振动整流法辨识加速度计非线性误差模型系数

Identification method of accelerometer nonlinear error model coefficients with vibration rectification

为了研究精确标定加速度计在线振动与高g的环境下的误差模型系数的方法。首先介绍了双轴离心机的特点。在反转平台上设计了双轴夹具,然后精确计算了加速度计3个轴的输入比力。经过主轴和反转平台轴正反角位置静态实验,以及主轴与反转平台轴以等值反方向的匀角速率旋转的动态实验,通过振动整流法,并补偿掉静态均值,精确辨识了加速度计的误差模型系数。依据仿真结果可得:该实验方法能够抑制离心机误差对标定精度的影响,其中反转平台的静动态失准角对标定影响最大,应该提高离心机静动态失准角的测试精度,并加以补偿。

In order to study the methods of calibrating the accelerometer error model coefficients accurately under linear vibration and high g composite environment, the characteristics of the dual-axis centrifuge are described at first. A dual-axis fixture was designed and fixed on the counter-rotating platform. And the input specific forces of the three axes of the accelerometer were calculated accurately. Then, the static test was performed,in which the spindle axis rotates to equal-spaced angular position and the axis of the counter-rotating platform rotates reversely to corresponding equal position. The average value of the static test was compensated with vibration rectification method. The dynamic test was performed, in which the spindle axis rotates with constant angular rate and the counter-rotating platform axis rotates in the opposite direction with the same angular rate;then the aecelerometer error model coefficients were identified accurately. The test simulation results show that the influence of the cen- trifuge error on calibration accuracy is suppressed greatly using this test method;and the influence of static and dynamic misalignment angles of the counter-rotating platform on the calibration accuracy is quite large and can not be ignored. The measurement accuracy of the centrifuge static and dynamic misalignment angles should be improved and compensated.