Identifiability of sensor faults and healthy-model discrepancy from a single voltage channel

Determine whether sensor-induced voltage faults can be distinguished from healthy-model discrepancy using only the single measured terminal-voltage channel when a fault is present at startup or the healthy-model discrepancy is inadequately calibrated.

Background

The estimator represents sensor abnormalities, model mismatch, hysteresis, and other discrepancies through a lumped voltage-residual state. Because these effects enter the same scalar voltage innovation, the commissioning procedure can recover the electrochemical state only conditionally, under a verified-healthy startup window and adequate healthy-residual calibration.

The paper explicitly limits the interpretation of the residual state: it provides voltage-domain accommodation but does not establish physical source separation. In particular, when a fault is already present at startup or the healthy discrepancy is poorly calibrated, the available voltage data do not distinguish the competing contributions.

References

If a voltage fault is already present at sample zero, or if the healthy model discrepancy is inadequately calibrated, the two contributions remain non-identifiable from this single voltage channel.

— When voltage sensors fail: Electrochemically constrained fault-tolerant state estimation for flat-plateau LFP batteries  (2610.05906 - Guo et al., 5 Oct 2026) in Section 5.2, “Initial-state uncertainty and intrinsic observability”