重力场26位置法的PIGA标定误差分析

Analysis of calibration error of PIGA based on twenty-six-position method in gravity field

关键词:  摆式积分陀螺加速度计  分度头  误差模型  角位置误差

Key words:  Pendulous integrated gyroscopic accelerometer (PIGA)  Indexing table  Error model  Angular position error

摘要:

为了提高摆式积分陀螺加速度计（PIGA）在重力场下的标定精度，针对PIGA在分度头上标定的26位置法进行了误差分析。首先，根据分度头的结构与PIGA的测试原理，建立了全误差标定模型，发现分度头旋转轴系的角位置误差一次谐波的正弦项对标定具有较大影响。若事先检定出分度头的角位置误差，再采用分度头标定26位置法辨识模型中的各误差项系数，并补偿其中的角位置误差一次谐波的正弦项，即可得到较高精度的PIGA误差系数。最终通过仿真分析，对比说明了分度头角位置误差对PIGA系数标定精度的影响，验证了该方案可以准确辨识出PIGA误差系数，且辨识精度达到了10-8。此外，还研究了在PIGA误差模型中加入高阶误差项对其零偏与标度因数标定测试的影响。

Abstract:

To improve the calibration accuracy of the pendulous integrated gyroscopic accelerometer (PIGA) in gravity field applications, this study analyzes the errors involved in calibrating the PIGA on an indexing table using the twenty-six-position method. First, an integrated error calibration model is established based on the structural characteristics of the indexing table and the operational principles of PIGA testing. Analytical results reveal that the first harmonic sinusoidal component associated with the angular position errors of the rotating axis of the indexing table significantly affects the calibration outcomes. This leads to the conclusion that if the angular position errors of the indexing table are pre-measured, and the indexing table 26-position calibration method is used to identify the coefficients of each error term in the model and compensate for the first harmonic sinusoidal component of the angular position errors, then high-precision PIGA error model coefficients can be accurately obtained. Simulation experiments demonstrate that there is critical influence of angular position errors in the indexing table on the calibration accuracy of the PIGA error coefficients. Verification shows that this method can accurately identify the PIGA error coefficients, with an identification accuracy of 10-8. Furthermore, the analysis quantifies the effect of high-order error terms added to the PIGA error model on the calibration accuracy of the zero bias and scale factor parameters.