Scratch and Surface Damage Detection

[Mr.Hydrogen]

Hello, All...

I'm new to this, and I'm just asking for recommendations.

A few days ago my boss asks me about a vision based Automated Inspection system, and he referred me to NI for this.

What we want to do is to detect surface paint scratches and presence detection of paint on the surface of the part.

We are considering the smart camera for this, but I'm not sure if additional software will be needed since the paint defects appear at random on the part. (is the shipped NI Vision Builder for Automated Inspection enough?)

Another thing is: will a monochrome camera be enough for our purpose?

Lastly, I have no experience with LabView, just some familiarity with C and programming in general, can someone refer me to some examples of study material related to this project?

[azp7 · Accepted solution]

Hi!

Is not a problem that the camera be monochrome, actually, don't use color cameras if is not extremely necessary. 

You will need software too, seeing your application, probably you will need Vision Builder for Automated Inspection (development) ( https://www.ni.com/en-us/shop/product/vision-builder-for-automated-inspection.html )

When you get the Vision Builder, it includes some LabVIEW examples that you can use as a base for your code.

As a recommendation, you can call a Sales engineer a NI, and explain the purpose of your project and what you need. If you don't have a lot of experience with LabVIEW tell him too. They can bring you a lot of help in your project more than just a sale.

[Mr.Hydrogen]

Thank you very much azp7, I will proceed with your recommendation, and call the sales engineers at NI.

[1100fps]

You will need a good definition of scratch and surface damage.  What level of scratch needs to be detected. Is surface damage a dent, or a rash?

You will need to select your camera resolution based on the size of defect you want to capture and the inspection area.

Lighting can be critical.  On a flat surface there are multiple lighting options that will bring out a scratch or other blemish.

Use of polarizers can enhance small defects. 

Speed may be an issue, which could narrow down your choice of hardware.

If the material being inspected comes in different colors, that could affect your choice of lighting.

I did mention lighting but will mention it again.  Lighting can be critical.

The Automate Show in Detroit in May will have a range of companies that sell all manner of cameras, lenses and lighting, you can bring a sample and get some pretty sage advice.

The is also Certified Vision Professional training offered (Shameless plug - I help teach one of the advanced modules).

I am a little irritated with NI, they do not seem to be putting much effort into improving the machine vision module, and they no longer offer smart cameras, and I detest subscription pricing.  

Another consideration is how many inspection stations do you need?  That can affect software costs.

Vision builder might do the trick for you.  I use the Vision Development Module, which is an add on to the Professional Development System.  It's what I know. Vision builder has limitations that may not bother your application at all. 

It's easy enough to download an evaluation copy.  You will still need a camera, lens and some lights.  Did I mention that controlling the lighting environment is critical?

Most camera suppliers supply cameras with a viewing module, so you don't need fancy software to set up a camera, but you do need a camera that standards Complient (Typically GigE Vision, and USB3 Vision) in order to work with most vision development software.

Avoid color cameras unless there is a need to evaluate the color of the subject.  Color cameras extrapolate color information through the use of a Bayer Filter, which can reduce resolution by 2/3 from a non-Bayer camera.

Sorry for the ramble. 

It's awesome that your boss is interested in pursuing Machine Vision, and a career growth opportunity for you.