摘要
调焦机构是变焦距镜头中重要的组成部分,为了满足经纬仪测量中对变焦距镜头的要求,针对目前对变焦距镜头的调焦主要采用凸轮机构的变焦方式体积大、效率低、精度差缺点,本文提出了采用直线驱动的方式进行调焦的原理与方法,介绍了一种应用系统,主要由步进电机、直线导轨、直线位移传感器、DSP控制器等组成,由步进电机驱动,通过齿轮变速和精密丝杠速比变换机构,利用直线位移传感器作为检测元件,带动镜组前后移动来进行距离调焦和温度调焦,从而改变了传统的调焦机械结构。具体给出了测量系统的组成结构和实验结果,并进行了精度影响因素分析。实验结果表明,测量精度可保证在0.005mm内,满足经纬仪测量所需要的结构紧凑、位移精度好的要求。
High accuracy zoom lens is used in theodolite measure. The focal system is an important inspect item in zoom lens. The cam mechanism is basically used in focal system now. The cam mechanism is bulky inefficient and low accuracy. The theory and methods for the zoom using beeline drive are discussed in the paper. An applied system is presented. The system is composed with stepper motor, liner track, liner displacement sensor and digital signal processor etc. The lens is driven by the stepper motor through gear and precision screw. Being the detecting element, the liner displacement sensor drastically improves the traditional focal mechanism. The principle and structure of the focal system are given in the concrete. The system accuracy is analyzed and controlled in 0.005 millimeter. It meet the requirement of the theodolite for compact volume and well precision.
出处
《光机电信息》
2010年第12期88-92,共5页
OME Information
基金
国防科技预言基金资助项目(No.1040603)
