A non-tactile sensor for seam tracking and vision applications

Concerns the design and development of a low-cost sensor system for use in seam tracking applications. One-pass weld seam tracking represents a major technical challenge. The main difficulties include the intensity of the arc, which is brighter than the sun and contains a broad spectrum of visible and invisible radiation, and the heat, smoke and red hot "spatter" produced by the arc. At present, relatively few commercial weld seam tracking systems exist. Such sensors are expensive, and none has gained widespread acceptance. Machine vision principles have been employed in the sensor design and automated inspection represents an important secondary application. Automated visual inspection techniques may be used to make a simple pass/fail decision based on the general appearance of an object or to obtain specific quantitative measures of characteristics such as surface finish or component dimension.