Research And Implementation Of The Method Of Generating Test Sequences In Engineering For Urban Rail Transit CBTC System

In recent years,the problem of urban traffic congestion has become increasingly prominent,and the construction of urban rail transit is regarded as one of the effective ways to solve the problem,and it plays an increasingly important role.Communication Based Train Control System(CBTC),as one of the core technologies of modern urban rail transit in my country,plays an important role in improving train passing capacity and ensuring train operation safety.Before the CBTC system is put into use,engineering tests must be carried out.At present,each CBTC system manufacturer uses their own test methods and standards in the engineering test phase,and there is no unified test process in the industry.The test efficiency of CBTC system is low,and the phenomenon of retest and missed test is very easy to occur,and the feasibility of the test cannot be verified,and security problems are prone to occur during the test phase.Therefore,it is necessary to study the general CBTC system test sequence generation method and improve the test efficiency.Most domestic and foreign researches on the generation of test sequences are concentrated on the CTCS-3 of high-speed railways.CTCS-3 system has a relatively complete development and has a unified industry standard and specification.Its system status is easy to comprehensively identify and can be modeled to facilitate the generation of standard test sequences.CBTC system engineering testing includes laboratory testing and on-site testing.The system status is numerous and complex and changeable,and unified modeling analysis cannot be carried out.The modeling method is not suitable for the engineering testing of CBTC system.The thesis mainly studies a method of generating test sequences in the phase of CBTC system engineering testing.By analyzing all the test cases in the test case library,the test cases can be divided into two parts according to whether the mode conversion of the vehicle equipment is involved,and the two parts of the cases can be connected in series.For the test case involving the mode conversion of vehicle equipment,it is transformed into solving the Chinese Postman Problem with a directed graph with multiple arcs.Use the Edmonds-Johnson algorithm to solve the Chinese Postman Problem,and combine with the LINGO tool for modeling and analysis,construct a directed Euler graph,and find the optimal solution for the postal route.Then a test sequence optimization method is proposed to solve the problem of low executability caused by the too long test sequence,so as to obtain the test sequence related to the function of the on-board equipment working mode conversion.For the other cases that do not involve the conversion of the working mode of vehicle equipment,the method of formal description is adopted.First,the test line is divided into several test sections according to a certain rule,and then the execution constraints of the test case and the characteristics of the test section are analyzed,and the design is matched.Algorithm to match the test case with the test section.After the matching is completed,the test case is connected in series using a series algorithm based on the consistency of train operation status,and a test sequence auxiliary generation tool is developed to generate a non-mode conversion test sequence.The two parts of the test sequence generated by the above method constitute the entire CBTC system engineering test sequence,which can be executed correctly when executed on the CBTC system automatic test platform.Comparing the test sequence generated in this article with the test sequence manually compiled,the results show that the test sequence generated in this article can significantly improve the test efficiency of the CBTC system engineering test,and provide a guarantee for the realization of automatic testing.