Research of Pipeline Robot Tracking & Localization Technology Based on ELF-EP Communication

The tracking and localization technology of pipeline crawling robot is indispensable in industrial engineering, such as pipe-wall inspection, obstacle avoidance, and pipeline maintenance etc. All these requirements are achieved based on communication between outside and inside of pipeline equipments. Generally speaking, high frequency electromagnetic wave is the preferred method, for its mature technique, such as GPS, RF etc. However, the closed environment of metal pipeline shields the propagation of electromagnetic wave. Though many kinds of ray have been successfully applied in pipeline inspection and localization, there are serious hazards to environment and biology. This paper presents a reliable communication method by applying extreme low frequency electromagnetic pulse (ELF-EP) to solve the shielding effect of metallic pipe wall. The propagation of ELF-EP is analyzed, and how emitting frequency affects the propagation distance is talked for low electric conductive medium and conductor, respectively. An effective localization method is presented by analyzing the distributing mechanism of ELF-EP along pipeline. Lots of experiments in Lab and industrial engineering have verified the applicability of this technique.