Toward a Holistic Approach to Verification and Validation of Autonomous Cognitive Systems

Abstract

When applying formal verification to a system that interacts with the real world, we must use a model of the environment. This model represents an abstraction of the actual environment, so it is necessarily incomplete and hence presents an issue for system verification. If the actual environment matches the model, then the verification is correct; however, if the environment falls outside the abstraction captured by the model, then we cannot guarantee that the system is well behaved. A solution to this problem consists in exploiting the model of the environment used for statically verifying the system’s behaviour and, if the verification succeeds, using it also for validating the model against the real environment via runtime verification. The article discusses this approach and demonstrates its feasibility by presenting its implementation on top of a framework integrating the Agent Java PathFinder model checker. A high-level Domain Specific Language is used to model the environment in a user-friendly way; the latter is then compiled to trace expressions for both static formal verification and runtime verification. To evaluate our approach, we apply it to two different case studies: an autonomous cruise control system and a simulation of the Mars Curiosity rover.