基于电容传感器的大型工件圆度误差测量系统

摘要

Roundness error of axial rotary workpiece is an important index for evaluation of processing level of machine tools.Aiming at large axial workpiece is unable to adopt traditional roundness measuring instrument,theoretical basis and mathematical model of the three-point method measuring axial rotary workpiece roundness error are introduced.Non-contact capacitive sensor is used to detect micro displacement,structure of sensor and basic principle of measuring circuit are given.Hardware system suitable for roundness error measuring is set up based on capacitive sensor,and special measuring system is developed by virtual instrument technology to realize data acquisition,linear correction,error separation and evaluation.In the end,experiment is carried out,reliability and precision of measuring system are evaluated through analysis on datas by multiple measurements.%轴类回转工件的圆度误差是衡量机床加工水平的重要指标.针对大直径轴类工件无法采用传统圆度仪进行圆度误差测量,介绍了三点法测量轴类回转工件圆度误差的理论基础、数学模型.采用非接触式电容传感器进行微位移测量,介绍了传感器结构与测量电路基本原理,搭建了适用于圆度误差测量基于电容传感器的硬件系统,应用虚拟仪器技术开发了可用于数据采集、线性校正、误差分离与评定的专用测试系统.最后进行了测试实验,通过对多次测量数据的分析评定测量系统的可靠性与精度.