Real-time vision-based control of weld pool size

A computer vision technique based on the real-time measurement and control of the upper surface or ‘topface’ weld pool size is discussed. The primary objective is to demonstrate the feasibility of using vision-based image processing to provide measurements and subsequent control of a weld's geometrical properties during the weld formation or molten phase. A novel reference feature – a correlation-based image analysis algorithm – has been developed, which may be configured to operate with a number of different welding processes. Upper surface weld pools with regulation via a simple classical feedback control algorithm have then been demonstrated to show how this approach may be used to improve weld uniformity and repeatability.