On-Sensor Inference for Uncertainty Reduction

This article presents an algorithm for reducing measurement uncertainty of one quantity when given measurements of two quantities with correlated noise. The algorithm assumes that the measurements of both physical quantities follow a Gaussian distribution and provides concrete justification that these assumptions are valid. When applied to humidity sensors, it provides reduced uncertainty in humidity estimates from correlated temperature and humidity measurements. In an experimental evaluation, the algorithm achieves uncertainty reduction of 4.2%. The algorithm incurs an execution time overhead of 1.4% when compared to the minimum algorithm required to measure and calculate the uncertainty. Detailed instruction-level emulation of a C-language implementation compiled to the RISC-V architecture shows that the uncertainty reduction program required 0.05% more instructions per iteration than the minimum operations required to calculate the uncertainty.