扫描隧道显微镜扫描器的迟滞非线性控制

发布时间：2018-10-10 07:50

【摘要】：压电驱动器被广泛应用于扫描隧道显微镜(scanning tunneling microscope,简称STM)的扫描器,但压电材料本身的迟滞非线性特性影响了STM的扫描精度。为了补偿由于迟滞非线性带来的扫描器控制误差,提高STM的扫描精度,基于迟滞非线性模型,设计了前馈控制器,并与PID反馈控制相结合。利用所设计的控制器进行了扫描实验,并与位移反馈控制扫描进行对比。实验结果表明,采用位移反馈控制时光栅周期相对测量误差和光栅线宽相对测量误差分别为4.41%和2.65%,采用迟滞逆模型与PID反馈的复合控制后,光栅周期相对测量误差和光栅线宽相对测量误差分别减小到1.26%和0.27%,迟滞引起的非线性误差得到了补偿,减小了扫描器控制误差,提高了扫描精度。
[Abstract]:Piezoelectric actuators are widely used in scanning tunneling microscope (STM) scanners, but the hysteresis nonlinearity of piezoelectric materials affects the scanning accuracy of STM. In order to compensate the scanner control error caused by hysteresis and improve the scanning accuracy of STM, a feedforward controller based on hysteresis nonlinear model is designed and combined with PID feedback control. The designed controller is used in the scanning experiment and compared with the displacement feedback control scan. The experimental results show that the relative measurement error of grating period and the relative measurement error of grating linewidth are 4.41% and 2.65% respectively when the displacement feedback control is adopted. The relative measurement error of grating period and the relative measurement error of grating linewidth are reduced to 1.26% and 0.27% respectively. The nonlinear error caused by hysteresis is compensated and the control error of scanner is reduced and the scanning accuracy is improved.
【作者单位】：南京航空航天大学机械结构力学及控制国家重点实验室;南京理工大学能源与动力工程学院;
【基金】：国家重点基础研究发展计划(“九七三”计划)资助项目(2015CB057501) 国家自然科学基金资助项目(11372133&51405235) 中央高校基本科研业务费专项资金资助项目(NE2015001&NE2015101) 中国博士后特别资助项目(2014T70514) 江苏省基金重点资助项目(BK20150061) 江苏高校优势学科建设工程资助项目
【分类号】：TH742;TP273

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