A model-based and efficient parameters correction method for low-cost MEMS IMU

Abstract

With the wide use of intelligent mobile terminals, inertial measurement unit (IMU) made by micro-electromechanical system (MEMS) has become an important part of their positioning systems. MEMS IMU has advantages of low cost, low power consumption and small size. However, the scale factor error, nonorthogonality error, and bias affect the measurement accuracy of MEMS IMU. In this paper, the output data of MEMS IMU at the six-position were analysed and modelled. A parameter correction method based on the model was proposed for obtaining more accurate scale factor, nonorthogonality parameters and bias. The proposed method has low-cost and the obtained parameters’ accuracy are consistency. Ten groups of two MEMS IMUs parameter correction experiments show that the parameters obtained by the proposed method have small fluctuation and high consistency. The navigation test shows that the navigation errors of the corrected data of one MEMS IMU reduce to 15.2 %, 9.3 % and 5.1 % in the east, north and up directions compared with the position errors of the original data, which proves the effectiveness of the proposed method.