In recent years, urbanization has accelerated, urban rail transit has gradually risen, and most cities have realized single or multiple subway lines in operation. The high throughput of subway gates requires higher stability and accuracy of sensors.A high quality subway gate will usually be installed with multiple groups of opposite photoelectric sensors to achieve pedestrian or object entry and exit sensing. Do you know how the infrared photoelectric sensor, the number one contributor to its technical support, is applied to the subway gates that pass through the card and QR code every day?

Photoelectric sensors in subway gates
What we call subway gate machine is actually AGM (Automatic Gate machine), which is an automatic device for passengers to enter and exit the station by swiping their ticket cards. The high volume of pedestrian traffic in subway gates requires higher stability and accuracy of sensors. The type of photoelectric sensor usually used in the wing gates at subway entrances is the opposite photoelectric sensor, which can detect the human body more accurately. A high-quality subway gate will usually install multiple groups of photoelectric sensors to realize the in and out of people sensing. We can understand it simply into three parts. We can understand it simply by dividing it into three parts: gate inlet, fan gate, and gate exit, such as the three parts A,B,C in the figure. And for precise sensing, some gates will have sensors at different heights in each part.
 

The photoelectric sensor at the entrance of the wing gate
In the process of swiping the card, have you ever encountered the situation that the gate channel cannot be opened when you stand inside the yellow line and swipe the card? This is one of the protection functions of the photoelectric sensor. The sensor installed at the entrance of the gate is used to sense whether the person invades the gate. When the card is swiped outside the yellow line, there is no object at the entrance of the wing gate, the sensor signal is normal, and the channel door will open. If the person walks to the yellow line, the sensor signal at the entrance of the wing gate changes, even if the card is swiped, the channel door will not open. The purpose of this design is to prevent the channel gate from opening and closing when the card is swiped in close proximity, and also to prevent ticket evasion.
 

Photoelectric sensor at the flap and at the exit of the wing gate
After the passage door is opened, the human body will pass through the second part, the sensor at the flap. When a person stands at the flap, the sensor senses the presence of an object and emits a signal to stop closing the flap so that the flap remains open to prevent pinching.
So at what point does the wing gate flap close? Why is there still news of being caught in the subway wing gate?
 

It turns out that after the pedestrian passes through the wing gate stopper, he walks to the third part of the wing gate exit sensor detection range. The sensor at this time senses the person through the reflected signal and sends out the signal of the wing gate stopper, so that the act of a single person passing through the passage gate is completed. If two people force through the wing gate, the former one goes out first, the wing gate stopper receives the closing signal, and the pedestrian passes through the sensor at the wing gate stopper too fast to make the sensor too late to convert the signal, it will cause the pedestrian entrapment phenomenon.
So understand the photoelectric sensor in the subway gate is how to apply, we should learn how to safely through the subway gate. Do not evade the ticket or go against the traffic, but line up in order on the outside of the yellow line and pass through in an orderly and normal manner.

I hope the above information can help you understand more about how the photoelectric sensor is applied on the subway wing gates. If you want to know more about the product application of infrared photoelectric sensors, you can also contact us by email. G-TEK has 20 years of experience in the infrared photoelectric sensor industry, and insists on providing the most suitable and reliable photoelectric sensor solutions for our customers.