基于限定自然语言需求模板的AADL模型生成方法

随着嵌入式软件系统在汽车、核工业、航空、航天等安全关键领域的广泛应用，其失效将会导致财产的损失、环境的破坏甚至人员的伤亡，使得保障软件安全性成为系统开发过程中的重要部分.传统的安全性分析方法主要应用在软件的需求分析阶段和设计阶段，然而需求与设计之间的鸿沟却一直是软件工程领域的一大难题.正是由于这一鸿沟的存在，使得需求分析阶段的安全性分析结果难以完整详尽地反映在软件设计中，其根本原因是当前的软件需求主要通过自然语言描述，存在二义性与模糊性，且难以进行自动化处理.为了解决这一问题，本文面向构件化嵌入式软件，首先提出了一种半结构化的限定自然语言需求模板用于需求规约，能够有效降低自然语言需求的二义性与模糊性.然后，为了降低自动化处理的复杂性，采用需求抽象语法图作为中间模型实现基于限定自然语言需求模板规约的软件需求与AADL模型之间的转换，并在此过程中自动记录两者之间的可追踪关系.最后，基于AADL开源工具OSATE对本文所提方法进行了插件实现，并通过航天器导航、制导与控制系统（Guidance，Navigation andControl，GNC）进行了实例性验证.

Approach for Generating AADL Model Based on Restricted Natural Language Requirement Template

As embedded software systems are ubiquitous in our daily lives, such as automotive, energy industries and aerospace. Failures of these systems will cause pollution of environment, property losses and even casualties. As a result, safety analyses have been critical for developing these systems. The traditional safety analysis method is mainly used in the software requirement analysis stage and the design stage, the traditional safety analysis method is mainly used in the software requirement analysis stage and the design stage. However, the gap between requirement and design is a challenge in software engineering area, due to that gap, it is difficult to transmit and reflect the analysis result of the requirement analysis stage into software designing. The primary reason is that the current software requirement is mainly described in natural language, in which there is ambiguity and fuzziness, and that makes it difficult to be automated processed. For purpose of solve this problem, this paper faced on componential embedded software and proposes a set of requirement template based on restricted natural language, which can reduce the ambiguity and fuzziness of natural language requirements. Then, to decrease the complexity of automated processing, we took requirement abstract syntax diagrams as the Intermediate model to realize the transition between software requirement specified by restricted natural language template and AADL model, and automatically record the traceability relations between them. Finally, we develope a tool for the method proposed above based on the AADL open source tool OSATE, and carry out an example validation through the spacecraft guidance, navigation and control system (Guidance, Navigation and Control, GNC).