In order to model the hysteresis behavior of a nano piezoelectric actuator(PA)on nano scale in a real time system,a new hysteresis modeling method based on an improved sub-pixel blocking matching algorithm with an optimal block size is proposed in this paper.First,Preisach model is introduced to model the hysteresis behavior of a piezoelectric actuator.Then,a real time block matching algorithm is researched and its block size is optimized with a standard object.Finally,experiments are performed with respect to a nanometer movement platform system,and the results show the feasibility and validity of the sub-pixel estimation based block matching algorithm and its application in modeling the hysteresis behavior of PA.
传统的离焦深度恢复方法(depth from defocus,DFD)在计算离焦图像的模糊程度时,均是基于几何光学成像原理,并没有考虑光波衍射对图像模糊的影响.然而,衍射现象是波的基本特性,以针孔成像为基础的光学成像系统中必然存在光波衍射.本文基于光学衍射和图像模糊机理,提出了一种精确的单目视觉全局景物3D深度信息获取方法.首先,详细分析了光学成像系统中的菲涅耳衍射机理,建立了衍射模糊与景物深度之间的关系曲线;然后,采用曲线拟合的方式建立了衍射模糊的模糊程度(点扩散函数扩散程度)与景物深度的数学关系模型,结合热辐射和图像相对模糊原理,构建了衍射模糊热辐射方程组,并把衍射模糊深度获取问题转换成一个深度信息动态优化问题.最后,使用标准的纳米栅格模板验证了衍射模糊深度重建算法在纳米尺度相对深度和绝对深度重建中的有效性和精确性.
