Mutation TAIO-Based Test And Evaluation Of Safety Function For New Train Control System

Train control system is the core equipment to guarantee system safety.With the rapid development of rail transit and the increasing demand of people,train control system is developing toward the direction of high efficiency,intelligence and low cost.At present,there are many researches on new train control system(NTCS)at home and abroad,and one of the hottest is the new vehicle to vehicle communication train control system,in which the interval control is realized by vehicle to vehicle wireless communication.As NTCS is a typical safety-critical system,once an error occurs,it will cause serious harms on human beings and huge losses on economic.Therefore,it is essential to guarantee the safety and correctness of system.As testing is an effective means to validate system correctness,the safety function of NTCS needs to be tested,and test suites need to be generated with the higher fault-covered score and stronger error-detected capability.In Mutation testing,errors will be injected into system purposely,and fault sets will be created to simulate the error action.Based on TAIO theory and mutation testing technique,this thesis proposes the framework of mutation TAIO-based test and evaluation of safety function for NTCS.After the software of test suite generation for this framework is realized,a case study for on-board equipment of NTCS is carried out.The main contents are as follows:(1)The researches of NTCS and its safety function testing at home and abroad are analyzed.At the same time,the structure and scenarios of NTCS are introduced,and the safety function of NTCS is formed based on FTA theory.(2)The framework of mutation TAIO-based test and evaluation of safety function for NTCS is proposed.Firstly,the modeling of NTCS(TAIO A)is realized based on TAIO theory.Secondly,eight kinds of mutation operators are designed to mutate TAIO A,which form the mutants(TAIO M).Then,timed input and output conformance relation(tioco)between TAIO A and TAIO M is converted to the k-Bounded model checking formula to determine whether the test suite should be generated.Finally,according to the test suite generation algorithm,test suites are generated automatically and the safety function of system is evaluated by conformance relation score(CRS),average conformance relation score(ACRS)and weighted conformance relation score(WCRS).(3)The software of test suite generation for NTCS is researched and developed.After elaborating the software's requirements and its implementation process in detail,the controller of mutant generation and the controller of test suite generation are designed to observe and control the process of test execution and test suite generation.(4)Taking the on-board equipment of NTCS as the object under testing,an application of testing for this framework is studied.As for the reference model of NTCS on-board,a total of 14778 mutants and 10515 test suites are generated at last.Through the analysis of CRS for each test suite,three faults of "change action","change invariant" and "sink location" could be detected effectively,but two faults of "negate guard" and "invert reset" need to be detected by addition observation action.In addition,The ACRS and WCRS of the test suites reach 0.72 and 0.8,indicating that it could generate test suites with the higher fault-covered score and the stronger error-detected capability effectively under the testing framework of the thesis,which has the negative values both in theory and practice.