CTCS-2级列控车载设备层次化组合测试方法

Hierarchical Combinatorial Testing Approach for CTCS-2 Onboard Equipment

对列控车载设备开展组合测试,可有效提高设备的安全性。针对现有组合测试方法未充分考虑车载设备测试过程中输入的时序性、设备状态等影响软件安全的各种因素组合的问题,提出一种车载设备层次化组合测试方法。首先,划分CTCS-2级车载设备测试过程中各种影响因素的组合层次,设置层次化覆盖强度。其次,提出了车载设备层次化组合覆盖准则,给出形式化定义,构建层次化组合测试模型。然后,提出一种两阶段层次化组合测试用例生成方法,高效精简构造层次化组合测试集。最后,以CTCS-2/0等级转换测试为例对方法进行验证。结果表明,在保证各种影响因素组合覆盖的前提下,相对于现有方法,在覆盖强度t={2,2,2}时,采用本方法的测试成本可降低23.53%,有效提高测试的针对性,验证了方法的有效性。

Applying combinatorial testing to the onboard equipment of train control system contributes to enhancing its safety.In response to the failure of existing combinatorial testing approaches to consider the factors of combinations of time input sequences and equipment state that affect software safety during the testing of the onboard equipment,a hierarchical combinatorial testing approach for onboard equipment was proposed in this paper.First,the input factors of CTCS-2 onboard equipment were identified and classified into levels with hierarchical coverage strength.Second,hierarchical combinatorial coverage criteria for onboard equipment were formally defined while a hierarchical combinatorial test model with classified input factors was created.Third,a two-phase hierarchical composite test case generation approach was proposed to construct hierarchical test suite effectively and efficiently.Finally,a case study of CTCS-2/0 level transition test was conducted to verify the method.The results show that when satisfying coverage criteria,compared with the existing approaches,when the coverage strength t={2,2,2},the test cost of this approach can be reduced by 23.53%,which effectively improves the pertinence of the test,and proves the effectiveness of the approach.