A Simple and Fast Method for Field Calibration of Triaxial Gyroscope by Using Accelerometer

Using field calibration methods without precision laboratory equipment, systematic faults of inertial sensors can be reduced and measurement accuracy can be increased. In this paper, a simple and fast method called improved least squares is used to find calibration coefficients of an accelerometer including bias, scale factor and non-orthogonality. Simulation results show that the measurement accuracy has improved by about 60%. In this method, this principal is used that the magnitude of acceleration measured by accelerometer in static condition is equal to the magnitude of gravity vector and a cost function is then defined.  Also, in gyroscope field calibration, sensor is rotated manually around all three axes separately and then it is put in the static mode. Changes in the angle obtained from gyroscope at each movement are compared with the ones obtained from the calibrated accelerometer. Calibration coefficients including bias and scale factor are obtained using least squares method. Simulation results show that accuracy of the gyroscope has increased by about 40% and comparison with the other methods proves that the proposed method performs well.

Keywords:

Accelerometer , Gyroscope , Bias , Scale factor , Non-orthogonality