Static and Dynamic Calibration of 9-Axis IMU Using UKF with Low Cost Setup

MEMS based IMU sensors are very popular for its small size, low-cost and low power consumption. However, for accurate and precise data collection, proper calibration of IMU is compulsory. In this paper we have proposed a technique for both static and dynamic calibration of IMU sensor. We have developed a simple low-cost setup and used least square (LS) fit and ellipsoidal fit algorithm for static calibration and further incorporated Unscented Kalman filter (UKF) for dynamic calibration. The accelerometer is calibrated using 108 position data for three axis and gyroscope is calibrated using specially designed low-cost setup with LS algorithm whereas for magnetometer calibration, ellipsoidal fitting algorithm is used. Accordingly, all the calibration parameters like bias factor, scale factor and misalignment for accelerometer; bias factor, scale factor and non-orthogonality for gyroscope; Offset, gain and cross-gain for magnetometer are obtained. Moreover, for dynamic models like real-time or sensor fusion applications, the UKF (Unscented Kalman filter) based algorithm is proposed to obtain the calibration parameters dynamically.