光栅编码器装调的偏心误差和使用中安装转轴的振动严重影响光栅编码器的测量精度，限制了光栅码盘的应用范围。为了消除光栅编码器偏心与振动对测量的影响，在双读头法的基础上，提出了四读头法消除光栅编码器偏心和振动影响的方法，并进行了理论推导和仿真。结果表明，采用沿光栅编码器圆周均匀分布的四读头读取叠栅条纹信号，并将检测相位相加除以4的方法比当前普遍采用的对径读头读数相加除以2的方法更能有效地提高光栅编码器的测量精度，从而降低了光栅编码器的装调要求。利用四读头各自采集的测量信号可以解算出偏心方向和偏心量，从而可以消除安装转轴振动的影响。对光栅编码器的进一步应用研究具有指导意义。

Presently, grating encoder is an important way to accurately measure angle, however, the eccentric inaccuracy of assembling adjusting and the vibration of rotating shaft influence grating encoder′s measuring accuracy and then confine the application range of grating encoder. A new method to eliminate the influence of eccentricity and vibration with four reading heads is proposed and the theoretical derivation and simulation results are given out. The conclusion hints that the method which gets moiré fringes signal by four reading heads well-distributed along the circumference of grating is more effective in improving the measuring accuracy than the one that uses double reading heads. Consequently, the new method decreases the requirements of assembling adjusting. The direction and magnitude also can be solved by four reading heads, so the influence of rotating shaft can be eliminated. All the results are useful to deeper research.