Design And Validation Of Fault Diagnosis Algorithm For Hydrogen-oxygen Combustion Cycle Engine

Some key technologies involved in fault detection and diagnosis for a new generation of large thrust hydrogen-oxygen combustion cycle rocket engine were thoroughly investigated,analyzed and developed in this paper.The research works related to modularization fault simulation,real-time fault detection algorithm under main operation conditions,and semi-physical simulation.The research results could not only be directly applied to the design of the health monitoring system of the new generation of large thrust hydrogen-oxygen combustion cycle rocket engine,but also have great reference value for improving the safety and reliability of various space launches in the future.The main research contents of this paper include:Firstly,it was expensive and extreme danger to carry on the liquid rocket engine test,which leads to some problems such as the lack of fault sample date,the incomplete of diagnosis knowledge and the incomplete of fault pattern library.So modularized simulation models of faults were founded.Then established the simulation module of each engine component and set up a simulation module library of key parts of engine.On this basis,according to the composition structure and working process of the new generation of rocket engine,the fault simulation model of the engine was established.And fault simulation and result analysis were accomplished for the typical faults such as the prechamber oxygen valve opening failure,the cavitation in the hydrogen pump,and the ablation of the hydrogen turbine blade.The simulation results fit well with the design values and it can provide important fault feature data for the research.Secondly,due to the requirements of the timeliness,real-time performance and accuracy of the real-time fault detection algorithm in the main working process of the engine,an improved ARMA model fault detection algorithm for the main operating condition of the engine was proposed.The algorithm had been verified by a variety of typical fault simulation data,and the results showed that it can diagnosis a variety of typical faults in the main operating condition of the engine in a very timely and accurate manner,and the fault could be judged within a few hundred seconds after the occurrence of the fault,which was much faster than the traditional red line shutdown system.Finally,a fault diagnosis algorithm needed to be verify by the actual engine before it applied to the engineering,but it had some problems such as long cycle and high risk toconduct specialized physical verification.So hardware in the loop work of the fault diagnosis algorithm was carried out.The result showed that the designed fault diagnosis system fully meted the practical needs of engineering,and can process key parameters data,real-time online alarm and other functions,and has the ability of the real-time fault diagnosis.