Research On Pendulum Shock Calibration System For Accelerometer

As the world economy rapid developing and science and technology progressing, the accelerometer, which is an important measuring instrument for vibration and shock test device, is widely used in aerospace, nuclear industry, instruments and meters, marine vehicles and military and civil field. The sensitivity coefficient of the long-time used accelerometer usually has drifted, and according to the provisions of the state administration of quality supervision departments, the long-time used accelerometer should be calibrated once a year. However, the majority of the calibration device has a relatively complex structure and poor environmental adaptability, which isn’t adapted to the growing demand for calibration.The paper has researched the pendulum motion characteristics and impact sensor calibration technology. Using shock waveform control and multi-channel synchronous data acquisition technology, it designs a pendulum impact calibration system with strong practicability, convenient operation and conform system uncertainty requirements. On the basis of research on the accelerometer impact calibration technology, it puts forward the overall technical scheme of impact accelerometer calibration system, and determines technical scheme of the impact device and the calibration measurement system. After the research scheme is conformed, it carries on the preliminary design of the pendulum impact test machine according to the functional requirements. And then it does pendulum structure demension optimization design considering the pendulum shaft impact, lightweight design, pendulum gravity position distribution and the pendulum impact original velocity. In addition, the pendulum initial angle, buffer material linear recovery coefficient and nonlinear recovery coefficient’s effect on the shock wave have been analyzed through the buffer impact dynamics modeling and simulation. In terms of impact measurement system technology requirements, the paper refers to using DSP+FPGA to complete hardware and software design of the impact measurement device. In order to reduce two sensor output peak measurement error of the back-to-back comparison impact calibration, it analyzes the multi-channel synchronous data acquisition function. Finally, buffer impact test, the impact test repeatability, multi-channel sampling synchronization test and shock calibration test are carried on with the pendulum impact calibration system, analyzing the test date and uncertainty evaluation, the results show that the designed system meet the state standard GB/T20485.2008.