Research And Implementation Of Safety＿SysML/VRM/Stateflow Tool Chain For Avionics System

Avionics system is a safety critical system demanding quality.Avionics software is the core of avionics system.With the development of avionics system towards integration and systematization,the proportion of safety functions undertaken by software is increasing.Compared with the previous simple modules,how to ensure the security of large-scale and highly complex avionics software has become the primary challenge that relevant avionics software research and development organizations must face.Practice and statistics show that in safety-critical software,most safetyrelated problems are rooted in requirements.Formal verification of requirements is currently recognized as a highly reliable method to ensure the quality of requirements.In order to support the diversity of avionics requirements and improve the flexibility and efficiency of development,avionics software usually adopts multiple development methods during research and development.Safety＿SysML is a formal modeling language for the requirements of avionics software system built by object-oriented thinking to solve the unsolved requirements formal modeling and verification problems in model-driven avionics software construction.The table-based variable relationship model VRM is a process-oriented formal modeling language.This modeling language describes the requirements of avionics software system in the form of tables,and describes the dynamic behavior of the system through state variables and behavior functions,so that the model has the characteristics of a state machine.Stateflow is a visual requirement modeling tool in Simulink,also known as state flow model;It is mainly used to describe the logic relationship of complex avionics system.In combination with other functions of Simulink,the stateflow model can be simulated to verify the correctness of complex avionics system requirements.In order to uniformly verify the demand models constructed by different methodologies and support the construction and application of the whole process tool chain for avionics software development,this paper designs and implements a set of model transformation tool chain,including Safety＿SysML2 VRM and SysML2Stateflow: Safety＿SysML state machine model is transformed into VRM model and Stateflow model.The main contributions of this paper include:1)Propose a safety＿SysML model to VRM/Stateflow model.Design Safety＿SysML model information extraction method and model structure information processing and analysis algorithm.Take advantage of Safety＿SysML model transformation method reconstructs the model components and converts them to the target model;2)Put forward the semantic equivalence transformation rules from Safety＿SysML model to variable relationship model(VRM)/Stateflow model,covering the static structure model and dynamic behavior model of requirements,and define Safety＿SysML model to variable relationship model(VRM)/Stateflow model conversion function;3)Design and implement Safety＿SysML2VRM/Safety＿SysML2 Stateflow model transformation tool;The conversion tool has the function of Safety＿SysML model element extraction,dynamic processing monitoring,model transformation and other functions can automatically generate structured data files conforming to variable relationship model(VRM)/stateflow model through graphical operation instructions;Finally,in order to demonstrate the effectiveness of the model transformation tool,this paper combines the flight stage display and control system and the aircraft landing gear warning system to illustrate safety＿SysML2 VRM and Safety＿SysML2 Stateflow model transformation tool in the field of avionics system.