Closed-loop control of friction stir welding process is helpful to realize welding automation in order to improve the stability and reliability of welding quality. Based on the friction stir welding pressure control system

this paper studies the variation of servo drive parameters in the welding process

in order to find out the optimal closed-loop control method. The results show that the spindle torque and Z-axis torque fluctuate greatly in the stable welding stage

and it is difficult to achieve closed-loop control as feedback signal. The closed-loop control of spindle power in welding process can be well carried out under different process parameters

and can be used as an index to measure the heat input of the weld. A closed-loop control method for welding process based on spindle power feedback is proposed

which provides a new idea for welding process control.