Automatic detection of 3-dimensions shape and the coordinates of the work-piece freely placed on the table

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Generally a work-piece must be placed on the table of the machine in parallel to its coordinate axis (X-axis or Y-axis) for accurate machining. However, this kind of operation needs higher skill and experience ; therefore the following alignment method is considered effective. Namely, a work-piece is first placed roughly, and next its alignment angle error to the coordinate axis is measured, and then for compensating it the coordinate axis of the NC program is rotated as much as the angle.In this study, first a camera searches where the work-piece is placed on the table, and detects its shape and then the coordinate of its position on the machine table. By various simulations, which had been experimented, it was found that detecting edge lines and then measuring the distance between the two facing lines enabled to recognize the general shape and the size of the work-piece. To be concrete, drawing the virtual lines crossing at right angles to the edge lines and then measuring the distance between the two points of intersection enabled to detect the general size of the width, length, and height. Its measuring accuracy was almost 1 mm, and this accuracy was good enough.In practice the measuring probe moves to the neighborhood of the work-piece and detects the coordinates of the two points on the sides of work-piece. Calculating the angle between the line linking these two points and the axis one, and rotating the coordinate of NC program as much as the angle degree enabled to make the precise positioning of the work-piece. These work arrangements were done automatically.Moreover, going ahead with this study, the combination with this positioning method of work-piece and the remote control method of the machine by utilizing Internet technology found out to be very effective.