Research On Test Technologies Of Embedded Software Used For Safety-related System

Safety is an intrinsic property which is indispensable for products. In modern society, it becomes more and more frequent for the use of escalators. The classical escalator performed safety functions through its main control system when danger or risks occured. In order to further improve the reliability and safety of escalator in functional safety, the latest national standard about escalator requires that escalator safety detection function should be separated from its main control system. On the basis of the software life cycle phase for the software of escalator programmable electronic safety-related systems, this paper carries out the corresponding verification work to insure that the software products meet the required safety integrity level. Since the programmable electronic safety-related systems is applied to escalator, the study fulfills the requirements of the latest national standard, and improves the security and reliability of escalator, which is practical and exploratory to some extent.Since the object of verification is the software of programmable electronic safety related systems, this article refers to the international functional safety standard, starts with the software validation model of its security system, and selects the relevant technical measures for the software verification. With the use of embedded software testing tools, the study carries out the customization and inspection of coding rules for software, the multiple analysis of software complexity and static data flow, the analysis of software quality report and diagram, which makes the verification work more rigorous. It also provides some modification of software about every quality indexes. Moreover, the paper researches coverage testing indicators of the software units in the dynamic test phase, and studies the design of the least amount of test cases, which improves the efficiency of the dynamic testing. Through the verification of datas from the process of test, the software dynamic testing meets the expected effect, and reaches the requirements of coverage indicators in relevant safety integrity level of the software.