Laser based inspection and path correction system for automatic sewing apparatus

This paper describes a laser triangulation inspection system which has been integrated into an automatic stitching machine used to stitch overlapping components. The inspection task locates defects that can occur prior to and during the stitching process so that the stitch path can be modified accordingly. The three-dimensional shape of the surface and component edge positions are extracted through the analysis of the laser line images captured by a high frame rate camera. Different stages of the data collection aspect of the inspection process are presented. These include calibration and laser line image processing techniques. The data modelling of the extracted edge points is based on least-square polynomial regression and parametric curve approximation. The obtained data model is used for stitch path planning. These techniques were tested on an automatic stitching machine.