Analysis of Interference Magnetic Field Characteristics of Underwater Gliders

Underwater gliders are a new type of unmanned underwater vehicle, characterized by high energy efficiency, long endurance, and low operational costs. They hold broad application prospects in fields such as ocean exploration, resource surveying, maritime surveillance, and military defense. This paper takes underwater gliders as the research subject, analyzing the characteristics of magnetic interference signals under different operational conditions. The study found that during full operational states, the motor’s operation generates interference signals at 17 Hz; during attitude adjustment, the movement of the moving block generates significant interference magnetic fields, especially during the forward and backward motion of the block, where interference signals at 20 Hz are particularly pronounced. To meet the objective of equipping underwater gliders with magnetic field sensors for underwater target detection, this paper proposes an adaptive filtering method based on the Recursive Least Squares (RLS) algorithm. The experimental results indicate that after filtering with the RLS algorithm, the amplitude of the noise signal has been reduced by over 60%, and it can effectively eliminate the noise components at 17 Hz and 20 Hz caused by the glider’s motor. This algorithm achieves an average increase in the signal-to-noise ratio (SNR) of 12 dB, which is equivalent to an approximately 80% improvement in accuracy. It significantly enhances the stability and signal-to-noise ratio of the magnetic field signals of underwater targets. This provides a feasible solution for equipping underwater gliders with magnetic field sensors for underwater target detection, holding important practical engineering significance.