On-line weld quality inspection based on weld indentation by us-ing servo gun

Resistance spot welding(RSW)is the primary join-ing method for car-body assembly.Control and inspection of weld quality have great importance to improve the performance of car.Based on the position feedback characteristics of servo encoder,on-line weld quality inspection method was proposed by using weld in-dentation.A spot welding experimental system including robot,robot controller,servo gun and weld controller was integrated.The devel-oped measurement program was used to acquie weld indentation on-line,and the measured results was calibrated by PLC displacement control system.The experimental results showed that the acquired weld indentation can reflect the real indentation on the 0.8mm low carbon steel(GMW2).The weld quality inspection rate can meet the demand for real production.The proposed on-line weld quality in-spection method can meet the demand of welded joint measurement in real plant environment