静电悬浮加速度计轴间耦合误差角的在线测量

静电悬浮加速度计轴间耦合误差角与悬浮质量块的平行度误差有关,而常规方法很难测量其大小和方向,故本文提出了一种变预载轴间耦合误差角在线测量方法。通过分析悬浮质量块平行度误差、耦合误差角、姿态角与静电力耦合的关系,推导了变预载法进行在线耦合误差角精确测量的原理和公式。设计了静电悬浮加速度计原理样机,并利用该样机对提出的测量方法进行了实验验证。实验测得X向对Y/Z向耦合误差角分别为-5.10×10-4 rad和2.36×10-5rad,与理论分析相符。该方法同样适用于Y向对X/Z及Z向对X/Y的耦合误差角的在线测量。上述结果表明该方法可以有效、精确地完成静电悬浮加速度计不同轴之间耦合误差角的在线测量。

Online measurement of coupled error angle between different axes of electrostatically suspended accelerometer

The coupled angles between different axes of an Electrostatically Suspended Accelerometer (ESA) are related to the parallelism error of a sensor head, and it is hardly measured accurately by using classical methods. Therefore, a novel online measurement method for the coupling angles was proposed by a varying preload voltage. By modeling the relationship of the parallelism error, coupled angle, attitude angle and the electrostatic force coupled angle, the mechanism and equation of the varying preload voltage method for online measurement of the coupled angles were given. A ESA prototype was designed and then it was used to verify the proposed method. Experiment results show that the coupling angles of X/Y and X/Z are -5.10×10^-4 rad and 2.36×10^-5 rad, respectively, which are consistent with that of theoretical analysis. The method is also suitable for online measurement of the coupling angles for Y/X, Y/Z and Z/X,Z/Y. The result shows that this novel varying preload method can online identify the coupled angles of different axes of ESA effectively and accurately.