Nowadays, more and more sensors have been installed in the car to increase active and passive safety, and a sensor with a high market penetration is a rain sensor to increase comfort and safety. If the car has a rain sensor, the driver does not need to adjust the wiper set to quickly stop the movement Sensor of the blade or get a better perspective. When driving on a wet road, the driver does not have to start the wiper, so the driver can concentrate on driving. If an additional 'auxiliary light switch' is installed, the lights will be turned on in a dark overtime condition and will not be wasted due to the lights being turned on. At present, most models are used in a single motor-driven wiper system. The advantages of this system is self-evident, the use of connecting rod drive two wiper, the cost is relatively low. But the wiper noise and rain and snow weather scrub phenomenon is still not happen.

  Most rain sensors use an optical system consisting of a light emitting diode, a light receiving diode, an ambient sensor, an electrical control unit, and several lenses. The light emitted by the LED is reflected at the total reflection angle on the outer surface of the windshield, and its angle must be between 420 (glass-air) and 630 (glass-water). If you say on the upper side of the windshield, some light will double the injection, and this will cause the current from LRD to reduce the current to evaluate the electrons, from the LED light reflected to the LRD windshield area Fuel Rail Pressure Sensor is called the sensor 'Sensitive areas'. Only when the rain drips into this area, can be detected. In order to be a sensitive and reliable system, the windshield area and the sensitive area must have a better ratio.

The car 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 and the wiper is designed to allow the driver to have a good angle of view when sweeping the rain. There are two different systems.

1, independent of the rain system: In this system, the rain sensor directly with the wiper rod switch, wiper motor relay and wiper motor to stop the signal connected.

2, the network rain sensor: In this system, the rain sensor connected to the bus, it receives all the information through the network and send all the commands.

After the driver opens the system, the rain sensor controls all sweeps, which commands a single wiper to be swept at low speed or at high speed. Because each driver is reflected by the different expectations of the wiper system, the sensitivity setting allows the system to meet the different needs of the driver. Bosch's new wiper motor can be continuously swept at varying speeds.

   The transmitter consists of an analog-to-digital converter (DAC) and a power supply. DAC analog voltage control determines the intensity of light emitted by the LED, under normal circumstances the use of 2 to 4 LED. The current regulation of the transmitter is very important because the effectiveness of the light conversion is very variable and has a temperature gradient. In general, in LEDs, light is pulsed to reduce losses and increase current. Another reason Pressure Sensor for using a wide range of transmitter currents is that light is not well regulated by the windshield and has a large tolerance range. General windshields are 4 to 6mm thick and are perpendicular to the surface of the IR by a specific launch level. Different suppliers of different upper and lower limits.

  The receiver has several LRD, current-to-voltage converters, clear or low-frequency offset filters, amplifiers and ADCs, which typically also include microcontrollers. LRD has a microcontroller that is controlled by a microcontroller to turn on and off. If there is interference light, LRD will be turned off. The wide range of transmissions is the reason for using variable current-to-voltage conversion to ensure that the remainder of the receiver system has good conditions. After the conversion, fortunately being filtered. All DC or low frequency interference will Speed Sensor be removed to obtain a pure signal. Interference is generally caused by the ambient light, the amount of interference measured by a microcontroller to determine whether the optical path is satisfactory, or is saturated with the sun, and will give a signal accuracy indication. The filtered signal is amplified and converted by the ADC.

  The microcontroller controls the entire system and evaluates the signal. The optimum operating point is evaluated before the measurement is performed. With the test to carry out evaluation work. The conversion ratio in the receiver is least desirable to have a saturation signal in the ADC with the maximum emission current. After the emission current is evaluated, it generates a signal in the receiver. It is defined between the upper and lower limits. The upper limit is determined by the saturation effect rather than by the accuracy of the ADC. The sensor starts at the operating point. Interference and signals are constantly being measured and evaluated. The received signal versus Throttle Position Sensor time gradient and the rule system are used to evaluate the correct sweep strategy, and the surrounding light is measured by an additional sensor to detect the day or night conditions. In the evening, because the water droplets have a greater impact on the visibility, especially if there are bright lights of other vehicles, so the sensitivity will increase.
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    Different sweep modes are used to optimize performance for all rain conditions, and in direct mode there is a single wiping action with low wiper speed. This is the most basic working condition when the automatic mode is reached and when the system detects dry windshields. In this state, each rain event triggers a single wiping motion directly. During wiping, the system decides at a low speed, continues to wipe or switch to high speed wiping. The intermittent mode is used for rain and runs a single wipe at low speed. Every few seconds, the sensor will detect the raindrops, the time between the two rains determines the intermittent between two single wipes. At the end of each intermittent period, the time will be recalculated, the more rain, the shorter the intermittent, and vice versa. In the calculation, the previous intermittent will be considered in order to achieve a harmonious state. Otherwise 'neurological behavior' will annoy the driver. If the calculated intermittent is longer than the maximum intermittent, the system goes to direct mode. In each wiping cycle, the sensor checks whether the conversion is made or the wipe continues. Continuous wiping In the wiping cycle, the number of rains will be calculated and the size of the raindrops will be evaluated for information on the intensity of the rain. Depending on this intensity, the rain sensor will produce low speed, high speed or specific wiping speed (eg 50r / min). Dynamic hysteresis, which relies on this event in the last loop, prevents Pressure Switch the system from quickly converting from one speed to another. Use the time reference of the wiper motor to stop the signal to ensure proper operation of all wiper motors under all conditions. If the motor is wiped at low speed, the detection time is reduced and the critical value between low and high speeds is automatically increased. The rain sensor mode always lows the speed from high speed to low speed to prevent the wiper from generating mechanical stress before stopping.