Modeling of Motion Simulation of Welding Robot Manipulator with External Force Interaction

Modeling of motion simulation of welding robot manipulator with external force interaction is studied in this paper. The modeling application of welding robot manipulator is for the welding of box girder on the offshore plant. Mechanical structure of robot arm consists of six rotational joints, thus the total degrees of freedom is six. Then, Denavit-Hartenberg method is used to solve kinematics of the mechanical structure of robot. Once kinematics is analyzed then dynamics is analyzed through the Lagrange's formulation with external force interaction model. We use optimization technique to create the motion of robot manipulator. In the optimization process, we set design variables, objective function, and constraints. The design variables are the joint angle profiles of robot manipulator for welding motion. The object function is multi objective function which is implemented in the summation of joint torque squares of each joint. Joint angle limits, torque limits, continuity condition, collision avoidance are imposed as time dependent and time independent constraints in optimization. All the joint space information include joint angle profiles, velocity profiles, acceleration profiles are obtained as optimal solution which can minimized joint torque to create the motion while the external force is interacted.