6-DOF Motion Platform-Based Dynamic Testing Method for the Sensitivities of Multiparameter Vibration Sensors

The multiparameter vibration sensors, which are composed of a multiaxial accelerometer and gyroscope, are widely used in pose estimation, vibration monitoring, and other engineering fields because of their ability to simultaneously measure the basic linear and angular motions. To ensure the performance of these engineering, it is necessary to test the sensitivities of these sensors regularly. However, the current dynamic testing methods for the sensitivities inevitably have problems such as high cost, low efficiency, and poor traceability, which are difficult to meet the practical requirements. In this study, a new 6-DOF motion platform-based dynamic testing method is investigated so as to improve the economy, efficiency, and traceability. This method converts the input spatial motion excitation of the sensors to 2-D planar motions of three laser spots by a physical dimensionality reduction way. Whereafter, the monocular vision method with subpixel accuracy is adopted to locate and track these spots, and the spot subpixel coordinates are converted into excitation displacements by the decoupling model to achieve the excitation measurement. Finally, the sensitivities can be calculated by using the relation between their outputs and the measured input excitation. The comparison experiments with the shaker- and turntable-based testing methods have been conducted, and their corresponding maximum relative deviations are about 1.5%, which confirmed that the investigated method can effectively and accurately determine the sensitivities. Additionally, the main error sources of the investigated method are analyzed to calculate the corresponding uncertainties.