| 摘要 |
To determine the position of a bend in a workpiece, a flat beam of light is projected onto the workpiece, the resulting line on the workpiece is imaged, windows W4-W7 are set on the straight portions of the line, equations of lines through the centres of gravity of the portions in the windows are determined, and their crossing point identifies the position of the bend. To overcome halation H, a reference point M used for setting the positions of the windows is determined by first setting windows extending in the Y direction on each line portion at a predetermined distance behind the front endmost point of the line image. M is the point centrally between the centres of gravity of the imaged portions in these windows. The position of a selected one or two of the windows W4, W6 is set directly from M, the remaining ones depending also on other points in the image eg the front endmost point. |
