Magnetometer zero offset calibration method

• Main Authors: PAN XIONG, YANG YANQIANG, ZHOU ZHE, ZHANG CHUNXI, DAI MINPENG, ZHU YI
• Format: Patent
• Language: Chinese; English
• Published: 01.02.2022
• Subjects: GYROSCOPIC INSTRUMENTS; MEASURING; MEASURING DISTANCES, LEVELS OR BEARINGS; NAVIGATION; PHOTOGRAMMETRY OR VIDEOGRAMMETRY; PHYSICS; SURVEYING; TESTING

The invention discloses a magnetometer zero offset calibration method. The method comprises the following steps: before a drill string rotates, collecting initial data of a three-axis gyroscope, a three-axis accelerometer and a three-axis magnetometer; when the drill string rotates at a constant speed, collecting real-time output data of the three-axis magnetometer; calculating the initial attitude of the underground measurement system according to the initial data of the three-axis gyroscope, the three-axis accelerometer and the three-axis magnetometer; and calibrating the zero offset of the magnetometer through the initial attitude and the real-time output when the three-axis magnetometer rotates at a constant speed. According to the invention, the mathematical relationship between the zero offset of the magnetometer and the output of the magnetometer during underground rotation measurement is analyzed in detail, and the method for calibrating the zero offset of the magnetometer while drilling under single-