The world is 3D - are you?

There’s an interesting story in Control Engineering (September 2008) about the application of 3D vision. Canadian integrator, Spoko Integrators Ltd., needed to check orientation of a stamped part. If you’re at all familiar with metal stampings, you’ll know that they tend to look much the same from one side as the other.

The problem was solved by using a 3D camera from SICK. This produced an image where relative height was indicated by color, and this showed which way the embossment faced. What’s not mentioned in the article is that this approach needs the part to move under the camera in order to generate height data from successive structured light images.

So while the SICK 3D cameras are an interesting product, and this is a neat way to determine orientation, part of me wonders if this was also a case of an engineer wanting to use a cool new toy. A low angle, darkfield, ringlight would be a cheaper solution - eliminating relative part-camera motion would simplify the system - although I willingly accept that there may have been some constraints of which I’m not aware.

So, the takeaway from this brief ramble is: if 3D is the only way to solve your application, then go for it, but not until you’ve proven that 2D isn’t up to the task.