Abstract: A method and apparatus for correctively guiding an item on a desired path along a material is provided wherein a guide path matching a desired path for an item to be guided along a material and a plurality of templates containing images of the material are inputted into a computer. The item is guided along the material in a path following the inputted guide path, and a need for correction of the actual path of the item along the material is checked and, where necessary, correction is made at predetermined, inputted intervals. Self-correction of the path the item follows along material is accomplished by visual recognition of templates containing images of the material matching previously inputted templates.

Abstract: A method and apparatus for controlling tension of lay-in warp yarns knitted on a warp knitting machine is provided for knitting a fabric having lay-in yarns with varying intermittent spacing between horizontally corresponding lengths thereof. The lay-in warp yarns of a warp knitting machine are preferably dividedly passed by two or more flutter bars which are simultaneously moveable in cooperation with one another to simultaneously and reciprocably increase/decrease and decrease/increase tension on lay-in warp yarns passing thereacross. Alternatively, the two or more flutter bars may simultaneously and reciprocably increase/increase and decrease/decrease tension on the corresponding lay-in warp yarns passing thereacross. Each flutter bar is a shaft with a parallel and spaced-apart contact arm for contacting yarn. The flutter bars are connected such that rotational movement by one flutter bar causes rotational movement of the other flutter bar.