NSF Engineering Research Center for

Reconfigurable Manufacturing Systems Study of Surface Porosity Using Reconfigurable Inspection Machine (RIM)

The University of Michigan, Ann Arbor

Surface Porosity Inspection – Research Objectives

• Establish a methodology necessary for non-contact inspection of porosity defects.

• Determine if the above methodology can reliably detect porosity defects according to GM/DCX specifications.

• Determine if the above methodology can be implemented in-line (i.e. at line rates). • Validate the method with production cylinder heads and blocks.

NSF Engineering Research Center for Reconfigurable Manufacturing Systems College of Engineering, University of Michigan 4/29/2020

Background: Why Inspect Engine Cylinder Heads ?

• Areas on the deck face of an engine cylinder head are isolated one from the other to prevent the mix of water, oil and combustion gasses.

Sealing Bead Fire ring Gasket body NSF Engineering Research Center for Reconfigurable Manufacturing Systems College of Engineering, University of Michigan 4/29/2020

Porosity Inspection is Currently Performed by Human Inspectors

NSF Engineering Research Center for Reconfigurable Manufacturing Systems College of Engineering, University of Michigan 4/29/2020

Reconfigurable Inspection Machine (RIM)

Illumination System CCD Line Scan Camera U.S. Patent #6,567,162 B2 Yoram Koren, Reuven Katz NSF Engineering Research Center for Reconfigurable Manufacturing Systems College of Engineering, University of Michigan 4/29/2020

System Operation

Controller Module

Vision System

Inspection Module NSF Engineering Research Center for Reconfigurable Manufacturing Systems College of Engineering, University of Michigan 4/29/2020

Easy to use User interface and Automatic Analyze and Decision

Zoom Window for Pore Analysis Defects Highlighted in Red

NSF Engineering Research Center for Reconfigurable Manufacturing Systems College of Engineering, University of Michigan 4/29/2020

Surface Porosity Inspection Study Achievements (1 of 2)

• Developed a Reconfigurable Inspection Machine (RIM) for porosity inspection on cylinder heads. • Developed algorithms, software for detecting and classifying surface porosity. (Able to classify pores by diameter, x-y location, and specification region.) • Conceptualized a method for depth validation of detected pores using side lightning.

NSF Engineering Research Center for Reconfigurable Manufacturing Systems College of Engineering, University of Michigan 4/29/2020

Surface Porosity Inspection Study Achievements (2 of 2)

• Able to detect pores with diameter > 300 micrometer.

• Able to detect isolated and edge-connected pores on aluminum and cast-iron parts.

• Created a user-friendly software interface for reporting and analyzing defects.

• Created a software tool for assessing the repeatability of the porosity inspection system.

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As a result of this research GM built an inspection machine and DCX is testing it in a plant.

NSF Engineering Research Center for Reconfigurable Manufacturing Systems College of Engineering, University of Michigan 4/29/2020

System Evaluation at GEMA

Over 600 engine blocks were inspected by the RIM. 85% of bad parts were correctly rejected. (15% missed detections due to defects other than pores and template misalignment) 90% of good parts were correctly accepted. (10% false alarms mainly due to template misalignment) NSF Engineering Research Center for Reconfigurable Manufacturing Systems College of Engineering, University of Michigan 4/29/2020

Future work

Inspection of porosity on pistons and cylindrical parts Defect inspection on auto-body panels Combustion chamber volume measurements Improvements of RIM performance reliability NSF Engineering Research Center for Reconfigurable Manufacturing Systems College of Engineering, University of Michigan 4/29/2020

The End

Questions are welcomed NSF Engineering Research Center for Reconfigurable Manufacturing Systems College of Engineering, University of Michigan 4/29/2020