Real-time magnetic disturbance determination for micro air vehicles via gravity and global navigation satellite system measurements. (16th January 2019)

• Record Type: Journal Article
• Authors: Wu, Jin; Zhou, Zebo; Zhang, Xiaohui; Chen, Man; Shao, Pengyuan
• Is Part Of: Measurement science & technology. Volume 30:Number 2(2019:Feb.)
• Publication Date: 2019-01-16
• Subjects: micro air vehicle -- magnetometer calibration -- attitude estimation -- numerical methods; Physical measurements -- Periodicals; Scientific apparatus and instruments -- Periodicals; Equipment and Supplies -- Periodicals; Science -- instrumentation -- Periodicals; Technology -- instrumentation -- Periodicals; Mesures physiques -- Périodiques; Physical measurements; Scientific apparatus and instruments; Periodicals; 502.87
• DOI: 10.1088/1361-6501/aaf553
• Languages: English
• ISSNs: 0957-0233

Abstract

Abstract: In micro air vehicles (MAVs), a magnetometer is usually employed for heading estimation. However, in real flight campaigns the magnetometer can easily suffer interference from external magnetic disturbances. In this paper, a simple novel method is proposed to conduct real-time calibration of the magnetometer subject to external disturbances with the aid of gravity and global navigation satellite system measurements. First, two equalities are derived from the rigid-body rotation equations. Then, the closed-form solution to the pseudo magnetometer biases is derived according to these equalities. To enhance the robustness of the solver, an optimizer based on a gradient-descent algorithm is proposed. The bifurcation analysis and convexity proofs are given to show that the proposed optimization has a unique solution and no local optimum. The execution time analysis of the proposed method also indicates that it is a very fast algorithm. Finally, the calibration parameters are determined by algebraic equations formed by pseudo biases. The proposed method is attitude-free, simple and easy-to-implement. The experiments on a real-world fixed-wing MAV demonstrate that the method is effective.