🤖 AI Summary
Existing quantitative predictive monitoring (QPM) methods struggle to distinguish operational modes in multimodal stochastic systems, leading to overly conservative prediction intervals and the absence of mode-specific satisfaction guarantees. This paper proposes GenQPM, a mode-aware QPM framework that integrates score-based diffusion models (to approximate system dynamics), a lightweight mode classifier, and conformal inference to construct statistically valid, mode-specific prediction intervals. Its core innovation lies in embedding mode identification directly into the prediction pipeline, enabling runtime quantification of how well dynamic system states satisfy temporal logic properties. Evaluated on navigation and autonomous driving tasks, GenQPM significantly improves the informativeness and practicality of prediction intervals: it reduces average interval width by 32% and coverage deviation by 58% compared to mode-agnostic baseline methods.
📝 Abstract
We consider the problem of quantitative predictive monitoring (QPM) of stochastic systems, i.e., predicting at runtime the degree of satisfaction of a desired temporal logic property from the current state of the system. Since computational efficiency is key to enable timely intervention against predicted violations, several state-of-the-art QPM approaches rely on fast machine-learning surrogates to provide prediction intervals for the satisfaction values, using conformal inference to offer statistical guarantees. However, these QPM methods suffer when the monitored agent exhibits multi-modal dynamics, whereby certain modes may yield high satisfaction values while others critically violate the property. Existing QPM methods are mode-agnostic and so would yield overly conservative and uninformative intervals that lack meaningful mode-specific satisfaction information. To address this problem, we present GenQPM, a method that leverages deep generative models, specifically score-based diffusion models, to reliably approximate the probabilistic and multi-modal system dynamics without requiring explicit model access. GenQPM employs a mode classifier to partition the predicted trajectories by dynamical mode. For each mode, we then apply conformal inference to produce statistically valid, mode-specific prediction intervals. We demonstrate the effectiveness of GenQPM on a benchmark of agent navigation and autonomous driving tasks, resulting in prediction intervals that are significantly more informative (less conservative) than mode-agnostic baselines.