Research On Localization Technique Of Pipeline Detecting Based On Even Low Frequency Electromagnetic Wave

In the applications of pipeline conveyance,the pipeline robot takes more important role in pipeline project,especially when the nondestructive detection technique has a real application in pipeline industry.The localization of pipeline robot is a key technology which decides the application of robot in pipeline.Although the wired robot solution is now the main stream,its shortcomings,such as cable weight and signal attenuation,greatly limit its working distance.The normal electromagnetic technology can not be used in the pipeline robot localization for the steel shield.So the robot localization without cable is one of the key technologies to improve the system performance and application level,this thesis presents a solution to mobile robot localization by using extreme low frequency (ELF) electromagnetic wave.The existed localization technology's merit and faults are analyzed As the ELF electromagnetic wave has the characteristics of penetrating different media,such as metal, soil,water,and sludge,the thesis studies an ELF electromagnetic wave-based localization method.Using analysis method of magnetostatic field and Maxwell's electromagnetic theory, this thesis studies the ELF electromagnetic wave(23Hz) penetrability and builds the ELF magnetic dipole transmission model,which describes the physics performance of EFL electromagnetic wave transmission and simplifies the application,magnetic dipole's academic calculation and the experiment results show that transmitting antenna magnetic field space magnetic induction strength amplitude has the law of symmetrical,double hump-shape distributing with the position changing.For the tracking and localization of pipeline robot,be based on the theory of magnetic dipole model,in practice fixing transmission equipment of EFL electromagnetic wave on pipeline robot,receiving equipment can receive the signal thought antenna.The signal be processed then enter the singlechip control system.GPS timing module and compass module are applied to note the position information and exact time of geomagnetism signal turnover,GPRS module is utilized to send or receive message.The results provide a solution for localization of pipeline mobile robot.