反射式超精密定位技术的研究

【作者】 徐慧；

【导师】 张金龙；

【作者基本信息】 南京师范大学 ， 电工理论与新技术， 2013， 硕士

【摘要】 精密定位技术是微型机械、精密加工、半导体器件制造业、电子产品组装生产线、生物工程及纳米技术研究领域的基础性关键性技术。同时,也是一门涉及激光理论、电子、光学、信息处理、伺服驱动、智能控制及其它周边支撑技术的综合性技术。精密定位技术具有定位精度高、稳定性好、系统结构紧凑等优点,具有广泛的应用前景。本文在傅立叶光学和物理光学理论基础上,研究了激光叠栅信号强度与反射式双级叠栅的相对位移的关系,在激光叠栅信号基础上进行高精度位置检测与控制,建立了反射式精密位移测量数学模型,对建立的数学模型应用数值分析方法进行了计算机仿真。为提高位置检测信号的精度及灵敏度,设计了以步进电机与压电陶瓷进行宏/微两级驱动的反射式精密定位系统。对宏定位系统的工作原理进行了阐述,完成了对步进电机的驱动控制,提出了基于反射式叠栅莫尔信号测量的宏定位算法,经实验验证,该算法具有速度快、稳定性高、精度高等特点。在对微定位实验系统的实验测试与力学分析的基础上确定了系统的驱动方式,实现了微定位系统中压电陶瓷的有效驱动。最后,经过对两级定位过程的特点的分析,提出了宏／微定位结合的方法,实现了系统的精密定位。实验表明,宏／微两级定位相结合的复合定位方法,可保证在较大的信号捕捉范围内,达到高精度高速度定位,有效解决了定位精度、速度与信号捕捉范围三者之间的矛盾。由于反射式精密定位系统存在非线性,精密定位模型建立困难,本文将模糊控制理论应用于精密定位系统中。神经网络PID控制的应用实现了模糊控制器的输入输出映射关系,建立了神经网络模糊控制器模型。具有了知识自动获取功能的模糊控制系统,能更好地适应工况环境。实验表明,模糊神经网络PID控制具有稳定性好、控制响应快、鲁棒性强的特点,既能缩时间,又能实现高精度定位。更多还原

【Abstract】 The precise positioning technology is an essential and important technology of miniature machine, precision process, semiconductor manufacturing, electronic product line, bioengineering and nanometer techniques research area etc. Meanwhile, It is also a comprehensive technology involving laser theory, electronics, optics, signal processing, servo drive, intelligent control and some other supporting techniques. Precise positioning technology has some advantages involving high positioning accuracy, good stability, compact system structure etc, which has a broad prospect of application.This paper presents a technology which detects the position and alignment with moire signal of laser. By applying theories of physics optics and Fourier optics, the correlation between displacement of double reflective gratings and the intensity of Moire signal was studied. Besides, a mathematical model of precise displacement detection based on the Moire signal was established and computer-simulated pattern changes were obtained.To improve the accuracy and sensitivity of position signal detection, a reflective precise positioning system which is composed of double reflective gratings measurement equipment and driving system with PT and AC servo motor has been designed. The working principle of the macro positioning system and the control of servo motor have been completed. Based on the reflective grating measurement, a macro drive arithmetic has been designed. The experiment proves that the arithmetic has the characteristics of high speed, high stability and high accuracy. Based on the experimental tests and mechanical analysis, the driving method has been determined. The effective driving of PT has been realied. Finally, according to the characteristics of two stage driving processes, the combination of macro and micro positioning has been realied to complete the precise positioning. By using the method of macro and micro positioning, the high accuracy and quick speed are obtained in the big signal acquisition range, which has effectively solved the contradiction among the position control accuracy, speed and signal capture range.In view of the existing non-linearity and the difficulty in establishing reflective precise positioning model, fuy control method is used in the precise positioning system. The application of neural network PID control realizes the relationship of input and output in fuzzy control and sets up the Fuy neural network controller model. The improved fuy control system which can obtain knowledge automatically has better adapt to the working environment. The Experiment Result shows that Fuzzy neural network PID control can perform excellent control effect, such as better stability, faster response and strong robustness. It could effectively improve position speed with high accuracy.更多还原