On the Tip–Path-Plane Flapping Angles Estimation for Small–Scale Flybarless Helicopters at Near–Hover

  • Mohammad K. Al–SharmanEmail author
  • Mamoun F. Abdel–Hafez
Part of the Studies in Systems, Decision and Control book series (SSDC, volume 175)


Observing the Tip-path-plane (TPP) flapping motion is essential for characterizing the helicopter’s main rotor dynamics. The high-order harmonics of the rotor blade flapping periodic motion are considered the major sources of helicopter vibration. However, incorporating precise information of the flapping dynamics with the overall helicopter dynamic model describes better the main rotor motion. This enables designers to innovate blade designs that have less dynamic vibration. Moreover, the flapping states are crucial for analysing the main rotor axial force and moment components. However, obtaining measurements for the flapping states is not directly possible. This mandates researchers in the field to exclude the flapping dynamics, despite being essential, and use some algebraic expressions and numerical approximations instead. This chapter addresses the problem of designing a model-based estimation algorithm for the unobservable flapping angles while a near-hover flight is being carried out. A Kalman state estimation algorithm is designed to provide accurate flapping estimates for the Maxi Joker 3 flapping angles. The presented estimator has succeeded in obtaining accurate longitudinal and lateral flapping angles estimates with small root mean square error of estimation of 0.3770 and 0.2464, respectively. Besides several simulation tests, a real outdoor near-hover flight was performed to validate the proposed estimation method.


Small-scale helicopter Flapping angles estimation State estimation Near–hover dynamics 


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Copyright information

© Springer Nature Singapore Pte Ltd. 2019

Authors and Affiliations

  • Mohammad K. Al–Sharman
    • 1
    Email author
  • Mamoun F. Abdel–Hafez
    • 2
  1. 1.Department of Electrical and Computer EngineeringUniversity of WaterlooONCanada
  2. 2.Mechanical Engineering DepartmentAmerican University of SharjahSharjahUAE

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