Advances on robotic welding - an introduction

摘要

Automatic welding is one of the most importantapplication fields for robots, especially industrial robots. Once the multiple-joints robot with six degrees-of-freedom ('Unimate' developed by George Devol and Joseph Engelberger which was applied on an assembly line at General Motors) was invented in the 1960's, welding was considered as one of its essential tasks. Robots have been widely used since then in the field of automatic welding because of their high reliability, flexibility and accuracy. Traditionally, welding robots work with the mode of Teaching by Showing (TS). TS mode has many advantages although its short-comings are obvious. After the robots are taught via a manipulation teaching box or off-line programme, they will repeat a given operation again and again despite any positioning errors of the work-pieces. There are a lot of welding robots working in TS mode today even though the high level of precision positioning of workpieces required makes automatic welding with robots extremely expensive.