Optimization of Pig Positioning Method Based on Uniaxial Magnetoresistive Sensor

Abstract

Uniaxial magnetoresistive sensors based on the HMC1001 can realize acquisition, processing, and display of magnetic signals, with measurement error controlled to within 1 %, basically satisfying application requirements for positioning of the pig labeled with magnets. Given that the HMC1001 sensor has only one sensitive axis, to ensure real-time detection of the maximum magnetic fluctuation when the pig passes, according to the one-dimensional coordinate classical positioning method for uniaxial magnetic sensors, the horizontal east–west direction pipeline is first modeled, and the magnetic fluctuations in the horizontal and vertical directions are calculated. The results show that fluctuations in the vertical direction were slightly larger than those in the horizontal. For other angles between horizontal and vertical, the angle variable is introduced, and the comparison reveals that the magnetic fluctuation curve smoothly transitions from horizontal to vertical. The optimal detection attitude of the pipeline in any direction is then simulated by using the same method, revealing that the vertical magnetic value is the largest. Finally, related equivalent experiments are conducted, and the experimental curves are basically consistent with the simulations. Therefore, it can be concluded that the HMC1001 sensor should be installed perpendicular to the pipeline for optimal detection when positioning the pig.