Development Of Measurement And Control System For Ground Test Of High Thrust Turbofan Engine

In this thesis,the development of a large-scale measurement and control system for the ground test of a turbofan engine is described.Including the interpretation of the design task before the formal design work,the mastery of the basic discipline knowledge involved,the step-by-step design of each subsystem during the formal design work,and finally the integration of each subsystem to ensure the integrity,compatibility and stability of the whole system.The measurement and control system of engine ground test is used for engine manufacturing and performance verification test after overhaul.The whole system needs to complete the control of the whole engine,the control of supporting ground process equipment,and the real-time monitoring of the working status of the whole system.Therefore,the system design is mainly divided into two parts,the first is the control system design,the second is the data detection and analysis system design.The control system is divided into hardware construction and program design,and the data acquisition system is also divided into hardware construction and software design.The control system is mainly used to control the process of engine test,including the control of engine starting process,test state,hydraulic loading control,electrical loading control,process equipment control,etc.In this design,PLC and virtual instrument technology are combined to design the whole control system.Firstly,the field control signal and feedback signal are connected to the PLC hardware,and the logic control is carried out by writing the control program.Then the virtual control interface is developed by virtual instrument technology,and the control signals and feedback signals collected by PLC hardware are reflected on the virtual control interface.The design idea can greatly reduce the number of control hardware and the design difficulty of the system,and has good follow-up improvement ability.The data detection and analysis system is mainly used to collect,calculate and analyze the parameters of engine test run.Including electric signal,pressure signal,temperature signal,speed signal,angle signal,vibration signal,etc.In this design,VXI field bus acquisition system is used as the main measurement method and distributed scan valve measurement as the auxiliary method.A large number of scattered field signals are introduced into the test cabinet through the test cable,processed by the signal isolation and transformation module at the first level,and then the processed signals are sent to the VXI bus system.In the other part,the field signals with the same signal type(such as K-type thermocouple and gas pressure)are centralized collected by the integrated and miniaturized front-end acquisition device(scanning valve).Through the network configuration,the two parts of data are packed into the data acquisition software system for unified analysis and processing.In the development of the ground test and control system of XX type high thrust turbofan engine,the design work is carried out according to the above design ideas.