基于线结构光的大型螺纹在线测量与重构方法研究

On-line Measurement and Reconstruction of Large Screw Thread Based on Line Structured Light

针对汽轮机内缸大型螺纹缺乏有效的在线测量手段,提出了基于线结构光的非接触式测量系统。通过CCD相机采集激光发射器投射的线激光图像,对图像进行预处理并提取螺纹条纹中心参数,得到螺纹特征点数据,并由此计算出螺纹大小径、中径、牙型角、螺距以及导程角参数。采用逆向工程软件对工件进行表面重构,试验结果表明,该系统测量效率高,精度可达30μm。

Regarding the lack of effective on-line measurement method for the large thread of steam turbine inner cylinders,a non-contact measurement system based on line structured light is proposed.The linear laser image projected by the laser transmitter is first collected by CCD camera,then the image is preprocessed and the thread stripe center parameters are extracted,thus the thread feature point data is obtained and the parameters of thread major diameter,minor diameter,pitch diameter,included angle,thread pitch and lead angle are calculated.At last,the surface of the workpiece is reconstructed by reverse engineering software.The experimental data show that the system has a high measuring efficiency and the accuracy can reach 30μm.