Helicopter Structural Life Modeling: Flight Regime and Gross Weight Estimation

Automatic regime detection for Rotor Track and Balance using vibration only sensor data

“…The alternative to this manoeuvre-driven, top-down view of regimes is a parameter-driven, bottom-up approach, where the regimes are determined purely through the combination and granularity of the parameters. In this way, some studies have identified lists of over 1,000 regimes for helicopter flight (1,6) which includes regimes such as climb, left pullout & left turn deceleration, though in this case the number of regimes is reduced to a mere 144 regimes for practical purposes by assimilating similar regimes (6) . Other studies set a more manageable limit of only 50 regimes, despite an OEM suggestion of 90 (7) , or use as few as 8 basic regimes as in Ref.…”

“…The large amount of variation in regimes means that the number of flight parameters can also vary considerably, with 40 (1) , 37 (including stick positions) (5) , 7 (6) , 22 (7) and 8 (8) parameters in a set as possibilities, although often not all the parameters are needed to identify all the regimes. In most of the literature reviewed, the parameters are not chosen using a truly systematic approach, with one exception where aero-mechanical equations are used to choose the most appropriate flight parameters for identifying a particular regime, as in Ref.…”

“…(10) uses a multilayer perceptron feedforward neural network with backpropagation algorithm, while Ref. (6) uses a more complex hierarchical set of 10 neural networks based on eleptic functions to classify a particular flight regime from flight parameter data, though the authors note that the number of networks can be reduced when considering only RTB regimes.…”