一种闭环微纳定位扫描系统设计

Design of closed-loop micro-nano positioning scanner system

针对小推力压电陶瓷的特性,提出了一种闭环微纳定位扫描系统设计。该系统以单片机80C196KC为核心,使用12位A/D转换器MAX120和12位D/A转换器DA7521做D/A转换,模拟驱动部分采用前置低压误差运放和后置高压精密运放组成双级放大模块;控制部分采用Fuzzy-PID复合控制算法进行非线性处理,很好地改善了压电陶瓷的迟滞、蠕变、非线性等不足,且提高了控制系统的精度。将本系统应用于白光相移干涉检测,实验结果表明:闭环电压控制的最大误差为18mV,置位重复精度为6 nm,系统相对误差为0.15%;在位移量为10μm的时间—位移阶跃响应曲线中阶越响应时间约为20m s,且在电压为80 V的蠕动曲线中,3m in内的蠕变为3.6%,3m in以后变化开始缓慢。

A novel closed-loop micro-nano positioning scanner system in accordance with the property of PZT under small thrust is presented. The main core of the system is 80C196KC, used 12-bit A/D converter MAX120 and 12-bit D/A converter DA7521 as D/A conversion, part of the pre-driven simulation uses low-voltage operational amplifier error and post-high-precision operational amplifier composed of two-stage amplification module. Part of control uses fuzzy-PID complex control algorithms for dealing with non-linear. The hysteresis, creep and non-linear of PZT is improved well. The system can be applied to white-light phase-shifting interference detection, experimental result shows that maximum closed-loop voltage error is 18 mV, positional repeat accuracy is 6 nm, system relative error is 0.15 %. With the displacement of 10 μm, the step-response time is about 20 ms in curve of displacement-time. In the wiggle curve with driving voltage of 80 V, creep within 3 min is 3.6 % and after the change is slower.