Research On Generation Method Of Test Sequences For CBTC System Based On Line Model

The Communication Based Train Control(CBTC)system has become an important part of the urban rail system by virtue of accurate train positioning technology and continuous vehicle-ground two-way communication technology.Before the line is opened for operation,the CBTC system has to undergo extensive testing to ensure its safety and reliability.As an important testing link of the CBTC system,engineering testing can be divided into the laboratory testing phase and the field testing phase.At present,because a unified test standard has not been formed,each manufacturer adopts different methods for testing,and because the test process is not uniform,the test sequence is mainly prepared manually,on the one hand,there is the problem of retesting and low testing efficiency;on the other hand,there is the problem of missed tests,which cannot ensure full coverage of security features.Therefore,in order to guide the testing work and improve the quality and efficiency of test sequences,it is of practical significance to study a CBTC system engineering test sequence generation method.Based on the existing test sequence generation methods for column control systems,the thesis combines the characteristics of CBTC system and engineering test features,proposes a test line-based engineering test sequence generation method for CBTC system,and verifies the rationality of the generated test sequences,the main work of the thesis is as follows.Firstly,based on the system specification for interoperability of urban rail transit,analyze the relationship between system test cases and test lines,and divide the test cases into level mode conversion test cases and non-level mode conversion test cases according to whether they involve control level conversion,and use different methods to concatenate these two parts of test cases respectively.Secondly,for the level mode conversion test cases,since the level mode can be transformed into each other,we construct a directed graph by simplifying and transforming the level mode conversion graph to form a directed graph with test cases as vertices and the shortest path between test cases as directed arcs,and finally convert the test sequence generation problem into a Traveling Salesman Problem(TSP),using the Modified Ant Colony Optimization(M-ACO)to find the shortest path,and truncating the generated test sequence according to the working mode of on-board equipment in order to improve the performability of the test sequence.Finally,For test cases that do not involve level mode conversion,first,analyze the relationship between test case execution conditions and test lines,and then formally describe the test cases,and select test lines to divide test sections and extract the amount of the test section characteristics;Second,evaluate the differences between the test case execution conditions and the test section characteristics to determine the locations suitable for test case execution;Finally,the dynamic planning algorithm is designed to convert the test sequence generation problem into a multi-stage decision problem,and the decision function is designed through the test case concatenation principle to seek the optimal test cases for concatenation at each stage in turn.This part of test cases is developed with the help of test sequence generation tools to generate test sequences suitable for "Running Laps" of trains.This thesis adopts the method of dividing the test cases into two parts and forming test sequences based on different characteristics of the test cases,which meets the requirements of CBTC system engineering testing,while ensuring full coverage of the test contents and reducing the repetition of the test sequences.The generated test sequences are tested and verified on the CBTC simulation test platform,and the test sequences can be executed correctly,which shows the correctness and performability of the generated test sequences and provides convenience for the subsequent automatic testing.