Research of pipeline robot tracing & localization technology based on ELF-EP communication

The tracing and localization technology of pipeline crawling robot is indispensable in industrial engineering application, 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 (ELFEP) which has advanced penetrating ability outside metal pipe-wall shielding. The propagation rule of ELF-EP is analyzed, and how frequency affects propagation distance is talked respectively through low electric conductive medium and conductor. 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.