Multimode multistate tracking joint positioning algorithm of the magnetic gradient tensor

At present, most of the magnetic gradient tensor positioning algorithms are isolated for a specific situation and specific conditions, and the applicability and practicability of the algorithm are not strong. This paper proposes the magnetic gradient tensor “multi-mode multi-state tracking” joint positioning algorithm, which contains three-seed positioning algorithm. The fusion switching strategy of subpositioning algorithm is designed and the formula of subpositioning algorithm is derived. Through simulation test and measurement test, we show that the relative error of the joint positioning algorithm is less than 8%, and the relative error is less than 34%. This method reduces the impact of the earth's magnetic field and the deficiency of the single algorithm, and provides theoretical support for the magnetic tensor positioning of the underwater vehicle.