Research Of Communication Based Train Control System Software Automatic Testing

In the field of urban rail transit,communication based train control(CBTC)system is the mainstream of the current signal system development.CBTC system has achieved the full duplex high-capacity two-way continuous information transport between train and ground,which not only protects the real-time and stability of communication but also improves the accuracy of the train positioning and driving efficiency.As a system directly related to traffic safety,CBTC system must meet the "fault-security" principle.So it is a safety demanding system.In order to ensure the safety of the system,the entire system should pass through rigorous safety certification before application.Software testing is an important part of ensuring system quality and plays an important role in the process of security certification.However,in software testing,test staffs' experience has a great impact on the efficiency of the test.Usually the level of test personnel will affect the progressandquality of test work.Therefore,how to improve the degree of automation of software testing and to reduce the impact of human factors on the efficiency of the test have become hot issues in the field of software testing.In order to improve the degree of automation in software testing,this thesis presents a test path generation technique,and use test coverage as an indicator to measure test results.Coverage is an important indicator to measure theresult of software testing,the testers need to select appropriate test paths to meet the coverage requirements.Test pathsshould be neither repeating nor missing,generally these paths are from artificial selection.According to the selected paths,testers prepare test cases for testing.In the case of codes with simple test logic,the manual selection of the test paths is more efficient.Once the program structure is complex with many branches and loops,the manual selection of the test paths will take a lot of time and effort,and prone to repeating or missing.This thesispresents a technique for automatically generating test paths that provides guidance for testers to perform coverage tests and improve the automation of testing.The automatic generation process of the test paths needs to formalize the tested code.In this thesis,the tested code is transformed into a formal node graph based on the Petri net theory.Programming based on graph search algorithm,search all paths from the entry to the exit of tested code,and finally display all paths.Testers write test cases based on the paths of automatic output,which saves time to find the paths artificially and improves the efficiency of the test.In this thesis,ATP subsystem software module is introduced as an example,this thesis generates test paths automaticallyand uses LDRA Testbed software for verification test.After verification,according to the automatically generated test paths,the code test coverage reaches 100%,which confirms that the test paths are correct and effective to meet the test requirements.