At the present time, with the growing flow of cars on the roads, in order to ensure the safety of movement, the drivers need to be more and more attentive while driving. After all, at the speed of 75-80 mph, even if you distract for a fleeting second, the consequences can be really bad.
But all the same, there are situations on the roads, on the way, that you have to distract for a while. You see, different parts of the car, such as headlights, air conditioning, windshield wipers, etc. require well-timed attention. Therefore, developers have begun to design different systems and devices in order to automate the activation and deactivation process. One of these devices is the rain sensor. It allows you to determine the weather conditions and, if necessary, turn on the automatic windshield wipers.
There is a situation where it is difficult to choose the appropriate mode of operation of windshield wipers so that they provide good visibility and thus, there shall be no such distinctive grating sound on the dry glass. After all, depending on the weather conditions, the water falls on the glass in different volumes. And when you find an appropriate mode of windshield wipers, then with increasing speed they will no longer produce the required quality for cleaning the glass. That's just why drivers constantly divert their attention to switching the levers of the windshield wipers.
Thanks to the designing of such a device as a rain sensor, it is possible to protect the drivers from this constant procedure of switching the windshield wiper lever. Its work is simple - it determines how much water is on the glass and sends the information to the so-called on-board computer, which in turn, already decides to turn on the windshield wipers or not.
The very first rain sensors carried out the measurement by means of visible light. But their work was difficult due to the window film. The sensors designed under the new scheme produce a measurement by means of infrared radiation and there are no problems with tinted glasses.
The principle of operation is quite simple, the sensor has a special LED light which directs the infrared ray at a certain angle to the windshield. Further, according to physical law, this ray is reflected on the special, so-called photodiode. But this law works only when the glass is dry. If it is wet, the reflected ray dissipates in the water and falls on the receiving photodiode to a lesser extent. And if there is more water on the glass, then less light returns to the receiving diode. Thus, the sensor is capable of determining the amount of water on the glass. Then, it just sends the information to the on-board computer and it determines whether to turn on the windshield wipers or not.
Modern rain sensors can shut the windows and sunroofs if it starts raining. The sensor can even determine the water which is formed on the glass due to the rain.
In conclusion, it can be said that the rain sensors will be gradually improved and their applicable scope will expand, thereby helping and enabling the driver to concentrate on the driving.