Need advice on machine vision

Hi everyone,

I will shortly start last year of college and thinking about final project ideas.
Last year i have made and programmed this palletiser machine. It is controlled by siemens 1200
https://www.youtube.com/watch?v=CyyraLJyzA4

This year I want to take it step further. I have kawasaki FS03N that I could use.

My plan is to design and make gripper arm for robot and use robot to load the blocks on the conveyor.
To make it challenging i would like to use some kind of vision system that identify and would load "good" blocks and reject "bad" ones. Type of block marking would be based on vision system capabilities.

To tell the truth I know nothing about the vision systems and need your help to steer me right direction.
First and foremost I have budget of 300 euros for camera (second hand obviously). The cheaper the better...
What should i look for?

I've used the IFM O2D series quite a bit. It uses contours/patterns over area (light/dark/blob). Four or five outputs and a couple of inputs. Ethernet IP capable. Software is free.

They come in different field of views and NPN/PNP flavors though, so a bit of research on their website to match it to your application is appropriate.

I usually see them on ebay for around 200USD

I haven't used the IFM mentioned above but their other products are pretty solid. I've always used Cognex for vision and they work very well but are usually more expensive. When I was working field service, this was the most popular system I saw so the experience would be good when you start your career.

You can sometimes find them cheap on eBay though. See link below(camera only, you'dstill need cables)
https://www.ebay.com/itm/COGNEX-IN-...1eb3ca8:g:i8kAAOSwroFbhb2C&LH_ItemCondition=4

with a 300 euro budget you will more than likely not be able to use cognex. I think even their lab kit IS2000 is around $1300 or so.

I have also used the IFM sensor, it does ok as long as speed isn't too important. It doesn't have a lot of flexibility as far as tools to use, but for a simple pattern match it should do ok.

I also think Keyence and banner make some fairly low end vision type sensors now, may be worth a look. Keyence is historically expensive, but I have not used one of these lower end ones to know for sure.