Process and system for detecting bend angle

A bend angle detection system provided with a light projector means for projecting a light ray to produce a linear projected light image on a surface of a workpiece, and pickup means for picking up a picture image of the linear projected light image produced on the workpiece surface, the system further comprising:

• (a) a first memory for storing a picture image of a first linear projected light image formed on the surface of the workpiece by the light projector means during abending operation, said picture image being picked up by the pickup means and;
• (b) a second memory for storing a picture image of a second linear projected light image formed on the surface of the workpiece, said picture image being picked up after a specified time period has elapsed after picking up the picture image of the first linear projected light image;
• (c) a logical operation unit for respectively assigning the picture images of the first and second linear projected light images to pixels arranged in a common plane represented by X and Y coordinates, dividing said pixels into two groups according to hue and brightness, executing a logical operation by making a comparison between each pixel associated with the first linear projected light image and its corresponding pixel associated with the second linear projected light image, these pixels having the same coordinates in the common plane;
• (d) a third memory for storing a new picture image which has been created by the logical operation performed in the logical operation unit;
• and
• (e) a bend angle computing unit for calculating the angle of a bend in the workpiece from the new picture image stored in the third memory.

A bend angle detection process in which a linear projected light image is produced on a surface of a workpiece, a picture image of the linear projected light image is picked up and subject to image processing, thereby detecting the angle of a bend in the workpiece, the process comprising:

• (a) a first step of picking up a picture image of a first linear projected light image formed on a working piece prior to bending of the workpiece;
• (b) a second step of picking up a picture image of a second linear projected light image formed on a working piece after completion of bending of the workpiece;
• (c) a third step of assigning the respective picture images picked up at the first step and at the second step to pixels arranged within a common plane represented by X and Y coordinates and dividing said pixels into two groups according to hue and brightness;
• (d) a fourth step of creating a new picture image through a logical operation which is performed by making a comparison between each pixel associated with the picture image picked up at the first step and its corresponding pixel associated with the picture image picked up at the second step in the common plane represented by X and Y coordinates;
• and
• (e) a fifth step of calculating the angle of the bend from the new picture image created in the fourth step.

A bend angle detection system provided with light projector means for projecting a light ray to produce a linear projected light image on a surface of a workpiece, and pickup means for picking up a picture image of the linear projected light image produced on the workpiece surface, the system further comprising:

• (a) a first memory for storing a picture image of a first linear projected light image formed on the surface of a workpiece by the light projector means prior to a bending operation, said picture image being picked up by the pickup means and;
• (b) a second memory for storing a picture image of a second linear projected light image formed on the surface of the workpiece, said picture image being picked up after completion of bending of the workpiece;
• (c) a logical operation unit for respectively assigning the picture images of the first and second linear projected light images to pixels arranged in a common plane represented by X and Y coordinates, dividing said pixels into two groups according to hue and brightness, executing a logical operation by making a comparison between each pixel associated with the first linear projected light image and its corresponding pixel associated with the second linear projected light image, these pixels having the same coordinates in the common plane;
• (d) a third memory for storing a new picture image which has been created by the logical operation performed in the logical operation unit;
• and
• (e) a bend angle computing unit for calculating the angle of a bend in the workpiece from the new picture image stored in the third memory.