An Underwater Robot Positioning Method Based on EM-ELF Signals

Abstract

In view of the limited positioning of underwater robots using GPS and high-frequency radio waves, extremely low frequency electromagnetic (EM-ELF) signals are effective ways to solve the positioning accuracy of underwater robots due to their strong penetrating power, low loss and low interference. Based on the localization method, first proposed by Sheinker et al. [1], and combined with the excellent characteristics of firefly algorithm, this paper proposes an underwater robot positioning method based on ultra-low frequency electromagnetic signals. The method in this paper has the following advantages: (1) It compensates for the problem that the accuracy is reduced in a short time when the electromagnetic signal is used for positioning, and the robustness of the positioning is improved; (2) Under the condition of not using the geophysical reference map, it can realize the autonomous positioning of the underwater robot all day, and improve the accuracy of the positioning system; (3) It has strong anti-interference ability and is suitable for underwater robot navigation under weak illumination and time-varying interference environment. The experimental results also show that the method has small positioning error and can accurately locate the underwater robot.