为了解决MARTE(Modeling and Analysis of Real Time and Embedded systems)在建立嵌入式软件模型时不够精确的问题,结合Object-Z和PTA(Probabilistic Timed Automation)的优点,本文提出了一种集成的形式化建模方法——PTA-OZ.该方法不仅能够对嵌入式软件模型的静态语义和动态语义进行精确描述,而且通过模型转换规则,能够将MARTE模型转换为PTA-OZ模型.并对模型转换的语义一致性进行了验证,证明本文方法在转换过程能够保持结构语义和行为语义的一致性.最后通过实例模型描述从嵌入式软件建模到属性检验的过程.
In order to accurately describe the software require- ments and automatically extract property formulas, the time prop- erty of the live sequence chart （LSC） is focused. For the time- sensitive LSC （TLSC）, the formal syntax and semantic are defined by introducing the formal definitions of clock and timing constraints. The main function of the TLSC is to extract the temporal logic formula, so basic rules and combination rules are proposed to translate the TLSC into the universal fragment of computation tree logic （CTL） formula. To improve the efficiency of model check, transitivity is also used to optimize the formula. The optimization method could reduce the size of the formula under the condition of equivalence. Finally, a case study is introduced to illustrate how to establish the TLSC of requirements. In terms of the proposed transformation rules, the time property formula is extracted from the TLSC, and the design model is assured which is consistent with the property formula. The results show that the method with respect to the automatic extraction of the logic formula from the TLSC can efficiently monitor the time property of software systems.
