Reference Accelerometers Compensation Method for Calibrating the Odd-Quadratic Coefficient of PIGA in Centrifuge

Accurate calibration of the intrinsic odd-quadratic coefficient of pendulous integrating gyroscopic accelerometer (PIGA) is of significant importance in high-overload applications. In order to eliminate the interference introduced by instrumentation errors in centrifuge during the process of calibrating PIGA, a calibration method based on compensation with the reference accelerometers is devised. First, the error mechanism of extrinsic odd-quadratic terms, represented by dynamic imbalance of centrifuge, is analyzed and experimentally verified. Subsequently, a multiposture calibration method for quartz accelerometers (QAs) is designed to identify second-order coefficients of QAs in preparation for the calibration of PIGA. The QAs are then employed as reference accelerometers to compensate for outputs of PIGA, and to identify the intrinsic odd-quadratic and the second-order coefficients of PIGA. Finally, the method undergoes accuracy evaluation and simulation. The results show that the calibration accuracy for two coefficients reaches the magnitude of 10−7 rad/s/g2.