More and more sensors are now installed in cars to increase active and passive safety. A sensor with high market penetration is a rain sensor for added comfort and safety. If the car has a rain sensor, the driver does not need to adjust the wiper settings to quickly stop the blade motion or get a better viewing angle. When driving on a wet road, the driver does not need to open the wiper, so the driver can concentrate on driving. If an additional "auxiliary light switch" is installed, the light will turn on under dim timeout conditions and will not waste fuel because the lights are always on. Most models currently use a single motor driven wiper system. The advantages of this system are self-evident, using a linkage mechanism to drive two wipers, the cost is relatively low. However, the noise of the wiper and the uncleanness of the rain and snow weather still occur from time to time. First, the rain sensor works Most rain sensors use an optical system consisting of a light emitting diode (LED), a light receiving diode (LRD), a surrounding environment sensor, an electrical control unit (ECU), and several lenses. The light emitted by the LED is reflected at the total reflection angle on the outer surface of the windshield at an angle between 420 (glass-air) and 630 (glass-water). If it is said upstream of the windshield, some of the light will be doubled, and this will cause a decrease in the current from the LRD. The current is measured by electrons. The light from the LED is reflected to the area of ​​the windshield of the LRD. "sensitive area". It can only be detected when rain drops into this area. In order to have a sensitive and reliable system, there must be a good ratio between the windshield area and the sensitive area. Second, the car wiper system The windshield wiper system consists of a rain sensor, a wiper motor, a lever switch, a relay, and an ECU. The rain sensor is mounted on the windshield. When the rain is detected in the sweeping area, the wiper moves in such a way that the driver always has a good viewing angle. There are two different systems. 1. Independent rainwater system: In this system, the rain sensor is directly connected to the wiper lever switch, wiper motor relay and wiper motor stop signal. 2. Network Rainwater Sensor: In this system, the rainwater sensor is connected to the bus, which receives all information over the network and sends all commands. Next page