Hardware-in-the-Loop Test Case Specification for Verification of Software Safety Requirements in the Context of ISO 26262

This paper proposes a methodology for the derivation of test case specification for conducting verification of Software Safety Requirements (SSRs) in a Hardware-in-the-Loop (HiL) testing environment under the context of ISO 26262 road vehicle functional safety standard. The proposed methodology consists of a two-stage logical workflow that is based on the analysis of safety mechanism instead of testing the SSRs one by one. By systematically determine the test objectives first, the workflow allows a more logical way to devise relevant test scenarios, which are executable in a HiL environment. One test scenario may cover one or more test objectives that in turn would satisfy the SSRs mapped to the safety mechanism in the first place. In addition, an application example based on a digitally controlled power inverter that drives the traction motor of a pure electric vehicle is also presented in this paper, in order to facilitate a better understanding of how the proposed workflow could be implemented to derive test cases in practice.