) ≥ 0.5 → observation
In the habitat-dx loop
Detection
lstm-binary
Hypothesis
gated / off in open loop
Evaluation
P(nom), P(anom)
Decision
not in Study C open
Execute
disabled
Detection publishes binary scores each tick
anomaly observation gates diagnosis when hyp / eval are enabled
solid = active in open-loop Study C
dashed = disabled / gated