High Precision Laser Triangulation Surface Flaws Detection

With the development of the science, the surface metrology has been developed rapidly. This field of metrology has been widely used in many fields of science and industry. The Surface features are used for different process. Therefore, it is important tout study the methods for non-contact surface flaws detection.A high precision surface flaws detection using laser triangulation technique is proposed in this paper. First, the postulate of the laser triangulation is introduced. Then the configuration of the measurement system is designed and calibrated. A red line semiconductor laser has been used as the light source which scans the object with the help of a motion controller. The images captured by a camera during scanning are subjected to preprocessing.3-D coordinates of all the laser illuminated points on the surface of the object are calculated using optical triangulation method. The obtained points cloud is submit to filtering operation. The x, y, z coordinates of the point cloud are fitted respectively. From the fitting operation, defects can be identified and then their parameters can be measured. At last this paper analyses the error and it’s propagation through the measurement process.