基于光纤布拉格光栅(FBG)原理的三坐标测量机测头结构  

Structure of Touch-trigger Probe Based on Fiber Bragg Grating(FBG) for Coordinate Measuring Machine

作　　者：范哲光[1] 费业泰[2] 丁邦宙[2] 

机构地区：[1]合肥工业大学仪器科学与光电工程学院 [2]合肥工业大学

出　　处：《工具技术》2010年第11期94-97,共4页Tool Engineering

基　　金：国家自然科学基金资助项目(50627501)

摘　　要：介绍了一种基于光纤布拉格光栅(FBG)传感原理的三维测头。FBG的实质是在纤芯内形成一个窄带的滤波器,布拉格波长方程为λB=2neΛ。外界应变的变化会影响光纤光栅的折射率调制周期Λ和纤芯折射率ne,并且FBG对轴向应变特别敏感。本测头采用三根竖直放置均布于圆柱面内的FBG,FBG的上端固定在一个固定架上,下部与一个支架连接。支架通过三根钼丝悬挂在内,测杆也固定在这个支架的中心,支架能够随测针一起自由偏摆。测杆与被测件接触时发生偏转,支架把偏摆量转化为对FBG的轴向应变,从而使FBG的布拉格波长变化。本测头传感系统采用匹配光纤光栅滤波的解调方式,选用四根参数一样的光纤光栅(其中三根做传感光栅,一根做参考光栅)。宽带光源经过耦合器进入传感FBG,从传感FBG反射的光经过耦合器进入匹配FBG,用高精度探测器测量匹配光栅的反射能量。当测杆偏摆时,传感FBG的布拉格波长受应变的影响而变化,从而使参考光栅反射的能量发生变化。本文主要介绍这种自主研发测头的结构分析,传感系统。A new structure of contact-probe based on Fiber Bragge Grating（FBG）is presented in this paper.FBG is a narrowband filter.The bragg equation is λBBB=2nBeBΛ.The mutative strain and temperature outside will affect the parameters nBeB and Λ.FBG is sensitive to the strain in axial direction.The probe have three FBG which are placed in upright direction in a cylindrical area.The top of the FBG is fixed on a holder which is immovable.And the bottom is fixed on a plank.The plank connect with the probe house by three molybdenum threads.The probe will have deflection when contacting with the workpiece.Then the deflection will be transformed to the strain in axial direction of the FBG by the plank.The result of the strain is represented by the shifted wavelength of reflected Bragg signals.The probe adopt the match FBG filter sensor system.This system has four FBG which have same parameter（three as sensor FBG and one as match FBG）.Broadband light source enter the sensor FBG through one coupler,the reflect light is imported to the match FBG through the other coupler.A high precision detector is used to measure the energy that reflect from the match FBG.The deflection of the probe leads to the change of Bragge wavelength of the sensor FBG.The result is that the light energy reflect from the match FBG change.This paper is about the structure and sensor system of this independence developed probe.

关 键 词：CMM测头 FBG 结构 FBG解调系统 

分 类 号：TG71[金属学及工艺—刀具与模具]