An economical vision system saves money on acquisition, but has to deliver on performance and ease of use or any savings could be lost downstream.
General Motors is one of the first users of Banner Engineering's (Minneapolis, MN) PresencePLUS Proô, a camera-based, low-cost visual inspection sensor aimed at functionality and ease of use. The automaker is using the sensor to measure hood-fender gaps on minivans. The sensor correlates pixels into millimeters and its processor assesses whether the gap is narrow, within spec, or wide. Another production line use giving real-time process feedback is inspecting the location of nut plates inside the sliding door subassemblies. This ensures that twin plates welded to a panel have their threaded holes aligned through other access openings.
While performance is obviously needed in such applications, GM Body Shop Engineer Alan Carr notes, "One of the most beneficial, yet simple, advantages of the sensor is its TEACH Tool for eliminating guess work and applying the statistical variation of a sample to a [production] tool's acceptable operating limits." With this startup aid, new users can follow a point-and-click guided setup sequence, while old hands are free to override automatic settings to come up with customized inspections. To set up an inspection, a user illuminates the target, focuses the camera, and selects the vision and analysis features needed. Inspection tolerances can be set up automatically or manually. Once set up using a PC, inspection parameters are stored in the sensor without need of the PC.
Carr adds, "Establishing optimum focus, lighting, and other photographic parameters is well facilitated with the aid of video output from the Banner controller." The sensor also performs multiple inspections simultaneously, inspecting for both translation and rotation variations.
For more information on PresencePLUS Pro by Banner Engineering, enter 533 at www.designnews.com/info.