Wireless tracking and locating system for in-pipe robot

This work focuses on a wireless tracking and locating system for the in-pipe robot, including an electromagnetic emitter and a magnetic sensor array. Based on the extreme low frequency electromagnetic pulse, signal transmitting is realized between inside and outside of metallic pipeline. The electromagnetic field in underground pipeline environment is modeling. By simulation, the influences of environmental geometric size, electromagnetic parameters, and emitting frequency on the signal intensity outside the pipeline are studied. In order to reduce the imitation error between the emitting coil and the equivalent magnetic dipole, optimum design of the coil structure is presented. Tracking and locating of the in-pipe robot is realized by applying the equivalent magnetic dipole model and the inverse calculation of the magnetic field. At last, the presented tracking and locating method is verified by field tests, with average errors less than 20 cm in location and 6° in orientation.