用于主动应力加工的力促动器及控制技术研究

发布时间：2019-05-17 09:03

【摘要】：随着科学技术的不断发展,非球面光学元件得到了越来越广泛地应用,特别是对于具有大口径或者超大口径等特殊要求的光学仪器。这些光学仪器中的光学元件大多采用拼接结构,所使用的非球面光学元件数量众多,形状特殊,精度要求高,研制周期短。这些广泛的应用需求给光学制造行业带来了蓬勃发展生机的同时,也使其面临前所未有的挑战,传统的光学加工方式已经无法满足现在光学元件研制的需要了。主动应力加工技术是在传统加工方式的基础上发展起来的一种新型抛光方法,它可以按照加工球面或平面的工艺来加工光学非球面,大大提高了非球面的加工效率。但由于加工精度不高,主动应力加工技术的发展受到了一定的制约。本论文对应力加工过程中造成加工精度不高的原因进行了分析,从应力加工支撑装置输出力的测量和控制着手,以提高输出力的精度和稳定性,进而提高主动应力加工的精度为目标,在气动伺服机构和控制系统这两个方面开展了研究。本文首先分析了各种主流力促动器的优势和劣势,接着对气动式力促动器进行了数学建模,并对气动式力促动器主要参数进行了分析。随后在控制系统方面进行硬件选型和设计、力促动器控制系统和硬点控制系统的软件的编写。其中硬件部分,采用了NI cRIO-9068嵌入式控制器,3块NI 9205采集卡作为输入模块,5块NI 9264采集卡作为输出模块,一块DMC2410C-A四轴运动控制卡用于控制步进电机。以减小干扰、提高精度为目标,优化了电气连接方式。软件部分,在labVIEW开发环境下,采用标准状态机模式,完成了消息处理模块、通讯模块、开环和闭环控制模块,人机界面,以及两个控制系统各自相对应的各种功能性操作模块,控制算法综合采用了带死区的PID控制算法、积分和矫正算法、可自调整的“野点”值弱化算法。最后,结合一套单点力测试装置和一块1.2m薄主镜,其中,1.2m薄主镜采用37点力支撑,并使用3个硬点对镜面进行定位,设计和进行了相关实验,对系统性能进行了综合测试。实验结果表明:将现有支撑力的精度提高到了目标精度,满足了光学元件进行应力加工的需要。
[Abstract]:With the continuous development of science and technology, aspherical optical elements have been more and more widely used, especially for optical instruments with special requirements such as large aperture or super large aperture. Most of the optical elements in these optical instruments use splicing structure, the number of aspherical optical elements used is large, the shape is special, the precision requirement is high, and the development cycle is short. These extensive application requirements not only bring vitality to the optical manufacturing industry, but also make it face unprecedented challenges. The traditional optical processing methods can no longer meet the needs of the development of optical components. Active stress machining technology is a new polishing method developed on the basis of traditional machining methods. It can process optical aspherical surface according to the process of machining sphere or plane, which greatly improves the machining efficiency of aspherical surface. However, due to the low machining accuracy, the development of active stress machining technology is restricted to a certain extent. In this paper, the reasons for the low machining accuracy in the process of stress machining are analyzed, and the measurement and control of the output force of the stress machining support device are started in order to improve the accuracy and stability of the output force. In order to improve the accuracy of active stress machining, the pneumatic servo mechanism and control system are studied. In this paper, the advantages and disadvantages of various main flow force actuators are analyzed, then the mathematical modeling of pneumatic force actuators is carried out, and the main parameters of pneumatic force actuators are analyzed. Then the hardware selection and design are carried out in the control system, and the software of the force actuator control system and the hard point control system is compiled. In the hardware part, NI cRIO-9068 embedded controller is used, three NI 9205 acquisition cards are used as input modules, five NI 9264 acquisition cards are used as output modules, and a DMC2410C-A four-axis motion control card is used to control stepping motor. In order to reduce the interference and improve the accuracy, the electrical connection mode is optimized. In the software part, under the labVIEW development environment, the message processing module, the communication module, the open-loop and closed-loop control module, the man-machine interface, and the corresponding functional operation modules of the two control systems are completed by using the standard state machine mode. The control algorithm adopts PID control algorithm with dead zone, integral and correction algorithm, and self-adjusting "wild point" weakening algorithm. Finally, a set of single point force testing device and a 1.2m thin main mirror are combined, in which 1.2m thin main mirror is supported by 37 points force, and three hard points are used to locate the mirror surface, and the related experiments are designed and carried out. The performance of the system is tested comprehensively. The experimental results show that the accuracy of the existing support force is improved to the target accuracy, which meets the needs of stress machining of optical elements.
【学位授予单位】：中国科学院大学(中国科学院光电技术研究所)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP273

【参考文献】