MEMS器件微结构的运动特性影响器件的性能和可靠性。为实现微结构周期运动过程中各个时刻的旋转角度的测量,提出一种基于傅里叶梅林(Fourier-Mellin)变换和相位相关算法的旋转角度测量方法。利用傅里叶梅林变换算法的旋转不变性,将图像空间坐标转换为对数极坐标的参数空间,旋转角度变化转化为平移的运动,然后利用相位相关的亚像素平移测量算法,得到微结构旋转角度。实验结果表明,该算法旋转角度测量分辨率达到0.01°,计算量较小且具有抗干扰能力。
The motion characteristics of microstructure are corresponding to the performance and reliability of MEMS devices. To realize the measurement of rotation motion to get the characteristic of MEMS resonators in every moment, a method is presented for measuring the MEMS rotation angle based on the combination of Fourier-Mellin transform and phase correlation. By using the rotational invariance of Fourier-Mellin transform, the motion in space coordinate is transferred to parameters of Log-Polar coordinate, and the rotation motion is projected to displacements. Then the displacements are measured by a phase correlation method to realize a sub-pixel motion measurement. Experimental results show that the proposed algorithm can reach angle measurement resolution of 0. 01° with less calculations and anti- interference ability.