基于精密离心机的三轴硅微谐振加速度计标定方法

Calibration method based on precision centrifuge for triaxial silicon resonant accelerometer

为更准确辨识三轴硅微谐振加速度计的误差系数,提高加速度计在飞行器上的加速度矢量测量精度,设计基于精密离心机的加速度计标定方法。分析硅微谐振加速度计的工作原理及误差项,在考虑离心机主要误差源的基础上建立包含零位偏移、标度因数、非正交安装误差、二次项误差与横向灵敏度的硅微谐振加速度计误差模型;设计离心机匀角加速度旋转的三姿态标定方法,在径向轴高g输入的同时,增加角加速度激励,可以更好标定加速度计横向灵敏度;对所提出的标定方法进行仿真,通过最小二乘法完成模型参数辨识。仿真结果表明,参数辨识相对误差可控制在2%以内,二次项系数与横向灵敏度辨识精度均小于1μg。

To accurately identify the error coefficient of the triaxial silicon resonant accelerometer and improve the measurement accuracy of the accelerometer on aircraft,an accelerometer calibration method based on a precision centrifuge was designed.The working principle and error term of the silicon resonant accelerometer were analyzed.On the basis of considering the main error sources of the centrifuge,a model was set up including zero deviation,scale factor error,non-orthogonal installation error,quadratic term error and transverse sensitivity.A three-attitude calibration method for centrifuge rotation with uniform angular acce-leration was designed,which better calibrated the transverse sensitivity of the accelerometer by increasing the angular acceleration excitation and inputting the large acceleration of the radial axis.The proposed calibration method was simulated,and the model parameter identification was completed using the least square method.Simulation results show that the relative error of parameter identification can be controlled within 2%,and the identification accuracies of quadratic term coefficient and lateral sensitivity are both less than 1μg.