Research On The Method Of Unit Test For CTCS-3Train Control System

:In order to ensure the safety and efficiency of the operation of the railway, and to check out whether the Train Control System meets the standard of the Software Requirements Specification (SRS), a variety of tests must be done. As test in code-level, unit test is the most basic test in the process of the software development and testing, whose role is to test the program code implementation. Only if the unit test is finished, and the complete implementation of the system code is worked out to make it meet the safety standard of the Software Requirements Specification, can the following steps of software development and testing be continued. So unit test is the fundamental step during the process of software development. In the background, through observation on the published data abroad and making research on unit test of the CTCS-3Train Control System, this thesis draws a detailed picture of the unit test process in the following chapters. The main work of the thesis is as follows:(1) Making formal modeling for vital computer system of the Train Control System. By using UML formal modeling language to make Active Diagram modeling of the Train Control System, the nine important system functions of the vital computer system of CTCS-3Train Control System can be clearly analyzed, then the ambiguity can be avoided. Through formalized modeling analysis of the main system functions of the Train Control System, all functional modules can be included into the model, not missing a functional module. At the same time, the functional structure of the system can be understood more intuitively, thus to guarantee that the unit testing can achieve safety testing standards.(2) Making test case for vital computer system of the Train Control System. In the beginning, two models are chosen as examples to research on the method of making test case. The two models are train brake model and information packet from ground to train. First, Use Case and Activity Diagram of these two models are made by using UML formal modeling language. Second, the characteristics of the units are extracted to generate the teat case. Third, the method ofcombinatorial testingis used to analyze the input value of the test code. Finally, suitable test input variables are found to improve the efficiency of the test work and to push on the unit testing.In a word, the generation of the test case is to guide the unit test, achieving the safety standards, and to build a tracking system for every test step. In this way, the problems can be found immediately.(3) Using the unit test tools to test the test case. First, the unit test tools are used to build test-driven functions and stubs functions for the unit test cases of the train brake model and information package from ground to train. Second, use the test-driven functions and stubs functions to push on unit testing of the test cases, to generate test statement coverage chart. Third, count the rate of the test statement coverage. Fourth, in contrast to Railway Application standards EN50128, if it not up to the standard of EN50128, it needs manual inspection to raise the statement coverage up to100%, in order to guarantee the quality of the code. In this way, the method of the unit test can also be proved effective.