Analysis and Optimization Method of the Vibration Rectification Error of a Pendulous Accelerometer

The vibration rectification error (VRE) of a pendulous accelerometer is a common problem in engineering applications. It is generally accepted that the accelerometer nonlinearity is the main cause of the VRE, but the nonlinearity reduction is a complicated procedure and is difficult to achieve. In this study, by analyzing the input and output relationship of an accelerometer, the pendulum deflection is also shown to be an important cause of the VRE both theoretically and experimentally. First, in order to ensure that the accelerometer pendulum moves in the linear region, thereby reducing the VRE, a theoretical model of the pendulum deflection angle is established. Next, the factors affecting the pendulum deflection angle are analyzed, and the relationship between the correction network parameters and the pendulum deflection angle is calculated and simulated. To validate the proposed method further, a fixed-frequency vibration experiment is carried out. The pendulum deflection angle and the VRE are physically measured, and the obtained results are consistent with the simulated ones. Further, random vibration experiments simulating real environments are carried out. The results show that with decreasing pendulum deflection angle, the frequency corresponding to the maximum pendulum deflection angle increases, and the VRE decreases. In conclusion, the performed pendulum deflection angle simulation, pendulum deflection angle measurement, and VRE measurement for pendulous accelerometers have a strong correspondence and are easy-to-implement and accurate methods for VRE analysis. In addition, we believe that this procedure can be extended to the study of similar instruments with moving parts.