Electrode clamping force regulation of servo gun mounted on resistance spot welding robot

In this paper, critical issues and various methodologies to improve resistance spot welding performance with electrically driven welding clamps controlled by industrial robots are presented, where previous research on position and torque control of electric servo motor is expanded into servo gun based spot welding application and particular attention is paid to the accurate output of clamping force over time. Several mainstream solutions concerning the force regulation of servo gun are reviewed and analyzed to summarize the state-of-the-art in this field, on a basis if a closed force loop is employed or not. Meanwhile, major influence factors on the force tolerance are studied and potential solutions are discussed in details.