Error correction of laser scanning system for reverse engineering

The current commercial laser probe is mounted on a computer controlled milling machine and the CAD/CAM integration can be easily achieved for the purpose of reverse engineering. As the laser probe is based on optical triangulation, the sensors are very sensitive to the parameters of the measured object, including color, material, roughness and relative angle between the laser beam and the object. We analyze the above-mentioned factors influencing the accuracy of the laser probes by simulation and experiment relatively. First, model of the systematic errors is developed based on principle of the optical triangulation and the simulation results of the model are given out. Then, experiments are carried out on the measurement error of the laser probe with respect to the color, material, roughness and the surface inclination. Finally, a software correction is applied the experimental calibration to the coordinate value of the measured point. The results show that the simulation model has the same changing trend as the experiment. The calibration to the laser probe by using the error correction method can improve the measurement accuracy for the free-form surfaces.