基于IECP的CTCS-3列控车载TSM曲线完备性测试用例集生成方法研究

Method of Generating Completeness Test Suit Based on IECP for CTCS-3 Train Control TSM Profile

作为CTCS-3级列控系统的核心安全功能,速度-距离模式曲线具有参数输入域规模大、故障模式复杂等特点,如何完备地测试列控车载设备速度-距离监控曲线功能异常困难。提出了一种基于输入等价类划分测试理论的CTCS-3级列控车载目标速度监控曲线完备性测试用例生成方法。首先,结合CTCS-3级列控系统需求规范,建立了满足司机制动优先和设备制动优先两种不同制动优先级情况下的TSM有限状态机模型,并利用反应式状态迁移系统的形式化语义,描述了不同输入情况下模型的内部状态迁移过程。其次,利用I/O等价原理和等价类划分理论,得到了两种不同制动优先情况下的输入等价类划分。在此基础上,通过引入了被测系统的故障模型和故障域范围,采用W-method测试用例集生成方法,在满足模型故障域的条件下,最终得到两种不同制动优先的目标速度监控曲线模型完备测试集。设备制动优先情况生成的测试用例数量高于司机制动优先约33.3%,且所需测试时间和内存消耗更多。

The distance-to-go control curve,which performs the critical safety functions of Chinese Train Control System Level 3(CTCS-3),is characterized by large parameter input domain and complex fault modes.There exists a great difficulty when it comes to the complete test of the distance-to-go control curve of train onboard equipment.Based on the input equivalence class partitioning test theory,this paper presented a method of generating Target Speed Monitor profile’s completeness test cases for train onboard equipment in CTCS-3.Firstly,according to the system requirement specification of CTCS-3,the finite state machine models of TSM were built to satisfy two different braking priority conditions,driver braking priority and ATP equipment braking priority.The formal semantics of reactive state transition system were utilized to describe the internal state transition of the finite state machines under different inputs.Secondly,the I/O equivalence and the equivalence class partition theory were applied to obtain IECPs with two kinds of different braking priorities.Finally,the fault models and fault domain of system under test were introduced,and the W-method was applied to generate test suits of TSM models with two different braking priorities,which were complete under the given fixing fault domain.The number of test cases generated under ATP equipment braking priority is higher than that of driver braking priority by 33.3%,costing more required test time and memory consumption.