Safety Test Case Generation of Train-ground Transmission Function for CTCS Based on Fault Models

Abstract

Fault-based safety tests are used to verify the safety functions of Chinese Train Control System (CTCS). The complex failure modes of the system bring some challenges to generate test cases including possible failure modes for specific safety functions. In this paper, we propose a method of generating safety test cases for train control systems based on fault models. The train-ground transmission function of train control systems is selected as the research object. The failure modes which may occur in the process of train-ground information transmission are obtained by using Failure Mode and Effect Analysis (FMEA). Then, the extended UML sequence diagram is used to describe the information interaction process of the train operation scenes in which failure modes are injected. The fault extended hybrid automata models of the system are established and verified. The safety test cases containing the faults are generated by an improved test case generation tool for hybrid system. Finally, the application of this method is illustrated by combining the wireless message’s loss with RBCs’ handover scene. The result shows that this method can generate safety test cases including faults, which are able to provide guidance for safety tests of CTCS.