Research On Scenario-Oriented Satety Testing Of The Train Control System

In safety critical system which is a typical distribution of real-time and concurrent system, sequential interactive behavior has become an important feature of the system function and safety. Scenario is an effective method to describe the dynamic behavior of concurrent and distributed multiple systems. And Scenario is often used to describe the system behavior layer of security requirements and functional requirements, which is a main basis of modeling software system. The scenario depicting the train control system has been located the industry standard by Railway corporation, and become the main basis for the third party testing.Full coverage of the test requirements of technical specification-oriented is the basic demand of this kind of safety critical system security testing. However, full coverage is not feasible in practice. How to generate specific test cases has become the focus of the research, especially generate test cases in different risk levels, become the key to the success of testing based on scenario.However, it is difficult to achieve the completeness of testing scenario oriented in practice. The actual testing requires provide a feasible technology, which can produce test cases covering specific behaviors, to rapidly detect different risk levels of system defects. This paper consider the interactive behavior of train control system based on the operational scenario, put forward a kind of testing technology based on pattern, which can quickly generate test cases for specified behavioral constraints and quickly detect the violation or compliance of system operation scenarios. The main contributions of this paper are as follows:(1) Propose a classification of pattern of the train operation scenarios oriented, defines the semantics of pattern using LTS and FSM, and defines the coverage criteria based on pattern.(2) Propose test case generation technologies of pattern based on graph theory, and proved the correctness of the algorithm.(3) Propose a method of broke down scenarios behaviors, and based pattern’s testing technology. Propose a test case generation technology of specific scenarios behaviors oriented.Through some examples show that the test case generation technology can quickly produce test case set based specific behavioral characteristics and constraints, on the one hand, it can effectively detect whether there is violation of specific patterns of behavior pattern, on the other hand can generate test cases covering behavior pattern, which can use fewer test cases test system specific behavior.