A broad-band and low-distortion excitation generation method for low-frequency angular vibration calibration

The angular vibration sensors must be calibrated regularly to ensure the precise measurement of dynamic angle motion in various engineering applications such as attitude estimation, inertial navigation, and machine automation. Currently, the high-accuracy vibration calibration has been developed in the medium and highfrequency range. However, it is difficult to accomplish such calibration over a wide low-frequency band because the current angular exciter cannot generate the high-dynamic and low-distortion excitation acceleration for the sensors. Aiming at this problem, a complementary filter-based data fusion control method is proposed and successfully applied to an exciter for achieving high-precision calibration in a wide low-frequency range. The results demonstrate that the proposed method has the ability to generate high-dynamic and low-distortion excitation accelerations in the range of 0.01 Hz-150 Hz. The maximum total harmonic distortion of these excitations measured by the commonly used laser interferometry and circular grating ruler method is 0.80 % and 0.42 %, respectively. In addition, the corresponding maximum relative standard deviation is 0.039 % and 0.005 %. The experiment results show that the proposed method can well meet the high-accuracy calibration requirements.