Abstract

The feeding stage of sport shoe-upper for automatic screen printing machine for printing press-segments on shoe-upper exists the following issues: Firstly, the locating shoe-uppers on the conveyor of screen printing machine is made by hand and based on the experience of workers. So, this reduces productivity and increases the cost of the product. Secondly, there are deviations of the press-segments on shoeupper after printing (the current deviation is ± 1 mm). So, these are affected to the next stage of sewing contour lines on the shoe-upper. Currently, the shoe manufacturing company in Vietnam wish solve these problems, but so far, in addition to resolve manually there is no feasible method has been given. In this paper, a precise position control of shoe-upper for screen printing machine using image processing techniques is introduced. A camera is used to capture the image of shoeupper. The binary image of shoe-upper is used for image processing to recognize the position errors in directions of X, Y and θ coordinates. A new algorithm to calculate the position errors of shoeupper is proposed in this paper. The shoe-upper is locating on X - Y - θ tables which can move X, Y directions and rotating angle. These tables are controlled by three servo motors. The mission of X - Y - θ tables are adjustable positioning accuracy of the shoes-upper by comparing the current position with its standard position that has been previously stored in the computer. The effectiveness of the calculation algorithm of shoeupper errors and the high accuracy of image processing and mechanical system are proven through experimental results