Gm Global Technolgoy Operations, Inc.

Michael E Swanger

John Stilianos Agapiou

Daniel K Owusu

Robert J Hogarth

A system and method for identifying the start location of the lead thread and the thread profile and quality in a threaded bore in a part, where the system and method can be used for determining the location of the lead thread in a threaded bore in a cylinder head for a spark plug in one non-limiting embodiment. The system includes a moveable table on which the part is mounted. The system also includes a probe having an optical assembly that is inserted in the threaded bore. A camera uses the optical assembly to generate images of the thread bore, where the images are image slices as the probe moves through the threaded bore. The image slices are unwrapped and then joined together to form a planer image to determine a start location of the lead thread, thread count, defects in the threaded bore and thread profile parameters.

Methodology for evaluating the start and profile of a thread with a vision-based system

A method and system are provided for non-contact evaluation of a machined surface of a cast-metal part, including a vision-based porosity inspection station. A digital image of the machined surface is acquired, oriented and scaled to an XY coordinate system, filtered, and inverted. A second image is generated with known design surface features eliminated. Each pixel of the inverted digital image is XOR-compared with a corresponding pixel of the second image. Identified common surface features common to both images is analyzed statistically for conformance to a threshold. A defect is identified as any identified surface feature common to both images which exceeds the threshold. The system moves the part for further processing if a statistical analysis of defects indicates an acceptable component, and alternatively, removes the part from further processing if the analysis indicates a flawed component.

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Almont, MI, United States of America

Michael E Swanger