Automated Translation of Natural Language Requirements to Runtime Monitors

Abstract

Runtime verification (RV) enables monitoring systems at runtime, to detect property violations early and limit their potential consequences. This paper presents an end-to-end framework to capture requirements in structured natural language and generate monitors that capture their semantics faithfully. We leverage NASA’s Formal Requirement Elicitation Tool (fret), and the RV system Copilot. We extend fret with mechanisms to capture additional information needed to generate monitors, and introduce Ogma, a new tool to bridge the gap between fret and Copilot. With this framework, users can write requirements in an intuitive format and obtain real-time C monitors suitable for use in embedded systems. Our toolchain is available as open source.

Monitoring ROS2: from Requirements to Autonomous Robots

“…FRET generates the Component specification that is given as input to the Ogma tool. The Component specification contains the generated specifications in pure Past-time MTL (in SMV format [9] and in Lustre code), as well as information about the variables used in the requirements (e.g., data types) [31]. The compilation process through Ogma and Copilot produces a monitor whose status at each point in time can be checked by calling a generated step() function.…”

“…Third, the monitor information produced by Ogma is sent through a second execution that produces the necessary ROS2 wrapper node for the monitoring subsystem. The first two steps of this process predated the current document, and were described in prior work targeting the flight software middleware NASA Core Flight System (cFS) [31]. The last step is an extension to Ogma and a novel contribution ( §2.3).…”

Capture, Analyze, Diagnose: Realizability Checking Of Requirements in FRET

“…requirements that can be processed by formal analysis tools [10,17,42,45]. Additionally, FRET has been used by external (to NASA) industrial and research teams, e.g., for the formalization of aircraft engine controller requirements [19].…”