The measurement and production control of woven mesh

In the weaving industry a variety of meshes are manufactured, using both metallic and nonmetallic materials, for a wide variety of filtration applications. At present the quality of the mesh is monitored at several stages of the manufacturing process to keep selected parameters within specified limits. This involves stopping the process approximately every half hour, manually assessing the mesh quality, and taking remedial action as necessary. There is a need to replace these manual checks with an automatic system that can continually monitor the mesh as it is being manufactured and, with appropriate actuators, control the loom on-line. The authors present initial results of research being conducted at Sheffield University to develop such a system for wire mesh. Early experiments proved that a contact measurement technique is inappropriate due to the severe vibrations and backlash nonlinearities present in most looms. The approach adopted here therefore, is to use image processing techniques. The instrument is transputer based so that the image processing can be performed on several processors to achieve the real-time performance necessary for on-line monitoring and control purposes