空间稳定平台通用误差模型

General error model for space stable platform

自由转子陀螺是一种二自由度机电陀螺,其漂移特性可应用二次型漂移误差模型描述。从二次型漂移误差模型出发,推导了壳体翻滚条件下的调制平均漂移误差模型,并推广到空间稳定平台上工作的极轴陀螺和赤道陀螺;列写了二次型陀螺漂移误差模型驱动下的空间稳定平台标称运动方程;经过扰动线性化,求解出平台标称运动轨迹增量坐标的解析表达式;基于扰动线性化模型并考虑到加速度计测量误差,证明了观测变量为纬度误差、经度误差及冗余轴转角误差时,空间稳定平台运动方程的17项误差系数都是可辨识的;分析了该17项误差系数的估计精度与加速度计组合件测量误差的关系。仿真和实验结果表明本文提出的通用误差模型是有效的。

The drift model of a 2-D free-rotor mechanical gyroscope is usually in quadratic form of specific force. Based on this form, the mean drift model modulated by case rotation-dwell device is derived for both the polar and equatorial gyroscopes on space stable platform. Following this mean drift model, the normal movement of the space stable platform can be modeled and analytically expressed by using perturbation theory. Based on the perturbation linearization model and taking into account the accelerometer＇s measurement error, it is proved that the 17-coefficients of the space stable platform are all observable when the observed variables are errors of latitude, longitude and redundancy frame angle. The relationship between the estimation precision of the 17 coefficients and the accelerometer＇s measurement error is analyzed and numerically simulated. The simulation and experiment results demonstrate the efficiency of the general error model.