Nonlinear Scalar Calibration Method of Three-Axis TMR Sensor Based on Assembly Process

With the increasing demand for magnetic field vector acquisition in both military and civilian fields, the development of three-axis magnetic sensors with high orthogonality is of great significance. Compared with other types of magnetic sensors, three-axis magnetic sensors based on the tunnel magnetoresistance (TMR) effect have advantages such as high sensitivity, low noise, small size, low power consumption, and a wide frequency range. However, problems such as non-orthogonality, zero bias, and inconsistent scale factors seriously limit the accuracy of their magnetic measurements. This paper proposes a novel assembled TMR sensor design and, in response to its error generation mechanism, presents a calibration method with a significant error suppression effect, achieving a suppression rate of 99.6%. At the same time, on the basis of the sensor’s already excellent indicators, the performance of the three-axis TMR sensor in measuring vector magnetic fields has been improved.