由于受到驱动器PZT(Pb Zr Ti O3)非线性、系统温漂与其他不确定因素的影响,原子力显微镜(AFM)探针在任务空间的位置存在不确定性。这严重影响了AFM探针观测与操作的效率,如何减小探针位置的不确定性,实现AFM探针的精确定位成为亟待解决的问题。针对此问题,提出用概率分布的方式描述探针位置的不确定性,通过建立探针运动模型,结合基于局部扫描的观测模型,采用Kalman滤波对探针位置进行最优估算。针对算法的实现,设计了模型参数标定方案。通过仿真和实验的结果验证了算法的有效性与可行性,实现了探针在任务空间中的精确定位,提高了纳米操作效率。
Due to nonlinearity, system temperature drift and other uncertainties of PZT ( PbZrTiO3 ) , there exists uncertainty for the position of AFM (Atomic Force Microscopy) tip in the task space. It seriously affects the observation and operation efficiency of AFM tip. Thus, to reduce the uncertainty of tip position, and achieve precise positioning becomes an urgent issue to be solved. Firstly, this work represents the uncertainties of tip position in the task space by using the probability distribution. Then, tip motion model is established, and local scan based observation model is combined to estimate optimal tip position by using the Kalman filter. In addition, a model parameter calibration scheme is designed to implement the proposed method. The validity and feasibility of the algorithm are verified by the simulation and experimental results. AFM tip precise positioning can be realized in the task space, and the efficiency of nanomanipulation can be improved.