A Geometric Error Modeling Method and Trajectory Optimization Applied in Laser Welding System

摘要

In this paper, a geometric error modeling method is carried out on six-axis motion platform (SMP) in laser welding system (LWS), and an optimized algorithm is proposed for the alignment in LWS based on the error model. First, the topological structure of the given SMP is analyzed, and related homogeneous transformation matrices which are used for standing the orientation of SMP are established. By these matrices, the geometric error model is developed mathematically. Then, the error model is used for predicting the alignment deviations. A corresponding series of experiments for calculating the optical power loss in alignment are employed, and the comparison between simulation and experiments results indicate the validation of the error model. Furthermore, an optimized algorithm is applied to search the optimum aligning trajectory. Compared to conventional method, this algorithm has a broader range in searching extreme value, which can reduce the computational volume and improve the efficiency. It is also beneficial for improving the success rate of escaping from the local minimum spot and finding the optimum alignment spot. The error model is helpful to analyze the error propagation process and improve the alignment efficiency in LWS, which can be applied to other similar multi-axis precise system.