01 THE CURRENT STATE OF INSPECTION
Only about 20% of the inspection process is automated
The manufacturing industry is now focused on a future guided by the concepts of “Industry 4.0” and “Smart Factory” that aim at a radical shift toward an integrated factory automation and rationalization. Most manufacturers have quickly recognized the limitations of human operations and have worked tirelessly to automate their manufacturing processes: machining, processing, convey and assembly. Inspection however sill lags behind, and well into this 21st century, many factories solely rely on the human eye to carry out this essential process.
Why are the dimensional and visual inspection processes not automated? This is because the human eye has unique capabilities that are hard to match: a high acquisition speed, a large field of view, a large dynamic range, a robust operation in various light environments and the possibility to detect features down to the 100 µm range. Although automated visual inspection has been massively introduced for the manufacturing of very small, low-profile parts like semiconductor chips, this is not the case for larger objects such as the many cast, forged and machined parts one finds in the engine or transmission of a car. In order to implement a robust and automated inspection process on such manufactured parts, it is actually necessary to measure shape irregularities at high speed, with high accuracy, while being completely impervious to the ambient light of the factory floor. However, in-line measurement equipment with those high requirement has not been available until now. As a result, only about 20% of manufacturing sites rely on automated processes for the inspection of medium and large parts, which has led to major issues for manufacturers.
OptoComb 3D scanners by XTIA, a breakthrough for automated inspection
There are several obstacles to automating inspection. The first and foremost is the required inspection speed. On the manufacturing floor, many parts have a takt time of about one minute that puts a heavy burden on all manufacturing processes. To implement the inspection process, there are two ways the dimensions of a part can be inspected, with drastically different performance regarding speed: contact and non-contact inspection. While the contact inspection method has a wide range of applications, its measurement speed is typically limited. It is thus used for sampling inspection, but it is not suitable for a total inspection of all manufactured parts. This is where non-contact inspection comes into focus. Conventional non-contact inspection methods that allow for defect detection typically include light triangulation and the white-light focus or white-light interferometry scanning method:
Unfortunately, on one hand, triangulation suffers from shadowing effects when applied to uneven and complex structures due to the angle between its incident and reflective light. On the other hand, white-light interferometry has a very short working distance and a very shallow depth of focus, which makes it unsuitable for inspection of large and medium parts with highly complex shapes.
This is where the OptoComb 3D scanners by XTIA come into play. The OptoComb inspection method uses a unique laser that presents a coaxial configuration, meaning that both its incident and reflected light beams propagate along the same axis: as a result, this method is not hindered by shadowing effects. In addition, the coaxial configuration together with the long working distance of the OptoComb provides the full 3D profile of the most complex parts such as cylinder heads, valve bodies, etc. where other methods fail.
4 advantages of OptoComb 3D scanners by XTIA
Some OEMs using OptoComb 3D scanners on their manufacturing lines
