Time Robustness in MTL and Expressivity in Hybrid System Falsification (Extended Version)

TL;DR

The paper introduces AvSTL, an extended temporal logic with averaged operators, enhancing robustness in hybrid system falsification and proposing a sliding window algorithm for efficient computation.

Contribution

It presents AvSTL, a novel logic for better robustness modeling, and a sliding window algorithm to improve computational efficiency in falsification tasks.

Findings

AvSTL captures space and time robustness more effectively.

The sliding window algorithm reduces computational costs.

Enhanced falsification success in hybrid systems.

Abstract

Building on the work by Fainekos and Pappas and the one by Donze and Maler, we introduce AvSTL, an extension of metric interval temporal logic by averaged temporal operators. Its expressivity in capturing both space and time robustness helps solving falsification problems, (i.e. searching for a critical path in hybrid system models); it does so by communicating a designer's intention more faithfully to the stochastic optimization engine employed in a falsification solver. We also introduce a sliding window-like algorithm that keeps the cost of computing truth/robustness values tractable.