Route Control Process Oriented Highly Efficient Testing Method Of Railway Signal Interlocking Software

Computer interlocking system is one of the key railway signal equipments. CIS controls the signal equipments (switches, signals, routes) under interlocking conditions and the stipulated time to realize interlocking functions and ensure the safety of train operation in railway station. According to the computer interlocking technology conditions issued by the Ministry of Railways, CIS should be able to meet the requirements of all kinds of station scales and transportation operations. Rigorous testing is absolutely necessary and important for such a high security, high reliability, high stability and real-time control system before taking into application.Software testing typically accounts for about40%of the time of the entire software development process. It would be more for CIS. At present, the main computer interlocking software testing method is manual testing method. Test cases are designed and executed by experts. The above method can achieve part of testing goal, but at the same time it has the disadvantage of low-efficiency because of high repetition. This paper presents a highly efficient testing method based on route control process with pair wise testing technology to improve interlocking software test efficiency. The main work of the paper is as follows:(1) Analyzing the methods and status of software testing and interlocking system and presenting the state changes of signal equipments in the route control process based on the interlocking software structure and proposing a high-efficiency testing method based on the route control system and the pair wise testing technology aimed at improving test efficiency.(2) Analyzing and comparing the advantages and disadvantages of typical algorithms and deciding to generate test cases with network combination algorithm, and then executing test cases according to route control process which can reduce testing redundancy on the basis of the test adequacy and all test items can be optimized into test sequences according to the route control process of route selection, route locking, opening signal and route release.(3) Discussing the design of the testing system in detail and proposing the implementation algorithm. Finally, taking a station for example, this method is employed to generate and optimize test sequence. The result shows that the testing approach covers all the functional requirements and repeatability is reduced by33%. High-efficiency and sufficiency is verified successfully.The result of the research work in this paper indicates that all the railway signal interlocking software functions can be tested with the testing approach fully and quickly. It earns a high coverage and low repetition rate, and this would be important significance for improving railway signal interlocking software testing efficiency.