Gas Path Performance Estimation For Aeroengine Based On Fusion Filters

Gas path performance estimation plays an important role in aero engine health management.The gas path performance estimation based on fusion filtering methods are applied for the turbofan engine in this thesis.To break through the limitations of the traditional centralized Kalman filter such as poor fault tolerance and filtering performance,a distributed sensor configuration with feedback is considered.Then the distributed cubature information filter(CIF)is derived from the extended information filter(EIF)and the equivalence of this kind of distributed CIF and centralized CIF is mathematically proved.To improve the numerical stability,the square-root version of the distributed CIF is proposed.Simulation results show that the multi-sensor CIF with distributed structure with feedback has enhance performance in term of fault tolerance compared with the centralized CIF.To deal with the problem that the dimension of the master filter is not equal to that of local filters in the conventional federated information filter,an improved federated information filter is proposed by using analytic comprehension approach to achieve optimal state estimation.The sensor measurements and health parameters of aero engine are classified into two local filters and the proposed method is verified in the simulation results.Considering the gas path performance estimation problem for the non-uniformly sampling system,the centralized and distributed filtering methods based on EIF and CIF are developed for the asynchronous sensor fusion problem.The centralized EIF and CIF is introduced by applying the concept of using size-varying output vector.The distributed filtering algorithms based on EIF and CIF with and without feedback of are also developed in this thesis.In addition,the distributed multi-rate cubature information filter is proposed and compared with the sequential multi-rate cubature Kalman filter,which is considered as the traditional approach for sensor fusion.Finally,the proposed gas path performance estimation based on the centralized asynchronous cubature information filter are tested on the semi-physical simulation platform.The experiments on semi-physical hardware in loop simulation reveals the validity of the proposed filtering method.