Novel Interference Compensation Method of Balancing Precision and Stability for Unmanned Helicopter-Based Aeromagnetic Survey

Aeromagnetic unmanned helicopters generate more complex maneuvers during survey flights compared to the conventional manned and unmanned aerial vehicles (UAVs), thus causing stronger multicollinearity in the coefficient estimation for the magnetic interference compensation. This inevitably degrades both the precision and stability of aeromagnetic compensation. Because the existing aeromagnetic compensation methods can only degrade a single adverse effect, they are unsuitable for special unmanned helicopter-based aeromagnetic platforms. To address this issue, a novel method of balancing the compensation precision and stability is proposed in this article. A regularization term incorporating a dynamic weight matrix is first introduced to constrain the feasible solution space of interference compensation coefficients, thus improving the compensation precision. To ensure the stability of aeromagnetic compensation, a parameter optimization method for the regularization term based on the cross-validation-gray wolf optimizer is also proposed to adaptively determine the optimal parameters. A dedicated unmanned helicopter-based aeromagnetic platform and a compensator were built to validate the above method. The results from two flight experiments demonstrate improvement ratios of 14.3 and 9.3 for the proposed method, corresponding to 2.0 and 3.0 times higher than those of the state-of-the-art commercial compensator and 6.2 and 2.0 times higher than those of the principal component analysis (PCA), enabling superior compensation precision. Additionally, the fluctuation in standard deviations is only 16.7% of that of the commercial compensator and only 9.1% of that of the PCA, confirming enhanced compensation stability.