陀螺加速度计交叉二次项的线振动台测试方法

Measurement Method for Cross-quadratic Coefficient of PIGA on Linear Vibration Table

为了提高陀螺加速度计的标定精度,有必要对交叉二次项进行精确的标定。提出了一种陀螺加速度计交叉二次项在精密线振动台上的测试方法,通过分析陀螺加速度计的测试原理建立了包含交叉二次项的误差模型。利用分度头将陀螺加速度计翻滚到不同的位置,测量陀螺加速度计进动整周期的相关时间参数和输出数据。通过计算加速度计模型输出与平均角速率积分之间的关系,准确辨识出陀螺加速度计误差模型中的各误差项系数。该方法可以有效抑制陀螺加速度计的输出误差,提高标定的精度。最后通过仿真分析,验证了该方法可以准确辨识出陀螺加速度计的二次项、交叉二次项等高阶误差项系数,辨识精度达到了10^(-7),进一步提高了陀螺加速度计在线振动台上的标定精度。

In order to improve the calibration accuracy of PIGA（Pendulous Integrating Gyro Accelerometer）,accurately calibrating the cross-quadratic coefficient is necessary.A method of measuring cross-quadratic coefficient of PIGA on precision linear vibration table is proposed.By analyzing the mechanism of PIGA,the error model is established including cross-quadratic coefficient.The PIGA is tumbled to different positions by using indexing table,the output data and the concerned time data of PIGA precession within integer periods are measured,the error coefficients of PIGA＇s error model are accurately identified by the relationship between model outputs and the integral of average precession angular rates of PIGA.By this measurement method,the output error of PIGA is suppressed and the calibration accuracy is improved.The simulation results show that the method can accurately identify the cross-quadratic coefficient and other higher-order coefficients of PIGA,the accuracy of identification is greatly enhanced and reaches 10^（-7）.