Analytical kinematics and working-condition simulation for friction stir welding (FSW) robot

In this paper, combining with the engineering reality needs, we developed a new type of friction stir welding robot welding system. Through the configuration analysis, introduces the structural components and functional roles of each part of the FSW robot, as well as the commonly used five kinds of typical working-conditions. Using D-H parameters method, establishment the forward kinematics equation of FSW robot and verify its rightness. With Piper criterion method, solve the inverse solution of FSW robot's kinematics equation. Finally, take melon petals welding condition for example, carry out trajectory planning for a given size rockets head weld and conduct welding simulation analysis. We have got different parameters' change curves relative to time on FSW robot's joint space and verified the correctness of its mechanism design and kinematics model

I. Introduction

Friction Stir Welding (FSW) technology is one of the most advanced solid-state welding process, invented and patented early by The Welding Institute UK. Compared with traditional fusion welding, Friction Stir Welding technology has many advantages. It has good welding mechanical properties that the strength of welding line is almost equivalent to even higher than the base metal, and has green environmental protection. The welding process do not need neither filling protect gas and welding wire nor pretreatment before it [1], [2]. In addition to the connection of different kinds of materials, Friction Stir Welding can be used to weld materials that can not be welded by traditional methods, such as high-strength aluminum alloy, non-ferrous metal, composite materials, etc. This welding technology has gradually become widely accepted and applied to all areas of the national economy, especially in marine vessels, rail transit and aerospace field, which has a strong demand for the materials above and the welding of complex thin-walled plate [3].