Improved Iterative Calibration for Triaxial Accelerometers Based on the Optimal Observation

Sensors

Jie Yang¹  Wenqi Wu¹  Yuanxin Wu² 

[1] College of Mechanical Engineering and Automation, National University of Defense Technology, Changsha 410073, China;

关键词: triaxial accelerometers;    maximum likelihood estimation;    iterative calibration;    nonlinear;    optimization;   

DOI  :  10.3390/s120608157

来源: mdpi

【 摘 要 】

This paper presents an improved iterative nonlinear calibration method in the gravitational field for both low-grade and high-grade triaxial accelerometers. This calibration method assumes the probability density function of a Gaussian distribution for the raw outputs of triaxial accelerometers. A nonlinear criterion function is derived as the maximum likelihood estimation for the calibration parameters and inclination vectors, which is solved by the iterative estimation. First, the calibration parameters, including the scale factors, misalignments, biases and squared coefficients are estimated by the linear least squares method according to the multi-position raw outputs of triaxial accelerometers and the initial inclination vectors. Second, the sequence quadric program method is utilized to solve the nonlinear constrained optimization to update the inclination vectors according to the estimated calibration parameters and raw outputs of the triaxial accelerometers. The initial inclination vectors are supplied by normalizing raw outputs of triaxial accelerometers at different positions without any a priori knowledge. To overcome the imperfections of models, the optimal observation scheme is designed according to some maximum sensitivity principle. Simulation and experiments show good estimation accuracy for calibration parameters and inclination vectors.

【 授权许可】

CC BY   
© 2012 by the authors; licensee MDPI, Basel, Switzerland