Electro-mechanical Modeling And Trajectory Simulation For Laser Welding Machine Tool

The welding structure, this paper discusses, has the characteristics of complex feature. To realize high quality laser welding, multi-axis welding machine tool and reliable control theory should be used to meet the position and posture requirement of the welding torch. Thus, its dynamic performance and welding trajectory should be researched deeply taking the structure, dynamics and controller into consideration. As a research object, the"5+2"axis laser welding machine tool is chosen. Based on the analysis of dynamic characteristics in ANSYS, some important component is optimal designed. Then, the dynamic modeling method for the"5+2"axis laser welding machine tool is researched. The validity of dynamic model is verified using experimental mode analysis. Moreover, its electro-mechanical simulation platform is finally built, considering both the dynamic model and the controller. By employing the platform, the integrated simulation of welding trajectory is figured out which plays an important role in studying its smoothness and feed rate planning. The main contributions of this dissertation are shown as follows:For the optimal design of the"5+2"axis laser welding machine tool, the structure and its operated principle are discussed to find out which components can be easily excited. Results indicate the improvement of dynamic performance of whole machine tool after structure improvement in ANSYS. To identify the different influence of variable structures'flexible deformation, the dynamic modeling method varies. This article studies a hybrid dynamic modeling method for mechanical system with lumped elastic and flexible parts, based on finite segment and finite element modeling. The method is applied to a multi-axis laser welding machine, leading to the establishment of its dynamic virtual prototyping. The validity of dynamic model is verified using experimental mode analysis.The mechanical and control subsystems of machine tool are simultaneously modeled concerning their interaction. Then, the main control parameters are optimized for better dynamic characteristic. Step disturbance is inputted into the control system to verify the anti-interference ability. Results indicate the reliable PID controls parameters.The welding trajectory is applied to integrated simulate in the platform. To identify the importance of smoothness for welding quality, two trajectories, before and after smoothing, are used as the input of the simulation platform and welding experiment. Experimental results realize the reliability of simulation results. Then, a series of trajectories in different feed rates are conducted to analyze the relationship between velocity and accuracy of welding to figure out the optimum feed rate for matching the dynamic characteristic of machine tool.According to the research above, a feasible method is proposed for structure optimum design, dynamic modeling, servo controller parameters tuning, feed rate selection and dynamic performance optimization of multi-axis machine tools.