SYSTEM FOR AUTOMATICALLY INSPECTING A FLAT WORKPIECE FOR HOLES

摘要

36 An inspection system is described for automatically documenting and verifying the position and dimensions of holes in a flat sheet metal workpiece (50). The system includes a transparent, light diffusing inspection table (1) upon which the workpiece is laid. A ball screw-driven yoke (6) travels continuously along the inspection table in the Y direction and includes a bottom bar for positioning a source of illumination (14) below the table and a top bar for positioning a plurality of optical sensor arrays (30, 32) above the table. A detector is interconnected to the sensor arrays to detect light-to-dark and dark-to-light transitions which are representative of the edge of a hole. Circuitry is provided to multiplex the optical sensor arrays so that each pixel thereof is sequentially read in order to provide data corresponding to hole locations in the X direction across the table. The position of the yoke along the ball screw (2) provides data corresponding to hole locations in the Y direction.