Study On Redundant Arc-welding Robotic System

So call "7-DOF", a metal arc-welding robot (Robotic welder) created for tubular T-joint (Branch) welding in piping work and steel structure industries, either in petrochemical construction, marine ship building, building structure or many others. The geometry model has been built and the kinematics analysis was done for the robot. The inverse kinematics problem was solved in the joints pace of the manipulator according to the geometric method and D-H matrix transformation. The expressions about the joint variables were obtained based on the welding characteristic parameters of tubular T-joint. It provides the design reference for trajectory parameter optimization of the intersection curves. Based on the actual welded spatial intersection curve, the simulation to the angle-variation of all joints was done.The outcome shows that all inverse solutions can determinately exist and meat welding requirements. The analysis results and theory can be widely applied for trajectory planning of welding intersection curve manipulators.A comprehensive optimization model focusing on energy minimization manipulator trajectory plan is built for Arc-weld Manipulator for Intersected Pipe based on Virus Evolutionary Genetic Algorithm (VEGA). This model can help to determine the optimal joint position and orientation in the robotic redundancy space. This optimization algorithm should meet four requiremenis, which are joint obstacle avoidance, position accuracy in trajectory tracking, mounting height limitation and joint torque and dynamics limitation.The simulation result of energy minimization by GA and Robottool written by Peter I. Corke who is from CSIRO Division of Manufacturing Technology shows that the energy consumed by the manipulator is minimized when the last linkage arms of manipulator is on the state of vertical orientation. This optimization algorithm doesn't need to find the inverse kinematics solution and can avoid the problem of singularity or pseudo-inverse matrix.The main ways and calculation formulae in this thesis which brought forward are based on relatively existing theory and aiming at real structure and function of redundant robot.