Research Of Aircraft Co-simulation Technology Based On FMI

With the development of simulation research objects from early simple mechanical engineering to complex aircraft systems nowadays,the coupling between the subsystems of the aircraft system and between the system and the external environment has become increasingly strong,and the interaction relationship has become more and more complex.The simulation model also evolved from the basic functional model and constraint model to the current spatial model and the multilevel abstract model.Therefore,how to stably integrate the simulation model with a complex aircraft system and perform highly efficient simulation testing has become one of the main research directions of aircraft system simulation technology.As some of the current mainstream simulation modeling integration specifications have certain compatibility issues,the aircraft system structure is complex.The design and R&D personnel from different subsystem vendors’ different specialties use the modeling software of their respective fields to conduct development modeling.The model format is not uniform and it is difficult to perform system-wide co-simulation.Based on this background and the requirements of aircraft co-simulation,this dissertation selects the Functional Mock-up Interface(FMI)standard,based on which the joint simulation technology of aircraft systems is studied.This dissertation first studies the typical aircraft system modeling method,extracts the characteristics of aircraft system modeling specifications,elicites the FMI standard,and interprets the FMI standard in detail.It designs the FMI simulation flow and uses this standard as the invoking protocol in the standard.Co-simulation platform interface specifications to encapsulate and integrate simulation models.Among them,the automatic generation method of Simulink model to FMU model is studied and implemented.Combined with the relevant project background,a distributed co-simulation platform framework was designed.Then the relationship between the input and output of the model is abstracted into a model topology with directed line segments under the complex model relationship,and the topological sorting algorithm is used to reduce the scheduling difficulty of the FMU model during aircraft system simulation.This paper analyzes the scheduling strategies for the interaction of various FMU models,and designs and implements a client simulation scheduling algorithm for the co-simulation platform.Finally,a static centralized scheduling strategy is proposed based on the distributed architecture.Based on the above research contents,the FMI-based aircraft co-simulation platform was designed and implemented.The UAS flight simulation test was used to test and verify the co-simulation platform.The analysis results showed that the technical specifications and method strategies used in this paper were obtained.The simulation algorithm can be well applied to the design of the co-simulation platform,which effectively guarantees the smooth running of the simulation test,and proves that the FMI-based aircraft co-simulation platform has good practicability and high efficiency.