State and Force Estimation on a Rotating Helicopter Blade through a Kalman-Based Approach

Abstract

The interaction between the rotating blades and the external fluid in non-axial flow conditions is the main source of vibratory loads on the main rotor of helicopters. The knowledge or prediction of the produced aerodynamic loads and of the dynamic behavior of the components could represent an advantage in preventing failures of the entire rotorcraft. Some techniques have been explored in the literature, but in this field of application, high accuracy can be reached if a large amount of sensor data and/or a high-fidelity numerical model is available. This paper applies the Kalman filtering technique to rotor load estimation. The nature of the filter allows the usage of a minimum set of sensors. The compensation of a low-fidelity model is also possible by accounting for sensors and model uncertainties. The efficiency of the filter for state and load estimation on a rotating blade is tested in this contribution, considering two different sources of uncertainties on a coupled multibody-aerodynamic model. Numerical results show an accurate state reconstruction with respect to the selected sensor layout. The aerodynamic loads are accurately evaluated in post-processing.

Unwanted Supplementary Vibrations of Helicopter Radio Communication Systems

“…The force rotating in the plane of rotation of the helicopter blades causes bending vibrations of the fuselage in the vertical plane and bending-torsional, i.e., transverse vibrations, in which the helicopter fuselage bends in the horizontal plane and twists around its longitudinal axis. These forces act on the antenna's moment attachment and other helicopter systems attached to the fuselage [2][3][4][5][13][14][15][16].…”

“…Any movement, i.e., a manifestation of force, desirable or undesirable, has a significant effect on the structural elements of a helicopter, including the antenna elements [1]. It is, therefore, necessary to examine the given area and describe it in detail, as the problem of corrective instability of helicopter flight is caused by the influence of the forces accompanying the flight [2][3][4]. These forces can have both a positive and a negative effect, and the helicopter is affected by them-ideally within the limits set for operational safety and the purpose of use [5].…”

Adaptive-Neuro-Fuzzy-Based Information Fusion for the Attitude Prediction of TBMs

“…The Kalman filter [ 24 , 25 , 26 , 27 ] is one of the most widely used methods because of its simplicity and effectiveness. A Kalman-based approach [ 27 ] could be used to estimate the state and force of a rotating helicopter blade. There are many methods used to improve the performance of the basic Kalman filter.…”