Falsification of Signal-Based Specifications for Cyber-Physical Systems
This thesis proposes new methods for analyzing and generating test cases as a means of being more certain that proper testing has been performed for the system under test. For analysis, the proposed approach includes automatically finding how much a given test suite has executed the physical properties of the simulated system.
For test case generation, an up-and-coming approach to find errors in Cyber-Physical Systems is simulation-based falsification. While falsification is suitable also for some large-scale industrial systems, sometimes there is a gap between what has been researched and what problems need to be solved to make the approach tractable in the industry. This thesis attempts to close this gap by applying falsification techniques to real-world models from Volvo Car Corporation, and adapting the falsification procedure where it has shortcomings for certain classes of systems. Specifically, the thesis includes a method for automatically transforming a signal-based specification into a formal specification in temporal logic, as well as a modification to the underlying optimization problem that makes falsification more viable in an industrial setting.
The proposed methods have been evaluated for both academic benchmark examples and real-world industrial models. One of the main conclusions is that the proposed additions and changes to analysis and generation of tests can be useful, given that one has enough information about the system under test. It is difficult to provide a general solution that will always work best -- instead, the challenge lies in identifying which properties of the given system should be taken into account when trying to find potential errors in the system.
Johan Lidén Eddeland
Chalmers, Elektroteknik, System- och reglerteknik, Automation
Automated Mode Coverage Analysis for Cyber-Physical Systems using Hybrid Automata
IFAC-PapersOnLine,; Vol. 50(2017)p. 9260-9265
Artikel i vetenskaplig tidskrift
Objective functions for falsification of signal temporal logic properties in cyber-physical systems
2017 13th IEEE Conference on Automation Science and Engineering (CASE),; (2017)p. 1326-1331
Paper i proceeding
Using Valued Booleans to Find Simpler Counterexamples in Random Testing of Cyber-Physical Systems
IFAC-PapersOnLine,; Vol. 51(2018)p. 408-415
Paper i proceeding
Lidén Eddeland, J., Claessen, K, Smallbone, N., Ramezani, Z., Miremadi, S., Åkesson, K. Enhancing Temporal Logic Falsification with Specification Transformation and Valued Booleans.
Lidén Eddeland, J., Åkesson, K. A Case Study of Optimization Solvers and Objective Functions for Falsification of Cyber-Physical Systems.
TESTRON - Modellbaserad testning av mekatroniska system
VINNOVA, 2016-01-01 -- 2019-12-31.
Robotteknik och automation
Chalmers tekniska högskola
Opponent: Mattias Nyberg, Kungliga Tekniska Högskolan, Sverige