Simulation of friction stir welding using industrial robots

Abstract

Purpose -The purpose of this paper is to establish a model-based framework allowing the simulation, analysis and optimization of friction stir welding (FSW) processes of metallic structures using industrial robots, with a particular emphasis on the assembly of aircraft components made of aerospace aluminum alloys. Design/methodology/approach -After a first part of the work dedicated to the kinetostatic and dynamical identification of the robotic mechanical system, a complete analytical model of the robotized process is developed, incorporating a dynamic model of the industrial robot, a multi-axes macroscopic visco-elastic model of the FSW process and a force/position control unit of the system. These different modules are subsequently implemented in a high-fidelity multi-rate dynamical simulation. Findings -The developed simulation infrastructure allowed the research team to analyze and understand the dynamic interaction between the industrial robot, the control architecture and the manufacturing process involving heavy load cases in different process configurations. Several critical process-induced perturbations such as tool oscillations and lateral/rotational deviations are observed, analyzed, and quantified during the simulated operations. Practical implications -The presented simulation platform will constitute one of the key technology enablers in the major research initiative carried out by NRC Aerospace in their endeavor to develop a robust robotic FSW platform, allowing both the development of optimal workcell layouts/process parameters and the validation of advanced real-time control laws for robust handling of critical process-induced perturbations. These deliverables will be incorporated in the resulting robotic FSW technology packaged for deployment in production environments. Originality/value -The paper establishes the first model-based framework allowing the high-fidelity simulation, analysis and optimization of FSW processes using serial industrial robots.

A Process/Machine coupling approach: Application to Robotized Incremental Sheet Forming

“…To compensate the tool path errors induce by the machine (robot) and/or the process compliance different approaches are available in the literature. Bres et al [2010] give a solution that consists in the dynamic elastic modelling of the machine or the robot structure in order to compensate by a linear or non linear feedback control the elastic deformations of the structure that degrade the TCP (Tool Center Point) pose accuracy. Outputs of such control consist in modifying the actuator torques.…”

Deformation prediction based on an adaptive GA-BPNN and the online compensation of a 5-DOF hybrid robot

“…In recent years, to realize curve welding and improve welding flexibility, FSW has been applied to industrial robots, most of which are series robots. However, for a workpiece with a large thickness, the required axial force is very large, usually tens of thousands of newtons, so it is difficult for series robots to support this force (Zimmer et al, 2010;Bres et al, 2010;Kusuda, 2013;. Moreover, the stiffness of series robots is poor, so the deformation is large under heavy loads.…”

Optimal Workplacement for Robotic Friction Stir Welding Task

“…Soron et al [3] proposed a modification to the former model using hybrid position/force feedback control, which worked quite well but it turned out that welding trajectory in 3D could not be precisely controlled. In another initiative, Bres et al [4] constructed a simulation platform for evaluating different control architectures to solve aforementioned problems. The simulation results were validated experimentally on serial industrial robot, KUKA KR 500-MT2.…”