行人导航系统中的MEMS误差在线修正技术

MEMS Error Online Correction Technology in Pedestrian Navigation System

关键词:  在线修正  逆向解算  主航向反馈修正  扩展卡尔曼滤波

Key words:  Online correction  Inverse solution algorithm  Heading feedback correction  Extended Kalman filter

摘要:

在基于微惯性器件的行人导航系统中，陀螺仪和加速度计的偏移是降低系统定位精度的重要因素。传统的标定方法大多在实验室中进行，后续导航解算都是基于标定后的固定模型，然而MEMS器件长时间工作后，标定模型参数发生变化会导致系统导航性能下降。通过分析行人导航系统及MEMS器件的特点，提出了一种基于误差模型的MEMS器件参数在线修正方法。根据行人行走的特点，检测并区分行走过程中的可修正区间与不修正区间。在可修正区间基于逆向解算算法实现了对陀螺仪和加速度计零偏的在线修正，并提出了主航向反馈修正算法，提高了行人导航系统长时间导航性能。实验结果表明，40m行走实验中，系统定位精度提升了9.07%；300m行走实验中，系统定位精度提升了13.14%。

Abstract:

In the MEMS inertial devices based pedestrian navigation systems, the bias of the gyroscope and accelerometer is an important factor to reduce the positioning accuracy. Most of the traditional calibration methods are implemented in the laboratory, and then the fixed model after calibration will be used. However, due to the long-time running of the MEMS inertial devices, the change of calibration model parameters will lead to the degradation of system navigation performance. Based on the analysis of the characteristics of the pedestrian navigation system and MEMS inertial devices, an online correction method for MEMS device parameters is proposed based on the error model. According to the characteristics of pedestrian walking, the correctable intervals are detected and distinguished from other intervals during the walking process. In the correctable intervals, the online correction of the MEMS inertial devices bias is realized based on the inverse solution algorithm, which improves system positioning performance. The experiment results show that the system positioning accuracy is increased by 9.07% in the 40m walking experiment and 13.14% in the 300m walking experiment.