SNAP-UQ: Self-supervised Next-Activation Prediction for Single-Pass Uncertainty in TinyML
This provides a practical, resource-efficient solution for on-device monitoring in TinyML, addressing the need for single-pass uncertainty estimation in memory-constrained environments.
The paper tackled the problem of estimating uncertainty in TinyML without requiring multiple passes or extra memory, achieving a 40-60% reduction in flash memory and 25-35% faster latency compared to existing methods while maintaining strong failure detection with AUROC around 0.9.
We introduce \textbf{SNAP-UQ}, a single-pass, label-free uncertainty method for TinyML that estimates risk from \emph{depth-wise next-activation prediction}: tiny int8 heads forecast the statistics of the next layer from a compressed view of the previous one, and a lightweight monotone mapper turns the resulting surprisal into an actionable score. The design requires no temporal buffers, auxiliary exits, or repeated forward passes, and adds only a few tens of kilobytes to MCU deployments. Across vision and audio backbones, SNAP-UQ consistently reduces flash and latency relative to early-exit and deep ensembles (typically $\sim$40--60\% smaller and $\sim$25--35\% faster), with competing methods of similar accuracy often exceeding memory limits. In corrupted streams it improves accuracy-drop detection by several AUPRC points and maintains strong failure detection (AUROC $\approx$0.9) in a single pass. Grounding uncertainty in layer-to-layer dynamics yields a practical, resource-efficient basis for on-device monitoring in TinyML.