Research On Test Case Generation Method Of Train Control Level Conversion Scenario Based On UPPAAL Model

The train control system is a complex system with strict safety requirements and requires comprehensive and detailed safety verification.Grade conversion is an important scene in the process of train operation,and its efficient and orderly operation helps to ensure the safety and stability of the train control system.At present,the test cases of level conversion scenario software are mainly compiled manually,which is low in efficiency,time-consuming,and heavy,and the quality of test cases is difficult to guarantee.If test cases can be generated automatically,the software development cycle will be greatly shortened,and software development costs will be reduced.Therefore,the automatic generation of test cases that can fully cover the system specifications has become the primary problem of level conversion testing.In this paper,firstly,based on the requirements and specifications of the train control system technical solution,formalized modeling of the level conversion scenario and completed system simulation and performance verification;secondly,based on the minimum test cost migration coverage criterion,the depth-first search algorithm was designed to solve the effective migration sequence and expanded to Test path collection;then,on the basis of logical expression analysis,a fast generation algorithm is introduced to materialize abstract test cases into test data,thereby generating specific test cases;finally,programming to implement test case generation tools to analyze test case coverage degree.The main work of this paper is divided into the following four points:1.Establish a time automata model.According to the requirement specification of CTCS-3 level train control system level conversion scene,according to the information interaction sequence diagram and the principle of time automata,using UPPAAL modeling tool,establish the time automata model of train control system level conversion,and obtain two conversion scenarios The state transition diagram of each subsystem.Then use the UPPAAL tool to perform system simulation on the performance variables and clock constraints of the model,and use the BNF temporal logic formula to verify the functional requirements and real-time requirements to ensure the accuracy and completeness of the model.2.Generate a test path based on the model.Analyze the XML file corresponding to the model,use the hash table to store and map the relationship between the state and the migration condition in the model,and design the depth-first search solution to obtain the effective migration sequence set that meets the minimum test cost according to the migration coverage criterion.It expands to a collection of complete test paths.3.Generate specific test cases based on the test path.Analyze the logical expressions in the migration condition based on the modified decision condition coverage(MC/DC)criterion.Based on the grammar tree theory,design a fast generation algorithm,calculate the test data set,adopt the "three-step method",and combine the corresponding Test path to generate the final test case.4.Design and implement automatic test case generation tools.Through the intuitive user interface,the test case generation function is demonstrated,which verifies the feasibility of the model and algorithm.