Trace-checking signal-based temporal properties

Abstract

Trace checking is a verification technique widely used in Cyber-physical system (CPS) development, to verify whether execution traces satisfy or violate properties expressing system requirements. Often these properties characterize complex signal behaviors and are defined using domain-specific languages, such as SB-TemPsy-DSL, a pattern-based specification language for signal-based temporal properties. Most of the trace-checking tools only yield a Boolean verdict. However, when a property is violated by a trace, engineers usually inspect the trace to understand the cause of the violation; such manual diagnostic is time-consuming and error-prone. Existing approaches that complement trace-checking tools with diagnostic capabilities either produce low-level explanations that are hardly comprehensible by engineers or do not support complex signal-based temporal properties. In this paper, we propose TD-SB-TemPsy , a trace-diagnostic approach for properties expressed using SB-TemPsy-DSL. Given a property and a trace that violates the property, TD-SB-TemPsy determines the root cause of the property violation. TD-SB-TemPsy relies on the concepts of violation cause, which characterizes one of the behaviors of the system that may lead to a property violation, and diagnoses, which are associated with violation causes and provide additional information to help engineers understand the violation cause. As part of TD-SB-TemPsy , we propose a language-agnostic methodology to define violation causes and diagnoses. In our context, its application resulted in a catalog of 34 violation causes, each associated with one diagnosis, tailored to properties expressed in SB-TemPsy-DSL. We assessed the applicability of TD-SB-TemPsy using an industrial case study from the satellite domain. The results show that TD-SB-TemPsy could finish within a timeout of 1 min for ≈ 83.66% of the trace-property combinations in our dataset, yielding a diagnosis in ≈ 99.84% of these cases; these results suggest that our tool is applicable and efficient in most cases.

Trace-Checking CPS Properties: Bridging the Cyber-Physical Gap

“…S2: 101 requirements were provided by the authors of SB-TemPsy-DSL [7]. They mostly refer to the physical dynamics of the satellite, as in "the beta angle [31] shall show an oscillatory behavior with a maximum period o f 2500 s".…”

“…Time-based languages (e.g., STL [2], STL* [3], RFOL [4], SFO [5], TPTL [6]. and SB-TemPsy-DSL [7]) interpret the records of the cyber and physical components as signals over a time domain. Specifications written in a time-based language express time relations over the occurrence of events.…”

“…Our results show that HLS could express all the requirements of our case study. We also compared HLS with SB-TemPsy-DSL [7] and STL [2], two specification languages proposed in the literature and for which trace-checking tools are available. The results show that HLS is significantly more expressive than SB-TemPsy-DSL and STL, which could only express 145 and 102 requirements, respectively.…”

“…ThEodorE yielded a verdict for 67.9% of the 337 trace-requirement combinations containing a requirement that can not be verified by any of the other trace-checkers. We compared the applicability of ThEodorE with SB-TemPsy-Check [7] and Breach [17], for the trace-requirement combinations containing requirements expressible in SB-TemPsy-DSL and STL. For these combinations, SB-TemPsy-Check and Breach were 21.9% and 4.9% more often applicable than ThEodorE, respectively.…”

Agents and Robots for Reliable Engineered Autonomy:A Perspective from the Organisers of AREA 2020

“…Pattern-based languages are a common solution to solve recurrent problems of many domains, including robotics [60,81], cyber-physical systems [82], self-adaptive systems [83,84], machine learning [85], IoT [86], and multi-agent systems [84,[87][88][89]. Existing design patterns in the field of multi-agent systems were classified in a recent survey [88].…”