RESUMO
Laser scanning projection can project outlines of assembled components onto a work surface accurately, which can improve assembly efficiency, and is widely applied in industry manufacturing. In order to achieve accurate calibration and projection, a mathematical model of the calibration process is developed, and the dual-diameter fitting method is proposed to extract the central positions of retroreflective targets. Then, a particle swarm optimization (PSO) algorithm is introduced to solve the coordinate transformation matrix between the world frame and the projector frame, and the optimal parameters of the PSO algorithm are obtained to improve the convergence probability of the transformation matrix solutions. The maximum error of the retroreflective targets' central positions between the calculated and theoretical positions is 1.82×10-6mm through the simulation experiment. Furthermore, a novel laser scanning projection setup and a control system based on LabVIEW are developed. Experiments are actually carried out by scanning six retroreflective targets on a standard workpiece, and the transformation matrix is solved correspondingly. The results indicate that the maximum beam steering angle error between the theoretical and actual values calculated by the abovementioned transformation matrix is 5.215668×10-9 degrees. Finally, the projection accuracy is verified by a standard workpiece with accurate patterns. The experiment results prove that the position error of the developed laser scanning projection system is better than 0.5 mm.
