Calibration of a MEMS inertial measurement unit

Abstract

Abstract: An approach for calibrating a low-cost IMU is studied, requiring no mechanical platform for the accelerometer calibration and only a simple rotating table for the gyro calibration. The proposed calibration methods utilize the fact that ideally the norm of the measured output of the accelerometer and gyro cluster are equal to the magnitude of applied force and rotational velocity, respectively. This fact, together with model of the sensors is used to construct a cost function, which is minimized with respect to the unknown model parameters using Newton’s method. The performance of the calibration algorithm is compared with the Cramér-Rao bound for the case when a mechanical platform is used to rotate the IMU into different precisely controlled orientations. Simulation results shows that the mean square error of the estimated sensor model parameters reaches the Cramér-Rao bound within 8 dB, and thus the proposed method may be acceptable for a wide range of low-cost applications. Keyword: Inertial measurement unit, MEMS sensors, Calibration. 1.