A model-based test case generation method for function testing of Train Control Systems

Potential faults in safety critical systems may lead to system failures thus bring huge human injuries. How to ensure the correctness of the system during the system development is very important. System function testing has been regarded as an effective approach which normally applied in the final stage of system development to ensure the consistence of system functions and specifications. In this paper, an integrated model-based test case generation method combining Hybrid Communicating Sequential Processes (HCSP) and Timed Automata is introduced, in which HCSP is used to formally model the scenarios of the system, while Timed Automata is used to verify the system properties in HCSP models. To bridge the gap between the HCSP model and Timed Automata model, transition rules are defined according to the characteristics of systems. Based on the Network Timed Automaton model, a tool chain (UPPAAL and CoVer) is presented to automatically generate test case with coverage criteria in a simple and flexible manner. The tool chain is also applied to analyze the typical Radio Block Center (RBC) handover scenario in Chinese Train Control System Level 3 (CTCS-3). Logical and timing properties of the case study are verified and different test case suites of Vital Computer (VC) components in RBC handover model are automatically generated with different coverage criteria.