Research And Application Of Model-driven Software Development Method For Civil Aircraft Display System

The avionics system is a complex system that includes cockpit displays,flight management,communications and navigation functions.At present,domestic civil display system software development uses code and document as the center of the traditional software development methods in the actual project.Manual coding and verification workload,high cost for requirement changes make it difficult to meet DO-178 B airworthiness requirements.The model-driven software development method in modern software engineering has become the mainstream method in the development of airborne software abroad.However,the domestic use of model-driven method in civil aircraft display system software development is still blank.How to put forward and implement a set of model-driven software that can meet the requirements of Airworthiness Review Level A target in the domestic civil aircraft display system software development methods,is of great significance.Regarding the issue above,based on the practical project of a large-scale civil aircraft display system,this paper puts forward an agile,supporting DO-178 B standard and model-driven software development method for civil aircraft display system(MDSDM).The tools of DOORS and SCADE,etc.,are used to implement the requirement analysis,architecture design,model design,code generation,software integration and verification during the software life cycle of the display system.This paper takes the two typical display system software development of the engine parameter display(EI)and the schematic diagram(Synoptic)as an example,to illustrate the concrete realization of the method and verify the feasibility and effectiveness of the method.The main works of this paper are as follows:1)In the requirement process,MDSDM analyzes the system requirements and the development of high-level requirements,through the SCADE Display tool to establish a visual display model,and timely communication with the user to confirm.A user-confirmed visual display model can be reused in the software design process.The implementation of the EI example shows a 52% reduction in the rate of change in requirements,a 33% reduction in requirement validation time,and a reduction in requirement development time.2)During the design and implementation,MDSDM uses UML to establish the physical architecture of the display system diagram,the system overview of the cross-linking diagram and functional level diagram.Then,the SCADE tool is used to build the architecture model,logical model and detailed display model of each function module,based on the logical model and the display model for joint simulation to find design errors.Automatically generating code based on the SACDE model described above,SCADE tools are used to establish requirement-model-code traceability relationship.According to the static analysis of project implementation of Synoptic example,the development speed of the project is improved by about 34%,the defect rate of the thousand lines of code is reduced by about 65%,which obviously improves the development efficiency.3)In the process of software integration,MDSDM presents an automated continuous integration process that is suitable for large-scale multi-team display system software development,and designs and implements a continuous integration environment to support the above process.This environment includes development libraries based on the SVN tools,compilation libraries and controlled libraries,Bamboo-based continuous integration server,and JIRA-based integrated problem management tools.Compared to traditional integration,the application shows that software integration is 40 times faster,the integration success rate is 25% higher and release time is 1/3 shorter..4)The software verification includes software requirement test,software design test,software integration test and verification.The main difference between MDSDM method and traditional method lies in software design test and integration test.This paper uses QTE of SCADE tool to implement the model-based function test,and MTC module of SCADE tool to implement the functional model coverage analysis.The applications show a 10-fold reduction in design testing,a 23% reduction in structural or model coverage analysis,and a reduction of more than one-third of the validation effort and cost.