步进电机驱动的直线变倍成像系统研究  

Continuous zooming imaging system driven by stepping motors

作　　者：李铮 戴明[1] 李嘉全[1] LI Zheng;DAI Ming;LI Jia-quan(Changchun Institute of Optics,Fine Mechanics and Physics Chinese Academy of Sciences,Changchun 130033,China;;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院长春光学精密机械与物理研究所,吉林长春130033 [2]中国科学院大学,北京100049

出　　处：《中国光学》2018年第5期779-789,共11页Chinese Optics

基　　金：国家高技术研究发展计划(863计划)资助项目(No.2013AA122102)~~

摘　　要：为了满足无人机光电载荷的体积和重量要求,并有效解决传统凸轮机构加工精度要求高、系统易产生机械振荡等问题,提高系统的响应速度和变焦精度,对基于步进电机驱动实现连续变焦的直线变倍成像系统进行研究。采用二相混合式步进电机驱动实现机械补偿式变焦系统的变焦聚焦功能。首先,本文研究了基于步进电机的直线变倍成像系统的工作原理与构成,完成硬件平台的搭建,利用单片机控制实现步进电机的加减速过程。然后构造适合本系统的图像清晰度评价函数,并采用扫描反馈搜索算法完成对镜头焦距值的标定,将标定结果载入聚焦算法。最后,完成系统的性能测试。测试结果显示,采用速度控制模型后,步进电机的定位误差显著降低,范围在0.010 mm以下,整个系统的变焦精度远远小于1%,而且光学性能和外场拍摄性能较好。该基于步进电机的直线变倍成像系统满足无人机光电载荷的适用性要求。In order to meet the volume and weight requirements of the unmanned aerial vehide′s(UAV)photoelectric payload,and effectively solve the problem of the high requirement of processing precision of traditional cam mechanism,and the problem that the system is prone to mechanical oscillation and improve the response speed and zoom accuracy of the system,a continuous zooming imaging system based on stepping motor drive is studied.The zoom focus function of the mechanically compensated zoom system is realized by a two-phase hybrid stepping motor drive.First of all,the working principle and composition of continuous zooming imaging system based on stepping motor are investigated.The hardware platform is built,and the acceleration and deceleration process of stepping motor is controlled by single-chip.Then,the image sharpness evaluation function suitable for the system is constructed,and the scan focus search algorithm is used to complete the calibration of the focal length value of the lens,and the calibration result is loaded into the focus algorithm.Finally,the performance test of the system is performed.The test results show that by using the velocity control model,the relative error of the stepping motor displacement decreased significantly,which is below 0.010 mm,and the zooming accuracy of the whole system is far less than 1%,and the optical performance and field shooting performance are improved.The continuous zooming imaging system based on the stepping motor satisfies the applicability requirements of the photoelectric load of the UAV.

关 键 词：直线变倍镜头 步进电机 加速曲线 自动聚焦 图像清晰度评价函数 

分 类 号：TP273[自动化与计算机技术—检测技术与自动化装置]