A Novel High-Precision Lightweight Mathematical Model of Underwater Active Electrosense and Its Application on Object Pose and Size Estimation

Weakly electric fish employ the self-established electric field to sense the cluttered and turbid underwater environment. Previous works on modeling underwater active electrosense have predominantly involved analytical models derived from the Rasnow model, as well as numerical models such as the finite element method (FEM) and the boundary element method (BEM). Both are hindered by poor precision and heavy computational burden, making them difficult to apply in real-world engineering. In this article, a high-precision and lightweight model excited by an electric dipole source was established for the first time. The simulation and experimental results validate the effectiveness of the proposed model and its superiority compared to the Rasnow model. A simplified slender robot equipped with active electrosense was made to estimate object pose and size with a purely model-based method. Despite some model simplifications and experimental errors, both the pose and size estimation achieved satisfactory results. This article offers promising perspectives on high-precision real-time processing for marine robots equipped with active electrosense.