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An improved multi-position calibration method for low cost micro-electro mechanical systems inertial measurement units

In this paper, the multi-position calibration method for low cost micro-electro mechanical systems inertial measurement unit (MEMS IMU) is significantly improved based on two principles. One is that the magnitude of the specific force should be equal to that of the gravity vector. Another is that the gravity vector should be equal to the computed gravity vector which is calculated with the gyroscope outputs. Thus, the error parameters of the MEMS IMU can be estimated without any equipment using the proposed method. Different from previous methods, this paper applied a Kalman filter to calibrate the gyroscopes. This makes the calibration method simple and convenient for the non-technical customers, as the calibration processes can be implemented only by hands. The validity of the method is verified by a real test with a set of low cost MEMS IMU, and the performance is compared with the traditional six-position and rate test methods. The results indicate that the proposed method is effective and efficient for it can be used to calibrate the low cost MEMS IMUs without any special equipment and significantly increase the measurement accuracy.