Simulated Off-Line Programming of Welding Robots

Abstract

The objectives of the work described in this paper are to develop and evaluate a method for calculation of interference between objects in a robot welding workstation, to develop a robot trajectory planning technique recognizing interference, inverse kinematics constraints, and welding parameter re quirements, and to demonstrate the trajectory planning tech nique using advanced computer graphics. Workstation mod eling and relevant kinematic relationships are discussed. A method of interference calculation is developed which allows rapid calculation of interference between convex polyhedra using a steepest descent graph search. If desired, exact sepa rating distances and directions can be found. A simple mod ule for automatic selection of welding parameters is de scribed. Interference-free trajectories that do not violate kinematics constraints are found by searching among possi ble inverse kinematic solutions for the desired welding torch trajectory. The above methods have been combined and implemented using interactive graphics in a prototype soft ware package called A UTO WELD.