Underwater source localization using a distributed composite artificial lateral line system with pressure and active electric sensing fusion

Learning about the lateral lines of fish for perceiving their surroundings, various artificial lateral line systems have been developed for underwater vehicles. However, previous studies of artificial lateral line systems for underwater source localization have only relied on single sensing of hydrodynamic or electric modality. Inspired by the functions of mechanoreceptors and electroreceptors in fish, we first developed a distributed composite artificial lateral line system integrating pressure and electric sensors. Then, a novel method was proposed for underwater source fusion localization based on maximum a posteriori probability by combining the sensor noise prior with the likelihood obtained from measurements. Finally, we conducted tank experiments to evaluate the effectiveness of dual-modality sensing fusion for localization. The work found that dual-modality fusion resulted in smaller and more concentrated localization errors compared to pressure or electric sensing. In three-dimensional space, the mean relative localization error based on the dual-modality fusion was approximately 11.2% when considering a source located within 1.4 body lengths of the artificial lateral line. Furthermore, we studied the effect of sensor type and quantity on localization accuracy using LASSO analysis. The relationship between source localization performance and distance was established. Additionally, the proposed method was applied to a dynamic scenario and exhibited excellent tracking performance on a target. The experimental results show that dual-modality sensing fusion is beneficial in improving the underwater source localization performance of the artificial lateral line system.