School of Electrical and Electronic Engineering, Changchun University of Technology, Changchun, China.
School of Electrical and Information Engineering, Jilin Engineering Normal University, Changchun, China.
Rev Sci Instrum. 2023 Jul 1;94(7). doi: 10.1063/5.0150909.
Piezoelectric stick-slip driven nanopositioning stage (PSSNS) with nanometer resolution has been widely used in the field of micro-operation. However, it is difficult to achieve nanopositioning over large travel, and its positioning accuracy is affected by the hysteresis characteristics of the piezoelectric elements, external uncertain disturbances, and other nonlinear factors. To overcome the above-mentioned problems, a composite control strategy combining stepping mode and scanning mode is proposed in this paper, and an integral back-stepping linear active disturbance rejection control (IB-LADRC) strategy is proposed in the scanning mode control phase. First, the transfer function model of the system in the micromotion part was established, and then the unmodeled part of the system and the external disturbance were treated as the total disturbance and extended to a new system state variable. Second, a linear extended state observer was used as the core of the active disturbance rejection technique to estimate displacement, velocity, and total disturbance in real time. In addition, by introducing virtual control variables, a new control law was designed to replace the original linear control law and improve the positioning accuracy and robustness of the system. Furthermore, the effectiveness of the IB-LADRC algorithm was verified by simulation comparison experiments and experimentally validated on a PSSNS. Finally, experimental results show that the IB-LADRC is a practical solution for a controller capable of handling disturbances during the positioning of a PSSNS with a positioning accuracy of less than 20 nm, which essentially remains constant under load.
具有纳米分辨率的压电式蠕动驱动纳米定位平台（PSSNS）已广泛应用于微操作领域。然而，实现大行程纳米定位较为困难，且其定位精度受到压电元件的迟滞特性、外部不确定干扰以及其他非线性因素的影响。为了克服上述问题，本文提出了一种将步进模式和扫描模式相结合的复合控制策略，并在扫描模式控制阶段提出了一种积分反步线性主动干扰抑制控制（IB-LADRC）策略。首先，建立了系统在微动部分的传递函数模型，然后将系统的未建模部分和外部干扰作为总干扰，并扩展到一个新的系统状态变量。其次，利用线性扩张状态观测器作为主动干扰抑制技术的核心，实时估计位移、速度和总干扰。此外，通过引入虚拟控制变量，设计了一种新的控制律来替代原有的线性控制律，提高了系统的定位精度和鲁棒性。最后，通过仿真对比实验验证了 IB-LADRC 算法的有效性，并在 PSSNS 上进行了实验验证。实验结果表明，IB-LADRC 是一种实用的控制器解决方案，能够处理 PSSNS 定位过程中的干扰，在负载下定位精度小于 20nm，且基本保持不变。
