Automatic Surface Defect Detection Using Fringe Projection Sensor
Micro-Epsilon’s 3D non-contact surface inspection system provides for defect detection and the inspection of the aesthetic appearance of non-reflecting surfaces such as matt, unpainted, plastic and bare metal.
The surfaceCONTROL system is based on the principles of deflectometry and fringe projection, which enables even the smallest of surface defects to be recognized reliably, as well as the inspection of surface aesthetics. The system has been designed for the inspection of diffuse surfaces such as metallic surfaces including uncoated, electroplated, EPD, plastic surfaces and ceramics.
The fringe projection sensor scans the surface and generates a 3D point cloud. This point cloud is subsequently evaluated using specially developed tools in order to recognize extremely small defects and discontinuities on the surface.
Sensors with different measuring ranges, areas and resolutions are available to suit any application.
One of the main application fields of surface inspection system is the identification and analysis of deformations and discontinuity in automotive body shell parts. In modern stamping lines, automotive body shell parts are produced in a cycle time of a few seconds. The processes which have to be controlled are very complex and require lots of experience. Because of the different material tolerances and variations in the process, unwanted shape defects such as pimples, bumps, dents and neckings may appear. A visual recognition of these defects on metallic surfaces is almost impossible. In-process detection and retraction of the failures helps to minimize quality costs.
The surfaceCONTROL 3D sensor can scan the surface of car body components in a few seconds and offers the detection and evaluation of local defects. A digital stone is used for the analysis. This block is moved over the 3D-data of the surface like a physical block. The length and direction of the block is adjusted according to the shape of the surface. The result is the DefectMap; a graphical representation of the defect with exact information about the height and depth. The determined values can be used for an automatic decision making.
Three different versions of surfaceCONTROL are available. surfaceCONTROL Robotic is for the inspection of large components. surfaceCONTROL Mobile, a portable system suitable for surface inspection of components in different locations and the surfaceCONTROL Compact available for the inspection of small test pieces whose dimensions are up to approximately 410mm x 300mm.
For more information: www.micro-epsilon.com
