Using proximity sensors to sense bottle caps

GEOFRA

Member
Join Date
Jul 2002
Location
Nicosia
Posts
99
I have been asked by a client which is a beer producer to check if plastic boxes that are running on a conveyor belt have been filled with beer bottles. The bottles in the plastic box are approximately 25mm lower than the top of the box. One solution I have thought of is to use inductive proximity sensors installed above the box and sense the metal cap of the bottles which are four in a raw. I have seen some sensors which can sense up to 40mm but am not sure if these could be reliable for my application. I would like also to know if it’s a good idea to have proximity sensors installed so close to each other as the bottle caps are approximately 65mm apart (center to center of caps). Please take into consideration the small size of the cap and also that when moving on the conveyor belt bottles are shaking little so the target is not so stable or big!
 
Talk to someone at a sensor company. Keyence, IFM, Balluff, etc. They will do all of the testing for you. The spec sheet for any good prox will explain how close the prox's can be together.

I would do vision with a Cognex camera if it was me... depending on belt speed.
 
Vision would be far more accurate and would reject things like improper sealing, improper threading / tension based on position of cap to bottle, etc.

Cognex checker is very affordable and will give you a good result in this application and Cognex engineers will work with you to make it happen.
 
Vision would be far more accurate and would reject things like improper sealing, improper threading / tension based on position of cap to bottle, etc.

Cognex checker is very affordable and will give you a good result in this application and Cognex engineers will work with you to make it happen.

+1 on the Cognex Checker. Perfect for this application and easy to set up!
 
Thank you all! It seems that Cognex is a good solution. Do you think I will need one sensor for each bottle or it can view all four bottles in the row withib the box?
 
Thank you all! It seems that Cognex is a good solution. Do you think I will need one sensor for each bottle or it can view all four bottles in the row withib the box?

You will be able to fixture the camera to view the entire box. There are many things you can check very quickly, but I would think a simple pattern tool will do the job nicely.

The nice thing is there is much more you can do with the Checker. I know once I started playing with mine I found at least 5 things I could look for with the checker in addition to the original inspection requirements of the project.

If you have a rep near by, give them a call and I'm sure they would love to bring one to you to demo. You will be able to try it with your application.

Dave
 
After reading a lttle bit about the senor at Cognex's site I am not sure if and how I can use it.It seems that am missing something here so please advice. The sensor has some intelligence on its own or is there some software installed sepearately on a PC that will process the information gathered from the sensor? In order to use this information in a small PLC (I have in mind SIEMENS S7-200 series)what do I need? I dont want to spend a huge amount for a PLC just to generate a simple alarm in case a bottle is not present.
 
the sensor has it's own internal storage which you program.
this is programmed by your notebook initially - you can access this over a network
you need to trigger (ext. pulse)the camera, this then checks the image and produces an OK output.
the PLC needs to give a 'Job' output to the camera to tell it which product is running. - if the physical product varies
 
They make a IO interface if you don't want to use a PLC but it's along the same price as a small micro Plc and far less functional.

If you are checking for cap placement and seal this is not a place to be cheap or cut corners IMHO but YMMV.
 
Hi Iant, when you say an OK output I guess you dont mean a physical output but a software output. I have an S7-200 PLC on which I can add an Ethernet CP243-1 card, on which I can connect the Cognex Sensor but am not sure if I can make these twwo talk together.
PLC kid this is actually a system that will sense if bottles are present in the plastic box or not. My idea was to sense the caps.
 
When I say output i mean output.
As far as E/net that is possible talk to Cognex
there is probably profinet or simler
 
Hi Iant, when you say an OK output I guess you dont mean a physical output but a software output. I have an S7-200 PLC on which I can add an Ethernet CP243-1 card, on which I can connect the Cognex Sensor but am not sure if I can make these twwo talk together.
PLC kid this is actually a system that will sense if bottles are present in the plastic box or not. My idea was to sense the caps.

Inline weigher?

1 bottle missing in a box of 6 is 17% light
1 bottle missing in a box of 12 is 8% light

etc.

Might be a cheaper solution if all you want to check for is full boxes.
 
a camera is by far the simplest soultion you only need one camera, have a look in these returnbottle machines they also work with a camera. just put your head in one and see how easy.

however when you want mechanical also no problem.
the bottle packer has exactly what you need.
lower a harnas with your sensors each time the box is below. you will need to stop the box.
and yes weighing is another good option, you can even se if there is a empty bottle in the box (it happens when the filler forgets to open a valve.
 
In most bottling processes you want to detect cap placement and seal right after the filler so they can be ejected and not waste packaging materials in addition to the bottle and partial liquid depending on the product.

As Daba said if you are trying to detect bottles present in package then a check weigher would be good and are very fast.

I have seen a few processes checkweigh bottles before they enter the packer and discard any that are not the right fill as well as check weigh the final package to insure perfect products go out the door which is mostly a quality check.
 

Similar Topics

Hi, First time posting a question so bear with my ignorance. I'm trying to figure out an easy way to use the pulsed output of a proximity switch...
Replies
22
Views
18,392
Hello everyone, I'm working on a project that involves controlling an array of nozzles within a CNC environment, where the nozzles travel along a...
Replies
5
Views
105
Hi, I was noticing that Profibus connectors have 2 ports on them that can house 2 separate cables. Can I use 2 cables with Profibus signals...
Replies
3
Views
108
Hi, Seeking consultation on an implementation matter, and have a question about Modicon Compact 984 communication through RS485: Three Modicon...
Replies
2
Views
76
Back
Top Bottom