Homework help - glass bottle detection

DLMUK · Mar 20, 2016

Hi,

I am after a bit of help please with my I&C HND. I have a question where I need to spec a sensor for glass bottle detection on a conveyor belt - I have found a suitable sensor (retro-reflective Banner Q26) which fits the requirements except for one...

"it is necessary to ensure that a change of sensor state occurs closer to the sensor when a bottle approaches than when it moves away"

It is not specified if the bottle is round or square, however either would be a symmetrical shape. The sensing distance requirement is 5-20mm which suggests to me that every bottle is not in a fixed position.

Could you mount the sensor at an angle?

Thanks

adisharr · Mar 20, 2016

I'm not exactly sure what they are asking unless they want to sense the approx. middle of the container. If that's the case, an ultrasonic would work better since they are distance based. They also work better if your containers are pressed together and don't offer any space between them.

Did they show any diagrams?

QvixoteRoux · Mar 20, 2016

I would use a very sensible optic (photoelectric or laser) sensor, capacitive could also be used, depending of speed, I think a simple arduin sketch with a cheap ultrasonic sensor and a couple of relays could make the trip, havent had the chance to use ultrasonic directly to a PLC

if all bottles are the same size, I would use a emitter-receiver optic or reflective and pont it near the cap, if bottles are not so translucid maybe a diffuse will work

amberman · Mar 21, 2016

DLMUK said:
Hi,

I am after a bit of help please with my I&C HND. I have a question where I need to spec a sensor for glass bottle detection on a conveyor belt - I have found a suitable sensor (retro-reflective Banner Q26) which fits the requirements except for one...

"it is necessary to ensure that a change of sensor state occurs closer to the sensor when a bottle approaches than when it moves away"

It is not specified if the bottle is round or square, however either would be a symmetrical shape. The sensing distance requirement is 5-20mm which suggests to me that every bottle is not in a fixed position.

Could you mount the sensor at an angle?

Thanks

Is this not just referring to normal hysteresis in a photoelectric sensor, i.e if the bottle approaches the sensor it turns on but there is a small travel distance going away from the sensor for the output to turn off again. Sounds like it to me anyway...!

boneless · Mar 21, 2016

Perhaps they mean you should use an analog sensor. So you could detect an increasing ramp and decreasing ramp. In stead of ON/OFF.

nhatsen · Mar 21, 2016

DLMUK said:
... I need to spec a sensor for glass bottle detection on a conveyor belt

Here's another option:

https://industrial.omron.eu/en/prod...ensors/transparent_objects/e3z_b/default.html

DLMUK said:
"it is necessary to ensure that a change of sensor state occurs closer to the sensor when a bottle approaches than when it moves away"

I guess they're asking for an edge detection. I mean, supposing that the sensor goes to high state when a bottle is detected, the logic needs to grant that the function invoked by the sensor (count, put a label) only occurs with the rising edge and not with the falling edge.

Homework help - glass bottle detection

DLMUK

Member

adisharr

Member

QvixoteRoux

Member

amberman

Member

boneless

Lifetime Supporting Member + Moderator

nhatsen

Member

Similar Topics