Investigation of an array technique for robotic seam tracking of weld joints

A noncontact optical preview sensing technique for possible application to a robotic seam tracking system is presented. This technique uses a structured laser illumination source: a SELFOC lens array (SLA) coupled to a fiberoptic and a phototransistor (photodetector) array. The experimental results with the SLA and fiberoptic array demonstrate the feasibility of linear fiberoptic array sensing of the weld joint. The intensity profiles acquired by the array were such that when combined with suitable data processing software routines, the sensing technique was able to provide satisfactory measurements of joint width and location of the centerline. An experiment demonstrates the viability of the approach for tracking of a weld seam. A clear profile containing the expected features was obtained at each cross-sectional location as the joint was traversed.>