Counting algorithms with phase sensitive detection for hover and S turn of aircraft flight

Abstract Hover and S turn of an aircraft can be characterized by flight yaw angle, but the yaw angle signal in actual fly parameters is not only non-stationary and non- ergodic, but also often appears violent mutations and weak fluctuations, which makes it difficult to work out service environment spectra related to the numbers of hovering and S-turning training times. This article develops intelligent counting algorithms for the numbers of hovers and S turns based on yaw angle data that from fly parameters. Using the median-crossing de redundant function of Phase Sensitive Detection (PSD) and analyzing the characteristics of 360° hovering fly parameters, a counting algorithm for the number of hovers during a flight profile is presented. Using the split-half function of PSD, a triangle layering algorithm about yaw angle signal is developed to count the number of S turns during a flight profile, where the signal of each sublayer is segmented into the median-crossing intervals so as to eliminate the redundant median-crossing marks from the previous layer. Compared with the artificial means, the counting results of flight example show that the intelligent algorithms presented are effective.