Structured light as an enhancement tool for low contrast features in additive manufacturing

Structured light methods have seen wide use in obtaining 3D measurements of complex shapes from consumer good to aerospace parts. The use of phase shift analysis and improved high speed methods have made the method a viable tool for many time critical production applications. However, not every application requires full three dimensional measurement of the part, but rather just suffers from being difficult to do with simple 2D machine vision methods. For example, just locating bumps or holes on a part that has low contrast features as with many cast parts can be difficult and even unreliable. One of the first applications of structured light was for just such an application. Powder bed additive manufacturing creates a similar low contract challenge today. This paper will explore improved methods off using structured light to reliably determine location and orientation of low contrast features, and discuss several potential applications of the method.