Automatic defect inspection of reflecting surfaces

The reflectCONTROL range of surface inspection systems from Micro-Epsilon has now been extended with new product variants.

The RC-Robotic system is intended for large objects such as complete automotive body shells. Here, the optical part of the measurement system as a sensor is located on the end effector of a robot arm. A measurement process covers an area of approx. 70 x 30 cm; the robot moves the sensor to different positions on the object to be inspected. The RC-Compact inspection system with fixed sensor is available for smaller measuring objects and is ideal for laboratory type inspection. The object to be inspected can be moved with a measuring table that itself can move on three axes and can be tilted for curved surfaces in order to inspect the complete object. The measurement of such a part requires around 10 to 30 seconds and can be automated for series production. This is achieved by generating a typical measuring task in which the sensor moves to stored measurement positions one after the other. In the case of flat objects, where the surface can be inspected in one complete measurement, the object is on a fixed part carrier. The loading is either performed automatically using a handling robot, or manually. The measurement time for this system variant is approx. 3 seconds per part. The appropriate solution for many products can already be found using the standard systems mentioned above. However, the manufacturer also provides an RC-Custom version for very special measurement applications. The optimum system arrangement for the measuring object is defined, customised for the client and integrated in the production process for this variant.

Based on the principle of deflectometry, reflectCONTROL analyses the reflections from smooth surfaces. In order to guarantee reproducible and well-structured light-dark transitions, a striped pattern is shown on a display and reflected in the object surface. Cameras record the image reflected from the surface of the measuring object and pass the data to an industrial PC for evaluation. An industrial LCD is used as the display. The measuring principle is suitable for automatic recognition of the following types of defects: contact, inclusions, fluff / hair, adhesive residues, mottles, craters, paint delamination, paint drops, runs, pinholing, overspray, moulding defects, scouring, shell defects, slide marks, welding beads, spitters, specks, partial / missing paint, soiling and water droplets.