When it rains, the driver manually removed from the opening operation of the wiper, the wiper may be turned on automatically.
1. The rain-sensing wiper advantages
· hr rainfall suddenly large repeatedly without driver’s manual adjustment of the wiper switch, which automatically adjusts the oscillation frequency of the wiper according to the size of rainfall. After
rain, wiper off automatically, eliminating the need for manual operation, to ensure safe driving rain.
2. Rain-sensing wiper Mistakes
· rain sensor detects hidden behind the front windscreen, rainwater coverage and only covers the speed of the front windshield is detected, acquisition and analysis were not weather outside the vehicle.
· wiper frequency stepless adjustment, the slower the fade rainfall rainfall bigger and faster.
fixed gear with several common wiper speed is not the same.
3. Rain-sensing wiper Principle
Currently the widely used two mainstream sensors are optical sensors and capacitive sensors.
The optical sensor works according to the principle of light refraction.
In the optical sensor has a light emitting diode, which emits a cone of light, which beam passes through the front windshield.
When there is no rain on the windshield, in a dry state, almost all the light will be reflected onto an optical sensor, when it rains, rain on the windshield will be there, will deviate from the portion of the light, which causing a change in the total amount of light received by the sensor, thereby detecting the presence of rain. The larger
an optical sensor capable of receiving the reflected light area, more detailed information is obtained.
The optical sensor is accurate, it is possible to accurately determine even the number of the rain falling on the sensitive region.
Another is a capacitive sensor, which is mainly used in the dielectric constant of water glass and a huge difference in design, wherein the dielectric constant of water is 80, the dielectric constant of glass is 2.
The usual practice is that the two fingers in a parallel state of the metal plate into the windshield glassWithin the glass between the outer metal plates of a set of fingers are interleaved, but does not touch the other fingers metal plate.
When the windshield in a dry state, the outer surface of the windshield and each finger is formed between the dielectric plate-like metal.
when the windshield becomes wet, depending on the amount of water in contact with the windshield, the windshield different dielectric constant change.
If the sensor is mounted on the surface of the windshield at or close to the surface of the windshield, which is advantageous for the operation of the sensor, since such mounting can play their best sensor sensitivity.
Disadvantageously, the capacitive sensor is mounted on the outer surface of the same problems occur with the windscreen resistance sensor, which will soon be scraped off the metal coating from the windshield wipers in the long-term.
4. Rain-sensing wipers associated Read
For some models the integrated control skylight window function in the induction and wiper functions, once the glass is covered with a quantity of water, the sensor immediately skylight and orders the windows, skylights and windows will automatically shut down immediately.