Proximity Sensor Suggestion

[codedRed]

Does anyone have a suggestion for some kind of proximity sensor that would detect if an object is sticking out of a cup? A stationary cup, so it would have to have a detection width of +/- 3 inches and a range of about the same. Trick is no sender/receiver sensor, only one housing, there is no room to mount two devices. Thanks.

 

[drbitboy]

Does anyone have a suggestion for some kind of proximity sensor that would detect if an object is sticking out of a cup? A stationary cup, so it would have to have a detection width of +/- 3 inches and a range of about the same. Trick is no sender/receiver sensor, only one housing, there is no room to mount two devices. Thanks.

need more info:

• are both contact and non-contact acceptable?
• what is the density of the object sticking out (mass, optical, etc.)?
• is there anything else that is going into or out of the cup, e.g. a stream of liquid filling the cup, to be ignored?
• how much room is available for the device (height, width, depth)?
• is the cup in an enclosure?

 

[parky]

There sensors that do not need a reflector or sender & receiver however, for very fine detection you could use ones with fibre optic sender/receivers as these are very small. and connect to the sensor control unit mounted quite a distance from the location.
Most sensor manufacturers have these.
I have used this type for detecting mis-shaped & odd height/width soap bars and misplaced lids on jars

 

[Yendor33x]

I usually use keyence cameras for stationary detection like that. GO/NO type trigger. Expensive option but execution is good. \
I don't think I've ever used a prox with a range of 3 inches.

 

[codedRed]

@Parky: Thank you for your response. The only problem with a fiber optic sensor the detection width, it won't see the across the whole plain (which would like the top of a cup and about three inches). Plus I would prefer to only mount a device on one side of the cup.

@drbitboy: Only no contact. And the part density is pretty high, it's about 3/4 inch wide. It's a white plastic part.

 

[codedRed]

@yendor: And that is an option, it's just that the mounting of a vision inspect here would be awkward

 

[parky]

Information is the key to correct response, if we knew what this was like i.e. a picture of the two most likely states i.e. good/bad it would help.
Is this a lid or overfill or what, it is unlikely you could find a sensor that gives a broad width without a broad depth. Some suggestions assume the cup always stops in the same position then mount the sensor at an angle to the centre of the cup, use a couple or more sensors over the 3 inches, or if moving then a cup sensor so you can program a window to detect only while the cup sensor is covered. Is this plastic bit uniform etc. so many scenarios.

 

[drbitboy]

My son wrote a simple algorithm in python using a camera to detect when their dog would go near the trash can in the kitchen, when they were out of the house. This should not be hard (as long as the piece of plastic looks like a dog).

 

[codedRed]

Information is the key to correct response, if we knew what this was like i.e. a picture of the two most likely states i.e. good/bad it would help.
Is this a lid or overfill or what, it is unlikely you could find a sensor that gives a broad width without a broad depth. Some suggestions assume the cup always stops in the same position then mount the sensor at an angle to the centre of the cup, use a couple or more sensors over the 3 inches, or if moving then a cup sensor so you can program a window to detect only while the cup sensor is covered. Is this plastic bit uniform etc. so many scenarios.

I wish I could provide you with pictures or what the product was but that is against company regulations. I can tell you that the cup has no lid, but indexes from position 1 to position 2 where there is guarding/cover over the top of the lid and jams occur if something (pencil like) is sticking out of the top of the cup. The problem with detecting while it is in motion is that the indexer is driven by an AC motor/drive and if there is a part sticking out while indexing from position 1 to 2 it would already be too late and the indexer would jam.

 

[drbitboy]

https://www.youtube.com/watch?v=TUvXIqWaIRA

 

[drbitboy]

... I can tell you that the cup has no lid, but indexes from position 1 to position 2 where there is guarding/cover over the top of the lid and jams occur if something (pencil like) is sticking out of the top of the cup. The problem with detecting while it is in motion is that the indexer is driven by an AC motor/drive and if there is a part sticking out while indexing from position 1 to 2 it would already be too late and the indexer would jam.

How long is the cup stationary at position 1?


The spot from a beam of light projected over the top of the cup and along the side of that cover could be easily detected, and if some object was sticking out of the cup the spot would jump from its expected path; the detection element would have to be offset from the source of the beam of light. The problem I see with this is that the source of the light would be best located in a space where the cup is likely passing through.

 

[alive15]

Check out keyence lr-tb2000c, it's shoots a laser dot and can measure up to 2000mm. Roughly $300, but I saw a used one on ebay for $110. Pricy, but easy to set up, and has a built in on/off delay timer too if you need. Can do Hysteresis or window setting.

 

[Holmux]

If there is enough space in front of the cup, you could use a 2D LIDAR scanner (Laser Scanner) that would do the trick

 

[drbitboy]

Check out keyence lr-tb2000c, it's shoots a laser dot and can measure up to 2000mm. Roughly $300, but I saw a used one on ebay for $110. Pricy, but easy to set up, and has a built in on/off delay timer too if you need. Can do Hysteresis or window setting.

This looks nice, it has a datum mode and can detect an offset from a reference surface. The cup could pass just under the beam directed across the cup path; then the object, when present, would be detected as something closer than the reference datum.

 

[Doug-P]

A laser background suppression sensor mounted to shoot over the rim as the piece comes in to position.