Monitor-Based Runtime Assurance for Temporal Logic Specifications

This paper introduces the safety controller architecture as a runtime assurance mechanism for system specifications expressed as safety properties in Linear Temporal Logic. The safety controller uses a monitor, constructed as a finite state machine, to analyze a desired control input policy online and form a sequence of control inputs that is guaranteed to keep the system safe for all time. A case study is presented which details the construction and implementation of a safety controller on a cyber-physical system with a nondeterministic dynamical model.