Question
What the two sensors over there are up to? Can I know their names, Mr Ninja?
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Answer
Short Answer
Part A - What the two sensors are up to?
The sensors look like those cheap infrared detectors hobbyists use for obstacle avoidance toy cars (Refs 5, 6).
However, unlike the bread production line application, the obstacle toy cars to avoid usually has a smooth surface to reflective light. But in this auto bread production line appliciation, detector is not moving, but obstacle is.
In this automatic bread production line application, the bread should not reflect light that well, so the typical trick is to place a stainless plate at the back of the obstacle to reflect light. Now the obstacle (bread) passes by will absorb the light, and so stope reflection. In other words, reflection stops means another bread arrives.
1. Sensor 1
Sensor 1 blinks Green when no bread in sight. Blinks Yellow as soon as bread comes up. So I guess it is a bread detector. Of course the yellow LED can be read by another smart guy to count and record.
2. Sensor 2
In the same video, Sensor 2 is not blinking at all. I think, similar to Sensor 1 above, reflection get interrupted means bread (in this case, another tray of bread arrives.
Of course the bread detector might be sophisticated enough to also measure temperature and do data recording etc, or even fancier do something below: If the bread surface is not hot enough to stick the sesames, hold on the tray for a little bit longer, at the same time blow hot air on it, before moving on for the rain of sesames.
This is only my wild guess. After watching the videos, I have the feeling that the auto bread system is actually very low tech, and high precision position and timing is not at all required.
I would think that there is not any MCU, not to mention SBC, is used in the whole bread production plant. The CNC like digital controlled oven might only need one Celius degree and one second timing accuracy.
As can be seen in the video, the oven does not seem to have any data record/database, everything is open loop and ready reporting. In other words, no feedback control. (I once talked to a barbabe pork and roast oven chef and found that the oven is sort of a microwave oven, you can set time and temperature, but the meat temperature is measured by a thermometer. In other words, all manual controlled by the chef. He would LOL if I suggest an Arduino and Raspberry Pi IoT oven.
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Part B - What are the name of the sensors?
I guess the OP is curious to do what those sensors are for, or their "names", not model or part number. As mentioned earlier, the sensor can be hobbyist level cheapy, low precision infra red reflective sensors. I have played with them in my Arduino days. I found them friendly for newbies. Of course the OP can upgrade to ultrasound or even laser sensors with cm accuracy, but of course, as I guessed, centimetre accuracy is an over kill, toy grade accuracy is "appropriate" technology.
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Part C - Discussion, conclusion, and Recommendation
Discussion
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Conclusion
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Recommendation
As I said earlier, the cheapy US$1 IR Reflective Sensor is hobbyist friendly, educational, and great fun. I would recommend the OP and other newbies to play with it. There are many good references out there, one of which is the following:
TCRT5000 IR Reflective Sensor - ProtoSupplies, US$1
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Long Answer
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References
(1) About Ozkoseoglu Group - www.ozkoseoglu.com
(2) ÖZKÖSEOĞLU Full Automatic Bread Tunnel Oven Production Line - 2014jul14
(3) OZKOSEOGLU Steam Pipe oven - 2017dec05
(4) ÖZKÖSEOĞLU Gold Series Oven - 2017Apr11
(5) AliExpress TCRT5000L IR Reflective Infrared LED Sensor Switches - US$3
(6) AliExpress Infrared Obstacle Avoidance Photocell Proximity Switch 3-80cm Detection - US$2
(7) TCRT5000 IR Reflective Sensor Module - ProtoSupplies, US$1
(8) TCRT500 IR Reflection Module - AliExpress US$1
(9) TCRT5000 Vishay, Reflective Sensor Module Product Sheet - RS
(10) TCRT5000 Reflective Sensor Datasheet - Vishay
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Appendices
Appendix A - ÖZKÖSEOĞLU Auto Bread Oven YouTube Screen Capture
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End of Answer