A method for aircraft magnetic interference compensation based on small signal model and LMS algorithm

Abstract

Aeromagnetic interference could not be compensated effectively if the precision of parameters which are solved by the aircraft magnetic field model is low. In order to improve the compensation effect under this condition, a method based on small signal model and least mean square (LMS) algorithm is proposed. According to the method, the initial values of adaptive filter's weight vector are calculated with the solved model parameters through small signal model at first, then the small amount of direction cosine and its derivative are set as the input of the filter, and the small amount of the interference is set as the filter's expected vector. After that, the aircraft magnetic interference is compensated by LMS algorithm. Finally, the method is verified by simulation and experiment. The result shows that the compensation effect can be improved obviously by the LMS algorithm when original solved parameters have low precision. The method can further improve the compensation effect even if the solved parameters have high precision.

Application of an Improved Calibration Flight Scheme in Aeromagnetic Interference Compensation

“…The general aircraft aeromagnetic interference compensation model proposed by Tolles and Lawson has been gradually developed to the classical Tolles‐Lawson equation (Bickel, 1979a, 1979b; Leach, 1980; Tolles & Lawson, 1950). In order to solve it, Leliak (1961) proposed a method to calculate the aeromagnetic interference compensation coefficients based on the aircraft's pitch, roll, and yaw maneuvering flight actions, and it has been in use since then (Du et al., 2019; Feng et al., 2022; Fitzgerald & Perrin, 2015; Hardwick, 1996; Hezel, 2020; Qiao et al., 2021; Rice and Joseph, 1993; Zhou et al., 2014).…”

Unmanned Aerial Vehicles for Magnetic Surveys: A Review on Platform Selection and Interference Suppression

“…The issue of minimizing interference for traditional aeromagnetic surveys has been addressed thoroughly by developing compensation strategies both in hardware and in software [115][116][117][118][119]. A calibration flight is required to establish the relationship between aircraft maneuver and the corresponding changes of magnetic field base on the T-L model [120]. Generally, these calibration flights are executed in box patterns and at high altitudes (above 100 m AGL) where the change of magnetic field gradient can be ignored, a total of 3 pitch (±5 • ), 3 roll (±10 • ), and 3 yaw (±5 • ) maneuvers are sequentially executed in four orthogonal directions.…”