Specification-guided Software Fault Localization for Autonomous Mobile Systems

Abstract

Verification and validation are vital steps in the development process of autonomous systems such as mobile robots and self-driving vehicles, as they allow reasoning about system safety. In the domain of cyber-physical systems, techniques using formal requirements have been show to enable rigorous mathematical reasoning about system safety through techniques for automatic test generation and performance analysis. In this paper, we show that system-level and subsystem-level requirements can also enable fault localization in autonomous systems that use heterogeneous functional components. However, writing correct formal requirements is challenging and requires a significant investment of time, effort and most importantly, expertise. To address this issue, we propose a specification library for autonomous mobile systems called TLAM (Temporal Logic for Autonomous Mobility). Our contributions are twofold: We provide a library of parametric formal specifications at both the system-level and subsystem-level for typical subsystems in autonomous systems such as those for perception, planning and decision-making. The specification parameters encode the design trade-offs for such components. Second, we introduce a new fault localization technique based on these parametric specifications that identifies the likeliest subsystem that has a fault.