采用神经网络控制的超精密平面定位

Ultra-precision plane positioning with neural network control

设计了一种基于激光莫尔信号的超精密平面定位装置,该装置可实现高精度位置检测及X-Y-θ 三自由度的全自动精密平面定位。激光莫尔信号传感器为相位相差 180°的两组衍射光栅,构成差动光栅技术,可有效提高位置检测信号灵敏度及定位精度。针对系统存在非线性,精确控制模型难以建立的缺陷,提出基于 RBF 神经网络的精密定位控制,其控制响应快、稳定性好、鲁棒性强,可有效改善控制质量,提高定位速度。实验结果表明,基于激光莫尔信号的精密定位装置可获得亚微米级的平面定位精度。

An ultra-precision plane alignment device based on laser Moire signal is designed. High-accuracy position detection and X-Y-θ three-freedom full automatic precision plane alignment can be realized by the device. The laser Moire signal sensor is of two sets of diffractive gratings with a phase difference of 180°, which form a differential grating and effectively improve position detection signal sensitivity and positioning accuracy. In view of the existing nonlinearity and the difficulty in establishing precision controlled model, a precision positioning control based on RBF neural network is proposed. It has advantages of fast, stable response and good robustness. The control quality and positioning speed can be effectively improved. The experimental results show that submicron level plane positioning accuracy can be achieved by the precision positioning device based on laser Moire signal.