针对小圆孔轮廓的精密测量难度大, 构建了一个基于线激光三角法的圆孔尺寸测量系统。对杂散光、激光点间距和激光线倾斜等误差因素进行分析, 设计实验, 搭建了基于线激光三角测距传感器、气浮位移平台和十字滑台的表面形貌测量装置。研究合适的测量系统参数, 通过MATLAB理论仿真圆和实验装置实际测量圆, 获取环规标准件圆孔三维形貌点云数据。利用HOUGH圆变换法、最小二乘拟合圆法和最小距离拟合圆法, 实现高效、准确地计算圆尺寸参数。测试结果表明, 圆心位置的微小改变不影响测量结果, HOUGH圆变换法优于最小二乘法和最小距离法。对于不同直径的环规标准件, 利用HOUGH圆变换法重复测量, 实验测量误差最小2 μm, 当圆孔直径过小时, 杂散光对测量结果影响明显。

For the precise measurement of the small round hole contour, a round hole size measurement system based on the line laser triangulation method is constructed. The error factors such as stray light, laser dot pitch and laser line tilt are analyzed, and the surface topography measuring device based on line laser triangulation sensor, air floating platform and cross slide is constructed. Configure the appropriate measurement system parameters, and use the MATLAB theory simulation circle and the actual measurement circle of the experimental device to obtain the three-dimensional shape point cloud data of the standard hole of the ring gauge. The circle size parameter is calculated by software using the HOUGH round transformation method, the least square method, and the minimum distance method. The test results show that the small change of the center position does not affect the measurement results, and the HOUGH round transformation method is superior to the least squares method and the minimum distance method. For the ring gauge standard parts with different diameters, the measurement is repeated by HOUGH round transformation method. The experimental measurement error is at least 2 μm. When the diameter of the round hole is too small, the stray light has a significant influence on the measurement results.