107 / 2021-07-23 20:21:30

Fault diagnosis of aero-engine under variable working condition based on improved Viterbi algorithm

Fault diagnosis of aero-engine under variable speed is a very challenging task, and the tacholess order tracking (TLOT) method is a feasible solution. However, the traditional TLOT method still has the problems of high computation complexity and low adaptability. Aiming at these problems, a new adaptive instantaneous angular speed (IAS) estimation method based on the improved Viterbi algorithm (VA) is developed. Meanwhile, aiming at the problems that the traditional VA cannot process the long time series and find the fundamental order automatically, an improved penalty function for ridge search is proposed. And the search band of IAS is adaptively optimized to speed up the ridge search. The experimental results show that the proposed method has satisfactory accuracy in IAS estimation, particularly it has less computation time, higher adaptability and fault diagnosis accuracy than the existing well-known methods.