Abstract: A nonlinear robust motion control strategy was proposed to achieve precise movement of objective motion carrier in context of large numerical aperture microscopy imaging technology, which required a long stroke, high precision, and large load capabilities. An optical path system and a virtual prototype of a large numerical aperture microscope were designed. In addition, a ball-screw-driven objective motion carrier was designed, and the backlash of ball-screw was eliminated by double nut preloading method. To achieve finite-time convergence of system state and improve system robustness, an adaptive technology was employed in nonsingular terminal sliding mode control. Furthermore, to address nonlinear friction effect in ball-screw transmission mechanisms, TDE technology was employed to realize online estimation and real-time compensation of friction forces. TDE technology and adaptive nonsingular terminal sliding mode control were adopted to achieve model-free control characteristics. The stability of closed-loop system was proved by Lyapunov theory. Consequently, a high-resolution optical microscope was developed to achieve precise movement of objective motion carrier, and microscopic images of mouse cardiac muscle cells were acquired to demonstrate the effectiveness of the proposed algorithm.

Key words: adaptive finite-time control, high-resolution optical microscopy, time delay estimation(TDE), nonsingular terminal sliding mode

摘要： 针对大数值孔径显微成像技术对物镜位移台提出的长行程、高精度和大负载的要求，提出了一种非线性鲁棒运动控制策略以实现物镜位移台的精密运动。设计了大数值孔径显微镜的光路系统、虚拟样机以及由滚珠丝杠驱动的物镜位移台，采用双螺母预紧的方式消除滚珠丝杠传动间隙。将自适应技术引入非奇异终端滑模控制，实现系统状态的有限时间收敛，提高系统鲁棒性。针对滚珠丝杠传动机构内部的非线性摩擦效应，采用时延估计技术实现摩擦力的在线估计和实时补偿，将时延估计技术和自适应非奇异终端滑模控制相结合获得无模型控制特性。通过Lyapunov理论证明了闭环系统的稳定性。搭建了一个高分辨率的光学显微镜，实现物镜位移台的精密运动，采集到小鼠心肌细胞的显微图像，证明了所提算法的有效性。

关键词: 自适应有限时间控制, 高分辨率光学显微镜, 时延估计, 非奇异终端滑模