Angle measurement error and compensation for decentration rotation of circular gratings

As the geometric center of circular grating does not coincide with the rotation center,the angle measurement error of circular grating is analyzed. Based on the moire fringe equations in decentration condition,the mathematical model of angle measurement error is derived. It is concluded that the decentration between the centre of circular grating and the center of revolving shaft leads to the first-harmonic error of angle measurement. The correctness of the result is proved by experimental data. The method of error compensation is presented,and the angle measurement accuracy of the circular grating is effectively improved by the error compensation.     

基于导航坐标系的捷联惯导系统旋转调制分析

针对提高长航时捷联惯导系统导航精度的问题,提出了基于导航坐标系的捷联惯导系统旋转调制方法,并给出了旋转机构的转动方案.应用该方法可以消除调制周期内载体姿态变化对误差补偿的影响.通过推导旋转式捷联惯导系统误差传播方程,说明了旋转调制的误差补偿机理,通过比较基于导航坐标系和基于载体坐标系2种旋转调制方法,证明了基于导航坐标...     

Angle measurement error and compensation for pitched rotation of circular grating

As circular grating is not vertical to the shaft,the angle measurement error of the circular grating is analyzed.Based on the moire fringe equations in pitched condition,the mathematic model of the angle measurement error is derived.The paper comes to the conclusion that the nonorthogonal angle between the circular grating and the shaft leads to the second harmonic error of the angle measurement,and the correctness of the result is proved by the experimental data.The method of the error compensation is presented,and the angle measurement accuracy of the circular grating is improved by the error compensation.