| Digital simulation is one of the essentials to develop aero-engine FADEC system with lower cost and shorter cycle.This dissertation built a full digital FADEC system simulation platform and carried out the corresponding key technology research.Research work includes the full digital FADEC system simulation platform framework,aero-engine component-level model,object-oriented FADEC system model,the fault injection module of simulation platform,the dual-channel switching algorithm of digital electronic engine controller.Firstly,according to the development requirement of aero-engine control system and the status of the digital simulation,both functional and technical requirement analysis for FADEC system simulation platform was carried out and the framework of simulation platform was designed.Based on TCP socket programming technology,a simulation platform framework was built by using C / S architecture to realize the function of remote connection in LAN.The multiuser connection function was realized by the client switching the connection between server and engine model.The client-side MFC interface was designed,and the effectiveness of remote connection in LAN and multiuser connection was verified.Secondly,the open source T-MATS JT9 D engine model of NASA was improved and expanded,the controlled object of simulation platform was established.Based on the exponential balance method,component characteristic data of the JT9 D engine provided by T-MATS was extrapolated to the low-speed domain,the modified JT9 D model can be run in the range of full package,the speed range of this model is 40%~100%.Finally,the Simulink Code Generation tool was used to translate the Simulink model to C++ model and the C++ model was integrated into the server of simulation platform.The simulation of the JT9 D model has proved that the steady-state error of the thrust is less than 2%,and its steady-state and dynamic characteristics are in line with the requirements for the controlled object.Moreover,based on object-oriented modeling method,a FADEC system simulation class library was developed on the client of simulation platform,and a generic FADEC system model was built based on the established FADEC system simulation class library.This section proposed the electronic controller function structure model for the first time,this model simulates the hardware structure and data processing of the electronic controller.Finally,the generic FADEC system model is verified by simulation in the simulation platform.The simulation results show that the generic FADEC system model,which is built with the FADEC system simulation class library,can be applied to the development,integration,testing and verification of the control logic and channel switching logic.In addition,FMEA and FTA analysis of the FADEC electronic components were carried out,the common faults of FADEC electronic components and their influences were determined.Based on the above analysis,fault injection module of simulation platform was designed to simulate the common faults of electronic components,which enables the design and validation of fault diagnosis logic and fault tolerant control algorithms in the simulation platform.Finally,the established full digital FADEC simulation platform was used for the research on channel switching algorithm of dual-channel electronic controller.A method to analyze the thrust sensitivity of the input parameters of the control system based on the back-stepping inverse model was proposed,and the channel switching logic of the dual-channel digital electronic controller was designed based on the thrust sensitivity of different parameters.The established generic FADEC system model was used for the verification of channel switching.The simulation results show that the electronic controller can switch channels according to the design requirements under different failures,and the system security is improved in theory. |
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